Sounds like a weight reduction plan. Bet it gets better mileage when you are done.
Way back then a lot of us ran 6s because that is what the car came with. We made the best of it and even got good enough at it that we took pride in our inlines. Pulling a V8, especially a BBC, to install a straight 6 is just about as far as you can go to make our point. Do you think there is something wrong with us?
Nice carving job on that now ex-double-sink . . .
Awesome parts washer! I saved an old stainless steel counter top with built in sink to make into a parts washer, don't think mine is gonna be long enough for inline 6 parts like that though, it's just a single well!
11cc dish, 72cc chamber, 3.935 bore, 4.062 stroke, .040 gasket gives static compression 8.8. Little lower than I would like but these are the parts I have. Plan to run Comp 252 camshaft. Cam card says intake closes 48 degrees ABDC at .006 tappet lift. I'm not racing this car, it's a cruiser and I'd like a broad torque curve. Rear gears are 3.08. Intake is 2 barrel rochester on an altered Johnson intake, headers not yet determined but probably similar to the altered truck headers in this photo, 1.5 inch diameter.
Interested in comments on camshaft and header choices.
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strokersix,
just curious as to how you got to the that stroke dimension?
What length rods etc.
I would like a stoke of 3.75 or so myself.
292 crank has a 2.1" rod journal? Turn it down .100" = 2.00" or?
Thanks
MBHD
I'd like to see you have a lift around .510 or so. The short duration is fine, but that also limits the amount of lift that can be had. The bolt in lumps help the most with flow above .3 of lift.
The full length headers will work the best for tq.
It's a modified 12 weight 292 crank. Destroked to 4.062, 2.00 crankpin, 6.0 rod length. Block is an '80 vintage 250.
I used the same crank in a previous build with 5.7 rods and 4.000 bore 383 v8 Chevy pistons so the crank has plenty of clearance to the wristpins.
This build has longer rods (r/s ratio), smaller bore (thicker cylinder walls), and lump ports (more flow) so should be better all around. And if it runs on 87 octane that's not a bad thing in my mind. We'll see.
tlowe or anyone: I have some $$ left in the budget for this build and would love to try a roller cam. Any suggestions?
Do you want to run a hyd or solid roller cam?
MBHD
I don't have any experience with roller cams. What are the trade offs between hydraulic and solid in a mild application like this?
Periodic lash adjustment with a solid is not a problem for me.
Is a rev kit required to maintain roller contact?
Need to know a few things.
Weight of vehicle, trans,manual, auto,if auto what stall on the converter?
Total displacement of engine.
Rear end gear ratio.
Daily driver w/good mileage?
Street/ocational strip/track times.?
Want just maninly low end & mid range?
And so-on.
I am not thinking you need a rev kit for a low comp/rpm engine.
A small roller solid cam is fine w/no rev kit or stud girdle.
MBHD
MBHD
Weight: It's a '72 Nova with all factory hardware and full interior, no A/C. I haven't had it on a scale but let's call it 3200 lbs.
Drivetrain: M20 wide ratio Muncie, 3.08 posi rear, 24.5 inch tall tires
Displacement: 296 in^3
Not a daily driver. However, I do want it to run comfortably with good fuel economy on the highway for short road trips. Occasional full throttle blast just for fun is desireable (of course!) but not primary goal.
Small solid roller sounds like what I need. I was happy with the Comp 252 performance last build (252 dur @.006, 206 dur @.050, .474 lift). How about same seat timing with more .050 and more lift? Call it 252 dur @.006, 212 dur @.050, .510 lift might do well.
Remember when figuring solid lift cams, figure in the lash. To net .510 you will need about .530 gross lift.
Depending on how agressive the ramp can be, a 220 dur @ .050 might be attained. That is something to find out from a cam grinder.
The valve springs will need to reset up again with the solid roller inthought. Not a biggie.
Maybe something like this from Comp Cams
Lift is a bit high ,but they should be able to provide less lift from there master cam profile catalog.
Solid roller
LOBE RATED DURATION IN LOBE TAPPET LIFT @ THEORETICAL VALVE LIFT
NUMBER DURATION DEGREES LIFT TDC @ “0” LASH ROCKER ARM RATIO
CAMSHAFT TYPE
@ .050” @ .200” 106° 110° 1.5 1.6 1.7
4870 256XSR 218 141 .360 .056 .045 .540 .576 .612
MBHD
Thank you guys for your comments.
I will continue to post progress which may be infrequent as I go back to work Monday. Doesn't mean I've abandoned the project, just that progress is slow at times. I purchased the JE pistons more than 10 years ago! I hope to have the Nova running this summer. We'll see.
Made some progress this weekend. Squared up the deck. Aiming for pistons .005 inch out of the hole. First time sufacing head or block with this milling machine. It's only an 8x36 table. I used 17 inches of table travel to cover the surface with the fly cutter. Tram was dead nuts. I can't feel the witness mark nor detect any flatness error with my straightedge so I'm pleased. Keyed slugs are fixture/main bore reference.
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Where on the piston are you checking to see that it .005 out of the hole?
Along the bore centerline (above wrist pin) will eliminate piston rock affecting the measurement if I understand what you are asking.
Test fit showed zero deck so I cut .005 to true it all up and give me .005 out of the hole.
Actually along the quench and spark plug side of the pistons are the more critical areas to check the deck, because the piston does rock as the engine is running. I have seen engines with less than .040 piston to head clearance have the pistons bump the head. The way you are measuring it, the piston can rock .010 to .015 more out of the bore at these points and cause you problems. It also increases with more piston to cylinder wall clearance, so this should be checked after the block is finish honed to ensure a more accurate reading.
Understood.
But seems to me the piston rocking will be dependent on piston and block temperature. Checking cold probably worse than when running. I would expect less bore clearance and less rock at operating temperature. But that's just a guess without knowing exactly how the piston will expand. I've read that piston geometry is specifically designed to match piston and block thermal expansion even though it's aluminum versus cast iron. In my case, I have no way of knowing and have to hope that JE did a good job with my pistons.
Are you suggesting piston/head distance of .035 (.040 gasket -.005 out of hole, not counting piston rocking) isn't enough? I'm going for high squish velocity and as much compression as I can get. If I find evidence of contact I can always trim a bit off my pistons.
If your intention is to gain the best quench you can, it would make sense to check your piston at the quench spots, not in the center of the bore where the chamber is above the piston. Once you bring your piston to TDC, move your indicator to the quench sides of the piston near the edge and rock it inward and outward. This will give you some idea of how much rocking goes on inside the engine. You will see that it is sticking out of the bore a lot more than just .005 at these points. Yes, I have seen pistons hit the head with less than .040(true quench). Don't be afraid to really push on the piston as hard as you can to simulate the rocking, you still cant push it hard enough to match how much the connecting rod rocks it, but you will be safer in making your measurements there. Also, even at an idle with the engine running, the pistons go past TDC 10 to 15 times per second, so by the time you hear a problem it will be too late to do anything. At operating speed(6000-7000)RPM, you could take a bearing out or bend rods, collapse pistons with even just a slight bumping of the head. Just be cautious when pushing the clearance that close.
