Why did nhra change the cam and valve spring rule in 1985?
 

While there are some comments about the older Jr. stockers on this site I had a flash back. Why did the rule change on cams and valve springs come about? Was it the lack of qualified people to do the job? Was it to much work? Do any of the older guys remember and know WHY? I can understand the duration and overlap being a pain to check and enforce but why didnt they just put a limit on the valve spring pressure of about 125-150 lbs seat pressure and 300-350 lbs open pressures across the board for all brands and types of engines? Easy to check while the head was removed for tear downs. This unlimited spring pressure rule is the primary reason you have to spend $700 to $900 on flat tappet lifters. Sleved lifter bores. It is also the reason for cut down crank pins, aftermarket rods, AND cheated up cylinder heads (air flow at higher RPM's) and intake manifolds. The valve springs most are running in "stock" today have more pressure than my old SS/IA Camaro had with an almost .700 lift roller cam and UNPORTED HEADS back in 1977-78. Mark, Woodro, or anyone have the answer from the good ole days of less expensive stockers????

Re: Why did nhra change the cam and valve spring rule in 1985?
 

I have to agree with you Terry! I'd also like to add that if NHRA would add a "valve spring pressure rule" to the books right now you would see the cost of Stock Eliminator racing decline and you would find that we wouldn't be having so many Stocker oil downs!

Re: Why did nhra change the cam and valve spring rule in 1985?
 

Thanks for replying Billy. Words from someone who has "Been there and Done that" go a long way. Do you think someone with the power to make a new ruling on valve spring pressure would step up to the plate? Naaaaaaaaaaaaa ! It might upset the apple cart.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

I think Tech Man has it just about right. It allowed the valve spring pressure check to be eliminated from the tear down procedure, making the process one step shorter. Seven Rimac machines up for sale. More money,less work. A no brainer on their part.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

I believe they changed the cam and valve spring rules. For 2 reasons
1 The GM guys were constantly crying because Mopar wrote "bogus" numbers for thier cams. On our Hemi car if we put as much duration and overlap as we were allowed it never would have been able to start.
2 Is they just got lazy not wanting to have to calibrate testors and measure the spring heights.

Back in the day. We would go through aload of used "battleship" outer springs to get 16 that would check legal. I think we were allowed 180 on the seat 320 wide open (these numbers are from my memory which isn't always right)

Re: Why did nhra change the cam and valve spring rule in 1985?
 

I believe they did it because.

1) You don't have to check it, therefore takes away all accountability (Someone to stand up and say it is wrong, better luck next time!)
2) Help vendors (that invest in the NHRA) sell products.
3) 1 less person to pay to work the races/teardown. They could get less experieneced. cheaper labor to do the job.
4) Speed up teardowns.

It just goes to show as soon as they legalize a go fast replacement part it opens up the next door, and then the next door. Legalize open spring pressure, then you find the next weekness (lifter, cam material) then you fix that and so on. Results, better products, more Hp, Lower ET's, Higher MPH, MUCH HIGHER PRICE TAG TO KEEP UP, Lower participation (Due to price tag), Higher HP factors (Due to the newly found performance). Stocker engines being priced sky high. The list goes on. Does anyone notice that in time past when money was tight, like it is now, there were allot of cars running. More participation? The reason that I see is people like rules, as long as they are the same for everyone. You used to spend your time working through your combo (testing). Now allot of people "checkbook race".

Re: Why did nhra change the cam and valve spring rule in 1985?
 

Billy Nees brought up one more thought.....ENGINE LIFE. Im friends with a very good life long 428 CJ (not noted for long life with stock rods) engine builder and racer. When the valve spring rule was in effect he could run a full year on one engine. Thats was approx 300 runs. Today he said the engines (all brands) when run hard enough to be fast only last about 75 to 90 runs then your on borrowed time. The rings usually go away before that many runs. Wouldnt it be smarter to limit RPMs from a stocker with valve spring pressures rather than making everyone run a diaper to contain the oil and flying parts from an over stressed "stocker" engine?

Re: Why did nhra change the cam and valve spring rule in 1985?
 

It's got to be a whole lot less expensive to change a set of valve springs than to re-engineer a Stocker so you can fit a diaper or pan on it.
OBTW, in this day and age it's not uncommon for S/G and S/C racers to check their valve spring pressures between time trials and between rounds so what's the big deal getting an NHRA Tech guy to check a few. There are plenty of unexpensive tools in the ND every week to check springs on the engine.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

NHRA told the prostock teams "NO EXOTIC MATERIALS IN THE ENGINES" , why is it allowed in stock eliminator? Schubeck lifters are made from an exotic material the last time I looked. You can't buy them at any local auto parts store that I know of.
NHRA doesn't want to do their job on policing rules and for that matter what we pay for from them when we buy our memberships. NHRA is streamlining for their benefit not to have to enforce rules that should have been kept up with, like valve spring pressures. The cars in stock would not be running 1.0 under if the valve spring pressures where set to factory spec. for sure. The valve spring spec on my 302 engine was 96 lbs on the seat and 204 lbs open pressure, no way could you get the motor to 8k rpm. Now, they are changing gears at 8200 rpm.
My vote is to go back to enforcing an across the board valve spring pressure so that you have to use stock (buy in any auto parts store) lifters again.

Casey Miles
248H

Re: Why did nhra change the cam and valve spring rule in 1985?
 

