What is my CR?
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Joined: Nov 2003
Posts: 644
From: Mustang OK
What is my CR?
3.50 stroke,4.030 bore with 5.7" rods and -5cc flat top pistons. 0 decked block,heads milled flat(not sure how much), 245/254 cam with 55ABDC. I know it is not exact specs but can someone help me out on finding where abouts my static and dynamic ratios are? I have been trying to figure it out with different calculators and such but i can't seem to get it right.. 
Thanks
Thanks
Thread Starter
Registered User
Joined: Nov 2003
Posts: 644
From: Mustang OK
Re: What is my CR?
Nm i was doing the ICL@.050 and it was screwing it up. Since i don't know the block deck or combustion chamber volume i was playing around with all the possibilities it could be(deck and CC) and it looks like at the least i have an 11.7:1 SC and at most a little over 12:1 but the dynamic with that cam is below 9:1 for sure. I may run a 101/91 mix in the summer just to be safe but it looks like i will be ok. It seems to be running well.. 
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Joined: Nov 2001
Posts: 3,515
From: Kansas
Re: What is my CR?
What cam do you have? Comp, Crane..? My calculator of ABDC doesnt match what you claimed givin the specs of the cam and ICL.. I suspect the ICL is wrong b/c im getting 84 degrees ABDC with a 112 ICL.
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From: tulsa ok
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Posts: 6,661
From: LA (lower Alabama)
Re: What is my CR?
Ya have 11.84 static and 7.83 dynamic,which is WAY to low to make HP. Ya will need a 4CC dome after the valve relief's are figured to put ya at 13.73static and 8.88 dynamic,a 5CC dome will get ya 9.02 dynamic with the cam ya have.
It is about 1CC per .008 of head milling which would be .032 (for 4CC's) to cut the heads and ya will have to get the intake side cut to compensate. Then ya have to make sure the port's line up with the intake.Ya will probably have to use thick intake gasket's.
Ya will have to CC the heads and see what ya got now and mill to take 4/5CC's out of the chambers.
It is about 1CC per .008 of head milling which would be .032 (for 4CC's) to cut the heads and ya will have to get the intake side cut to compensate. Then ya have to make sure the port's line up with the intake.Ya will probably have to use thick intake gasket's.
Ya will have to CC the heads and see what ya got now and mill to take 4/5CC's out of the chambers.
Last edited by 1racerdude; Oct 24, 2005 at 07:33 PM.
Thread Starter
Registered User
Joined: Nov 2003
Posts: 644
From: Mustang OK
Re: What is my CR?
Originally Posted by 1racerdude
Ya have 11.84 static and 7.83 dynamic,which is WAY to low to make HP. Ya will need a 4CC dome after the valve relief's are figured to put ya at 13.73static and 8.88 dynamic,a 5CC dome will get ya 9.02 dynamic with the cam ya have.
It is about 1CC per .008 of head milling which would be .032 (for 4CC's) to cut the heads and ya will have to get the intake side cut to compensate. Then ya have to make sure the port's line up with the intake.Ya will probably have to use thick intake gasket's.
Ya will have to CC the heads and see what ya got now and mill to take 4/5CC's out of the chambers.
It is about 1CC per .008 of head milling which would be .032 (for 4CC's) to cut the heads and ya will have to get the intake side cut to compensate. Then ya have to make sure the port's line up with the intake.Ya will probably have to use thick intake gasket's.
Ya will have to CC the heads and see what ya got now and mill to take 4/5CC's out of the chambers.