Rocker Arms---Does an official clarification exist

[FSA1673]

Originally Posted by SSDiv6

This was discussed on a previous post and Travis Miller made it clear the ratio can be checked.

http://classracer.com/classforum/showthread.php?t=25533

Rule wording has changed from 2010 to 2014.

[Alan Roehrich]

Originally Posted by Rusty Davenport

Today's email from Bruce Bachelder------

" AS LONG AS THE CAM LIFT, CHECKED WITH A SOLID LIFTER, DOES NOT EXCEED THE SPEC YOU ARE ALL SET "

SOUNDS PRETTY CLEAR TO ME, THE NUMBERS DONT MEAN A THING ON THE ROCKER

That's fine. Get it in writing, with the NHRA logo, and some sort of digital signature, and keep it with the car. There needs to be zero doubt that it is the absolute official word from NHRA @ Glendora.

[Jeff Teuton]

I got thrown out 3 or 4 years ago for that. Cam checked, but rocker are stamped 1.65 and specs call for 1.60. I'm not sure if the rule has changed.

[Tom Moock]

When did they go back to using a stock solid lifter to check lift? The last time I set the record they used there adjustable lifter. I think nhra. should sell a adjustable lifter if they are going to check with one. chevy stock solid lifter has different height than a smith lifter. I was told by well known engine builder that with roller rocker arms, longer & shorter push rods don`t change lift, like stock rocker arms. Tom

[Adger Smith]

I've been involved in rules as well as in Tech at EMC. We were dealing with the same issue (rocker ratio) at Engine Masters Challenge. I have come to the conclusion the NHRA rule (As written) is not enforceable..I have had the input from a very notable former NHRA Tech person who is on our team and he concurs. That is the reason we have no Rocker Ratio rules at EMC. I think NHRA should re write that rule. I also think it is just asking for trouble to have any stamped ratios on rocker arms. When the wrong person tries to verify the ratio it can come up way wrong. That ratio number being wrong "could" be grounds for action by the NHRA.

[Mark Yacavone]

Originally Posted by Tom Moock

When did they go back to using a stock solid lifter to check lift? The last time I set the record they used there adjustable lifter. I think nhra. should sell a adjustable lifter if they are going to check with one. chevy stock solid lifter has different height than a smith lifter. I was told by well known engine builder that with roller rocker arms, longer & shorter push rods don`t change lift, like stock rocker arms. Tom

I believe he misspoke on that, Tom. He probably meant to say a solid lifter.
You are going to be allowed to match the overall height of what you're using.
Trust me on that.

[Adger Smith]

Yes, Mark after the fiasco in Div 4 concerning cam/valve lift I would think proper procedure might be followed a little closer.

[terry1]

Direct excerpt from 2014 NHRA rule book:
"ROCKER ARMS
OEM or aftermarket rocker arm permitted.Needle/roller bearing
pivots and roller tips are permitted for all applications.Must remain
same design as original application(i.e. stud mount must retain
stud mount, pedestal type must retain pedestal type, and shaft
type must retain shaft type. Stud girdles prohibited.) Stamped steel
OEM and OEM-type rocker arms may be reinforced."

It's obvious what's not mentioned!

[Bill Diehl]

Originally Posted by terry1

Direct excerpt from 2014 NHRA rule book:
"ROCKER ARMS
OEM or aftermarket rocker arm permitted.Needle/roller bearing
pivots and roller tips are permitted for all applications.Must remain
same design as original application(i.e. stud mount must retain
stud mount, pedestal type must retain pedestal type, and shaft
type must retain shaft type. Stud girdles prohibited.) Stamped steel
OEM and OEM-type rocker arms may be reinforced."

It's obvious what's not mentioned!

The ratio is listed in the blueprint specs

My 2 cents would be....who cares what any of the numbers are on any of the parts as long as the lift at the valve is within spec. The system can be engineered and designed to function much better and be a lot easier on parts than some of the stuff that's currently in use now, and still remain inside the "lift" rule

[terry1]

[QUOTE=Bill Diehl;450834]The ratio is listed in the blueprint specs

Your right.