I currently have my stock 250 torn down to a short block in chassis. Motor is in a stepside short bed truck. Want to build a fun DD with decent power

Parts already purchased:

Clifford Intake manifold
Clifford Shorty headers
Weber 38/38 DGES 2 barrel carb (I believe it is rated at 380-390cfm)
Weber FPR
194 small chamber head

Parts/mods considering to complete build:

1.84I 1.6E valves with appropriate head work
Comp Cams 260H Cam kit(lifters/springs/timing gear) 212/212 .489/.489 on a 110LSA
Carter Electric Fuel Pump

Please critique my build plan

Sounds like a decent plan. On the 194 head, many that I do are cracked. Get some unshrounding done around the intake valves. Other wise there will be no gain with the higher compression head.

thanks for the reply. I purchased the head from a gentleman on ebay who deals with chevy inlines exclusively (mrhotrod I believe)....anyway the head was magnafluxed and surfaced as well as cleaned up very nicely. I appreciate the insight and I will double check for cracks here locally.

Your head from Mrhotrod6 will just as he says. They are checked Before and after any work is done to them. Just to be sure they are at 100% before going out the door.

I did gain a bunch more power when I switched over to a 194 head.

Mainly because of the increased compression.

9:1 to 12:1 compression, what a difference in power!
Sure glad I switched to a 194 head.

MBHD

Im fixing to hurt your feeling real bad Hank. I have a Sissell catalog that has his thoughts and test findings about the 194 head and actual articles he personally wrote and had published in Hot Rod magazine and other publications about the use of that head. Im scanning it right now and will add it tonight when I get it formatted. He was very Anti-194 head oriented and tested hundreds of them in his time in every configuration they could have been modified.

With me reading the results from Kay would not hurt my feelings one bit. I love a good read.
The 194 head was head & shoulders above my 250 head, track tested & street race proven. Just stating my facts.

Everybody's results will differ.

Mike Kirby likes the 194 head & he was Sissells right hand man, correct?

MBHD

Your results were heads and shoulders above the open chamber head because you performed mods that were heads and shoulders above what you did to the open chamber head. If you had done the same mods to the open chamber head and obtained the same compression, you would have a different opinion. You never compared the different heads on a one to one basis to know which is the better head.

Kirby was his right hand man and stepped into Sissell's shoes, but by no means did he fill them.

My 250 head had a 1.9" intake & 1.6" exhaust valves, mild bowl porting, chambers untouched.

My 194 head had 1.88" intake & 1.6" exhaust valves minor bowl porting & chambers untouched.

My cranking compression was 150-160 psi w/the 9:1 250 head & 220-230 PSi cranking compression w/the 194 head.

The 194 head was shaved quit a bit.

Both heads were similar in porting but the 250 head had a little bit larger intake valve.

With having 220-230 cranking compression w/the 194 head, the low end torque was very apparent (over the 250 head), & was a real stump puller.

The heads were swapped onto the same short block. Back to back.

I might be able to flow test the 194 head, I am sure it did not flow well @ all, never did I use lump ports.

MBHD

Were the bolt-in lumps available at the time you built this engine?

Different article, but basically says the same thing as the previous one about why not to use the 194 head. These were taken from his catalog for Sissell Automotive and were articles he wrote personally in Hot Rod Magazine and the National Dragster.

Hank,

What cam were you using?

Fuel burned and actual dynamic compression ratio are the two big factors for engine power/torque and efficiency.

To bad we can't read them.

But interesting is that it says weber's will give 60hp over multi carb set-ups.

That was once thought to be true, but when Headrick switched to(3)Holleys and picked up 40 HP and .2 tenths of a second in the quarter, every body else that was running Webers quit using them and switched to Holley's also.

The section about cylinder heads in the article starts off by saying, "Any head except the one for the 194 engine is a good core for modification....." And goes on to explain why the shortcoming for the 194 head cannot be corrected in anyway to offset the shrouding that is caused by its poor chamber design.
I can read the first article fine, but the second one is smaller print and harder to read. I can type out what it says for those that want to know what it says in more detail. But these were articles he had in his catalog that he wrote at one time stating the problems with trying to use the 194 head for performance usage, and they should be avoided.

One thing that should be readily apparent to any astute head porter comparing the 194 head to any of the open chamber heads is that the chamber for the 194 head is designed for an engine that has a bore of only 3.562". But if you don't know anything about the dynamics of how those things interact between head and cylinder, you will blindly follow the countless sheep that have also made the mistake of those before them. Placing it on an engine that has almost a 4.000" bore places the edges of the chamber way too far away from the cylinder bores to breathe freely and greatly shrouds both the intake and exhaust flow. The casting just isn't thick enough to allow it to be corrected when placing it on a bore of this size.
This can often be traced back to the "copy cat" syndrome of, because it works for a small block, it will work on this engine. As many professional engine builders have found, this isn't always true. The reason the closed chamber head swap on the small block works and it doesn't on the 6 cylinder, is because like the open chamber head for the SBC, the closed chamber for the SBC is also designed to be used on a 4.000" bore, thus the smaller chamber does not restrict or shroud the cylinders breathing ability.
And for the 6 cylinder, the open chamber head is always going to be the better choice. All of the top 6 cylinder head porters and engine builders have known this for over 40 years. If anyone tries to sell you the small chamber head swap as being the better choice, they either know that many hotrodders have sipped the "Kool-Aid" and have bought into the "because it works for the SBC" mentality, and are simply taking advantage of you being naive to know any better, or they themselves have sipped the "Kool-Aid" and have no clue either.

