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That hg lookes bad a$$


Josh
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I just got to my job in St. Louis for the summer so I'll be slaving away on my code until the beginning of august. All I need by the time I get back is a comprehensive plan for the machine work I need to have done.

My plan is...
Cut head for larger valves, install valve seats, install valve guides
Pull old rockers, mill boss down to install 7/16" screw-in studs, tap hole and install new studs
Probably tell them to install the lump kit
Remove old rod bolts, press in new ARP bolts, re-round and shot peen rods
Press on new forged pistons to rods
Magnaflux block, bore .040" over and hone for the new pistons.

Then at that point I'll get them to cc my heads and I'll talk with them about figuring out how much I need to deck the block to achieve my desired compression and/or open up the combustion chamber and/or notch the pistons. Then I'll confer with you guys and go from there.

Last edited by snowman4839; 05/28/14 06:19 PM.

69 Buick Special Deluxe. Intercooled Turbo Chevy 250 @ 15psi on a stock long block. It's kinda fast.
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I believe you can use the LS valves. They have 8MM stems.
When you install valve guides get the ones for an 8 MM valve stem diameter.
Smaller diameter than stock 11/32, should flow a bit more also.
Just check valve lengths to be sure.
Just a suggestion BTW.
Should be cheap, they are the most popular valves out there now IMO.

On your con rods, you would want to side grind/polish the forge lines so they are smooth.
Then have them shot peened & then magnafluxed


Examples: https://www.google.com/search?q=polished...52F%3B500%3B375

Instructions

1 Weigh each connecting rod and note the weight. They will be very close in most cases, but not exact. Determine the lightest connecting rod and begin removing the casting lines on each side of the rod with a grinder. Use a course-grit stone and work vertically along the seams.

2 Change stone grit to medium and continue to work on the rod, reaching a smoother finish. Work in one, vertical direction along each side, finally using a fine-grit stone to finish the machine grinding. Completely finish the mechanical sanding on the lightest rod. Weigh the finished product and use this weight as a benchmark for all the other rod weights.

I usually use a carbide burr,( just watch out for the sharp burrs flying) then finish w/sanding drums or sandpaper flapper roll.

Sounds like a plan.
Good luck.

MBHD







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Anything


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Must be making $$ & saving up?


MBHD


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MBHD got it. Should be getting my first paycheck next week and I can start amassing parts. Just got back for a few days to spend time with the family and hang out. Snuck a trip to the machine shop today and worked out a build plan.

$150 - Line Hone (if needed)
$300 - bore and hone
$60 - File and fit ring gap
$75 - Press off and press on pistons
$90 - Install ARP bolts and reround rod
$350 - remove, drill/tap/mill boss, for 7/16" rocker studs
$350 - cut new valves and valve job
$100 (if needed) - remove and install new valve guides
$100 - deck block to clean it up
Once we get all that done we'll determine how to fix the compression ratio down to about 8.8:1 wether it be modifying the pistons or opening the combustion chamber or whatever.

Max for machine work should be $1685 after taxes but I might be able to knock it down to like $1300 depending on if I need the valve guides done and the line hone.


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Most of these inlines don't need line honed.

Do not skip the new guides when rebuilding the head.

I think he is high for the rocker stud work. It is a bit of work , but not that much.


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 Originally Posted By: tlowe #1716
Most of these inlines don't need line honed.

Do not skip the new guides when rebuilding the head.

I think he is high for the rocker stud work. It is a bit of work , but not that much.


X2 , way too high for rocker stud install, tell the guy for a better quote, that is outrageous..

Snowman, what pistons did you get? Tlowes?

Glad you are going to build a nice motor. You will see a big power increase.

MBHD


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I'm actually just going to forgo having the machine shop do my head and just have Tom do me a head. I figure who better than a fellow inliner. Plus I trust Tom to do the lump ports correctly over myself and especially a machine shop.

