Stock Valve Lift

BlueOval Ralph · 09-10-2009, 06:15 AM

Can any one tell me how NHRA measures valve lift in stock??
With Race spring at retainer?
With lite checking spring?
Lash or no Lash?

Alan Roehrich · 09-10-2009, 06:18 AM

Supposedly zero lash, at the retainer, with your spring. If you have a hydraulic lifter cam, however, they measure your lift with their solid lifter. Be aware that the pushrod cup in their solid lifter may be in a different location than the pushrod cup in your hydraulic lifter, and it may change the lift as measured at the valve.

ron mattson · 09-10-2009, 07:15 AM

Alan is right on, i would set up for .010 less than max lift as each time i have tore down
the measurement nhra came up with was different than mine due to the adjustable lifter
that they use.

larry dowty · 09-10-2009, 09:30 AM

ALAN has any one ? that when they know it is diff.

Jeff Lee · 09-10-2009, 11:59 AM

It's NHRA's testing procedure so they should have the tools necessary to do the job. If their lifter does not match your lifter's plunger height you "could" argue it is an invalid test if the test shows you are out of compliance. But if you want to avoid such issues (and I recommend you do), carry your own checking / solid lifter with the correct specs. And yes, the check is made at zero lash.
My opinion is finding every .001" of lift is not a real big deal. The rest of the cam specs is what really makes a big deal. I've been .015"-.020" under max lift and never felt it was a problem. Point is, like Ron Mattson stated below, give yourself a cushion.

Alan Roehrich · 09-10-2009, 01:08 PM

Jeff, I asked this very question a week or two ago. I was told by a division tech director that NHRA supplies the solid lifter for checking lift on a hydraulic cam and you may not supply your own. I was working on a hydraulic lifter engine, and was going to just get an extra solid lifter and check everything, and give the guy the lifter to keep with him. I was told NHRA would not use any lifter I was going to provide, they would use their own.

Gary H Humrichouse · 09-10-2009, 10:18 PM

The check lifter they use it made by Clark Holroyd. He will sell one to you.

Alan Roehrich · 09-10-2009, 01:10 PM

Quote:

Originally Posted by larry dowty

ALAN has any one ? that when they know it is diff.

Larry, I am not aware of anyone successfully challenging a ruling in that manner. I am aware of a couple of cars being tossed, despite being able to provide their own solid lifter and show it was a normal standard solid lifter for the car, as well as showing the correct lift with their checking lifter. I do not remember the names at this time, I think one of them was a small block Chrysler of some sort.

Jeff Lee · 09-10-2009, 05:18 PM

Alan,
That's fine on a "normal" application; i.e., SBC, SBF, the normal big blocks, etc.
I raced a 2.2L FWD with cam followers or tappet buckets, whatever they were called. I set records with the car. NHRA has nothing close to those in their arsenal.
I can't see the problem if you can show the checking lifter is identical in specs to the lifter that came out. But it is their game and you are right.

09-10-2009, 06:15 AM	#1
BlueOval Ralph Banned Join Date: Feb 2008 Posts: 852 Likes: 0 Liked 0 Times in 0 Posts	Stock Valve Lift Can any one tell me how NHRA measures valve lift in stock?? With Race spring at retainer? With lite checking spring? Lash or no Lash?

09-10-2009, 06:18 AM	#2
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,105 Likes: 1,561 Liked 1,788 Times in 408 Posts	Re: Stock Valve Lift Supposedly zero lash, at the retainer, with your spring. If you have a hydraulic lifter cam, however, they measure your lift with their solid lifter. Be aware that the pushrod cup in their solid lifter may be in a different location than the pushrod cup in your hydraulic lifter, and it may change the lift as measured at the valve. __________________ Alan Roehrich 212A G/S

09-10-2009, 07:15 AM	#3
ron mattson Member Join Date: Nov 2005 Location: cloquet mn Posts: 465 Likes: 17 Liked 66 Times in 29 Posts	Re: Stock Valve Lift Alan is right on, i would set up for .010 less than max lift as each time i have tore down the measurement nhra came up with was different than mine due to the adjustable lifter that they use.

09-10-2009, 09:30 AM	#4
larry dowty Member Join Date: Jan 2005 Location: chewelah wa Posts: 283 Likes: 0 Liked 11 Times in 4 Posts	Re: Stock Valve Lift ALAN has any one ? that when they know it is diff. __________________ larry dowty 6388 SS Last edited by larry dowty; 09-10-2009 at 11:12 AM.

09-10-2009, 11:59 AM	#5
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: Stock Valve Lift It's NHRA's testing procedure so they should have the tools necessary to do the job. If their lifter does not match your lifter's plunger height you "could" argue it is an invalid test if the test shows you are out of compliance. But if you want to avoid such issues (and I recommend you do), carry your own checking / solid lifter with the correct specs. And yes, the check is made at zero lash. My opinion is finding every .001" of lift is not a real big deal. The rest of the cam specs is what really makes a big deal. I've been .015"-.020" under max lift and never felt it was a problem. Point is, like Ron Mattson stated below, give yourself a cushion. __________________ Jeff Lee 7494 D/S '70 AMX

09-10-2009, 01:08 PM	#6
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,105 Likes: 1,561 Liked 1,788 Times in 408 Posts	Re: Stock Valve Lift Jeff, I asked this very question a week or two ago. I was told by a division tech director that NHRA supplies the solid lifter for checking lift on a hydraulic cam and you may not supply your own. I was working on a hydraulic lifter engine, and was going to just get an extra solid lifter and check everything, and give the guy the lifter to keep with him. I was told NHRA would not use any lifter I was going to provide, they would use their own. __________________ Alan Roehrich 212A G/S

09-10-2009, 10:18 PM	#7
Gary H Humrichouse Junior Member Join Date: Jan 2008 Location: calif Posts: 11 Likes: 0 Liked 1 Time in 1 Post	Re: Stock Valve Lift The check lifter they use it made by Clark Holroyd. He will sell one to you. __________________ Gary H Humrichouse 736 STK

09-10-2009, 05:18 PM	#9
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: Stock Valve Lift Alan, That's fine on a "normal" application; i.e., SBC, SBF, the normal big blocks, etc. I raced a 2.2L FWD with cam followers or tappet buckets, whatever they were called. I set records with the car. NHRA has nothing close to those in their arsenal. I can't see the problem if you can show the checking lifter is identical in specs to the lifter that came out. But it is their game and you are right. __________________ Jeff Lee 7494 D/S '70 AMX