Pure Stockers New Camshaft Rule !!!

[Steve Stickel]

From the 2014 IHRA Rule Book... Pure Stock lost a little "Purity" today .. This is posted for the guys who might have a cam on order or will be soon..

12/10/13
p. 48 Pure Stock: Camshaft: Camshaft must retain stock lift for horsepower claimed per IHRA Technical Bulletins. OEM duration and overlap is optional


Can't get too crazy as the valve springs still have to check at OEM pressures, open and closed. Guess this was changed to speed up tech / tear down or maybe lack of data supplied by the OEM's?

Originally Posted by Steve Stickel

From the 2014 IHRA Rule Book... Pure Stock lost a little "Purity" today .. This is posted for the guys who might have a cam on order or will be soon..

12/10/13
p. 48 Pure Stock: Camshaft: Camshaft must retain stock lift for horsepower claimed per IHRA Technical Bulletins. OEM duration and overlap is optional


Can't get too crazy as the valve springs still have to check at OEM pressures, open and closed. Guess this was changed to speed up tech / tear down or maybe lack of data supplied by the OEM's?

Wow! Thanks for posting that. Thanks also to IHRA for changing this a few months after I had Bullet grind a Pure Stock cam with STOCK duration. I could have really went fast if I wasn't restricted to that. Ugh!

[countrypuppy4865]

Sounds like 10 second pure stock cars are just around the corner!

Originally Posted by countrypuppy4865

Sounds like 10 second pure stock cars are just around the corner!

Perhaps. We were in Dallas for their Thanksgiving race and the air was well below sea level. Went 11.58 with a 1.50 60' 150 lbs. heavy for B/PS. I'm not sure if there would be 4 tenths in an unlimited duration cam with any spring but we haven't been in the heads yet either.

I like the rule; just wish I would have known it two months ago before I changed the cam and springs.

Scott

[gbur]

Originally Posted by Tar Heel

Perhaps. We were in Dallas for their Thanksgiving race and the air was well below sea level. Went 11.58 with a 1.50 60' 150 lbs. heavy for B/PS. I'm not sure if there would be 4 tenths in an unlimited duration cam with any spring but we haven't been in the heads yet either.

I like the rule; just wish I would have known it two months ago before I changed the cam and springs.

Scott

Wasn't that with bogus gas ?

Originally Posted by gbur

Wasn't that with bogus gas ?

No, we were legal. It still has the oxygen sensors so we have to run unleaded.

Scott

[Dan Fahey]

Originally Posted by Steve Stickel

From the 2014 IHRA Rule Book... Pure Stock lost a little "Purity" today .. This is posted for the guys who might have a cam on order or will be soon..

12/10/13
p. 48 Pure Stock: Camshaft: Camshaft must retain stock lift for horsepower claimed per IHRA Technical Bulletins. OEM duration and overlap is optional


Can't get too crazy as the valve springs still have to check at OEM pressures, open and closed. Guess this was changed to speed up tech / tear down or maybe lack of data supplied by the OEM's?

What does OEM duration and overlap optional mean?

OK.. emailed Mike Baker ..and it is true.
Can use any OEM Spring.

This is Mike's response to my email..
"If it is oem design and size it is ok"

D

[HandOverFist]

Originally Posted by Dan Fahey

What does OEM duration and overlap optional mean?

D

I think it means they didnt want to copy/paste the NHRA rulebook for Stock...not a bad idea in itself.

[Lyn Smith]

I can finally retire my General Kinetics special Pontiac lobe(thats what they called it even though it was in a Buick) stock duration cam i had made in 1980 .I think i will mount it on a board and put it on the wall in the man cave.LOL

[Bob Pagano]

I know one that will go 10s 67 vette 427- 400 for sure.