I just got my first paycheck so the parts should start rolling in soon. I don't imagine I'll find a better deal than the Ross pistons Tom has so I'll probably end up getting those. Then I can zero deck, the block use that 0.041" gasket to get the appropriate quench, and then just get the combustion chambers up to 78cc to get a 9.0:1 comp ratio. I believe that was something Tom could do while preparing the head.

I just ordered a set of micrometers and I got a dial bore gauge earlier this summer so that I can do assembly correctly and confidently. During the week I have between my job and school beginning next semester, I will be taking apart the block I'm going to get machined. During this same time, I'm going to be packing up the head and the Tom's head rebuild kit to send off to Tom to get that started. Then I can just have my block and pistons/rods at the machine shop getting done while the head is prepared at Tom's. Then I'm guessing some time in October, I'll have all the parts back and other parts purchased and I can begin assembly.

Other parts I plan to buy during this time period (in this order): new engine wiring harness, a stronger clutch and pressure plate, meth injection system (brand recommendations anyone?), and a J&S safeguard (most likely).

Few questions for y'all.
-Was original rocker ratio 1.7 or 1.75?
-I'm going to get a set of roller rockers to go with the new head and valvetrain. My cam's lift is .5145" (I'm assuming that's with the 1.75) but the springs can handle up to .550". Why not just get a set of 1.8 rockers and bump that up to .529"? Is there any reason not to add valve lift?
-I was looking at a few of Tom's turbo cams and wondering...
--why have different intake/exhaust durations (Toms is 218/212 vs my recommended 218/218)
--same question about lift (.521/.512 vs .5145/.5145)
--why not get the max lift your springs/valves can handle?
-how will the cam gear set work with the new cam? Is that something specific to the cam or can I just press off the stock gear set and onto the new one?
-is there a way to screw up the cam install? shouldn't it just be match the cam gear dot to the crank gear dot? It seems like I remember some gear sets let you advance or retard the camshaft to change the power band (which also leaves room for error)
-will I need to worry about piston-to-valve clearance with this larger lift, decking, and slight head shaving?

lastly, will I need to worry about measuring all the clearances and sizes and whatnot of the engine before sending it off to be machined? Like do I need to KNOW that it needs a line hone (and go measure all the mains) or can I just tell the machine shop to line hone it if it needs it i.e. will they do all the measurements anyway making all the my pre-machining measurements superfluous.


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I forgot the cc's on my larger chamber head, but it has 2.02" intake 1.60" ex, & the cc's are in the 80's, I will measure it so I can tell you the exact measurement when I get the chance to.

I just put it through a steel abrader (SP) machine so it looks new. Need to hot tank it & then I'll cc's the chambers.

This head was done many years ago.

I was thinking it was 84 cc's?

1.75 ratio is original spec.

1.8 rocker arms will put more load & wear on to your valve train components, no real gain from what I have been told.

Springs, you should have a bit of cushion & not go to max lift, it's safer.

You would be better off getting a custom grind from Comp Cams with the specs you want rather than a generic off the shelf cam IMO.

Call Comp Cams & they will help you w/a choice, or I can help you w/the specs if needed.

Block usually does not need a line hone. I never heard of anyone doing it on our inlines.

If the cranks spins nice & easy with new bearings & lubed up, it is straight.

Cam gear, heat w/a torch & it will fall off, then reheat to reinstall.
It you do not use heat, it will shear off some aluminum & will become a looser fit & will fail.

Having an adjustable gear set gives you more options, IE, need more low end, top end, mid range? Those adjustments will make a difference.
Plus you can use an offset wood drift key also to get even more timing gear movement.

Main thing to do is actually check to see if the camshaft is ground where it is supposed to be ground at & to check & see if the timing gear slots are correct also.

I never came close to hitting my pistons, & my camshaft specs are 238 degrees duration intake 248 exhaust @ .050 w/ approx .550-.580" lift,115 lobe center, there was a mile of room.

I doubt your camshaft will have more overlap than mine does currently,, it is pretty, rough idle for the street use. but,,, you are always supposed to check it regardless.