I do not know. Engine was built about 20+ years ago.

Brazed lumps were available, but cost too much @ that point in time.

MBHD

I knew the brazed version was, just didn't know about the bolt-ins.

I have use many different cams, but, IIRC, specs were about 236 degrees duration @ .050" .520" lift on a 110 lobe center.
Solid lifter camshaft.

MBHD

I know they had gained more when they stepped away from those weber's. I just wasn't really thinking about how OLD that print was LOL. Besides I dout I'd ever give up my holleys about the only way I'd do that is if went Injection.

CNC,
thanks for posting Kay's articles.

They are a bit out dated as you said, Weber carbs were down on power as compared to running 3 Holley's.

Mike Kirby had told me you can get 194 head to flow good & you do not cut into water jackets as the Hedrick 320 CFM head did.

Mr Hotrod6 has proven the 194 head can work w/the help from Twisted6.

Just because racers from the past did not like the 194 head to race with does not mean a newer generation of racers cannot find new ways to improve a head to work better.

Thanks again

MBHD

Don't get me wrong Larry, Webers were used by many good racers back in the day, and they can still be a good choice if you like that kind of thing. Im partial to Holley's also. I think the Webers were more popular back then because most of all the aftermarket multi-carb intakes were Weber oriented or the primitive Rochester or Stromberg style, but not Holley. And yes, I can see how the Weber would be a better performance choice compared to those carbs. Once guys started making sheetmetal intake and using Holley's more and more, they switched away from the Webers.

Hank you may get that kind of flow out of a 194 head, but it will take the brazed lump treatment and huge port openings to do it. But it still shrouds the cylinders badly because of the chamber being too far away from the cylinder. A flowbench wont show you that.

Many people have proven the 194 head can work! No body is saying they can't. The open chamber head is always going to be better....

You might have gotten 350 HP out of your 250 with the 194 head, but if you had done the same thing to the open chamber head you might have gotten 400 HP.

Wow! that 194 head is worth a good conversation!

I purchased the 194 head mainly because I was switching from an integrated to non integrated head and didn't necessarily trust the quality of some of the online mass cylinder head places. Not many of these heads running around my neck of the woods or at least during the period of time I was looking for one anyway(always seems to work that way)

What I am going to do is run all this info by my buddy who will be doing the work or maybe I will be doing the work in his shop (TBD)and see what his take is on it = really smart dude.

I'll report back what I find out(if anything) and hopefully my little 250 with this 194 head makes some good power when we're done with it.

There are some dyno tests on here that will be worth reading before you spend any money. About 4 years ago both a 250 and 292 were dynod using many different cam, intake/carb, exhaust and cylinder head combos.
Dyno results

My 0-cents. On a mild single carb, shorty headers, daily driver build I'd use the 194 head in a heart beat. I might or might not open it up a bit around the 1.86 intakes. You know the head is a solid one. The small boost in compression will likely give you as much as you'd gain with the extra flow from the other head. They are not all race cars.

VARY GOOD POINT beater Not every Build is a Race Car Or is intended to be one. And as for the Bolt-in Lump Yes is was around 20yrs ago , at the vary least. And yes I know the weber's
are good. I just like my holleys and always have. And they have never let me down. I have been using them If I had to guess well
over 30yrs now.

Correct, not every build is a race car, but every build using a 194 head will be shrouded except for a 194 engine, regardless of the power level. Tom's dyno tests showed and confirmed what these experts have been telling us for decades, that even in the 200-300 HP range the 194 head was already showing signs of the effects of shrouding. Larry, Tom will give you and ship you as many 194 heads as you can afford to pay the shipping for anytime you want them.....

can you explain why the size of the bore makes a difference in terms of the intake valve being shrouded? That's the piece I don't understand. The relationship between bore size and the 194 closed chamber head?

That is something that is easier explained with a visual drawing or simulation so you can better visualize what is happening. I'll see if I can draw it up in a CAD model so you can see what is taking place.

But just to give you something to be thinking on while I do that, if you were to place an open chamber head on the tiny bore of the 194 engine, the chamber would overlap and the deck surface and the incoming airflow would hit the top of the block deck before it could even reach into the cylinder, greatly impeding and restricting the flow.

Unless I missed something In all this Who said anything about putting a big chamber head on a 194? And WHY would you even think about it. First off like you said the chamber is Over the Bore DIA. secondly You would lose compression in doing so. It would no dout take you from it's stock 8-1 down to what 7.5-1 maybe even as low as 7-1 That would surely turn that pour OL 194
into a slug for sure. LOL

Yep, you missed it! I was giving a reverse comparison of how the open chamber head would overhang the tiny bore of the 194 block, in the same way, but reverse the tiny chamber designed for the tiny bore of the 194 would be shrouded by the large bore of the 230,250 or 292 because the chamber is too far away from the cylinder bore and severely shrouds the heads breathing. What ever compression you would wind up with in the 194 engine is irrelevant because it wasn't part of the demonstration, just that the large chamber overhangs the small bore and vice versa. Just trying to give moregrip a "grip" on the difference between the two until I get a CAD model drawn for him.

I guess a dueljet and 194 degrees of intake valve duration puts me in the non-race group.

Non-race group here too. I just want it to be strong between the stoplights. As much under the curve as I can get from idle to peak.

