The Stovebolt Site Forums The Shop Area Engine Shop All 194/230/250/292 inline 6 enthusiasts please respond

In building my 292 inline 6 cylinder engine one thing I found out is that Mike Yoder of Kansas Kustoms, while his work appears to be good, does not split the later 6 intake manifolds. So if you're a person like myself who wants to run dual split exhaust but wanted to retain the factory heat riser instead of fooling with plumbing water heat, then you're SOL!

It seems the only available options for us are tube headers or Stovebolt Cast iron headers. Seems that tube headers have leakage issues sooner or later with daily driven street rods (which is what I'm building). The Stovebolt headers, while a great quality product, are relatively expensive in my opinion at $259 a pop (plus $18 for the installation kit + shipping). And if you want to heat your intake you must buy a water heated Clifford intake or find some other makeshift method to provide heat.

With all this said, I'm wondering what the demand is for split 194-292 factory exhaust. If you could have a service such as Kansas Kustoms to split your manifold, or could purchase a quallity cast iron reproduction 194-292 split dual exhaust manifold providing exhaust heat for a reasonable price would you do so?

Thanks for your participation!

Ftyler- Is it possible to run soft copper header gaskets & french-lock header bolts on the headers to prevent leaks? Just an idea.

whatchoo doing for manifold heat?

good luck

Have you spoken with Mike Yoder about it? I would think that if he doesn't do them there must be a reason. But maybe just because he doesn't list them doesn't mean he won't do them.

I guess it's possible. But I've seen lots of people post problems on this board, Clifford's board (when it was up) and inliners international about leaks with tube headers. If not sooner, then later.

I'm thinking of a real solution for those of us who want dual exhaust sound/performance without the hassles or fears of leaks (tube headers) and the expense ($300 after shipping and install kit) of Stovebolts.

-ftyler

He says he doesn't do them because of problems with cracks and getting good welds with the nickel he uses. Let me see if I can retrieve his email to me.

Found it.... Here's a copy of the email he sent me from last June.

"Fred,
I'm still welding manifolds and the price is the same. But the bad news is-I've really discouraged orders for the late chevy 6 manifolds 230-292. I've done several (probable a couple dozen) and had problems welding them, seems to be a crude grade of cast iron. I've also observed more cracks in stock late manifolds than in early ones(216-235, I've done over 150 of them).

It seems like about 1 out of 3 just wont weld and must be trashed. For this reason I just cant offer to to split yours.

Thanks, Mike"

Sounds like the answer is to get the cast headers. A few more $$$s, but they will last forever. I've had more problems with the newer six exhaust manifolds warping and cracking, now I know why.

The cast iron are twice the price of tube headers but will outlast ten sets of tube headers. Are you selling it once it's done? If it's a keeper, then the choice is pretty easy unless you like swapping headers. They rot from the inside out and while I can't vouch for ceramic coating, that puts you into the cast iron price range.

Plumbing water heat is simple, beginner fabrication stuff, not makeshift. Compared to all the rest you are doing on your truck, this is nothing. You're modifying it - modify it a little more.

Now if you get a set of stainless steel tube headers with 3/8" thick flanges...

The purpose of this poll is not to help me make a personal decision about my project - I am going with tube headers, by the way. I ain't paying $300 + coating for Stovebolts. chuckthetruck your logic makes sense, but I ain't shelling out the money

I'm checking to see how much of a demand there is. There may be a potential market there and if there is I'll talk to several local machinists and welding shops and see what they can do. I may even contact a few engineers and share my plans with them and see what they can draw up.

-ftyler

I seen at a swap meet a dual exhaust manifold from a pontiac ohc six that looks like it would fit a chevy six,and with it was a intake that accepted a quadrajet. I dont know if its a rare setup but its something to think about and I wish I had bought it cause the guy just wanted to get rid of it. I thought about trying to make it fit a 235

I'd go for the split headers, but the engine I bought came with tube headers already...kinda depends on pricing more than anything.
Being in Arizona, I don't need a water heated anything ('cept the pool in December)

Maybe an ambitious Stovebolter can whip up some durable tube headers. Notice the classic cast iron Fentons and the clone design for the newer 230-292 6's are a short tube tri-Y design.Long tube equal length(flow) headers aren't required on street engines.If the header flanges were 3/8 inch thick with a machined finish, they would last.Some newer production vehicles use fabricated sheet metal headers .I believe even some S10's with the 2.5 had a sheetmetal manifold.How much are the tinny tube headers they sell now, $125?

Ftyler,

Your e-mail from the manifold guy explains why I had such a difficult time finding a decent stock exhaust manifold for my '72 C-10 w/250.

Most were cracked at the outlet (mine was cracked almost in half from the outlet right up through the riser to the intake mounting), the sixth one turned out to be usable.

Guys I've revised the question in the initial post. Now I'm basically asking if you had available now exactly what I would have liked to have had for my project, at a reasonable price, would you purchase.

I have heard longer tube headers give a 15% improvement in power vs 5% from the shorter cast iron. Has anyone else heard this?

It's a reasonable assumption, tuning tube length (which needs to be quite long for low RPM torque) gets you quite the power boost at specific rpms.

Check my math, but wouldn't 15% be a fairly big increase in power for a 6 cylinder?

150 HP x 15% = 22.5 HP for 172.5 HP.

Not at all, chiphead. Done right, headers can provide as much as a 30% power boost. Here's a LINK to a header manufacturer who claims a minimum 14% gain in horsepower on a stock engine.

Now the Porsche 928 is a well-designed, multi-valve, aluminum eight cylinder engine. A bone stock, cast iron, six cylinder Stovebolt would benefit even more from the freer breathing.

I'm interested in this topic because I talked to a guy at a muffler shop the other day that said he could split my manifold and run dual pipes w/glasspacks for $300.00 on my 250 six. It sounded pretty good,until I got home and took a good look at the exhaust manifold, I'm not sure how he would do it and get another flange on the "unflanged" piece, There isn't much metal to work with on the manifold. Would there be any gain from splitting into two pipes right behind the flange on the existing manifold?
Thanks,
Marshall

30% HP increase on an otherwise stock engine? This is right up there with the slick-50 claims. Pure and simple advertising baloney. Notice they don't mention where in the RPM range the alleged increase is shown. And these are all high output multivalve examples - a 292 is stifled by the non-crossflow, siamesed head design that can't be improved without major work and expense. Headers provide a minimal increase on a truck engine designed for low and mid-range torque.

Cast headers cost more because they are more costly to produce and machine (they don't pop out of the molds ready to bolt on), but you absolutely get more for your money. Longer life, no rust-out, quieter operation, etc. etc.

The Fenton and Stovebolt cast headers are reasonably priced for a niche market product. If cheap is the only criteria, go for the tube headers, just be ready for some grief down the road.

Jack I don't think it's a question of the quality of the product. I'm just wondering if there were enough of a demand for this type product to devote some research (and resources) into looking at developing something as good (or better) cheaper.

Fact is there is only ONE choice for long-lasting headers for 230-292 engines - the expensive stovebolts. And we all know what happens to prices in a monopoly driven market. Competition has a way of forcing increased qualilty of products and driving down prices. I'm all for that.

-ftyler

Thanks to those who participated. I hope to begin seeking alternative exhaust solutions for the 194-292 I6s soon.