Somebody here might know the approx specs on a camshaft that will come close to hitting the pistons, I do not know, my camshafts never ever came close.
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Hank,
Jeeze that's a huge cc combustion chamber. Good thing to know that 78cc is possible then and that I can go ahead and zero deck the block

I thought I had posted the recommendation from Lunati but I looked at the past 3 pages and could find it. So here it is,
Single pattern grind
219 @ .50 for intake/exhaust
.5145" lift
recommended 112* of lobe separation but I asked for 113 or 115 I think, I'll have to find the sheet again.
Recommended springs were installed height of 1.85", 125lbs seat, 325lbs compressed
The springs I got from Tom are 1.75", 100lbs @ 1.7" (so it will be slightly less at 1.75"), and 320lbs at .500" lift. So the seat pressure is kinda low (enough to cause a problem?) and the compressed is right on the money.
Tom also guessed the bind height was 1.150 giving .600" from seat height to bind height giving my cam .0855" clearance to bind which should be fine. When I get back, I will throw a spring in a vice and measure it's bind height to be sure.
It was similar to Tom's cam he used on the turbo dyno 250 which was slightly more lift, slightly less duration, and 110*? separation? I think it was an N/A cam actually.
I'm hopeful that if he can make 350hp on that cam then adding a little more lobe separation would put me nearer my goal.

To get that cam gear off, you think a even heating with a mapgas torch should do the trick? Do you mean literally it will "fall off" or at least be loose enough to pull apart by hand??
Just heat it back up to install on the new cam?

Then I won't be particularly worried about piston-to-valve clearance if it wasn't close on that radical of a cam.

I just got a degree wheel and will be degreeing my cam on assembly.



So updates...
I just got the ball rolling on parts tonight. Bought tom's Ross forged pistons for the stock 5.7" rods. Then I also bought new ARP rod bolts (and floor pans but that's unrelated haha). I will hopefully getting those engine parts by next week so I can make a trip home, get the engine torn down, and off to the machine shop with the new pistons and rod bolts so they can start working on that. I'm also going to go ahead and get the head torn down and sent off to Tom.

Now that I have a set of micrometers and a bore gauge, I'm going to measure the mains crank and check the clearances. Maybe I just happened to get a bad reading on that first engine because of assembly lube I didn't clean off or something. Now I have a good accurate way of measuring it. That will give me a good indicator if I need to have the crank turned or something is out of whack with the mains.

Is it worth the money to invest the other $200 for ARP hardware for the mains and heads?
The stock bolts and head gasket seemed to work pretty well for what I've been doing and it seems like I remember someone saying that in Brazil, they've used the stock bottom end up to 1000hp, but I'm not sure if they were including the hardware with that factoid.

Last edited by snowman4839; 07/18/14 12:47 AM.

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If its an aluminum gear becarefull heating it if steal once heated yes it will literally fall off and i put mine in the oven to reinstall


Josh
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I would hold the camshaft verticle with the gear towards the ground (close to the ground), heat it up evenly w/your mapp gas, & when it is heated enough, the gear will literally fall off.

Apply the heat towards the center, not on the teeth.

Remember Toms turbo dyno 250 was only running 5 psi of boost pressure to make 350 HP, I think you are going to run more than 5 psi?

I think if Tom sold you the springs & he is going to set-up your cyl head, he should know how to set it all up.
You should talk it over w/Tom since he is doing the work.

As far as ARP main & head studs.

For you being turbocharged & you are going to push it , I would recommend the head studs @ a minimum.
The studs will give you a better clamping force than stock head bolts. less likely to blow a head gasket w/ARP head studs.

Are you going to use a Felpro 1025 gasket or a MLS head gasket?
Example: http://www.ebay.com/itm/201113338861?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


As far as the main cap hardware, I think you can get by using the stock bolts, maybe someone else might recommend them.

I never blown up a 6 cyl yet, not saying it can't happen.
I used to run to 6500-7500 RPM range on stock main cap bolts.

