Thread: '51 Chevy 235 engine performance help

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My '51 235 has 105 hp stock, and a 6.6 to 1 copression ratio. I want about 150 hp but, around 200 would be better. I know the '53 Vette 235 had 3 carbs and dual exzaust I think, and that was rated for 150 hp but, that was the newer, preassure oiled 235. I was thinking about an offenhauser 3 carb intake and fenton headders but, the most I think I can coax out of it with that is about 130 hp. I was thinking possibly adding a 4-71 Blower with the fenton headders but, I'm not shure about hood clearence or even where to get a 4-71 that will bolt to the old 6 cyl. Does anybody know where to get them and how much they cost.

Take the head off and shave a suitable amount off of it,,,that will bring your compression ratio up,,,,give it some cam,,,and multi carbs,,,,headers,,,and smoke dem tires.

I agree with Thunderbucket plus a .30 over bore will help. Lighten and balance the crank. If you want to stick w a 6cyl, then just take that enging out and put in a mid 60's 250 straight 6 from a truck and follow the ideas posted . The 250 is stock with 155hp , plenty of torque, and can be built up to put out well over 200hp.

Originally posted by David
I agree with Thunderbucket plus a .30 over bore will help. Lighten and balance the crank. If you want to stick w a 6cyl, then just take that enging out and put in a mid 60's 250 straight 6 from a truck and follow the ideas posted . The 250 is stock with 155hp , plenty of torque, and can be built up to put out well over 200hp.

I have to keep the 235 in it 1 reason is, I'm keeping it 6 volt ( to be diffrent ) and the other, the car has the rare original 235 with powerglide 2spd auto and is worth a lot because of that, so I'm planning the entire car around the engine and trans, it's going to be a slight high end custom of the mid '50's, that's why I was considering a tri power intake, and fenton headders, and also smithy's mufflers and eco can tips ( all parts that were available in the '50's ), I'm not shure if a 4-71 was produced back then but, it may have been. It will also be a medium dark grape purple painted in single stage, wide whites with baby moons. Putting a 250 in out of a 1960's truck, won't fit the theme, plus, the 235 runs great and dosen't smoke at all.