I'm torque plate honing next, then I'll do another test fit and check as you suggest.
Remember though, I'm not racing this one. Don't plan to spin much over 5000 rpm. I will pull the head and check for witness marks after breakin.
Hoping to maximize performance with 87 octane, that's why I'm after the squish velocity.
When you did your crank did you narrow the journals for V8 rods, or get standard 6 widths in a 6" rod?
I've been toying with having the crank welded then reground for big journal SBC rods, this would open up a bunch of rod/piston combos. Not sure that the cost of the crank work would not be less than the cost of custom rods, particularly if several combos were to be tried.
Also, why not a hydraulic roller if it's mostly a cruiser? Would get rid of that annoying lash problem....
I bought Crower rods for Chevy six, 6" long.
Stock 292 crank has 2.1" journals same as 350 SB.
Last build was with 5.7" stock 250 rods. I clearanced the crank by turning it round in my lathe as small as possible. Then set up on my milling machine to roll on the crankpins. Had a bar on the flywheel flange to roll the crank under the milling cutter for final clearance. With 6" rods you might not need to do the second milling operation. Then I had a local shop grind the crankpins to 2.0" and 4.062 stroke. I try to do as much as I can myself but I don't own a crank grinder or balance rig. Yet.
I thought about altering SB rods by adding material to the big end. I bucked up for the Crower rods so never tried it. I would avoid welding on the crank.
2.0" crankpins and 4.062 stroke almost clears the fuel pump lobe on a 250 camshaft. Slight grinding on the rod plus reduced fuel pump lobe diameter will clear. I altered the mechanical pump to compensate for the reduced lobe. This won't be required if you use a 292 camshaft and electric fuel pump.
I'm going to run the same Comp 252 cam with altered fuel pump lobe to start with. Already own the parts. Then figure out what to do from there. I would like to run a roller, solid or hydraulic.
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Cleaned up the head bolt threads in the block and installed the torque plate today. I threaded the studs in the same depth as OEM head bolts. The bores were round before I torqued the studs. They pulled to .003, maybe even .004 inch oversize with studs torqued to about 100 lb-ft. I was expecting .001-.002, not .003-.004. I'll never hone a block without a torque plate again.
Have to think about this a bit because my bores are already to size and I sure don't want to open them up another .004. Maybe back off the torque to 80 lb-ft, then run the hone in to knock off the high spots rather than all the way round. I feel more comfortable with .001-.002 oversize at the top of the bore.
One solution is to bore another block and use the torque plate this time.
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Nice.
Who makes that torque plate?
How much piston to wall clearance does it have now?
MBHD
Tom loaned the torque plate to me.
Have not measured the pistons yet. JE made them to fit 3.9355 bore per my request which is right about where they are without the torque plate. Need to do some closer measuring and figuring.
I have not posted a project like this before. Everyone gets to see the screwups as well as the success. With over 1000 views it appears there is interest so I'll keep posting.
Nice.
Who makes that torque plate?
MBHD
Fairly sure this is the torque plate that I made.... it went south to Tom when he bought my 292 a few years ago...
How far down the bore did the distortion take place? I have found it to go almost 1 inch. That is why rings have a hard time breaking in. They can never quite conform to the square hole.
It'll be hard to get that out-of-round out without adding some more clearance, just try to keep your hone at the top of the cylinder as much as possible. That's one reason why more people don't use a torque plate, they don't think it makes that much difference. Lightening up on the bolt torque isn't going to stretch them properly, i'd opt for more clearance instead of possible blown head gasket issues.
What kind of ring gap are you looking to run.
Stroker, what surface finish is that on the deck?
Distortion is down about an inch but I need to do some more measuring.
I plan to use OEM bolts so I need to install them on this torque plate to see if they pull the bore less. If so, then I can back off the stud torque a bit. That's what I meant. I'm not proposing less clamping at assembly, rather less clamping for the honing operation. And I don't think I need to go all the way round. With all the engines out there running with .004 distortion, mine included, surely if I left .001 distortion it must be better. I haven't thought about ring gap yet.
I don't know the surface finish. It's from the fly cutter I posted above then dressed a bit with a file. Measures true, looks and feels good to me.
Another concern when trying to run tight operating bore clearance is thermal distortion. An article in one of the lubrication engineering magazines I receive for work discussed engine bore operating clearances. This article was related to engines achieving very low emmissions and good fuel economy. The article stated that operating bore dimenisions change more due to the thermal stress caused by the coolant temperature increasing and reaching operating temperature than that due to the mechanical stress induced on the block from torquing the cylinder heads.
Setting up a 180 degree F coolant loop (with pump)for an engine block when mounted in a shop boring machine would take a little work. Doing so would be a good learning experience. Effort for results? Also, I wonder what the running versus cold tolerances would be as a final result. An engine has to operate during cold starts with sufficent proper cold clearances before reaching good operating clearances.
See how much difference there is in distortion from the fully torqued state compared to the lesser amount you are considering. Also, cast rings will conform and seal to distorted shapes in the bore much easier than a moly ring will, so if you are using moly stlye rings several thousandths of distortion might still be too much for adequate sealing. A moly ring is just more rigid and less flexible than a cast ring is, and they need a more precise bore to ride up and down in....if your running moly rings.
I think moly rings are in fact cast iron, with a thin insert of molybdinum usually applied to the cast iron in the form of a plasma spray.
This quote - taken from the following website:
http://aapistons.com/index.php?main_page=page&id=2&chapter=106. Molybdenum (Moly) Ring-Cast iron ring which uses a Molybdenum alloy as a face material.
Yep, the moly is a coating on the rings outside edge. Its wear edge is harder than a plain cast ring, and doesn't seat in as fast if the bores are less precisely machined. They also require a much smoother grit stone for finish honing than a cast ring also.
I think I've had a dozen different engines in this car.
Did some measuring and figuring today.
Studs torqued to 90lb-ft deflect the bore the same as OEM bolts torqued to 90lb-ft. Same as close as I can measure anyway. Pulls the bore about .0015-.002 on diameter or .00075-.001 under each fastener. I thought it was more because there is about .001 taper in the bore from the last build. I torqued the studs to 80lb-ft and the next step will be to hone. I think I can get the bores round or nearly so at 3.937 top and 3.936 bottom. Pistons are 3.932. JE specs .004 minimum clearance for these pistons so I'm in good shape.