In the dyno testing we did a few years back, this puts you right in that range. As I already said, this is a problem that occurs at any and all levels of modification, from bone stock on up and is not a race only issue. So you will be affected by this problem regardless of your intentions.

As I understand it, with the 194 bathtub head, the air coming out of the intake flows out and hits the shrouded wall of the 194 chamber. It then has to turn go down and round the corner to then spread out to fill the cylinder. This reduces the flow and ruins any kind of swirl you might have. While the open head allows the mixture to flow out with minimal redirection to the edge of the cylinder. Is that oversimplifying it or is that basically the problem?

I've been running numbers with the cams I can find an ABDC for, and even with a 4cc flat top piston, zero deck and the thick .040" gasket; you got to have a 64cc chamber for a static CR of 10.0:1 to achieve a dynamic CR of 8.51:1 with a Comp Cams 260 cam to run on premium with good quench. That's a lot of milling on the stock open chamber head. You can achieve the same DCR with the Comp Cams 240 or 252 cams and a 68cc chamber. If you go bigger, the DCR starts dropping off toward the regular unleaded friendly zone. However the Comp Cams measure their ABDC at .006 instead of .050, so they might be a little higher in DCR then the math predicts.

Your only gaining DCR to loose out to inefficiency and lower power output for no reason. You will have a better combo with a lower DCR and the open chamber head. The myth that people can't seem to wrap their head around is that with the 6 cylinder, unlike other engines, the closed chamber head does give a boost in compression yes, but it also results in a HP lose across the entire RPM spectrum compared to same components using the open chamber head.....so what are you gaining?

Yes, you are correct in your understanding of the how and why the 194 head shrouds the engine. So knowing that this is going to occur and you will lose HP and engine efficiency, why do you think still this is a good choice? There is no gain to be had that will be of any advantage at all except that you will now have to run premium gas with no increase in power.

Don't get me wrong, its your money and your build. Just don't be fooled into thinking you are getting a gain when you really aren't.

I didn't say it was a good choice. I was commenting on having to mill down the open chamber head to 64cc to get the advantage of using high octane fuel with the engine parts combo. I'm not even sure if an open head can be milled that far. But yeah, if you have a choice of running premium with a 194 head, or running regular with a milled down down open chamber head, both making the same power with the same cam then you might just want to go with regular gas. But you might even be making less power with the 194 head over the entire rpm range, so using regular gas seems like a better option.

The DCR numbers really show the L6 and open chamber head to be optimized for street builds with cams under 260 advertised duration, but it gets harder and harder to hit that DCR of 8.5:1 without hitting the stock heads limit on milling. I've only got Comp Cams and Crower's cam cards to go off of. Maybe there are some other manufacturers with ABDC that gets you closer with more street/strip profiles.

NOT a problem I'd take them. If they are not cracked and he really wants to part with them.

To be honest, I don't think he even disassembles them before he scraps them. Im sure you could work something out with him to have them cleaned and magged, but im sure you'd have to pay for that 'cause he'll have too as well.

I thought that was some kind of inside joke. I need an L6 head or two to practice on, and it's hard to find just a cracked junker locally to use the die grinder before I do it on the head I want to use. If I just have to pay for shipping, practicing on a 194 head is probably the best deal before I buy an open chamber head. I'll have to inquire.

ok been researching the closed vs open chamber situation.

In general this is what I've learned:

1. open chamber heads typically flow more cfm
2. open chamber heads are typically lower compression
3. closed chamber heads typically flow less cfm
4. closed chamber heads are typically higher compression

that's probably stating the obvious at this point

It seems, in general, the closed chamber head (various makes/motors) is typically regarded as a performance head even at the sacrifice of head flow.

My question is why?

Quench; as I understand it, this is a desirable relationship and something that can be optimized in several ways to introduce swirl within the combustion chamber.

Using the 194 head on a 250, taking the intake valve shrouding out of the equations for a second, is it wrong to say in a stock 250 shortblock configuration, when the piston is at TDC, it is actually in the hole(i.e. not flush with cylinder deck height)whatever that amount is. Now using the typical FEL-PRO replacement gasket, would the closed chamber head would be desirable?

I guess my point is, is it possible to mitigate the short comings of the 194 head (the two I know of are the intake valve shrouding and cylinder bore size) so that I can take advantage of both the increase in compression and swirl effect? or am I just not understanding what's going on?

thoughts?

I have had great results when running my 194 cyl head.

I had 12:1 compression on pump 91 octane, it also helped I had a positive deck height. Quench,& quench area had a big part of how I got to run 12:1 compression.

MBHD

[quote=CNC-Dude #5585 Larry, Tom will give you and ship you as many 194 heads as you can afford to pay the shipping for anytime you want them..... [/quote]

Seems a bit strange when I see on the 12 bolt sight he sells them, No where does it state he will not use, or refuse to use a 194 head.

The one he had on his sight sold, he must have twisted the customers arms forcing him to take it. LOL.


MBHD

Wow, that's a lot of compression. Was that with the .040" Fel Pro gasket? Did you deck it the 194 head to get less than 64cc chamber volume? I'm presuming this was a domed piston?

Just don't make no kind of sense even cleaning one of those heads would be just a waste, sarcasm. LOL
And it sold for $1200.00?????? He should have given to Larry.

Not to mention this head was done after the famous dyno results.
Why bother with that 194 head w/such lousy results proven on the dyno?

Free bump to improve sales!!!

http://www.12bolt.com/250292_products/cylinder_heads_and_rocker_arms

Here is what it stated about his 194 head.