Yepper......But how are you going to get the associations to change that rule? If I was still working the IHRA deal I woud push for it but I know it would be shot down. That would eliminate just about every NHRA car that wanted to cross over and the car counts are low enough already. NHRA would have to mandate it then IHRA would follow the rule change. All one can do is send letters to the powers that control this stuff and complain and try to reason with them about the cost and potential oil downs. With a head off already for a CC check and the valves out for a size check the checking of a couple of valve springs would take only a few moments. Let the stockers keep their crazy overlap and duration specs as that was a pain in the ***** to check.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

If you check out the rules for IHRA pure stock you find a class thats in line with the original intention of stock eliminator. A person can put together a competitve car for a lot less money. If rules are enforced theres no problem. As far as reliability, while I don't race as much as most, my 327 has been in the car for 5 years without freshening and only minor repairs and still runs the number. Pat

Re: Why did nhra change the cam and valve spring rule in 1985?
 

An across the board number is no better than what you have now. Heavier valves need more spring pressure to control the valve. If you went back to using the specs that would be more equitable. But still not perfect.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

You guys need to get a TIME MACHINE...
They make the rules as you go along.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

The problem is that they change the rules as they go along. Instead of ***** footing around, why not allow roller cams to match the newer engines with roller cams and also fuel injection while we are at it. Did I also miss crank trigger?
The rules in stock, should be stock and not with all the after market parts that don't belong. I like it to see someone squeeze out HP with limited parts to their disposal, with controlled regulations and not just put in (full advantage) after market parts that they find on the shelf. I'm sure most of the time, NHRA will accept parts, if we pitch a bitch enough about how hard it is to get originals even if their are plenty of those originals still around.

Casey Miles
248H

Re: Why did nhra change the cam and valve spring rule in 1985?
 

I wrote the rules for pure stock.....the problem is the enforcement of the rules.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

[QUOTE=X-TECH MAN;195663] That would eliminate just about every NHRA car that wanted to cross over and the car counts are low enough already.

I think that you'll find that NHRA doesn't want Stockers "crossing over" to SS!

Re: Why did nhra change the cam and valve spring rule in 1985?
 

[QUOTE=Billy Nees;195742]I meant if the NHRA stockers wanted to run IHRA stock....... If IHRA changed the valve spring rule to a max seat and open pressure for stock IHRA would loose ALL of the NHRA stockers wishing to race with them unless they ran S/S because of the NEW valve spring pressure rule. .

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

Thank you.......RPM is the main killer and cause for expense not to mention all of the other "Stuff" that is being done to take advantage ot the RPM ranges the stockers are being run in today,

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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?

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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. .

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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)

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.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

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!

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!

Re: Why did nhra change the cam and valve spring rule in 1985?
 

lol

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.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

[QUOTE=Billy Nees;195806]Its nice to day dream and BS about it but what does it take to get it done? I dont have any "pull" anymore and NHRA wont listen to anyone or their own committie so what can you do? Build your combo with the lower valve spring pressures to make it less expensive, get more runs and run slower or just keep on spending the big bucks for the trick of the week, rebuilding them every 75 to 100 runs and/or blowing up very expensive engines I guess.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

I dont know how hard the blown Mustangs turn their combos and what kind of spring pressures they use but maybe they would only blow by you at 145 MPH instead of over 150+ MPH.......LOL.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

Take away an engines ability to rev and it will be less likely to hurt itself. NHRA is looking for ways to cut down on "down time" so it would seem to just be a common sense rule. BUT I did say NHRA and common sense in the same sentence didn't I? Isn't that like saying Military Intelligence?

Re: Why did nhra change the cam and valve spring rule in 1985?
 

OHC engines use very little valve spring pressure. They don't need it.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

And all SBC combos from 1967-1991 used 84 lbs on the seat and 206 lbs @ .450" compression. NHRA allowed an additional 10 lbs on the seat and 20 lbs open for a dampener, if the factory specs called for one.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

I remember when I got my brand new 68 Z-28 I could sling it to 7000 RPM easy and I never had the valve covers off yet to shim the springs and lash the valves. The springs had to be around 70 lbs on the seat or close to it. I did pull 4 studs (68s had pressed in studs) one evening (car was 2 days old) due to a missed shift with the OEM clutch sticking to the floor at 7000......lol. Probably lucky I still have my legs as I still had the OEM cast flywheel and no scatter shield yet. Dumb ***** attack on my part.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

The trouble with setting a specific # for valve springs in this day and age is that the cam manufacturers are building cams that a flat tappet lifter just can't follow even with the best springs! I believe that some of the really sharp Stocker engine builders are actually getting away from "square" cams and going back to "softer" lobes at least on the exhaust as they're finding they're "cleaning up" the intake charge by not bouncing the exhaust valve around on the seat. Think about what the "harmonics" of that exhaust valve bouncing on the seat is doing to the intake charge not to mention the cylinder pressure.
Another good reason for "softening" the lobe is simply to use less spring. Heavy springs just "tie up" horsepower that can't be used to accelerate the vehicle.
I guess where I'm going with this is that as much as I'd like to see a "valve spring spec" rule put in the book it would make a lot of cams in use today unuseable and I don't forsee any of todays Stocker engine builders or cam manufacturers lobbying for a rule that will make their stuff unuseable.
But these are just the ramblings of a bored, crazy old fool living on a hill in Pennsylvania.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

It might make some of the "square" cams unusable but a max spring pressure rule would put everyone in the same boat and keep more engines in one piece. Less chance for a broken bouncing valve destroying an engine and maybe less chance of being forced to run a diaper in the near future. Not only the "SQUARE" cams but what about some of the 55mm cams I have been hearing about in stock. I wouldnt think they would be legal but they are out there. Ramblings of an old retired foolish dumb tech guy living in the flat part of Florida.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

Terry, You need something to do.......I know, you can join the hunt for the 25 foot python seen in your driveway last month. Billy Chupacabra was seen in the area of your Hilly home, be careful at nite they sniff out empty beer bottles left about.

Re: Why did nhra change the cam and valve spring rule in 1985?
 

Yeah...Im bored. I already shot a snake in my yard a couple of weeks ago.