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Cc limits

Posted: Tue Jan 30, 2018 9:06 am
by AMXstocker1
Has anyone ever considered that using intake runner cc as a class rule is crazy and would only work if all the competing vehicles used the same engine platform. If not he who has the shortest runner cylinder head wins because they can have a larger average CSA all the class's should be limiting CSA Not CCs it becomes very tempting to start milling the intake side of the head back as far as possible and building a custom intake manifold.

Re: Cc limits

Posted: Tue Jan 30, 2018 9:11 am
by Krooser
The ridiculous thing is who is going to tech this stuff?

Re: Cc limits

Posted: Sat Feb 03, 2018 1:14 am
by cgarb
Restrictor plate racing.

Re: Cc limits

Posted: Sat Feb 03, 2018 4:42 pm
by SupStk
NHRA has the maximum intake and exhaust runner CCs and minimum combustion chamber volumes for each head accepted for stock and super stock engines. They DO check 'em.

If the OP is talking about open competition with no engine distinction, the obvious advantage does go to the shortest runner.

Re: Cc limits

Posted: Sat Feb 03, 2018 10:23 pm
by AMXstocker1
yes we run a class with a straight 230cc intake runner volume limit. so he who has the shortest runner wins. sounds like i'm bitching i'm just thinking about it and it seems like saying a max of a 2.30 inch CSA would be easier to check and more effective. NHRA uses supposed factory volumes, but i've heard plenty of griping about bogus cc#s for some combinations over on classracer too.

Re: Cc limits

Posted: Sun Feb 04, 2018 6:34 pm
by miniv8
Have you thought about milling the manifold face of the head?

(edit, but I agree, the rule is kinda stupid..)

Re: Cc limits

Posted: Sun Feb 04, 2018 9:15 pm
by SupStk
AMXstocker1 wrote: Sat Feb 03, 2018 10:23 pm yes we run a class with a straight 230cc intake runner volume limit. so he who has the shortest runner wins. sounds like i'm bitching i'm just thinking about it and it seems like saying a max of a 2.30 inch CSA would be easier to check and more effective. NHRA uses supposed factory volumes, but i've heard plenty of griping about bogus cc#s for some combinations over on classracer too.
During the 80's NHRA was checking runner volumes, venturi and throttle plate diameters during stock and super stock teardowns. This was before they had to conform to published specs. I wondered at the time what it was all about. In retrospect we know now.

Re: Cc limits

Posted: Mon Feb 05, 2018 9:16 am
by 6.50camaro
I my be wrong ,but I think a Ford FE would be a good candidate for this class. Dan

Re: Cc limits

Posted: Mon Feb 05, 2018 8:32 pm
by AMXstocker1
We are milling the manifold face mainly to correct the angle heads are being angle milled rolled over to closer to a 17 degree angle than a 18 so the face will be milled some to correct this. Also the indy head we run have intake surface that is flush with the manifold side of the head were a factory head has a 1/8th inch lip that manifold sets under i think were going to go ahead and take that 1/8th off the heads. Ours are being ported hemi adkins hes a superstock racer from va and these heads will be like a bigger cc version of his SS heads.

Re: Cc limits

Posted: Mon Feb 12, 2018 3:20 am
by JohnsnsFord2@aol.com
6.50camaro wrote: Mon Feb 05, 2018 9:16 am I my be wrong ,but I think a Ford FE would be a good candidate for this class. Dan
Why do you say this?

Re: Cc limits

Posted: Mon Feb 12, 2018 3:22 am
by JohnsnsFord2@aol.com
I think some of the hemi heads are done like this in the AH class...

Re: Cc limits

Posted: Mon Feb 12, 2018 6:09 am
by pdq67
6.50camaro wrote: Mon Feb 05, 2018 9:16 am I my be wrong ,but I think a Ford FE would be a good candidate for this class. Dan
Probably because the old FE engines have most of their intake runner lengths in their WIDE intake manifolds is why.

pdq67

Re: Cc limits

Posted: Mon Feb 12, 2018 7:39 am
by 6.50camaro
pdq67 wrote: Mon Feb 12, 2018 6:09 am
6.50camaro wrote: Mon Feb 05, 2018 9:16 am I my be wrong ,but I think a Ford FE would be a good candidate for this class. Dan
Probably because the old FE engines have most of their intake runner lengths in their WIDE intake manifolds is why.

pdq67
Yes ,that is one of the reason . With the new Trick Flow Specialties heads flowing 330+ cfm @175cc seems to me that you could get all the flow you want with out pushing the cc limit . Multiple sizes from 352- 428 if working with lbs /cu.in. rule . Aftermarket stroker parts if working with min. weight/ max cu.in. rules , relatively light engine weight are a couple of the others . I remember back in the mid 70's a guy in the town I grow up in had a 67 cyclone gt that he pulled the 390 out and put in a 428cj . Before the swap he could run pretty close with 440 cudas and 396 chevelles in town. After the swap all they he was the quickest car in town running on the street. Dan

Re: Cc limits

Posted: Mon Feb 12, 2018 8:06 am
by 6.50camaro
Correct that , it was a 68 cyclone gt. Dan