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-   -   Why did nhra change the cam and valve spring rule in 1985? (https://classracer.com/classforum/showthread.php?t=26781)

art leong 07-02-2010 02:55 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Quote:
Originally Posted by Dwight Southerland (Post 195751)
I am with you guys on this one. The current valve spring rule was the most expensive hit NHRA has done to Stock Eliminator racers. I agree with you, Terry, that if they would set a max of say 135-140lbs on the seat and 350 or so at .500" compression the cost of an engine would decrease, the reliability and down-time would increase and the smart guys would have another avenue to snooker people with.

If someone would start a referendum, maybe we could exert some pressure on them. Lots of people would benefit.
That would take all the street Hemi's and send them to the old cars home. The stock ( as came on the car) springs are higher than that.
They already have Super Chevy races Do you want to make them all that way?

Michael Beard 07-02-2010 03:16 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Quote:
Originally Posted by Mark Yacavone (Post 195762)
You guys are forgetting the fact that many of the current crop of racers would have trouble just getting the valve covers off. Forget about monitoring spring pressure.
Not banging on anyone in particular. That's just a fact of life.
Bad memories.... changing a rocker arm SIX times in one weekend in a Super Stocker. I knew when the owner handed me a box full of rockers and instructions on how to change them before sending me on my way that it was going to be a long weekend... LOL

But anyhoo, I agree... get that party started, Mr. Bell! I'm questioning my sanity, but for some silly reason, I've been daydreaming about building a "traditional" Stocker motor for the Volare.

X-TECH MAN 07-02-2010 03:25 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Quote:
Originally Posted by art leong (Post 195769)
That would take all the street Hemi's and send them to the old cars home. The stock ( as came on the car) springs are higher than that.
They already have Super Chevy races Do you want to make them all that way?
The 69,70, 71 Street Hemi had single springs with a damper at 150 lbs on the seat and 320 open pressure specs. I have my old NHRA/IHRA engine spec book right in front of me as I type this. The 68 Street Hemi had 131 lbs on the seat and 280 open. The 66-67 Street Hemis had dual springs with the rating of 114 lbs outer and 53 lbs for the inner spring on the seat with 189 lbs outer seat pressure and 96 lbs for the inner open pressures (add them together) with solid lifters.The 68 and 69s had solid lifters also while the 70, 71s had hyd. lifters. The 68-71 had single springs with a damper. This was good for 7000 RPM operation. The street Hemis with an OEM oiling sytems and pans dont take to kindly to 8200+ RPM shift points for very long. I would think most all of the brand of engine combos would be OK with 150 lbs seat pressure and about 320 to 350 lbs open pressures unless they are running a cam with square lobes on it. By the way the 1969 440 six pack had a 150/320 lb pressure spec also.

X-TECH MAN 07-02-2010 03:42 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Quote:
Originally Posted by Michael Beard (Post 195773)
Bad memories.... changing a rocker arm SIX times in one weekend in a Super Stocker. I knew when the owner handed me a box full of rockers and instructions on how to change them before sending me on my way that it was going to be a long weekend... LOL

But anyhoo, I agree... get that party started, Mr. Bell! I'm questioning my sanity, but for some silly reason, I've been daydreaming about building a "traditional" Stocker motor for the Volare.
I dont have any say so any more. Im afraid its up to the racers to decide what they want and to really push for any changes IF they see someway to reduce the cost of running over a season of racing. Even then the NHRA dosent listen very well. Get used to what you have. I see more oil downs and diapers in your future if you want to remain competitive and be one of the fast guys. .

art leong 07-02-2010 03:42 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Quote:
Originally Posted by X-TECH MAN (Post 195776)
The 69,70, 71 Street Hemi had 150 lbs on the seat and 320 open pressure specs. I have my old NHRA/IHRA engine spec book right in front of me as I type this. The 68 Street Hemi had 131 lbs on the seat and 280 open. The 66-67 Street Hemis had dual springs with the rating of 114 lbs outer and 53 lbs for the inner spring on the seat with 189 lbs outer seat pressure and 96 lbs for the inner open pressures with solid lifters.The 68 and 69s had solid lifters also while the 70, 71s had hyd. lifters. The 68-71 had single springs with a damper. This was good for 7000 RPM operation. The street Hemis with an OEM oiling sytems and pans dont take to kindly to 8200+ RPM shift points for very long. I would think most would be OK with 150 lbs seat pressure and about 320 to 350 lbs open pressures unless they are running a cam with square lobes on it. The 440 six pack had a 150/320 lb pressure spec also in 1969.
I thought it was 180 on the seat. The memory is the second thing to go LOL.
I know it was critical. We would set up a motor with stock valve springs put it together and reve it in to 7500 a couple of times. Then pull the heads and change the valves and springs. It was legal to put notches in the piston as long as the motor did it not the machine shop.

PS we shifted at 7200 when we were trying to go fast. The only time the motor would go any higher was in the water (once in a while)

X-TECH MAN 07-02-2010 05:07 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Just to remind some of you guys the 1969 396/375 and the 427/425 used a single valve spring with damper that had 106 lbs on the seat and 327 lbs open before the 1985 rule change. The max wedge was less than the street Hemi and the Chevy. The 428 CJs really sucked at 97 lbs seat pressure and 298 lbs open. I think 150/350 lbs would handle just about any current stocker running today and the expensive flat tappet lifters would no longer be needed. A new rear gear might be required for those who delite in slinging the snot out of their combos.....lol.

Billy Nees 07-02-2010 05:31 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Quote:
Originally Posted by James Perrone (Post 195676)
You guys need to get a TIME MACHINE...
They make the rules as you go along.
James, I can see that you need a good "balance job"! I think about 2oz of lead behind your right ear would be a good start!

Billy Nees 07-02-2010 05:35 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
[QUOTE=X-TECH MAN;195800] I think 150/350 lbs would handle just about any current stocker running today

That's about "entry level"today! I'm running that on my 6 cylinder! Even if you made it 170 or 180 it would help!

X-TECH MAN 07-02-2010 05:54 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
Quote:
Originally Posted by billy nees (Post 195804)
james, i can see that you need a good "balance job"! I think about 2oz of lead behind your right ear would be a good start!
lol

Ed Fernandez 07-02-2010 05:59 PM
Re: Why did nhra change the cam and valve spring rule in 1985?
 
This topic is very amusing to me.I think that the standard shold be 130#/350# as my springs meet the parameters.Does this mean that all those intimidating ABC cars are
going to be slower bearing down on little old me?
I think if it can be proven that the seat pressure is higher than 130#/350# from the factory then that should be the standard for that combo.
Bill,nice comeback.


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