MBHD


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Alrighty I'll give the mapp gas a try next weekend.

Yeah, 350 @ 5psi on a non turbo cam it's incredible. I told the guys at Lunati to recommend me one for 15psi. Plus I'm adding meth injection so I might be able to turn that up a hair higher but we'll see. Can't wait to see what mine will do.

I did talk it over with Tom and he said it should be fine and I imagine it will be especially with less lift. I believe him but I just want to make all the math add up too. I also want to do everything I can to prevent rounding the cam on first startup which is why I'm so concerned about the 325# spring pressure on the nose for break in. I can't find anywhere what the max spring pressures for a flat tappet cam should be.

Yeah I'll go ahead and get head studs. No machine work required for that so I might as well.

I'm going to go with the felpro 1025 because I just can't justify $200 for a head gasket especially when I've had such good luck beating up the other 1025s without a problem as well as having head studs for even more assurance.

I think I'll leave the mains stock. Seems that people have had good luck with em so why mess with a good thing.

What type of springs specs and cam did you have when turning 6500-7500?


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Use to turn those solid lifter 270 hp 57 Chevys running Jr. Stock Class 7200 RPMs and NHRA would only allow 56# on the valve seats. When you won stock class you had to pull a head and they checked it along with every thing else. The Hi-Rev hydro lifters will go 7000 RPMs a few times and then start falling off to about 6200 RPMS with Clifford springs set up at 170 spring hight and 125# on the seats. I have about 20,000 miles on my 250 with this set up now and the lifters will start pumping up at 5800 now. I may have missed it with your set up but 300+ lbs. on the seats must be for some sort of roller cam...


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Just got off the phone with Lunati. Told them about the 100lbs @ 1.7" and 325lbs @ 1.25. He didn't like that much. Said it was much too low on the seat. I also just did the math and it would be 75lbs @ 1.75" installed height which is not good. It also means that the spring rate is 488lbs/in which seems wrong.
I'm just hoping that the seat pressure is incorrect. I do not want to float these valves.

Lunati also said keep the springs under 100lbs seat and 270lbs for break in. I hope my stock spring will fit the newly machined head since they're perfect for break in @ 60?lbs seat and 185lbs open (on the stock cam's lift).

Scrapiron - it wasn't 300lbs on the seat. It's 75lbs on the seat, 325lbs on the nose. It's a flat tappet. What do you mean by "pumping up" at 5800?


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 Originally Posted By: snowman4839

Yeah I'll go ahead and get head studs. No machine work required for that so I might as well.

I'm going to go with the felpro 1025 because I just can't justify $200 for a head gasket especially when I've had such good luck beating up the other 1025s without a problem as well as having head studs for even more assurance.

What type of springs specs and cam did you have when turning 6500-7500?


I need to recheck my spring pressures.
Don't quote me, going off of memory, but IIRC, 100-120 seat pressure & 300 lbs over the nose.

If those springs you have are at 325 lbs over the nose,, seems a bit too much, I'll ask my friend if you would like?

My camshaft is a solid lifter camshaft, is yours a hydraulic camshaft? It makes a difference.

Spring technology has come a long way in the more recent years.
You can purchase springs that have good seat pressure & do not go crazy high pressure @ full lift,= much easier on the camshaft & lifters.

Good choice on the head studs.
The thing that is good about the MLS head gaskets is that they are reusable, but they do cost $$$$

MBHD


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Here are some better pics of a cleaner 2.02 in 1.6" ex chamber.

You can kinda compare to you current cyl head & see these chambers are pretty big.

Still need to CC them.





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when those hydo lifters start pumping up (float) they hang the valves open same as solids when you go past the valve springs. I do know it don't take near as much valve spring with solids to turn 7000 rpms. Back in the Junior Stock Days after about 30 or 40 1/4 mile passes you would start loosing some ET due to the loss of MPH.. The car just wouldn't pull in high gear.I would pull the springs and they would be down around 10# on the seats. I would replace the springs and be back on my number. In those days if you wanted to compete in the Jr. Stock classes and pass the inspections you had to on the edge. All the legal guys were with in a tenth of each other... then you hsd the CHEATERS !!!