Honed the bores today. Rigid hone is Lisle brand, not sure of the grit but guessing 280-ish by the look of the stones. Didn't take much out. Basically just knocked off the high spots then ran the dingle ball hone though to make it pretty. Next up is a thorough cleaning and trial assembly.
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Nice to have your own tools?
MBHD
Stroker, how do you like the Lisle hone?
I've only used a Sunnen, looks like the same setup though.
This Lisle hone is the only one I have any experience with. I expect Sunnen is much nicer but the Lisle seems to work OK. It's a lot of work to hone .002 and have to be careful to hold size for the length of the cylinder. I try to run the boring bar as close to size as possible to minimize honing.
I would rather buy a tool than pay someone else. I'm sure many members here feel the same way. I like to figure out how to do it myself. There are limits though. Pretty tough to justify a crankshaft grinder in my shop.
I would rather buy a tool than pay someone else.
Amen to that.
Thanks for the insight.
Any udates on your positive deck height remeasurment? 
MBHD
Nope, not yet. Honing result is cold clearance .0045-.0055 against JE recommended minimum .004.
Polished the crank with 500 grit and measured main clearances. Had to dance to follow the crankpins. 1-6 are right about .003 on the diameter while 7 is .002 with thrust at .008.
Measured crankpin to deck, all within .001 resulting in the piston proud of deck by .003. Right where I wanted it for .037 piston to head clearance.
Rock the piston with my thumb and the quench side is up .018 and the opposite side up .012. What's the deal here?
Another rookie engine machinist mistake, that's what. When I set up the block to machine the deck I had equal packing under the oil pan rail. If I had laid a level across the bellhousing dowels I would have caught the error. Should have shimmed to cut level relative to the dowels or dialed in the bore.
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Stroker, you made the cut to your deck correctly, based on the method in which you checked deck with. And as you confirmed, it is now .003 out of the bore as you intended. Initially, you only checked the deck height of your pistons in the center of the bores....which as I pointed out in an earlier post, is not the correct way to check your deck. And you can see know how inaccurate that using the center of the bore method truly is because it doesn't account for piston rock on either side of the piston, which is more critical. Many people have made that same mistake because they just dont know. You can still cut the pistons to compensate, which is very common to have to do anyway to obtain the right deck height. I think you mentioned that you had already taken your setup down before I mentioned this to you, but if you had been able to check how much piston rock you had before cutting your deck, you still would have seen around +.015 difference from the center of the piston as you are seeing now.
My deck isn't square to the bore. The bore could be off but I don't think that's it because I checked the distance from dowels to oil pan rail and that dimension is off the same direction. If I had leveled to the dowels my piston would rock proud .015 on both the quench and opposite sides instead of .018 and .012.
Checking the deck height in the center eliminates skirt clearance from the equation. Then deal with the skirt clearance as another variable.
I expect the piston rocking to be less at operating temperature when the forged aluminum piston has expanded more than the iron bore.
I set up and cut the deck again. Square this time. I leveled off the dowels and ran an indicator down the bore to check.
Should give piston proud of the deck by .005 inch above the wrist pin and .018 on each side when rocked. .022 inch clearance to head when cold and loaded with my thumb.
Loved the pictures of the crank. I can see where you turned it down to just above the crankpin rod faces, then milled for piston skirt clearance. What suprised me was the amount of balance drilling after that, I would have thought that Mallory metal would have been needed after all that metal removal. And what's with the big notch ont the weight next to #2, was that to hlep balance? Wow that's a lot of metal gone!
The guy who balanced it for me did a good job balancing but not such a good job making it look pretty.
The skirt clearance cuts will clear 5.7 inch rods. I am using 6 inch rods this build. I used a big lever to swing the crank on crankpins under the milling cutter to make the cuts.
No Mallory required. Balance the crank all by itself or with damper and/or flywheel but no bobweights like you need for a v8.
Stroker,
What head gasket are you going to use? Thickness?
I measured the fire ring thickness on the used gasket I have hanging on the wall at .040 inch. It's a "Printo-o-Seal" or something like that. Maybe Felpro, not sure. I think (hope?) I have a couple new ones just like it in my gasket pile. I'll need at least two. One for run-in and a second for after I pull the head to check for witness marks on the pistons!
Open to suggestions.
A Felpro performance 1025 is .041 thick. That is the one ran on the dyno mules. Ran the exact same gasket with all the head changes.
You may consider turning your piston crown down a few thousanth's. Best time to do it.
Do you really think I'm in trouble with .022 piston to head quench clearance cold? I think clearance should increase to .030 or so when hot. The piston should rock less when it expands and reduces bore clearance from .005 to let's say .002 at temperature.
I've read in various magazines that .035 is a good clearance and .030 bare minimum. I always assumed that was a measurement taken on center? My on center clearance is .035. Bad assumption, poor source?
Yeah, don't believe everything you read in magazines :D. I have seen pistons hit the head at .035 quench. At .030, the pistons can hit hard enough to close the ring gaps up and cause cylinder wall scoring. As close as your going to be running it, you can pound the bearings out of the rods and even bend some if you dont shut it off quick enough. Also, you loose piston to head clearance when the engine heats up, not gain it. So you will end up almost even .005 closer to the head than you are now....You need to cut your pistons before you damage your engine beyond being able to fix it.
you loose piston to head clearance when the engine heats up, not gain it.
???? Won't the tighter bore to skirt clearance at temperature reduce rocking and therefore increase clearance? What am I missing here?
Granted, piston rocking loads are greater than my thumb pressure, I've made no allowance for rod stretch at TDC exhaust nor crank deflection under load. And I'll lose .001 or so due to rod bearing clearance and maybe another .001 for main bearing clearance. Maybe all that adds up to more than .020 inches? I'm not so sure.
Please tell me what engines you've seen contact on, what pistons and bore clearance, and how may rpms you were running when it happened.
One thing that you are not thinking of is thermal expansion. When these components get hot, they expand, not shrink. The cylinders get larger, not smaller. The pistons, being aluminum, grow more than the cast iron block does, so you do have some reduction in piston rock to some degree, but all dimensions of the piston expand along with its diameter. The pin bores gets larger, the ring grooves get wider, etc., all concievable components grow and expand from the heat. The rods get longer also when they heat up, and possibly stretch as well. When exposed to the near 1000°F combustion chamber temps, aluminum can have an expansion of 1/32" of an inch, compared to what it mics sitting on your workbench. It doesn't have to be race type engines at racing RPM to have these problems, i've seen many stock rebuilds experience damaging results because of trying to run the quench too tight. As far beyond what I would consider a safe margin of quench as you are right now, i've seen similar engines have the closing of ring gaps and beating the bearings out at break-in RPM before they could even shut the engine down. Just trying to keep you from tearing up good parts.....Your just so far beyond the safety net, I hate to see you have problems needlessly.
