I bought this '68 Dart with a 505' stroker motor. It runs good. Doesn't over heat. Runs well on 93 octane. But who of us can ever leave anything alone? :lol:
This motor has stock steel heads on it but the seller says the machine shop shaved the heads and it "has a lot of compression". It was a little hard to crank when I first got it so I turned the timing down a bit and it cranks fine now. Seller says it was the compression not the timing. But he doesn't know any details really. It has been 20 degrees since I got the car so I haven't really spent much time looking at it.
How can I figure out how much compression I have here? I took the part number from the stroker kit and found out the Scat pistons are forged and supposedly have a D shaped dish for valve clearance. The flat top version would have been better I think. The stock heads were shaved but nobody can tell me how much. I figure I can do a cranking pressure check but I wouldn't know how to convert that to compression ratio. Anybody have a rule of thumb? 160 lbs. = 10:1 compression, etc.???
In the future, I'm thinking of going with aluminum heads. For a street/strip car what compression ratio do you guys recommend on 93 octane with an aluminum head?? I know they are not real popular here but I may go with the 440 Source heads since their casting looks like a stock head. I can paint them and it will work real well with my whole Sleeper theme. :p I hear they offer a fully CNC ported set that flows 320 CFM and has an intake port of 255. That's bigger than the TFS 240 head. It will be plenty big enough for what I want to do.
Thoughts?
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