"Here is a head that has had the works thrown at it! This head will fit all 194, 215, 230 ,250 and 292 engines. This head will easily raise your compression by almost 1 point on a 250.

This head started out as a small chamber 194 head. The combustion chamber has been unshrouded around the intake valve to improve flow in this tight chamber.

This head has:

Casting has been hot tanked, Magnafluxed, and sandblasted.

New guides installed
Hardened exh seats installed
Factory rocker studs pulled, Stud boss's milled down
Screw in rocker studs (7/16)
1.84/ 1.60 valve sizes, Undercut stems, stainless construction
HIGH FLOW lump kit installed
Had street porting performed, This includes removing of excess material in valve bowl for the larger valves
Decked .030 Chamber size 70CC
High Performance springs setup for .550 lift Hydraulic cam
Lite weight retainers
3 angle performance valve job
Modern valve seals
Fully assembled"

[quote=LifeguardWow, that's a lot of compression. Was that with the .040" Fel Pro gasket? Did you deck it the 194 head to get less than 64cc chamber volume? I'm presuming this was a domed piston? [/quote]

.038" on the head gasket.
The 194 head was decked quite a bit. Chamber volume was in the 50s CC range IIRC. No unshrouding the chamber walls for better flow.

Flat top 307 SBC pistons w/4 valve reliefs.
Cranking compression was 220-230 PSI on all cylinders.
The pistons came out of the block, .002-.005" range

MBHD

How are we doing? Is this what you were looking for?

lol, I'm somewhere in between sick to my stomach for wasting money on a 194 head and slightly optimistic.

Well you know how I feel. I have a 194 head and the same weirdness that makes me an inliner to begin with will probably cause me to use it some day. All of this has got me taking another look at the 194 as a whole. With the same outside measurements as the 230 & 250 and a 3.563 bore I wonder about cylinder wall thickness.

No worries, truth be told, I love a good technical conversation. I haven't given up on this head 194 head yet; maybe I have a ringer!

I think I mentioned it earlier.....my buddy owns his own cylinder head shop so I may just go ahead and see if I can't talk him into a little extra effort and see what this thing flows bone stock. Then maybe modify one chamber, and retest. If improvement looks promising, then finish her up and run it, if not, well then I suppose I'll have more to think about.

Before I do any of that though I need to unwrap her and get a better look.



Off topic: I think I read from another thread where Hank had used the Balance Shop in Reseda for some of his work, well if that's the case, small world, I used him as well for an LS build back in 05.

I have to admit, based on your findings, my situation isn't looking very promising! In your tests how much power were you down using the 194 head vs everything else? Did you happen to post the data online? link?

Thank you!

moregrip, for your intended purpose you have nothing to fear with using the 194 head. Sure it might not give the engine all it can, but what really pisses me off if when people try to convince others something is better than something else based on urban legend or just bad info instead of facts. And that is what happens everytime this topic comes up. You have people that are never going to accept 50 years of fact and truth by professionals. And if someone wants to try to run one simply because they can thats fine. But know the facts and see if after you know them you still think the same way. If you do thats also fine as well.
But that is what forums are for, to share and give solid advice so those that might not be as knowledgeable can make good choices and be pleased with the choices they do make. Good luck, and don't let this get you down. Make sure you continue to share your progress with us as you complete your build.

Tlowe has all the dyno test results. Or you might search thru the links of the dyno testing I posted a few days ago to find them.

thanks brother, I've been searching and reading like a mad man, was just hoping there might be a consolidated location, easier to compare apples to apples. Appreciate your insight even if I don't necessarily like it!! At least my eyes are open to what my obstacles could be!

Like I said, I do appreciate it......still researching.....I'm sort of a OCD research-aholic. I will definitely provide updates and share what I find. thank you!

I suppose you could sleeve your block down to a 194 bore size

When tlowe did the dyno tests he asked for help in the form of donations. those who donated got copies of the results as a thank you. As far as I'm concerned it would be good to post the full results here for all to see and debate. For my part the money I sent would have been turned into urine long ago and is of no importance any more. As to this discussion it is the job of the knowledgeable to sort fact from fiction. It is my job to see that future pundits have stuff to sort.

If a 194 had enough wall thickness which I don't think it does one could bore it out to3.740 and use stock 305 pistons. The new Vortec pistons are pretty good. Just a thought. Jay 6155

lol, I imagine that would be $$$$

I think I have a legitimate part time job researching and sorting !

BTW, I was just in Nevada last week for work, Fallon to be exact!

You could sleeve a 250 block and then bore it out to 3.740" for a 305 piston. GM flipped the idea of a wide bore and short stroke of the 307, to the narrower bore and longer stroke of the 305 (using a 262 bore with a 350 stroke), which supposedly is better at making more torque for the same engine size. But the 250 stroke is longer than 3.48", so maybe it might equal out power-wise with the 250?

I just wonder if the 194 walls might be a little thicker and be able to handle more boost than the other blocks.

Ok, I went ahead and purchased the Power Manual 2nd edition for Kindle and nearly read the whole damn thing. Great info! According to what I read I think I'm going to be just fine with the 194 head even if I'm down a few HP. Lot's of great info in there! T6Racing very highly regarded among others!

Just plan on doing a little more work to the 194 head. Like I said earlier, unshroud the chamber around the intakes and the exhaust wall side, enlarge the valves and perform some porting. It will work out great.

