Super stock head porting

l88427 · 02-21-2021, 10:51 AM

Does anyone recall what year NHRA allowed porting and then chamber modification in Superstock? Thanks

Mike Pearson · 02-22-2021, 10:58 AM

They allowed it long before it actually became legal by the rule. Porting and covering it up with blasting and acid was common before it was legal by the rule. Mid to late 80's would be my recollection on porting. Chamber mods came after that as a separate modification t the rules. Early on there was no port CC size and the ports were not poured during a tear down inspection.

Jody Lang · 02-23-2021, 01:49 AM

Chamber mod was the start of 2004 I recall at Jegs race in 03 they were taking pics of all the SS chambers.

nhramnl · 02-23-2021, 10:23 AM

Quote:

Originally Posted by Jody Lang

Chamber mod was the start of 2004 I recall at Jegs race in 03 they were taking pics of all the SS chambers.

I've heard they keep a scrapbook titled "Photos of cheating we FINALLY had to acknowledge (after YEARS of having it blatantly going on right under our noses), but still did nothing about at the time, instead taking the path of least resistance and just making the cheating legal".

Dwight Southerland · 02-23-2021, 12:06 PM

Porting for SS was first in the rulebooks in 1990. Port volumes were published and enforced way before that. When Chevrolet cast up the replacement 291 big block heads in 1987, the as-cast exhaust ports were bigger than the NHRA specs for the original production versions and several racers had problems with tech until NHRA changed their spec.

02-21-2021, 10:51 AM	#1
l88427 Junior Member Join Date: Feb 2012 Posts: 58 Likes: 10 Liked 14 Times in 6 Posts	Super stock head porting Does anyone recall what year NHRA allowed porting and then chamber modification in Superstock? Thanks

02-22-2021, 10:58 AM	#2
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,321 Likes: 546 Liked 1,629 Times in 502 Posts	Re: Super stock head porting They allowed it long before it actually became legal by the rule. Porting and covering it up with blasting and acid was common before it was legal by the rule. Mid to late 80's would be my recollection on porting. Chamber mods came after that as a separate modification t the rules. Early on there was no port CC size and the ports were not poured during a tear down inspection. __________________ Mike Pearson 2485 SS

02-23-2021, 01:49 AM	#3
Jody Lang Member Join Date: Mar 2002 Posts: 299 Likes: 28 Liked 81 Times in 25 Posts	Re: Super stock head porting Chamber mod was the start of 2004 I recall at Jegs race in 03 they were taking pics of all the SS chambers.

02-23-2021, 12:06 PM	#5
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,980 Likes: 53 Liked 724 Times in 177 Posts	Re: Super stock head porting Porting for SS was first in the rulebooks in 1990. Port volumes were published and enforced way before that. When Chevrolet cast up the replacement 291 big block heads in 1987, the as-cast exhaust ports were bigger than the NHRA specs for the original production versions and several racers had problems with tech until NHRA changed their spec. __________________