Open a camshaft catalog and go to the last couple of cams in the race section, close your eyes and point at the catalog, what ever large cam you point to is the one you want.

Typically the longer the overlap the lower the actual cranking pressure will be. I am by know means a cam expert, so I am sure somebody will pipe up with some better information. Here are my specs

http://www.compcams.com/Company/CC/c...?csid=920&sb=2

I do remember talking to a lot of the cam spec guys and they always wanted to sell me a little dinky cam. I was always frustrated with them. So I went and talked with a local drag racer/engine builder, and did some of my own research. I knew I was going to be pushing it with my high compression, and I wanted to make sure i wasn't going to have to run race fuel. Somehow that is the one I came up with, and I love it. Very rough idle, but screams from 3k-7200. It works great with my 4.30 gears.

 

AHAHAHA...I wish it was that easy.

 

Don't forget, you wont actually be lowering your compression ratio with a larger cam. You will simply be reducing the cranking PSI. The compression ratio is a calculation between how much volume your have at btc compared to at tdc. Correct me if I am wrong anybody. The only way you can lower the compression ratio is dishing/decking the pistons, thicker head gasket, larger head chamber, etc.

All the cam is doing is letting a little pressure escape before the valves are all the way closed. Not good for lower rpm motors, but great for high revving screamers. So when the cam has over lap, it is when both valves are slightly open at the same time. Again, correct me if I am wrong anybody.

 

That makes sence. I might just change the pistons.

 

What is your plan with the motor? If it is a street strip car, I would stick with the pistons, do some research and put a cam in it that will allow 92 fuel. If it is going to be a daily driver, yeah I would think about doing something to bring down the compression. Shaving the pistons could be an option, or shaving, and cutting larger valve relieves too, maybe you could even get away with running a thicker gasket.

Also, have you run the calculations to figure out exactly what your compression will be? Don't forget to calculate in your gasket thickness and bore, valve relieves if you have some, piston dish if you have some, head chamber size, and anything else i am forgetting. It all makes a difference.

One last thing. Don't let the tech guys scare you! They always wanted to sell me mild cams, low compression pistons, hydraulic lifters, etc.
I eventually started telling them it was a drag car only.