It is harder to find a uncracked casting, and opening the valves to a 1.94" intake is risking hitting water on these "194" heads. Especially for people not familiar with doing work to the inline heads.

It is just extra work that would not have to be done to a open chambered head to get the same performance.

I am currently working on one now for a customer and will try and post up some pics. It is being setup with 1.94/ 1.6 valves.

After reading the book there is certainly more I want to do straight out of the shoot, more deburring in general, matching the port openings to Fel Pro gasket on the head and Clifford intake manifold, polish intake ports with 40grit, clean up combustion chamber/exhaust port with 80grit, and of course unshroud valves.

Thanks for the advice! Much appreciated!

Also, the flow data enclosed in the power book is very promising! Kinda surprising the potential theses heads have.

My next question is that in lieu of performing the lump port mod they talked about modifying the bolt boss in the intake port like a "wing", can someone explain this a bit better? Anything I can do labor based will save me $$ in this build.

Your best bang for the buck is going to be to fully remove the bolt boss compared to leaving it intact, but reshaping it. Tom dyno tested that mod on several engines and saw no additional gains between the bolt boss untouched vs. tapered or "wing" shaped. So no, that mod doesn't give you any benefits.
Try to find the thread for the 292 dyno tests, it has a wealth of info in it and can connect the dots to many questions you might have. Titen really should have made those and the 250 dyno tests a sticky because they keep getting lost in the archives.

Yeah, my budget plan after I read his cylinder chapter was to do the valve work and cleanup to get the flow numbers that the flowchart for the Kramer head got. But I was scratching my head at what he meant by "wing shaped". Plane wings are not symmetrical in cross-sectional shape, so I assumed he meant to shape the boss like a teardrop. Taking material off on either side and then bringing to a point on the leading edge. But I'm not sure if there is enough material on the boss to create this shape? I think I'll just take the casting flash off the bosses and intake ports leaving the ports the stock size to maximize velocity with a good valve job.

Understood, I'll start saving my pennies for the lump port mod!

I interpreted the wing as a tear drop shape as well.....may just be easier to go with the "lump" after-all.

Just think of making the port window bigger.
If you can make the window bigger it should flow more.

I would not make the sides of the port bigger, I would grind down the bosses, if you are going to keep the bosses & not go w/lump ports.

Nothing here was ever posted on what Tom did to his 250-292 dyno heads.

Who knows how much material was removed from the bosses?
What were his final dimensions of the intake ports?

Like I said before, you cannot think of his dyno results are the final say so on every configuration on how our inline 6's react with different techniques of porting, different valve jobs, throat angles, camshafts, carbs, intake mainfolds, etc etc & so-on.

They just give you of his results. Good basic results.

Other people have had different results than his dyno tests, and other dyno tests will different results also.

Dyno results will also give you different result when the engine is put into a vehicle. Could be better than expected, could be worse. Point is, you just do not know until the engine is put into a moving working chassis.

What works on a dyno does not absolutely mean it will work in a chassis the same way.

Don't take it the wrong way, dynos are a great tool for tuning,, a chassis dyno is even a better way to tune for real world street & race tuning IMO.

They all have a place to get good feedback on how different combos work & what will not possibly work.

A great flowing head can be an absolute dog of an engine for driven daily driver. This great flowing head on a flow bench can look great on an engine dyno, but it could be a pig when actually installed into a car/truck or?

MBHD

If I recall correctly, enlarging the valves to at least 1.86"/1.6" intake/exhaust was one of the biggest gains. The bolt-in lumps gave a 5 - 7 hp gain throughout the entire rpm range. The lumps didn't provide any benefit till the valves were enlarged.

One thing that "just bugs me" about the 250 large combustion chamber, is the overlap of the combustion chamber with the deck surface of the cylinder block. This cannot be conducive to flow. And, I am not partial to grinding and tapering the top edge of the cylinder wall. The 194 combustion chamber should be able to avoid this. To help reduce this overlap with the large combustion chamber, offset cylinder head dowel pins have been used by some. However, I have not found a source for cylinder head dowel pins with offsets of greater than 0.030". In the Power Manual, one engine builder gave offsets of 0.060" to 0.090".

Winter, the chamber overhang is negligible and is dictated by the core shift of the block and/or head of each engine. Not all of them even have an issue. But notching the cylinders for valve clearancing and enhanced breathing is one of those "hidden" speed secrets that all engine builders do that the average hobbyist might not know to do, or is skeptical about performing. We used 2.150" intake valves and 1.625" exhaust valves in our heads and didn't offset the head. That is one of those mods that isn't necessary and was probably concieved out of imitation from some other engine type, while truly important other mods were overlooked, but stuck in someones mind as being critical when it isn't.
The chamber on the 194 head places the chamber in the opposite direction from the cylinder wall and too far away to be corrected and will shroud both the intake and exhaust more than can be gained by attempting to unshroud it. It simply can't be undone regardless of the effort put into it.
GM, all the top 6 cylinder engine builders and head porters, GM engineers like Tom Langdon and countless top racers have known that about the 194 head and have shown and proven it for decades. Why is that so hard to accept.
We were part of that crowd as well at one time and like others, did some good things with the 194 head. But once the advantages of the open chamber head were discovered, there became no point in persuing it any longer, as many others discovered that as well. At our level of power, this was about a 45-50 HP gain over the 194 head. Tom showed about a 10 HP gain with the open chamber head across the entire RPM range, even after unshrouding the 194 head. So bottom line is, you will do more and spend more, but get less with the 194 head. So everyone got to see first hand that this was confirming what all the top guys had been saying all this time.

