To All; I'm doing research on my newest build. I want to put a 292 in my '57 chevy, but, I have a question concerning this combination. I'm planning to use a Fenton 2X1 intake with custom carb adapters that are 2 inches thick. The carbs measure 3 3/8 inches from mounting flange to air cleaner mounting surface. I want to use turbocharger 'bonnets' for cold air input, and these project 3 1/2 inches above the mounting surface (air cleaner) of the carb. The risers on the intake are 5/16 inch tall. Added up, this combination requires 8 13/16 between the hood and the intake manifold's main runner.
My question is: does anyone know how much room there is between the hood and the intake manifold's carb flange? (A suspect the Fenton's carb flange is pretty close to the height of the stock six's manifold. Thenks
Hi toolman . . . cool project. I like the idea. And indeed the 292 is almost two inches taller then a 250 . . . so I can relate to your concerns about clearances under the hood. But neither of these power plants are native to a '57. So you face specific fabrication work just to mount the engine/trans and perhaps rework of the steering gear. Seems the finished height of the intake manifold is pretty much in your hands:
TriFive Posting circa '12 regards,
stock49
You have good reason to be concerned. The hood on a 57 has a lower profile then does the 55-56 and hood clearance is always a problem. I was contemplating the same swap for my 57 but decided to keep the car old school (its my high school car from the 70s)so went with a 261 instead. You can get a 292 in there but you will have get it in and then sort out an intake. The 292 itself is taller then a 235/261 and you are stacking adapters onto the manifold, and hoods for the carbs on top of that. I would say, with pretty good certainty, that the set up you are contemplating will not fit under the hood. What kind of carbs are you trying to use if I may ask?
By the way, I have never seen a Fenton 2X1 for a late 6 motor so that is pretty cool. You may very well have to machine down the pads or do a good but of cutting and welding to get it all in. Have you considered using a Clifford 2X2? Lower profile and already has a hot water chamber cast into it. Clifford makes them for 235/261 motors as well as the late chevy 6 motors, jeep and some others. I have one on my 261 with 38 mm webers and it was a marked difference in power from my Weiand 2X1 with adapters and 5200 holleys. Clifford will sell you just the intake if you are not going to use the 38mm webers (I asked before I decided to get the entire set up)
If push comes to shove you could always raise the body a bit rather than cutting the hood. I saw a 250 in a 57 in the junk yard years ago. Granted it was pretty stock looking, and had homemade front engine mounts on it. And a 250 would be shorter and probably rev higher safely with the shorter stroke. Food for thought!
Good Luck with your project. At least you had a goal in mind.
David Chandler
I'm still doing research on my 292 / '57 Chevy combination, but the information I've received here doesn't sound good due to hood clearance issues. SO, I'd like to find out something else. Can anybody tell me what the designed deck height is for the 235/261 engine? Perhaps I can make a comparison between those engines and the 292. Thanks
Toolman
its not the motor that is the problem. The 292 will fit, and frankly, will be a terrific runner if you make the swap. If I ever get my hands on another decent 57 chevy, that is the swap I intend to make. The problem as I see it is the intake and carbs that may be the problem for you. I say may be the problem because my perception is that you are making really high adapters to bolt on some other fairly high style carbs with the addition of a pair of hoods (presumably a blow through turbo maybe?) What carbs are you thinking about using and can you post a photo of the fenton intake? Again, the new dual Clifford manifolds with the hot water chamber, and even the old Clifford dual manifolds without the water chamber, can be used with dual Holley 4bbls, dual Holley 2300 two bbls, dual Weber two bbls. Its a low profile manifold an I believe it will fit no problem. If I can get out to the garage (snow), I will try take a rough measurement from the top of the block on my 261 motor to the top of my air cleaners. That should give you some idea.
I can't post any pictures yet, I don't know how to do so. I do have a digital camera, but I don't know how to do the rest. Perhaps I'll take some pictures and try to find someone to help.
Currently. my '57 has a bad 235 (with head removed) still mounted in it.
If I can find the 'deck' height for the 235, I can set a 292 head (with my intake) on the 235, and get some measurements with childs modeling clay.
If your not hard set on the 292, an alternative is to use a GM 4200 - its overall height is lower that the top of the air filter/bonnets on the 292 you want to run. It will provide better power and 1.5x the fuel mileage that the 292. This has been proven in my 51 GMC.
Another carb option is the Holley 1940, it is an inch or so lower than the Rochester BV carbs. The Carter RBS is also a low-profile carb, used on the Ford 250cid for the same reason.
I made a home-made Trips setup for my 292 Nova - the middle and rear carbs fit with a Rochester BV and 2" air cleaner, but the front carb will hit the hood, so I have to use a shorter Holley 1940 and 1" air filter. Those doggone 292's are tall.