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MBHD - why did you decide to go with the 2.02 vs the 1.94"? That's a huge valve! Is it because you already planned on taking out so much from the combustion chamber that it wasn't a big deal to deshroud it?
Also let me know the CC of your heads when you get around to measuring them

Scrapiron - I had never heard it called pumping up the lifters but I gotcha now.



So a bit more math and I like what I see. I got my dad to measure the uncompressed length of the spring and the bind height. The bind height was 1.13" and the uncompressed was 2.05". If Tom got 320lbs at 1.25", then it has a spring rate of 400lbs/in. If the installed height is at 1.75 then it will be compressed .3" on the seat giving it a seat pressure of 120lbs which sounds perfect.
Again I'm just hoping there was a mix up at measuring the valve seat pressure. I will take a spring to the engine shop when I'm dropping everything off and see if they can measure it real quick to double check.


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 Originally Posted By: snowman4839
MBHD - why did you decide to go with the 2.02 vs the 1.94"? That's a huge valve! Is it because you already planned on taking out so much from the combustion chamber that it wasn't a big deal to deshroud it?
Also let me know the CC of your heads when you get around to measuring them


This head was done about 25 years ago, I knew we were going to open up the chambers quit a bit so figured it might be OK to try some 2.02" valves.
Plus I figured I was going to use the Paxton supercharger to force the air fuel mixture into the combustion chambers.

This is the cyl head I installed my hand made upper lumps & the same head that propelled my Camaro to run low to mid 12 second 1/4 mile passes, the fastest my Camaro ever ran.

There really should not be any advantage running these 202's because you cannot really open up below the valve seats, did not want to risk hitting water, it does not have enough material below the seats, therefore no more airflow. My cyl head was made for the street, not ever a race car, had to be reliable & risk hitting a water jacket was not in the plans.

I will get this head flow tested & cc'd (just thinking to myself) it might get a little more airflow @ lower lifts than a 1.94" but I am not counting on that it will.

We shall see how good or bad it flows w/the 2.02's.
Stay tuned, but it will take time, my friends are busy porting heads & flow testing heads, so I need to squeak in between there jobs.

I have not run any super high lift cams, but I believe if you have the cam open the valves past the actual height of the combustion chamber it can flow more air because the chamber is not shrouding the valves, but the bores are still small, so that does not help either.

MBHD


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We used 2.125" intake valves in all of our race heads. I don't use anything smaller than 2.02" valve in the heads I do. You need to look at these engines on a volume level instead of it being just a lowly 6 cylinder. A 250 has the same cylinder volume as a 350, so a 2.02" valve isn't too big for it at all. It does require a little more careful bowl cutting, but you can easily get it to 80% of the seat size. We never struck water even with putting a 2.125" valve in one.



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You can see the bowl is opened up for the 2.02" valve ,just did not want to risk hitting water.

We tried cutting for 2.02" valves on a couple of 194CI heads, those hit water jackets,(JUNK) so I took it easy on this larger chamber head.

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I mean I thought 1.94" was huge. In this case is bigger really better? Would it make that much difference on a forced induction engine? I'll be waiting for those flow numbers Hank.

I'd still like to have Tom do my heads but I'm not sure if he'd want to do the extra bowl work required for larger valves. Plus I don't know where to start on finding valves.
The valves I got from Tom are .342" stem diameter and about 4.970" OAL. Here are some springs that are a 2.02 with a matching 3.42" and 4.970" for a Mopar http://www.summitracing.com/parts/edl-9366/overview/ would that work? Are the keepers and retainers only dependent on the stem diameter or are they valve specific?