CNC-Dude, I am not partial to either head. I have one of each, with the 194 just setting. I'm not arguing with the general consensus of the 250 head flowing better. But I do wonder a little if Twisted6Larry or Mean-Buzzen Half-Dozen Hank didn't do something slightly different with their 194 heads, that these other guys didn't try. I do have a copy of the dyno run results by Tom Lowe, which are very informative.

On the photos of modified 194 heads that I have seen, none have the extent of de-shrouding that follows the current trends of cardioid, kidney, or figure 8 combustion chambers. Is this due to lack of wall material in the combustion chamber before hitting the cooling jacket, on the spark plug side of the intake valves?

Something else they used to do was shave the heads on a angle. Cutting more of the spark plug side and then re-drilling the head both holes.

Because the chamber was designed for such a small cylinder bore, the material available in the casting to unshroud it is too limited to actual accomplish it. And being able to create these newer modern chamber shapes just isn't able to be accomplished. It isn't with the open chamber head either, but you also don't have the shrouding problem either.

As far as them trying something different than these other guys. These other guys being Kay Sissell, Jim Headrick, Glen Self, Tom Langdon and General Motors....do you really want to hear my answer!LOL

I can tell you what Hank didn't do, and that is try the same mods on the open chamber head as he did the 194 head. He went from 9-1 compression on the open chamber head and increased the compression with the 194 head to 12-1. And then added side draft carbs and changed cams but gave all the credit to his gain to the head....Not a very accurate comparison! If he had then repeated those mods on the open chamber head and compared it equally at 12-1 compression he would have a different prospective. Yes he got good results with 12-1 compression with the 194 head, but he would have still been leaps and bounds ahead of the game with the open chamber head if he had done the same with it.

Reflecting: If I take all the input I've received based on individual experiences, what I've read/researched, expert input, and this discussion it appears results with the 194 head range from "down 45-50hp" to a "great performance head".

My goal is to be on the right side of that equation if that makes sense!

Thanks for the healthy discussion, I think I have enough data to formulate marching orders. I will post what I find out for your future review as well. And by all means please don't stop the discussion, more info is better than less (well, usually)

Lastly, what about my other choices? Are they sound in your eyes?

Don't worry, this discussion has been going on for almost 50 years, it won't ever stop.

As far as the power the 194 head is down, let me say that the 45-50 HP i'm referring to is at the top of the ladder for an all out race engine, and the 10-15 HP mentioned is more at the stock and medium performance level of 150 HP and up.

btw, here's how my project sits now. Looking forward to starting back at it soon. pictures are newest to oldest.

Per-tee! Freshly painted blocks are always nice to look at. Is that chevy engine orange, it kinda looks red in the pics but it might just be the light? So you're using the stock dished pistons? Did you zero deck the block?

here's a closeup of one of the cylinders:



and no I didn't leave the firewall unfinished





all work done with various wire wheels and fiber discs.

that is my stock block in the chassis, just cleaned everything up a bit. Yes Chevy Orange (VHT brand). Stock pistons/no decking. All bolt holes chased and air blown dry.

Oh, so you haven't rebuilt the short block. What is this engine in?

No rebuild, shortblock is used. It's a 250cid in a chevy C10 pickup.

Would you be kind enough to measure how far down the piston is at TDC? Jay 6155

no problem at all......as soon as I get back home from TAD. I'm active duty military and the Navy is keeping me busy these days!

Yeah, a street engine or daily driver works in the sub-4500 rpm, and big ports are don't work well in that range. Big ports at low rpm have low velocity, while at high rpm the work very well. It's like breathing in through you nose, small port and air moves fast, while breathing the same amount of air through your mouth is a big port which slows the air speed down. A street engine wants velocity to make up for the low rpm of the engine and shorter lift of a street cam, so you don't want to remove anything unless it is tripping up flow in the throat. Keep the port as narrow as possible, this is why the SBC Vortec cylinder head works so well. I made this little chart based on the flow tests I've seen:



Now the Autowerks (from tlowe) numbers are directly comparable to each other, but the test from the Santucci book and the T6Racing are done on different flow benches, so their numbers are not directly comparable with the Autowerks. But as Santucci recommends in his book, the stock valves with a good valve job and a little port and bowl cleanup showed a lot of flow improvement over stock. While taking the bosses out actually made the flow worse over just the minor improvements. I'm not sure what improvement adding bigger valves would make with the bosses in place. But adding the lumps with bigger valves obviously improved flow even more, and with the material from the lump added back to the port it likely improves velocity over just the valve job (tlowe noted that there was no improvement from a lump with stock valves). The flow numbers suggest that lumps are optimal for a street engine, but if you're on a strict budget a valve job and basic cleanup is still a significant improvement over stock.

What year C10?

Well it's a squarebody and in an effort to have a rust free truck it's part 73,77,and 87, lol

The stock valve only flows about 170cfm, with the lump it with flow just over 200cfm.

On the Autowerks site tlowe said that there was no change in running a lump with stock valves, you need to enlarge to at least 1.84/1.6 to see a change. Are you saying that the lumps do benefit even a stock valve?

Yes But once again Bigger the valve the better the gain.
And If I remember right it was like 204-6cfm at 500 lift.
And Is what I got out of my heads with My first Lump design an a stock valve.

Lifeguard,
My tests with lumps/ no lumps were on a dyno. That was with stock valve sizes and only the lump to modify anything. There was no power gain. Bigger valve and port work, then your talking. Power gain.