No Mallory required. Balance the crank all by itself or with damper and/or flywheel but no bobweights like you need for a v8.
Interesting. I asked this on a different forum and was told that it needed bobweights. if you are truely making the crank neutral balance than you would be able to swap rod/piston sets (assuming each rod/piston in a set is the same mass)without rebalancing the crank. Thus you can change rod length and piston height at will, using the same crank?
If so, this would save a lot of $$ and time when trying out several combinations.
Correct. No bobweights required. Swap out rods and pistons all you like as long as they are matched sets of six.
My cut down crank probably has more bending loads because I've reduced the counterweights but I think my light pistons should offset this somewhat.
The counterweights on inline six are there to reduce crankshaft bending loads only. v8 cranks are different story. v8 counterweights reduce crankshaft bending loads but also make a tradeoff of the unbalanced force directions. Inline six does not have the unbalanced forces.
There are only a few exceptions, but inlines as a rule do not require bobweights. You can compare them to a see-saw, if you remove 1 pound of material from the counterweight side of the crank, then you have to remove 1 pound from the rod throw side to keep it balanced.
And what determines the counterweight mass?
Correct.
The counterweights on inline six are there to reduce crankshaft bending loads only. v8 cranks are different story. v8 counterweights reduce crankshaft bending loads but also make a tradeoff of the unbalanced force directions. Inline six does not have the unbalanced forces.
For a great case in point of these unbalanced forces in action go find a 1960's GMC V-6 or early Buick V-6. Nothing like odd fire engines!
And what determines the counterweight mass?
In my case the counterweight mass is determined by how much clearance I needed.
I expect I'm paying a penalty of increased crank bending and main bearing loads compared to a stock 292. Hopefully offset somewhat by lighter pistons. My rods probably weigh about the same as 292 rods but my pistons are much lighter at 403 grams. Don't know what stock 292 pistons weigh but I would not be surprised if they are 700 grams.
This is likely the biggest reason for the change from 6 weight to 12 weight cranks. Reduce main bearing loads and improve crankshaft durability.
Looking good!
I think you will sleep better, having done that.
You are quite Houdini when it comes to running your mill. Nice job!
Good looking set of connecting rods you got in there!
Crower rods and JE pistons are nice parts for sure. About $1300 nice! The rest of the build is fairly low budget.
Good progress.
Do you have any side shot pics of your intake port?
What mod, if any have you done to your intake manifold?
MBHD
Someone once said "one thousands too tight and everyone knows, One thousands too loose and no one knows".. Maybe you can get someone to stand on the pan when you button it up. Stay with it STROKER..It will either be OUCH or AMEN
strokersix,
who makes that intake manifold?
Do you have any pics of your lumps by themself?
Just curious of the whole layout.
Thanks for the pics.
MBHD
I don't know much about the manifold. It has "JOHNSON" and a part number that might be General Motors issue cast into it. I found it on eBay. Supposedly a propane intake. I modified for 2 barrel Rochester, hot water, and the tapered transition into the head.
Lumps are modified tlowe parts. They are attached with the scab plates you see in the photo instead of a cap screw up from the deck surface. 3/8 inch tall at the gasket instead of tapered to nothing. I was shooting for constant cross section area from the manifold corner to the valves. I know I took more photos but can't find them. I'll post them if I do.
When is that bad boy going to get fired up? Nice work.
Think it will be driving by the spring picnic?
Here is a Johson LP intake that came on a 292 I have.
I got my invitation in the mail yesterday for the picnic. As long as I don't break any parts between now and then, you'll see it there! If I do break parts you'll get to see the evidence.
Just came in from a long day in the shop. Very nice to see your motor in the engine bay.
Like to see the steel bell housing and the added bracing on the muncie. Tom
Looking good.
Just curious, what size flywheel is that 168 tooth?
I like to use the smaller 153 tooth,weight is closer to the centerline of the crankshaft,revs quicker.
My friend w/his BBC 509 Dougnash 5 speed used the smaller 153 tooth held up fine. He also used to race roundy round cars & would always use & recommend using smaller flywheels. Helped him win championships & a lot of races.
MBHD
It's a 168 I had balanced with this pressure plate and crank so I'm kind of stuck with it for now. I'd rather have the 153.
Here are some header photos. The rusty ones are my cut up pickup truck headers 1.5 inch tubes and 2.5 inch collectors. The clean ones belong to tlowe and are 1.625 tubes with longer collectors also 2.5 inch. I know my rusty ones clear everything but they do hang a little lower. That could be fixed. The larger headers hit my power steering box. I think they might be OK with manual steering. The one tube hitting could easily be moved enough to clear. Also, the lower edge of the flange is resting on the side of the block. Not sure if this is truly an interference or not. If so, some time with a grinder on the flange would fix it.
What I'd like is the larger 1.625 tubes and longer collector but routed like my truck headers. That's a big project.
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Your set does hang down low.
I had Clifford headers for my Camaro & a manual trans.
Not sure there is a Co that made headers tuck up close? Other than custom headers.
My headers got all smashed up for being too low.
Not sure if you considered Toms cast iron headers?
I do not think you would loose too much power over headers.
Plus headers seem to always leak, blow out gaskets etc.
Tlowe dyno tested a 250 w/headers & Langdons cast iron manifolds,,, but I think when the testing was done w/the cast iron manifolds is when the balancer/damper was failing therefore creating massive amounts of vibrations which absolutely kills power output.
Just a thought.
http://stoveboltengineco.com/http://stoveboltengineco.com/index.php/c...t=0&sort=normal http://stoveboltengineco.com/index.php/c...product=1395980Your exhaust will tuck in very close to the belly pan & will last a lot longer than headers.
MBHD
I wonder if they will clear my Johnson intake? Looks like a lot less hassle than headers.
I wonder if they will clear my Johnson intake? Looks like a lot less hassle than headers.
The intake looks simular to a Clifford intake.
MBHD
They are a lot less trouble than headers. Nice product. I have a set and believe they will fit the Johnson with no trouble.
Headers will give you more low end tq. You are after that.
My dyno tests only show problems with the power when harmonics hit at high rpm. Stroker is not aiming to remotely go to those rpms.
strokersix
Those headers are not much lower then most V8 headers and No where as low as the ones clifford used to make for the
62-67 chevyII bodys.Because they had to pass under the drag link,and they were only like ?? MAYBE ??? 2in off the ground.
Tom, Will you post a couple photos of the Langdon cast manifolds and Johnson intake together on a head? Thanks.
Stroker,
Will get the pics you need later this week.