If I ended up getting a longer valve to allow for more lift (not likely but I want to know), how does that affect the spring/retainer/keeper selection? Wouldn't the higher location of the keepers increase the installed height of the spring necessitating taller springs so it doesn't lose its pressure on the seat? Or is that where you machine the pockets down to allow for the extra installed height?

When do you need to start worrying about there being enough lift for the keeper to be pressed far enough down to contact the valve seal? Or is coil bind always going to happen before this ever will?

Why isn't uncompressed height a specification given on springs? Isn't that what you would use to determine spring selection for a longer valve stem?

Last edited by snowman4839; 07/19/14 11:39 PM.

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The 2.02 valves are not going to make a huge difference in power IMO.
Bigger is not always better.

If you install 2.02 valves and do not open the chambers, your cyl head will flow less than what a 1.94" valve would flow.

I am not sure if Tom has tried 2.02" valves & flow tested them?

You just cannot leave the chambers stock, & you do not just install a cutter on a pilot & just notch the side of the chambers & expect for the head to flow well. It does not work that way.

Your valves are probably just S.B.C valves, 11/32 stems.
You can get .050" & .100" long.

A.F.A.I.K., .100" long is standard size you would use.

Just relax, Tom should be able to set-up your head & not have any problems.
Call him up & tell him your concerns & your questions.

You add shims to get your seat pressures, you don't keep cutting the spring pockets to get your installed height correct.

There are many different retainers you could use that have different located steps in them to achieve your required installed height. 10 degree locks are better & are the ones you should get.

MBHD


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Going to a 2.02" valve will be beneficial if you are looking to get 350 HP or more. My last head with 2.02" intake valves and my billet lumps flowed a little over 290 CFM. But like any oversize valve, if you don't open the bowl up to correspond with the larger valve you won't get the maximum benefits from putting them in. Also, as Hank mentioned, the +.100 long valves are what I use. They also help with the larger cams that you will typically use when seeking HP in the range I mentioned.



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 Originally Posted By: snowman4839

If I ended up getting a longer valve to allow for more lift (not likely but I want to know), how does that affect the spring/retainer/keeper selection? Wouldn't the higher location of the keepers increase the installed height of the spring necessitating taller springs so it doesn't lose its pressure on the seat? Or is that where you machine the pockets down to allow for the extra installed height? Using a longer valve can be used to your advantage in several ways. One critical error that many people do when installing larger valves is they try to sink the seat to the same depth as the original valve seat. This kills the SSR airflow, because as the valve size increases, so should the SSR. Plus, it also increases the chances of hitting water. So in essence, a longer valve installed correctly and having the seat created as shallow as possible may not increase the installed height that much, and can kinda' balance out and allow you to use the intended springs.
The flip side to that is someone using the stock length o/s valve and having to sink the seat to retain an acceptable spring height, when they should have used a longer valve to prevent the shortcomings that they have now created by not doing so.


When do you need to start worrying about there being enough lift for the keeper to be pressed far enough down to contact the valve seal? Always! Or is coil bind always going to happen before this ever will? Not always, but coil bind is very destructive, and installing the springs too close to coil bind is just as bad, and greatly reduces spring life.

Why isn't uncompressed height a specification given on springs? Isn't that what you would use to determine spring selection for a longer valve stem? Uncompressed spring height is completely irrelevant to spring selection. What the springs installed height is determines that. You can have a taller uncompressed spring have less installed seat pressure than a shorter spring. It's only by being compressed to a specified height that has any meaning.



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The free length, plus the spring rate, determines the pre-load (seat pressure) at any assembled height.

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Well I'll talk it out with Tom sometime this week then. The springs should be fine up to .550" or .560" cam lift with that bind height @ 1.13" so I should have room to upgrade the cam lift and duration, but I only want to do the machine work once so I need these valves sized right the first time.

