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View Full Version : 1957 Chevrolet 2-barrel cam profile verses the Power- Pac 4 barrel cam profile



nomad
08-09-2023, 01:06 PM
I just dropped off my 1957 283 V-8 motor to have it rebuilt today and am going from the 1957 Turbo Fire 283 V-8 which was the 2 barrel version with a compression ratio of 8.5 to the 4 barrel version Super turbo Fire with a 9.5 compression rating . I gave the rebuilder a set of correct 539 4 barrel 1957 heads and a correct 4 barrel intake manifold . My question is dose anyone have the both the 2 barrel and the 4 barrel cam profiles so I can inform the engine builder of the 4 barrels cam profile . thank you very much , Dom

chevynut
08-09-2023, 01:30 PM
Some info here. http://chevy.oldcarmanualproject.com/chevyresto/57050.htm

nomad
08-10-2023, 06:07 AM
bantamben on April 26,2011 on the Tri-five says that on page 6-89 of the 1957 Shop manual it says that the 185hp , and the 220hp , and the 245hp , and the 250 hp all used the .3987 hydraulic lift cam . Dose anyone have the 1957 Chevrolet Manual and can confirm this information

BamaNomad
08-10-2023, 06:58 AM
An image from page 6-89 of my Service Manual. This chart shows the intake/exhaust lifts being the same for all the 283 ci V8 models, but doesn't provide the duration or any other cam specs.

13595

Rick_L
08-10-2023, 08:27 AM
Only the high hp dual quad and FI engines got the 097 Duntov cam. The rest got a generic low lilft low duration cam.

nomad
08-10-2023, 09:10 AM
Bama , your a life saver as always ! I just had my son send the information to the engine builder . It seems that it was the different heads that picked up the compression with different size chambers and not so much the cam's profile . Thanks for taking the time to post the actual picture from the service manual , my restorer friend still hasn't found mine yet .

Rick_L
08-10-2023, 11:19 AM
Camshaft does not affect static compression ratio, which is what's specified.

nomad
08-10-2023, 04:08 PM
Camshaft does not affect static compression ratio, which is what's specified.
Thanks to all who responded . I sent the information to the engine re-builder .

chevynut
08-10-2023, 04:55 PM
The link I posted shows the valve timing. Did you look at it?