The Stovebolt Site Forums The Shop Area The HiPo Shop Split exhaust on a 292

I have a basically stock 292 engine that I'm hoping to get a little more power out of. Will a split exhaust give me anythnig extra?

Second question: Will the stock intake manifold work with split exhaust? I am wondering because in a stock configuration, they are bolted together for the heat transfer.

Any help would be great!

Thanks,
Craig

I have a L6 292 inline and my suggestion is spend the bucks and get headers. There is no comparison to output when you compare headers over splitting the stock exhaust manifold. The flow for exhaust discharge increases considerably and that is what will improve the engine performance.
Normbc9

Thanks! Do you mean something like Langdon's? And what about using the stock intake with headers?

Craig

I have Langdon's on mine. I used the stock intake for awhile till I put the Offy on.

And did you notice significant improvement with the stock intake? Were there clearance issues?

Craig

Once you separate the two manifolds, you will have to deal with the heating of the intake. I assume Idaho gets pretty cold! Heat helps the fuel stay vaporized even in warm climates, buts really important in cooler areas.

Langdon's headers look like quality parts and should work pretty good but long tube headers will provide more torque due to the long primary tubes. Cast headers will be quieter and will last forever, tube headers don't seal as well, burn paint off quicker, and are a little noisy (you can hear the exhaust pings in the pipes). The split stock exhaust manifolds are worthless for any kind of application other then for noise. The second outlet is at such a poor angle, I doubt much goes through it.

Joe

Joe,
Your engine looks GREAT! I assume that is a long-tube header you have. Where did you get it? Do you have any trouble with the heating of your triple manifold? You're right, we get cold here. In fact I had to scrape ice off the window this morning! So I don't want to deal with a tempermental beast in the winter. I plan to drive it all year long.

I'm not interested in making noise - the quieter the better! I'm just looking for some inexpensive horsepower and wondering if the dual exhaust is a viable option and worth the $$.

Thanks,

Craig

Mine has a stock exhaust manifold on now. I got tired of the noise of the header, and it really wasn't much of a header. The primary pipes were really short running into a tapered pipe, very much like the lake style headers hotrods use. The intake was very hard to drive in cooler weather with out the heat under it, it took forever to get warmed up.

I ran mine at the dragstrip with three carbs and the oddball header, then went back the next week with stock one barrel and factory manifolds, both weeks the truck run the same numbers down to a tenth of a second and the same mph. So I figured why bother if it doesn't run any better!

Joe

I doubt much goes through it?

Exactly as much as the front outlet.

Hey, I appreciate all the input, guys! It sounds like I'll be keeping my stock set-up. I guess these engines pulled lots of trucks and trailers around for years. . .Maybe not as fast as that new Cummins Turbo Diesel, but with way more style! My 292 might not get me there fast, but I know I'll get there!


Thanks again,

Craig

The 250/292 engines are really good at doing what they were ment to do, haul all day trouble free! For the best info on hotrodding an inline Chevy L6, get Leo Santucci's book on them called Chevrolet Inline Six-Cylinder POWER MANUAL. I haven't seen an automotive engine that doesn't respond to improved breathing yet, but there might be one out there. I drove the modern Chevy L-6s so many miles that I just don't remember any more! There are amazing hotrod products in Argentina and Australia for the L-6s. Look around here, too! Chevy did all kinds of things in bigger trucks. Plus, the L-6s are so dependable because of all the main bearings. You can't beat one main per rod! Have fun!

Leo Santucci's book is amazing! I never would've guessed that there were so many possibilities. . .But it seems like it is geared towards racing and I'm not really looking for speed. I'm wanting the power to haul my truck, trailer and me around without having traffic back up behind me. Tom from Langdon's e-mailed me back and suggested a 4 bbl carb intake. I might try it out but there goes fuel economy. I wish I had unlimited time and money to try different things, but I'll just have to shoot from the hip I guess.

Craig

Well, this is an old thread!

For warming the intake manifold, how much effect does the warming kit have that uses engine coolant?

It looks good, that's about all. When you really need it, while the engine is warming up, it's as useless as windshield wipers on a duck's butt. Exhaust gas is several hundred degrees at a minimum and it happens s soon as the spark plugs fire. Coolant gets up to 200-ish degrees after several minutes of operation. As the pointy-eared guy on Star Trek would say- - - -"That isn't logical!"
Jerry

I love the 292. The I6 gets a bad rap when it comes to performance. It's primary and secondary forces cancel out. Something a V-8 can never do. It has 7 mains. People think I6 and they think small. My 292 is punched to 308ci, That's over 5 liters. Mine is being designed for 1300hp but will never see over 1000hp on race gas and 500ish on pump gas. As Mike Kirby once told me "the magic is in the head". The rest of it is just trying not to have the crankshaft leave the building. If you are doing the intake and exhaust I would suggest a lump port kit. They are not expensive and can be done with a few simple tools at home. If you want to get into impressive performance then in my opinion some serious head work needs to be done. They are expensive to build but there is nothing like the sound of an angry I6. They are so well balanced and you will never rev it over 6000 rpm that they last a long time, even built. I know a guy running a 1000hp 292 (turbo) on the strip and he has 8 seasons on the same engine without a rebuild. I'm running a Ryan Falconer V-12 head on mine. Leo talks about it briefly on page 126 and 127 in his latest printing. He's been very helpful to me and sometimes has to reel me in a little. So along with the V-12 head I have Crower billet crank cam and rods. 5 stage dry sump. Electromotive coil over direct fire ignition. 6-71 blower with 2 Quick fuel 650 DP. NOS. Meth. It's going in my 53 3100 with a 5 speed. Sorry so long. Thank you for your time.

I always wondered how much good that would do. I have a 4 bbl intake for my 235 that's from the early 80's made by what was then called Clifford Research. It has 2 copper lines that you welded bungs into their headers and circulated exhaust gases through a plate on the bottom of the intake. I also have the block under the carb that hot water goes through.

I'm an old six fan myself.
I think the magazine articles use to say to do the exhaust and cam first, and then the carburetion.
They may have been quoting Jack Clifford.

Mick53: What 5 speed are you going to use with that much hp?

Chevoldsmoyota You can split it but it will sound ugly,the 216,235,261 are noted for a special purr that most rodders like to hear!!

FWIW, the OP's last post was in 2019.

Water heat does nothing for a while.
Both water and exhaust heat can be regulated, even underway, with a little imagination.
Almost every car 1965-80 has hot air ducted to the AC can by passing it over the exhaust manifold, then automatically and gradually shuts off in favor of cold air from the grill. Some of those JY parts can be adapted.

Sorry I missed your question. I have a Tremec TKO 600 that has been built up for 900 ft lb torque by Hanlon Motorsports in PA. I picked the higher first gear because of the torque of the 292. I will also be mitigating The shock with a Biknell torque arm with triple biscuit on my Frankland QC and a carbon drive shaft. Frankland built the rear end for me. It's the shock that gets you. I also have a clutch instead of a button.