Hank,
Don't want to take away from Strokers fun build thread. Tom
I am thinking the 1.5" tubing is a bit small.
Your engine is pretty good size now.
You could run the 1.5" tubing & step it up to a bigger size, that way it will still have great low end grunt & still be able to breath more for top end power.
Just a thought anyways.
Goodluck!
I am thinking my Clifford headers were 1 5/8 1.625 & worked great on my 254 CI L6.
I'd have to go measure them to be sure or look @ a old Clifford catalog.
MBHD
Hank, I expected you were going to say that! I've been carrying these mandrel bends around for almost 20 years. This is the best opportunity I have had to use them.
If I were buying new mandrel bends I would buy 1.625.
Even with an unported exhaust port, an 1-1/2" header tube restricts the stock port opening quite a bit. Have you placed your header flanges on the head to see how much of the ports are being covered up by the flanges themself.
CNC, No I have not because I have not made them yet. The flanges will be whittled out of bar stock so I can make them whatever I want. Also I will swage the tube out a bit to match the ports. I wish they were all the same. Exhaust ports one and six are taller and narrower than two through five.
I think you do flanges is that right CNC?
I have them in sizes incremental from 1-5/8",1-3/4",1-7/8" and 2".
Nice work! Keep going, the picnic is coming up.
I am thinking, either you have a lot of time on your hands or you don't want to buy any parts from other members here?
At any rate,, your doing great!
MBHD
Thanks for the encouragement guys. I've had the materials for 20 years and this is the first opportunity to use them. Stainless makes some very pretty parts but is difficult to cut and grind. On the plus side it welds nice. The mandrel bends are 316. Some of the bar is 316 and some is 304.
Hank, what parts are you referring to? Langdon cast headers?
I thought there are a few members here that make header flanges?
MBHD
LOVE the header fab! Cant wait to see those things completed!
Collector flange position, head flange fit on head, and swaged tube entry placed in flange. I'll beat to close the gaps in the corners before final welding.
I'm not sure about order of operations. There are some spots I can't reach for welding that have to be welded first. It's going to be kind of tricky I think. It's nice to have the old headers for a pattern.
http://i965.photobucket.com/albums/ae131/strokersix/DSCN3943.jpghttp://i965.photobucket.com/albums/ae131/strokersix/DSCN3944.jpghttp://i965.photobucket.com/albums/ae131/strokersix/DSCN3945.jpghttp://i965.photobucket.com/albums/ae131/strokersix/DSCN3946.jpg
I like the work. Keep going! Want to hear those pipes rattle at the picnic. Tom
strokersix,
with your excellent fab skills, I can see you making a turbo install pretty simple for you.
Ever thought of do a turbo install?
MBHD
More header fab:
Beat to fit.
http://i965.photobucket.com/albums/ae131/strokersix/DSCN3949.jpgI'll probably clean it up with a file later.
http://i965.photobucket.com/albums/ae131/strokersix/DSCN3952.jpgNote weld between tubes I can't reach later.
http://i965.photobucket.com/albums/ae131/strokersix/DSCN3951.jpghttp://i965.photobucket.com/albums/ae131/strokersix/DSCN3953.jpghttp://i965.photobucket.com/albums/ae131/strokersix/DSCN3954.jpgI will purge with argon while final welding. There is some mismatch in the tube fit. This will wash out into a smooth bead if I get the penetration right along with the argon purge. Better if the mismatch wasn't there though.
Could you have welded them tubes before you installed them into the header flange???
Just a sugestion on the collector flanges.
Maybe purchase some V-band clamps.
No gaskets needed & they dont leak.
Example:
http://cgi.ebay.com/ebaymotors/NEW-2-5-V...sQ5fAccessoriesLooking good BTW.MBHD
Thanks.
No gasket on the collector flange. Since it's a rigid flange instead of the usual loose flange I think it will be more robust but we'll know soon.
That's what I call TUBE PORN! Good job, you are on a roll. Keep it up.
Even though you installed a ridged flange it will eventually leak.
There are only 2 bolt holes?
W/a V-band clamp, there is constant pressure applied evenly all the way around the flange.
I work on multi million dollar airplanes & that is the style flanges they all use & they do not leak.
The planes I work on have been using them since the 1960's & are used still today.
Just dont want you go go through leaks, especially if you can do it now before it gets installed.
There are so many CO's making these, there are low quailty ones,so watch out for thin sheet metal ones.
They are pretty affordable & I do not see why anyone would want to use an inferior design.
Just my two cents thrown.
MBHD
Hank, I believe you.
I may rework these collectors in the future. Originally I was planning to go from 2" at the collector inlet tapered out to 2.5 inch at the collector flange. I decided to make it 2.25 straight for now to reduce the effort. I can revise the flange connection at that time.
Bet your stomach is getting alittle tighter. That looks like a lot of exercise!
I'm not done yet. Still have to build connector pipes to the exhaust system.
Believe me, I'm in no hurry to build more headers. It's a buttload of work. My family has been patient with the noise.
Finished welding headers and built connector pipes. Hank, I think you are right about the 2 bolt flanges. Engine torquing around will pull on the flanges and cause leaks in short order, gasket or not. I bought some pickling gel to clean the heat stains, also need to add an O2 sensor port. Both can wait for now.
http://i965.photobucket.com/albums/ae131/strokersix/DSCN3968.jpghttp://i965.photobucket.com/albums/ae131/strokersix/DSCN3970.jpg
Great job!
What are the details on the rest of your exhaust system? Size, muffler/s crossover etc.
MBHD
Connector pipes are 2.25". Pipes back to the transverse mounted muffler are 2.5" with a 2" crossover. Muffler is a Flowmaster, I think it's really just two mufflers in one case but not sure about that. 2.5" out of muffler then 2.25" resonators out back exiting under the outer corners of the bumper. Resonators are altered JCWhitney glasspacks opened up for full 2.125" inside diameter thru and shorted to about 10" long to fit the available space.
The big block configuration was 2.5" all the way from 3" header collectors to the front of the resonators. I never took it to the track but the intent was to remove the resonators at the track.
Cool, what happened to the gas tank, time for a new one?
MBHD
Can't wait to hear the buzzin! Keep going.
I removed the fuel tank, drained it, and let it ride around in the back of my truck for a week to ventilate. Also blew the fuel out of the lines. I try to minimize flammables in the house, especially when I'm welding under the car.
Thanks for the encouragement guys!
Are you contemplating welding the tank for some reason? If so, we need to talk before you die. I know how to do it safe... most "safe" ways are not. People have died trying to weld empty, "ventilated" gas tanks.
Jan
I tack welded the exhaust connector pipes. Fuel tank isn't even in the same room.
That's a lot of RED
Nice!
