I just wanted to throw this out at you guys. See what everyone else would do. I'm building 406 small block for my camaro. I have a good start on it but now I'm at the steps that make or break the engine. I have Dart 200 runner heads, 11.5 compression, either a Edelbrock RPM air gap or Victor Jr. intake and a 750 carb. Now I'm getting ready to pick the cam to compliment everything. I have a Coan 700R with a 10' 3400stall convertor with 3.73 gears. I am either going to but a 230/236 @ .050 or a 240/246 @ .050 cam in it. the car will be a semi daily driver. It has to be reliable tho. So what do you guys think...I think the 230/236 cam would be more practical for vacuum for power brakes and daily driving. I still would like around 400hp though.

 

If you're only looking for 400 HP then the smaller cam will easily exceed your expectations. If you're building a "gorilla" then go big with the cam. The 400 will swallow a cam that big far better than many people expect, assuming the rest of the combo is up to is (sounds like it is).

 

11.5:1 compression is too high for the available street gas (93-94 octane) unless Sunoco GT 100 is available in your area.

 

11.5 is not to high...there are plenty of cars that run 11.5 on the street with street gas just fine. As long my cylinder pressure isn't too high(cam selection and lobe seperation) I'll be perfectly alright. 92 octane gas can be used to power cars up to 13 and 14 to 1 compression. I have seen it done more than enough times.

 

You'll be able to cruise around town at part throttle fine (low cylinder pressure), but
at full throttle you'll need to over richen the fuel mixture (fuel dumping),(reduces power)
retard ignition from optimum (reduces power)
Over camming the motor, (reduces power) to cover will not help
The laws of physics say you will heat a vol of air
a known amount/per increase in compression.
It's the heat not the pressure that causes detonation.
You will never hit the 32-36 optimum ignition advance or 12/12.5 airfuel ratio for best power. Water Injection (intercooling) can get you there,but unless carefully controlled it will also reduce power (over cooling) Allumium heads are good for about 1/2 a cr over cast iron but need that to make as much power. I've seem people try and get around this and they all had to compromise the tune to aviod detonation
and didn't make as much power as the same setup with 10.1 cr. Then with the proper Hi-octane they were fine. I helped a guy get a 400 sb camaro with 11.5 cr, tune his and we were unable to get more than 28 deg total timing with a rich mixture. The same car was a champ on 110 octane and 36 deg timing.
Its hard to get around the laws of physics.
You may actually have less than 11.5 cr when actually measured. This can vary from advertised specs with head cc, piston deck height etc. I'd go along with 10.6 cr actual cr alumium head motor with carfull tuning.

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[This message has been edited by F-BIRD'88 (edited October 29, 2001).]

[This message has been edited by F-BIRD'88 (edited October 29, 2001).]