SleeperDart505
Stock wheels, Stock Paint, 505" Stroker, Full Cage
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?
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. 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?
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. 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?