It looks like that intake manifold makes a carb sit higher than a standard intake or Cliiford or Offy?
Are you using the bigger dual-jet carb?
MBHD
Manifold height is very similar if not identical to stock one barrel intake. I do plan to try a spacer under the carb at some point. Carb is the larger two barrel. It's from a '69 full size big block 265 horse 396 application. Should be similar to what you would find on 327, 350, 400 small block '69-'72 or so.
OK, the pics just looks like the runners 1,2 & 5,6 are sloping down, thinking the center is higher, thats all.
Has it fired up yet?
MBHD
I drove it around the block
Went for a drive yesterday and drove it hard. It runs strong. I'm glad I have the big 168 flywheel and clutch. I can lay two decent black stripes on the pavement and a healthy chirp going into second and even into third gear too! I wound it up pretty tight and nothing broke yet. Time for an oil change and see what's in the pan.
My younger son was with me and he thought it was cool but a little scary. That's encouraging in today's electronic iphone video game etc. world.
Cool!,
videos of this type of thing goes a long ways so everyone can enjoy, hint, hint. 
I forgot the specs on your camshaft What did you end up getting?I doubt you have anything bad in the pan.MBHD
My younger son was with me and he thought it was cool but a little scary. That's encouraging in today's electronic iphone video game etc. world.
You are lucky I think having a kid in a hot rod is a form of child abuse in California.
Got a ride in this cool rig today! Here is a short vid of it.
http://www.youtube.com/watch?v=t7VIZpI4lfQBest part is, he let me drive it! And told me to let it RIP. The throttle response is instant, no shortage of torque.
Stroker, Thanks for the ride. Tom
Sweet sounds great!
Just curious,, does it feel faster than your Elky?
MBHD
I've ridden in and driven Tom's car. I think Tom's car pulls harder with the turbo. I bet I would beat him off the line and give a decent run at 1/8 mile but I'm sure the turbo would win at 1/4 mile.
He told me chassis dyno showed 250 horse at the Elco wheels. My goal was 250 horse at the crank. I'm probably short of that number but not by a lot. A little more cam (comp 252 hydraulic), a little more carb (Rochester 2 barrel), and a little more gear (3.08 posi) would improve 1/4 mile time. It runs so well as it is today I'm in no hurry to change it. I have some brake and suspension work that is more urgent. Cut a coil off the big block springs first!
Nothing broken yet. Oil had typical metallic look of first oil change, nothing alarming. I've spun it up to 5500 or so (still pulling at 5500) repeatedly while driving it hard. Kind of hard to tell exactly since the factory Nova tach is tiny and calibrated for v8. I will pull the head for a look and better head gasket. It is a cheapo rebuilder gasket now. I'll swap to a nicer print-o-seal gasket. Pistons rattle a bit when cold but nice and quiet when warm. Runs well on 87 octane, no ethanol.
Sounds Real good strokersix.
Now I am convinced, you have worked on engines before. LOL.
Goodwork!
Have you ever checked your cranking compression?
MBHD
Thanks. I've worked on engines for most of my 46 years.
No, I have not checked cranking compression. All cylinders are the same based on the sound when cranking but I don't know the number.
Can you post pics of the flame pattern on top of the pistons? That tight quench has to show up in the pattern.
What type of valve seal were you running?
It's interesting how parts of the piston stay clean (like new) in the tight quench area. Wished I would have taken pics of the dyno 250 piston tops last time it was apart. They had a pretty swirl going on.
I was running white teflon seals that had been used a couple times. They are in the trash now, replaced with the seals I got from you.
Strokersix,
Nice build, I am following it closely.
With all the 16 pages of detail I just had to run this one thru the DeuceCoupe Gonkulator computer.
Here is what it computed to, with the info you gave and assuming that 396-2v carb is the 1.25" venturi style (381cfm at 3.0" rating)
I also computed a 9.46cr, not sure how you got 8.8cr unless I missed something?
Anyway here goes:
Torq 324 at 3300
Powr 257 at 4500
And with a good bite:
2.18 60ft
9.25 at 75.8 1/8mi
14.52 at 92.2 1/4mi
Using 1-5/8 headers instead of 1-1/2 only added 3 hp, and was better by about .02 sec and .2mph. Not worth it.
Adding a 600cfm Holley was good for 28hp, about 25sec and over 2mph in the 1/4 mile. But then you'd lose the fun of showing people your Nova taillites with not only a six, but a 2-barrel six.
Thanks! Hey, you can run the numbers anytime you want if they come up that nice. My goal was 250hp. I took this car down the dragstrip with a stock 350/th350 and ran 15.4/94mph about 15 years ago. That's the one and only time I've driven on the strip.
Yes, 1.25 venturis. I'm not sure where I got the 8.8cr. It's more like 9.5.
I'm adding a 1/2 inch spacer under the carb because it seems like the throttle plates almost touch the intake floor. I'm exxagerating but I do think it will help flow to raise the carb a bit. The spacer will also hold the throttle cable and return springs so it's a triple purpose part.
DeuceCoupe: Gonkulator numbers are gross at the crank (like '60s musclecar), correct?
DeuceCoupe: Gonkulator numbers are gross at the crank (like '60s musclecar), correct?
Yes they are SAE Gross ie 60F 29.92 dry air, open exhaust, water pump belt only, no air cleaner.
Also said 218 net hp (today's rating) and 191rwhp.
Gonkulator is still just a computer of course, but running it against Tom Lowe's dyno tests helped, it is fairly accurate on the Chev 6. I am always looking for dyno or timeslip data to compare to though!
One header with welding and exhaust heat stains and one cleaned with pickling paste:
Polished with some scotchbrite and soapy water for more even texture. Should turn consistent dark straw color instead of welding heat stains.
Installed:
1/2 inch carb riser plate. I'm hoping this will improve flow by making an easier turn below the carb plus some plenum volume. Still working on a throttle cable bracket that doesn't require baler wire:
Looks good.
Isn't it going to go back to the same color as before?
I see it looks like you have a nice radius feeding #'s 3&4 cyl, did you do the same to feed 1,2,5,& 6 ? Hard to tell from the pics.
I had put a large radius on my Cliiford intake & went too far , had to weld up both areas fwd & aft where carb mounts.
It(the radius) helps the air/fuel turn into the fwd & aft runners better & yes & carb spacer does help it does also change the fuel needs a bit also,depending on how thick a spacer you install.
MBHD
Yes, but now the weld color will match the tube color.
Absolutely nothing to do with performance. I just wanted to finish the job and make it look nice. Very minimal leakage on the two bolt flanges. I did grind a bit based on the carbon witness marks and added a small bead next to the bolt holes to seal them up even better.
