VCCA Home Forums TECHNICAL - 1945 AND NEWER 1955-1957 1957 Chevy six cylinder engine

I am wondering, was there a six cylnder 261 engine made for Chevy trucks? My frined is having his 57 engine rebuilt. It is not the original engine. When we put is in years ago, I needed to swap oil pans from his original engine so the steering linkages would work.
His rebuilder says his engine is a 261? Does this sound right? I never heard of this. Thanks.

Go here and look up the 57 trucks. It does show that engine on certain models.

http://www.gmheritagecenter.com/gm-heritage-archive/vehicle-information-kits.html

But did this engine exist?

If it is listed, it existed ......

My Chevy books show the 261 available, beginning in 1954 trucks with a 7:7 to 1 compression ratio.

Bob

Yes it has been a popular engine for straight six performance fans since 1954, It was a different casting with two pairs of 3 cylinders siamease cast whick had a different head with 2 extra "steam" holes between #3 and # 4 cylinders the 261 was used right up until the 250-292 C.I. truck engines came into use in 1962. The 261 was used in some 1963 Chevrolet 4x4 trucks until the supply ran out. The 235 external parts mostly fit the 261. It did have a different Rochester Model B carb with a slightly larger venturi and larger main jet from the factory. The Block was cast differently than the 235. The 261 in my 1962 Belair was a very good sleeper engine with a Mallory distributor, a pair of Rochester Model B carbs and a shop split manifold The engine was balanced and the intake was ported and relieved. The car wasn't much of a 1/4 mile drag car but cruised right up there with the 56 265 power-packs on the wide open spaces of Texas highways.

Thanks one and all.

The 261 engine was available on large trucks only in the US. There is no reason a 261 could not be installed in place of a 235 in a 1957 passenger car. The main difference would be the oil pan due to frame/suspension differences.
The small Canadian Pontiacs, which were just a Chevrolet with different trim, came with the 261 engine.

That's is what we learned, thanks.

Hey Guys,

I have a real stumper of a problem that a dozen mechanics have not solved so I need you to put on your thinking caps!
My 57 chevy has a 350 small block 75 truck engine in it..I bought it last year. I put in a new griffin radiator, Hi-flow 180 thermostat, hi-flow water pump, 2 10" electric fans on the engine side of the radiator. I put in a/c and can idle the engine for hours when its 100 degrees outside with the a/c on and the engine gauge reads 185/195 same withe driving low speeds but when I go on the highway at 60/65 after 20 min or so the engine heats up to 220,230,240,and climbing until I turn the air off then goes down to 220 or 210. some people say its air flow, one says clogged heater core. Its bizarre.
some say to put a pusher fan on the front condenser side and have it switch on when the a/c comes on and punch business card size holes in the upper and lower shroud and put rubber over the holes so when im going highway speeds they rubber flaps open and the pusher fan allows more air to cool. At this point I just dont know. HELP!!
THANKS!

To much refrigerant is the a/c system? High side psi going way up at higher rpm's.

Basically the amount of heat that must be removed by the radiator is 1/3 of the BTUs in the fuel burned. As the engine speed is increased so are the BTUs produced.

Your problem is either radiator capacity or air flow restriction or combustion gas leakage into the coolant. First I would inspect the electric fans to see if they cover too much of the core. Yes they need to pull air through the core at speeds less than ~15 mph. Speeds above that produce enough air flow to exceed the amount that can be pulled in by the fans. Also check to see if there is a restriction for air into the core.

Are you sure you have the right size Griffin radiator?