Moregrip, thank you and all others here for your service. I'll gladly wait until you get the time. Jay 6155

That's right, you mentioned no power gain with stock valves and lump, but you didn't have flow bench results for that combo, just dyno.

I know you guys want to sell lumps, but for those of us building a 250 for the street on a budget, what's the difference between a valve job with bosses on the stock valves versus 1.84/1.6 with valve job and bosses? Does the bigger valves make a difference with the bosses in place or are they they only useful once you remove the bosses and put the lumps in.

Lifeguard, here's a quick run down on how these dyno tests came to be. I had some good magazine connections from back when I used to write engine building tech columns for several national magazines. I was going to write and get published some articles for Tom on his lumps and the various stages of mods that you can do to them.
I ended up getting some face time with the then editor of Hot Rod magazine in 2009 through a mutual acquaintence that was the former VP of Hot Rod. After a couple of calls and emails, he told me point blank that for an article segment such as this, that flowbench data by itself was totally worthless and meaningless to any magazine publication. He said that for any professional magazine publication to be interested in such a story it had to be carried to completion and dynoed before that flowbench data would have any meaning. He said they won't even do comparisons for SBC heads in his mag without doing dyno comparisons as well, because comparing two heads by themselves is meaningless without seeing the end result.
So he challenged me to include a series of dyno builds along with the lump porting build-ups and he would make a series of articles out of it.
Long story short, as the magazine industry goes, he was axed from Hot Rod before all the dyno tests were completed.
But back to the question, dyno results say it all, flowbench data does not.

Sorry, I misquoted you too. Improved flow but that does not necessarily mean increased power. It's all in having a matched parts combo.

[/quote]Improved flow but that does not necessarily mean increased power. It's all in having a matched parts combo.[/quote]

Well, first and foremost, dyno testing says it all, flowbench testing does not!

I've read several articles over the years, and more so in recent years, that suggest the best way to plan a engine build is to start with the cylinder head and build your motor around that. I realize that that logic has not always been "en vogue" so to speak but what I can say from first hand experience, is that when I applied that train of the thought on my last motor build the end result was it absolutely hauled the mail.

Lifeguard and Moregrip, do you have Tom Lowe's dyno testing results? From observing y'all's level of interest and understanding, having access to the results would be very informative.



By Lifeguard
"..... what's the difference between a valve job with bosses on the stock valves versus 1.84/1.6 with valve job and bosses? Does the bigger valves make a difference with the bosses in place or are they only useful once you remove the bosses and put the lumps in."

To be specific, nobody has answered your question for these exact conditions, and I do not recalled any dyno data with exactly these conditions posted in the past. A little digging may find something. The question is relevant though.

Winter, I to would like to know the power difference with just a valve size change. I wasn't around here when the dyno tests were done. How does a person get the results? I would be willing to donate to help pay for them as these tests cost a lot to do. I hope that a valve change only test was done. Jay 6155

Jay, here is the long version for both the 250 and 292 tests. There were over 200 tests conducted with both engines and not all of the results are discussed in the posts for the reasons mentioned in them, but what you are asking was tested. The gains from installing larger valves with the bolt bosses remaining intact are still gains none the less, but not as much as from removing the bosses entirely or by adding lumps. But you might see it mentioned in the posts. Tom can tell you if you still need that info though. Also, the long awaited printed and published version of these tests is arriving soon.


292 Dyno results 250 Dyno results

Jay, to contact Tom Lowe for the dyno tests:

Send him a personal message, he has posted on this thread as "tlowe#1716"

Or contact him at his website, http://www.12bolt.com/

I have Tom's results and graphs from e:mails, but I would be very interested in any published results that CNC-Dude just mentioned.

Yes, its been a long awaited moment, but it has finally come to the forefront and in sight.

I hope the results will be published soon. Any Idea of when? I would like to own a copy. Jay 6155

Jay, I recently started my own publishing company to fulfill my many own automotive book publishing needs and Tom is onboard to have me bring this to fruition in a printed book form. But don't worry, it will be the most complete and concise compilation of data that has ever been published on the subject.

Is most of the info based off of engine dyno results & no actual results of testing @ a track, G-Tech meter, or grudge racing on the street, or any chassis dyno sessions? (actual engine/s installed into a car or truck?

Thank you.

MBHD

They are the results from the dyno testing done a few years ago that was intended for magazine articles.

CNC Dude that reminds me to get the first stovebolt book from you also. The one with the 56 Chevy on the cover. Will you be kind enough to let us know when they can be had? Any rough idea? Thanks Jay 6155

Yes it is. When you or anyone else steps up to do their own testing, then it can be critiqued also.
There are many ways to gather data. The dyno is a very good measure and the way it was done was deliberate to show power changes with part changes.

CNC is ready to help get this dyno info put into a book. It will be great info to have for future engine builds.

That will be a good thing. Put me on the list.

Jay, im just polishing up a few last minute details with the cover design and some final pics for the Stovebolt book. I already have my first book published and in my hands about a month ago, so im ready to start cranking out more and more, as the demand has never been higher for them than now.

How true Tom! Since 1948 when Hot Rod magazine was first on the book shelves, it has always featured dyno comparisons like every other automotive magazine has as well. I personally think just like Hot Rod and other magazines did, that the millions of persons reading this info for the last 65+ years will also be smart enough to figure out how this info can better apply to them personally and help them reach their own personal goals.