My horsepower goal is in the 400-600hp range. Hopefully 350-400 @ 15psi without alcohol and into the 500s with alcohol. I'm not sure if that's hopeful or not but it seems to be a reasonable goal with...
-higher compression (9.0:1) @ 15psi
-mild porting (part of tom's head work I believe)
-lump ports
-deburred combustion chambers (lessen detonation)
-port matching
-holley double pumper 600cfm 4bbl (with the hangar 18 blow through mod)
-MSD BTM or megasquirt timing control
-alcohol injection
-intercooled
-little larger ball bearing name brand turbo like this Garrett GTX3582R which is a 63mm T3 turbine turbo with similar A/R ratios and a recommended hp range of 450-750. EDIT: This actually might be a china turbo ripoff but this turbo nonetheless http://www.ebay.com/itm/GTX3582R-Turbo-c...f6d64e8&vxp=mtr

Last edited by snowman4839; 07/20/14 03:16 PM.

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That China turbo is low price as compared to a name brand like Garrett.
Here is one, but is a Garrett. http://www.full-race.com/store/turbos/garrett-gtx-series/garrett-gtx3582r-turbo.html

The turbo you have a link to will not come close to 750 HP on your 250, it is too small.
IIRC, the turbo you have now has a 57 MM compressor housing, the turbo you posted has only a 62.5 MM wheel, it's bigger, but not enough to get 750 HP.

The turbine wheel is too small also on the turbo you have a link to.

That turbo is not enough for you to get to 600 HP either.

"My horsepower goal is in the 400-600hp range"

The HP you are looking for, is that crankshaft HP or at the wheels HP?
I am thinking you are talking about crankshaft HP. Correct?

MBHD


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Well I was hoping to get 500hp+ at the wheels when it's running perfectly. But yes, 400-600hp was at the crank

I was being conservative with that turbo choice. I know it needs to be bigger but I also don't want it to need 4000rpm to spool. What size were you thinking for that hp range? I was planning on calling garrett when the time came.

EDIT: Is this more what you were thinking? 67mm inducer available in the similar A/Rs I have now http://www.ebay.com/itm/CT4-6767-GT4088R...e77944a&vxp=mtr

Last edited by snowman4839; 07/20/14 06:08 PM.

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 Originally Posted By: snowman4839
Well I was hoping to get 500hp+ at the wheels when it's running perfectly. But yes, 400-600hp was at the crank

I was being conservative with that turbo choice. I know it needs to be bigger but I also don't want it to need 4000rpm to spool. What size were you thinking for that hp range? I was planning on calling garrett when the time came.

EDIT: Is this more what you were thinking? 67mm inducer available in the similar A/Rs I have now http://www.ebay.com/itm/CT4-6767-GT4088R...e77944a&vxp=mtr


That last turbo link is better suited for what you are looking for. Turbine wheel is still a bit small I believe.
Not sure of what the turbine specs are though. Does not tell exact specs of the compressor wheel either. It only states one side for each.
There are 2 measurements for a turbine wheel & a compressor wheel.

How many blades on the turbine wheel?

I would like to see you use a large turbine wheel.
Something closer to this size turbine wheel.
http://www.ebay.com/itm/Turbine-Wheel-Ga...c32b509&vxp=mtr

Run a larger turbine wheel that will allow the exhaust to breath & a bit bigger turbine housing, maybe a .82-.84 , & no,, not a .96-.115 A/R (unless you are willing to sacrifice, low RPM boost?) for a turbine housing . The boost will come in a bit later w/a .82, but when the boost comes in ,look out!

MBHD


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These are the measurements I'm going off of. http://www.turbobygarrett.com/turbobygarrett/turbocharger#GT4094R

Anything larger than that GT4094R (the 70mm+ compressor inducers) don't have turbine A/Rs lower than 1.01.

Like everything in the GT42xx series is all 70mm compressor inducer and all turbine housings are > 1.01 A/R

I just did the math and learned how to read compressor maps. You are right, that GT4094R turbo is a bit small for the build. It is perfect if my goal is 450hp but it becomes less and less suited as it goes 500hp+

EDIT: The GT4202R or the GTX4294R look like my best best for my current projected path. They work great on their lower end at 450hp but have good room up to 700hp. They're 74mm and 75mm compressor inducers and 82mm turbine exducers. But again, the turbines don't have any lower A/Rs than 1.01

Last edited by snowman4839; 07/20/14 10:28 PM.