Yes, I did blend in a radius to all three ports. It's not a lot since the top of the manifold casting is only about 5/16 inch thick.
I noticed one pushrod wasn't spinning based on witness marks from the guide. That raises the question of whether a lifter also isn't spinning so I checked all the lobe lifts. All were .266-.268 versus .2706 on the cam card. I think and hope all is OK with the cam. This is the fourth engine I've had this cam in and at least the second set of lifters so it doesn't owe me anything.
And the throttle bracket:
Got any tracks near you so you can run some 13's? Just need sticky tires.
Should be able to run some desent times, you got the torque!
Looks good.Nice job on the headers.
What RPM does it make power to?
Any cold air going to the carb?
MBHD
Cordova IL track is close. 13's? That seems optimistic but maybe. Will for sure need sticky tires instead of my street radials. And perhaps a better driver?
Thanks. I figured with as much work as I put into those headers I should finish the job and make them look nice. I think the welds will disappear when colored by exhaust heat. Plus I needed the O2 sensor bung. Don't know if I really needed two of them but it might come in handy some day. I did buy a wideband sensor so I'm anxious to see what it says.
I've run it up to 5500 rpm or so repeatedly. It's still pulling that's just where I chicken out. Now that I have a good set of valvesprings and have verified no piston/head contact I'll wind it up higher to see what happens.
No cold air yet but that's a possibility. What do you think about a rev limiter? Then I could keep my right foot planted while I run thru the gears. I hesitate to do that now because my shifter is a little sloppy. It's an old Hurst Competition Plus on top of the Muncie M20 wide ratio. Tranny is well used but in good shape. I did sleeve the countershaft pin (it's the larger 1" pin), square up the case (corrected warp from welding on the ears), and replaced a few parts inside.
Hey strokersix
If you every want to put in a 60s style hurst inline shifter i may have a extra one or two.I might part with.
What do you think about a rev limiter? Then I could keep my right foot planted while I run thru the gears.
I would,, Maybe a MSD 6AL box?
They seem to hit soft & not make any sharp or abrupt change when it hits the rev limiter.
I ran one in my Camaro when it was Paxton supercharged, very mild hitting.
I remember when I put in a 6000 RPM limit chip in the box, my Autometer tach needle would read about 5500 RPM & the engine was missing, I did not think it was actually hitting the rev limiter, engine reved quicker than the needle could move.
My friend told me to put the 7000 RPM chip in the MSD box & bam, that was it no miss,, damm engine reved too quick LOL.
BTW, what M20 do you have, close or wide ratio?
As far as running good ET's, IIRC, my best ET @ a 3000+ elevation track was when I ran a wide ratio M21 4 spd a very, very mild 250 .030 over, approx 10:1 compression,4 bbl intake & a small 500 CFM AFB. 4:10 gears
I ran a 14.3 which I thought was slow @ the time, I was always comparring to the V-8's, come to find out here, it would have been a record that would still be standing here today in the International inliners record books, I still thinks that funny.
I have run many different combos, memory fads a bit but I found the timeslip w/what combo & had @ the time I ran.
I had the original 3spd, horrible 2nd to 3rd gear RPM drop,4spd Muncie,5 spd T50 & a TH350, next a 4L85E
MBHD
My Muncie is a wide ratio. It's a compilation of Muncie parts of unknown history, 10 spline input, 28? spline output, 1" countershaft pin. Rear gears are 3.08 8.5 inch with factory posi. I had 3.42 gears in the car at one point but I didn't like the freeway rpms so went back to 3.08.
Limited mechanical advance by adding weld to the weight tips.
The added 1/2 inch riser under the carb required air cleaner modification for hood clearance and now has a big block engine decal. Also note the header tubes and welds are turning color already. Hooked up my old Edelbrock O2 sensor (not wideband) and indicates the carb might be a bit rich but not excessive.
Now the bad news. Something broke in the valvetrain. Not sure what. It sounds like a 250 in an old pickup truck, no offense to truck owners here, just a reference to the typical well used 250 ticking valvetrain. My first guess is a cam lobe went flat but we'll see. Maybe I should drive a little slower.... NOT!
Is the weld limiting the mechanical advance?
I just weld up one of the slots under the advance weights.
MBHD
Yes, the weld limits mechanical advance. In the second photo you can see the tip of the weight contacts the cam close to the center axis. The weight can't get enough leverage to continue advancing the timing. The vise keeps the weight cool so it doesn't soften or damage the bushing while welding. The tip is soft and will eventually wear away but this car won't see enough hours for that to be a problem.
As I'm sure you have observed, I don't always do things the same way others do.
Good news! Pulled the valve cover tonite and it was immediately obvious that #5 intake rocker was loose. Pulled all 12 rockers off. I checked all the cam lobe lifts (Comp 252) and all good. All 12 pushrods are now spinning. Torqued the head bolts to 95 lb-ft, some were at about 85, some didn't move. Then reset all 12 rockers to 1/2 turn preload and cinched the locking setscrews tighter this time. Manifold fasteners all tight. The loose rocker doesn't roll as silky-smooth as the other 11 but I think it's OK.
That is good news! Had me worried. Glad it was something simple. Did you take it back out for a spin?
Nope, not yet. Maybe tomorrow.
While your taking it for a spin, go to Cordova IL track & see what it can do,,, if you want to.
MBHD
It's back! Runs good. I have some work to do on the ignition. Mechanical advance curve still needs improvement and I'm going to look into a rev limiter. Anyone used and recommend the HEI style that swaps in place of a stock module?
Great!!, how much initial timing do you have?
MBHD
...The loose rocker doesn't roll as silky-smooth as the other 11 but I think it's OK.
Eeewww . Maybe the needle bearings are going away. Or the pushrod tip galled up the cup in the end of the rocker. Been there. I would recheck the rocker arm for damage sometime soon. If those little needles get loose and scurry throughout the lubrication system It won't be pretty.
Yes, I'll keep an eye (ear?) on that rocker.
Tom checked my advance curves when I visited (thanks Tom!) for a baseline. I added the weld on the weights to cut off the top end of the curve. Didn't get a chance to work with it yet so I don't know for sure what the curve is now. I intentionally made the welds bigger than needed and I'll trim them to get the curve I want. I set initial at about 12 degrees. I'm getting some spark knock just off idle so perhaps 8-10 degrees initial would be better. 87 octane no ethanol. It's a work in progress.
Interested in total mechanical (initial plus centrifugal) timing suggestions. 250/292 engine, 9.4 static compression, Comp 252 cam (206@.050 I think), naturally aspirated. 32 degrees about right?
I believe Tlowe has said the best timing is @ 32 degrees, did he not tell you? Dyno proven results w/a 250 & 292.
I would suggest to put the car on a dyno & see what your engine likes. 2 cents thrown
Hows your A/F ratios?
