Cylinder head CC

Stocker · 11-08-2023, 04:34 PM

My sbc exhaust port is at 64cc. NHRA spec is at 65cc. Is it maximum or minimum ?

David Lee · 11-08-2023, 05:06 PM

Quote:

Originally Posted by Stocker

My sbc exhaust port is at 64cc. NHRA spec is at 65cc. Is it maximum or minimum ?

what does the rulebook state

JIM MARSHALL · 11-08-2023, 05:57 PM

Posted intake and exhaust runner cc is maximum
Posted chamber cc is minimum
Posted valve lift is maximum
Posted overbore is maximum
Posted piston assembly is minimum
Hope this helps

Larry Hill · 11-09-2023, 08:59 AM

Don’t forget the weight of the crankshaft just in case they will be going to Indy for the first time!

J.R. Haddad · 11-09-2023, 10:58 AM

Larry, where would one get the weights on the crankshafts? NHRA doesn't
list them on Blueprint Specs, and Dwight doesn't have have them listed.
Never has.

Thanks,

J.R.

Larry Hill · 11-09-2023, 03:23 PM

I’m not real sure. A core supplier would be a good source. We used to grind crankshafts and would ship some but most of them were hurry up we need it by this weekend. And I still have some waiting to be picked up and we closed the business over 25 years ago.
The AERA would be a very good source.

Hope this helps.

David Lee · 11-09-2023, 07:41 PM

Quote:

Originally Posted by J.R. Haddad

Larry, where would one get the weights on the crankshafts? NHRA doesn't
list them on Blueprint Specs, and Dwight doesn't have have them listed.
Never has.

Thanks,

J.R.

would replacement crank shafts get us in the ballpark?

J.R. Haddad · 11-09-2023, 08:06 PM

You would think they would. I just want to know where the ball park is!!

J.R.

David Lee · 11-09-2023, 08:14 PM

Quote:

Originally Posted by J.R. Haddad

You would think they would. I just want to know where the ball park is!!

J.R.

what combo?

J.R. Haddad · 11-09-2023, 11:10 PM

Any combo. While it points ouet what we can't do to a crank, ie, knife edge.
excessive lightening etc. If we buy a lightweight crank, which a lot of S/SS
people do, and it doesn't look like its been put on a serious machine shop
diet, it passes. yet if we are out 2 grams on something else, we get treated worse in tech than some of the Pro Stock drivers have lately.

J.R.

11-08-2023, 04:34 PM	#1
Stocker Junior Member Join Date: Nov 2003 Location: Canada Posts: 34 Likes: 0 Liked 0 Times in 0 Posts	Cylinder head CC My sbc exhaust port is at 64cc. NHRA spec is at 65cc. Is it maximum or minimum ?

11-08-2023, 05:57 PM	#3
JIM MARSHALL Member Join Date: Mar 2002 Location: Indian Land SC Posts: 104 Likes: 107 Liked 224 Times in 30 Posts	Re: Cylinder head CC Posted intake and exhaust runner cc is maximum Posted chamber cc is minimum Posted valve lift is maximum Posted overbore is maximum Posted piston assembly is minimum Hope this helps __________________ Jim Marshall 1967 STK

11-09-2023, 08:59 AM	#4
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,301 Likes: 1,656 Liked 9,531 Times in 1,976 Posts	Re: Cylinder head CC Don’t forget the weight of the crankshaft just in case they will be going to Indy for the first time! __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

11-09-2023, 10:58 AM	#5
J.R. Haddad Senior Member Join Date: Jun 2012 Posts: 632 Likes: 528 Liked 898 Times in 203 Posts	Re: Cylinder head CC Larry, where would one get the weights on the crankshafts? NHRA doesn't list them on Blueprint Specs, and Dwight doesn't have have them listed. Never has. Thanks, J.R.

11-09-2023, 03:23 PM	#6
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,301 Likes: 1,656 Liked 9,531 Times in 1,976 Posts	Re: Cylinder head CC I’m not real sure. A core supplier would be a good source. We used to grind crankshafts and would ship some but most of them were hurry up we need it by this weekend. And I still have some waiting to be picked up and we closed the business over 25 years ago. The AERA would be a very good source. Hope this helps. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

11-09-2023, 08:06 PM	#8
J.R. Haddad Senior Member Join Date: Jun 2012 Posts: 632 Likes: 528 Liked 898 Times in 203 Posts	Re: Cylinder head CC You would think they would. I just want to know where the ball park is!! J.R.

11-09-2023, 11:10 PM	#10
J.R. Haddad Senior Member Join Date: Jun 2012 Posts: 632 Likes: 528 Liked 898 Times in 203 Posts	Re: Cylinder head CC Any combo. While it points ouet what we can't do to a crank, ie, knife edge. excessive lightening etc. If we buy a lightweight crank, which a lot of S/SS people do, and it doesn't look like its been put on a serious machine shop diet, it passes. yet if we are out 2 grams on something else, we get treated worse in tech than some of the Pro Stock drivers have lately. J.R.