I think your already on the list. Tom will be in charge of distribution.

No I do not, was researching previous posts but it was difficult to compare results from the different threads. Is there a one stop shop?

I was able to read about various combos in the power book and that gave me a sense of how some successful builds where spec'd.

I'm looking forward to more info for sure though. Maybe I'm wrong, but I tend to think all data is good data. Starting with machining processes, balancing of internal parts, cylinder head flow and/or velocity, supporting components like induction and exhaust, where to make compromises, dyno testing both at the flywheel and to the wheels, and lastly where it's supposed to all come together, in how your combination runs in your vehicle whether that be on the street, at the strip, or both!

Evidently I'm on a lot of lists. Getting on good ones seems to be a problem.

CNC Dude that sounds really close to being able to buy to me. Beater instead of being on a list I just make lists and then lose them. Jay 6155

It really is, just waiting on Tom to collate the data in an order he wants it flow in so I can configure it into a ready to print format for the printer.

Yummy new book to digest. Where will it be available?

Tom will be the distributor of this dyno testing book, while I will be the publisher and distributor of my performance series of books.

So they will be directly distributed from your websites?

When the book is done. It will be available on my website. Just need to get the info compiled and sent to Scott.

Quick update: the gentleman I bought the 194 head from on ebay (Mr HotRod) was kind enough to give me a call and discuss all things Inline 6; learned alot! Was pretty awesome hearing stories about the some of the smart dudes, past and present, and their part in making this a pretty cool little community. Just wanted to publicly thank him even though he doesn't blog, thank you sir!!

Still haven't made it home to do anymore work on the project truck, Navy is a busy place nowadays!!

moregrip,

if you could possibly post some pics of your 194 cyl head.

What all was done to your cyl head?
Thank you

MBHD

Hank,

As soon as I get home I will post some pics. I'm down in San Diego for a few more weeks and then I should (fingers crossed) have a chance to head back home to the Valley and hopefully make some progress on the project truck. I believe the head was checked for cracks, cleaned, new frost plugs installed, surfaced on both the cylinder head side and the intake/exhaust side. I haven't even unwrapped it from shipping yet. The plan is to take the head and pics of the procedures I'd like performed to my buddy Richard @ WCCH in Reseda.

He usually sells his heads with all the cleaning and checking done to them like, magnafluxing, pressure testing, etc...Just gets them prepared to go to the next step by the buyer.

Moregrip,

Sounds good.
You could give the head to Richard, but most likely Dave is the one going to do the work.

MBHD

LOL, probably so.
I built my last hot rod motor there (2005) with Rex, Richard, and company! Was quite the thrash! Great bunch of dudes!

heading home this weekend!!! woot woot!! will get those pics and measurements for sure!

Update:

All stop! Currently work has taken over all my spare time as well as the foreseeable near future. Hopefully I'll get some time to start working on her again towards the end of summer. fingers crossed!

On a positive note,............that gives me a chance to purchase a few additional goodies for the build

ok folks I'm back at it!

It only took me 3 years, a military retirement, a move to another state, and a new project truck to get me back to this point!

Loooong story!

I'm still as passionate as I was to build a nice 250 inline 6!

Only problem is now I'm on the hunt for a solid short block! Unfortunately that didn't make it in the move......

Good to be back!

Is your intentions on the build the same as they were originally or have they changed any?

There's a wrecking yard up the way from me with a running 250 in an '84 truck. IntegratedJay was interested in the Varajet head and exhaust. Northern Illinois area. I gotta check what they wanted to pull it.

I still have all the parts new in boxes so most likely, yes, same idea, are you referencing the head?

Looked it back up again. The boneyard wants $300 (plus tax) for the running '84 truck 250. IntegratedJay said he wanted the Varajet head and exhaust for it, but didn't suggest how much of the $300 he would cover. It's in northern Illinois and you are in southern Nevada, and I have no travel plans to the west in the future. PM if interested.

Man! sure wish I was closer! That's a 24hr drive!

Indeed. I have a brother in Ohio I can send the head with to IntegratedJay, but I don't know anyone traveling that way with a truck or trailer. If we can find someone going that way, it makes it possible. I'm also assuming it's still in the boneyard, it was there a month ago and I was the only one who asked on it.

that would certainly work and I thank you for being so helpful. Please let me know if this becomes a possibility.

Same for you if something pops up for you. I would buy it and hold onto it, but I am in a financial slump at this point until my next windfall.

Ive got a 250 short block which i pulled out the crank (have the 230 crank). About 1975. Rusty, the cylinders have some minor corrosion, stock pistons. Ive got pictures somewhere.

You can have it, but I'm in Washington state.

Thanks guys! Just got back from a family vacation and found my 250 shortblock attached to a chevy C10 truck I bought on the drive home!

Here is a pic of the engine bay. 250 inline 6 with 83k original miles; someone had removed the cylinder head previously to me purchasing it and went ahead and knocked a hole in the piston while removing it otherwise this would have been a ready to run motor. Luckily I saved my old non integrated inline 6 head from my old truck build.

I'm curious as to how somebody could have punctured the piston during a head removal? Could be the potential buyer got mad at the potential seller for not coming to terms on the cost?

Perhaps you've never seen "Handyman Corner" on the Red Green show . . .

Between unconventional techniques and ham-fisted execution I could see Red managing to punch hole during head removal . . .

Heck he pulls engines to perform an oil change

I honestly have no idea, I was told it was a hammer blow but who really knows. onward!