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Snowman,

You just need to figure out what exactly what you want.

You can get the smaller A/R turbine housings machined to fit larger turbine wheels.
There are companies that will custom make any turbo specs you want.

For the street I like to use a large turbine wheel that flows a lot & use a somewhat small A/R on the turbine housing, this allows me to use a tighter torque converter & spools up quickly.
Yes, it is somewhat choked up some, but I like the way my Syclone runs, on the verge of 11's w/91 octane 100% stock untouched long block street truck.

Your combo is different, manual trans, but it sounds like you want the boost to come in early, question,, what RPM do you want to see full boost? if you say 3000-3500 RPM you can use a larger A/R on the turbine housing, but I would not go bigger than a .96 or so.

Most any good turbo company can help you w/your needs.
You just need to tell them what you are looking for, quick to spool, your OK if full boost is not till 4000 RPM etc..

MBHD


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I quite awhile before I get to buying the turbo. I just wanted to get a general handle on it while I was thinking about it. I'll start crossing that bridge after I get the long block sorted out.

I'm also going to redo the up-pipe. I'm going to get a welder I know to TIG it, and I'm going to get a slightly larger 44mm blow off valve when I redo the wastegate mount so that I can actually route it into my exhaust. Then I can finally get a muffler and listen for detonation.

Still planning on getting home this weekend to send off the head and block off assuming the pistons and rod bolts get here there on time.


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Snow, I hope you are an engineering student. It would be a waste of talent for you to do anything else. Your build is inspiring. I frequently ask myself ..."What is snowman going to do next!?"


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Originally Posted By: JStewart
Snow, I hope you are an engineering student. It would be a waste of talent for you to do anything else. Your build is inspiring. I frequently ask myself ..."What is snowman going to do next!?"


You have no idea how happy that post made me. Thanks man!!

I'm actually in engineering...ish. I'm in computer science (technically in the college of engineering at my college). Computers was what I was good at before I got into cars when I was 15 when I got my Buick. I still remember being 15 and getting giddy about taking my manifolds off for the first time.

I'm 19 going into my junior year on my way to getting my master's degree in comp sci by 22.

I chose not to pursue a mechanical engineering degree (though I seriously considered it) because I didn't want to mix business with pleasure. I love doing custom work on cars but not the menial jobs. I know this because my first job was at a body shop where I learned quite a bit about body work but learned to dislike that kind of work. Maybe it was my sketchy boss, who knows. Plus I figured computer jobs were a growing industry and wanted to secure some job security especially for a guy my age in this job market.


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Originally Posted By: snowman4839
Originally Posted By: JStewart
Snow, I hope you are an engineering student. It would be a waste of talent for you to do anything else. Your build is inspiring. I frequently ask myself ..."What is snowman going to do next!?"


You have no idea how happy that post made me. Thanks man!!

I'm actually in engineering...ish. I'm in computer science (technically in the college of engineering at my college). Computers was what I was good at before I got into cars when I was 15 when I got my Buick. I still remember being 15 and getting giddy about taking my manifolds off for the first time.

I'm 19 going into my junior year on my way to getting my master's degree in comp sci by 22.

I chose not to pursue a mechanical engineering degree (though I seriously considered it) because I didn't want to mix business with pleasure. I love doing custom work on cars but not the menial jobs. I know this because my first job was at a body shop where I learned quite a bit about body work but learned to dislike that kind of work. Maybe it was my sketchy boss, who knows. Plus I figured computer jobs were a growing industry and wanted to secure some job security especially for a guy my age in this job market.


Good philosophy. Don't let work take the fun out of something you love to do. I get it.

I look forward to seeing what the Snowman will do next. That Buick rolled off the assembly line with a higher calling, for sure.


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