MBHD
Yes, he told me that.
I think A/F ratio is pretty close by how it runs, possibly a bit rich based on the narrow band O2 sensor output.
No dyno until I'm happy with the tune. There is clearly work to be done.
I thought you have a wide band?
Works much much better more accurate & fast acting. That will speed up your tuning greatly.
MBHD
The dyno motors were tested at higher total timing (34-36). We were running much higher octane though (110 sunaco).
32 degrees ain't bad and much safer with low octane fuel. The bathtub chambers do like plenty of timing.
8-10 initial will help back the total down also.
You need to get that WBO2 hooked up. Do not expect the engine to like running at stoich (14.7 to 1). Mine likes 12.75-13 at idle. The guage will be more of a reference. It is effected by plenty of variables. Cam, timing and exhaust leaks will make it read funny. I was told long ago to use it as a reference to find where the engine likes to run at. This A/F varies at different rpms and loads.
Does the engine run any differnt with the last head/ valve setup?
Runs about as strong as before. Which is good because I hope it runs even better when I get the ignition sorted out. I plan to work on it today.
O2 sensor shows rich but not terribly so. Usually it tapers off to lean while cruising and it's not doing that. I agree, I need to install the WB sensor.
Try to get some more vids.
How about that shifter? It will take longer to install that. But it will put a big grin on your face.
I'll have to pull the seats, console, and carpet, then do some floor modification to get the shifter installed. Need to work up motivation for that. Seats out will be a good time to install the WB gage.
Nobody here has run the HEI module rev limiter??????
http://www.northernautoparts.com/ProductModelDetail.cfm?ProductModelId=15650
I would just get one of these. MSD made them smaller than before.
http://www.amazon.com/MSD-Ignition-6425-...13859749&sr=8-3These work great also.
http://www.msdignition.com/Products/RPM/...ng_Control.aspx You can advance your timing when trying to get max MPG.
Great for when you run nitrous & you would need to retard your base timing.
It worked great for me.
MBHD
Ok here is where I ended up: Centrifugal advance starts at about 800rpm goes up to 15 degrees at 3000, topping out at 18 degrees. Initial 12 degrees for a total of 30 degrees mechanical advance. Vacuum advance starts at 5 inches up to 18 degrees at 13 inches. Idle speed 700rpm.
Runs good. It only rattles if I intentionally lug it down hard, not a normal operating condition. Rich/lean indicator flickers lean when cruising 40-60mph, holds steady rich cruising at 70.
Centrifugal could probably come on a bit stronger, full in at 2500 perhaps. A/F ratio could lean a bit at high speed cruise but I'm not in a hurry to fiddle with that because it's pretty close now.
I am ready for a bigger camshaft. This one (Comp252 )starts to give up over 5000rpm. I think I would like to get up to 5500-5800rpm.
Hank, The advance control knob in the cabin sounds cool. My HEI works fine, what benefit other than the remote timing control will the red boxes give over my HEI? Multiple sparks for more complete combustion? Big red boxes don't fit well with my sleeper look but if there is a performance advantage I might consider it.
You will get a hotter spark,more complete combustion.
If you ever seen first hand between a stock HEI spark @ the plug & compare it to the multiple sparks of the MSD unit,I think you will most likely buy one from that comparision alone.
You could make more power & better mileage w/an MSD unit installed.
I know of guys running there stock HEI units on there Syclones & Typhoons that when they run a methanol injection system, it is causing there spark to blow out, then to reduce the tendacy of the spark blowing out they will close there gap down to as much as .022".
I to, use the stock HEI unit on my Syclone & run methanol injection, but I just added a MSD6 box, I never have to close up my spark plug gap & I run 24 psi of boost pressure & spraying a lot of methanol.
Features
•With Soft Touch Rev Control
• Higher output with 530 primary volts and 135mJ of spark energy
•Efficient components use less current to produce more power
•Set an rpm limit on the 6AL with two rotary dials
•Same bolt pattern as the original 6AL with a lower profile housing
•Built-in LED for system checks
I would not say you are pretty close w/your ideal A/F ratios until you install a wide band set-up. You will be in for a surprise.
Narrow bands are really an inferior product as compared to the wide band.
MBHD
I would not say you are pretty close w/your ideal A/F ratios until you install a wide band set-up.
That's OK. I think I'm better able to judge this than you anyway because I am here with hardware I am familiar with and you are not. I may be surprised, maybe not, we'll see. Either way I'll post here what I find.
BTW, my 2-bolt flanges are not leaking.
I am not saying you cannot tune w/a narrow band, it's possible & has been done for many many years.
It's just the narrow band is so slow in response time your A/F ratios could be way off @ especially during gear shift points.
I did tune my Syclone w/a narrow band O2 & w/that (narrow O2 sensor) I had the worlds fastest stock turboed Syclone, for about 8 years. I had no extra cash to get a wideband.
I did have a reading problem during the shift points though, the narrow band would show full rich @ the top of each gear change (thinking it was fine) but actually was dangerously lean,there was a couple second delay with the readings w/the narrow band O2.
I now use an old Innovate LM1 unit on the Syclone.
It was not until I wanted to turn up the boost & lean on it a bit more, (lean it out)I would only feel comfortable doing this with a wideband. I could have done it w/a narrow band,just much safer w/a wideband IMO.
Guys still tune there Buick GNs & Regal T-Types w/there stock narrow band, getting advise that has been passed down from older owners, there were so many of those cars made it's pretty easy to get good info on what works & what does not work & what's lean & what is rich, all measured in millivolts w/there scan tools.
One of the main reasons I tell guys to get a wide band O2 is to speed up the tuning process, most times you do not need to take out your plugs to look @ them.
It would be absolutely essential to get a wideband when you are forced induction, being too lean will destroy an engine very quickly & a wideband takes away the guessing, you know exactly when it's too lean or too rich right there & right now.
When I had the Paxton superchager on my inline 6 I did it the old fashion way, I jetted it richer right off the bat as compared to my normally aspirated set-up. Took plug readings (a lot) It was a somewhat long process tuning 3 DCOE's, but hey I learned.
MBHD
Any updates?
I love this thread!
X2
I'd like to hear about it also.
MBHD
I cleaned and painted my power steering pump and removed a couple extra fittings from the high pressure side.
Headers are a nice pretty color now. I'm very pleased with how they turned out.
I did get the car out for a blast this weekend. It really runs well. Not sure what to change next. Inline shifter and wideband O2 sensor are possibilities. What I'd really like to do is tear it down, reweld the subframe, and install subframe connectors. Maybe some lighter weight front suspension would be cool too. Got my eye on those Detroit speed hydroformed subframes but that would eat up several years worth of car project budget.
