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-   -   Explain to me again, please (https://classracer.com/classforum/showthread.php?t=81249)

Billy Nees 01-07-2022 11:08 AM

Re: Explain to me again, please
 
Quote:

Originally Posted by Stan Weiss (Post 655134)
As has been said by a few here already, limit valve spring pressure. While a flat tappet does impose some limits as to what a cam lobe designer can do. Some of these limits maybe lifted with a roller lifter. Then what happens when the next weak link shows up? Another rules change?

Stan

Ya know, every time "we" get an enhancement, "we" have to go running back to the dyno to figure out just how "we" can exploit it.
Well, maybe it's time for the Tech Dept. to give an un-enhancement a try. Put a "valve spring rule" in place (200# sounds good) and watch how fast "we" go about figuring out how to make it work. I'll bet it will fix the AHFS in a hurry too!
If ya think about, it's kinda funny how a rule change can have the same effect but in a different direction. Instead of giving us roller lifters that "we" will spend loads of time and money figuring out, take away the big valve spring pressures that let us over rev our "Stock" engines and watch how quickly "we" will figure it out.
And maybe, "we" won't have to spend stupid money on aftermarket rods, cranks and blocks that "we" can't get anyway.

Rules are a funny thing!

Stan Weiss 01-07-2022 11:36 AM

Re: Explain to me again, please
 
Quote:

Originally Posted by Terry Cain (Post 655151)
https://www.youtube.com/watch?v=Qt-RycUnoW4

I understand there's a big differences between a full race lifter and a street motor lifter BUT some of these suppliers are advertising M2 Tool Steel Lifters. They are made over seas. So we now have junk tool steel lifters floating around, too. Grrrrrr

Little change of subject. Has anyone pulled the puck off of a Schubeck? How is it attached? Thinking maybe I could take a set of old lifters and weld M2 tool steel to bottom and have grd, hardened and coated. .


You need to reverse your order. Just like the cam core is done you want to harden / heat treat then ground.


Stan

Dan Bennett 01-07-2022 02:14 PM

Re: Explain to me again, please
 
Quote:

Originally Posted by Billy Nees (Post 655153)
...Put a "valve spring rule" in place (200# sounds good) and watch how fast "we" go about figuring out how to make it work. I'll bet it will fix the AHFS in a hurry too!...


...take away the big valve spring pressures that let us over rev our "Stock" engines and watch how quickly "we" will figure it out.


One of the last conversations I had with Jere Stahl involved exactly this issue. As most people know, Jere had done an incredible amount of research and testing on headers that allowed him to develop formulas that were very effective. He was attempting to do the same thing with camshafts at that time.

His view was that the stratospheric spring pressures being used were just a crutch for less than optimal cam design. Yes, they were fast, but he was convinced that if the profile was designed correctly those pressures would not be needed. And like Billy mentioned, that eliminates a lot of other problems just by itself.

The team I working with that he was consulting for never felt the need to devote the time to come up with the data and measurement for our best (and worst) stuff that he said he needed. So I can't say if he was right or wrong, but looking at his career he was right a lot more times than he was wrong.

Stan Weiss 01-07-2022 02:25 PM

Re: Explain to me again, please
 
While I have never personal done it. I have heard from people who have been on a Spin Tron that they is what they have found. (The need for lose spring pressure)


Stan

Terry Cain 01-07-2022 04:56 PM

Re: Explain to me again, please
 
Quote:

Originally Posted by Stan Weiss (Post 655156)
You need to reverse your order. Just like the cam core is done you want to harden / heat treat then ground.


Stan

Understand. 40 yrs. tool maker/maintenance/machinist, and floor sweeper. Hmmmm, maybe closer to 50 years.

john ancona 01-07-2022 07:13 PM

Re: Explain to me again, please
 
Quote:

Originally Posted by Terry Cain (Post 655176)
Understand. 40 yrs. tool maker/maintenance/machinist, and floor sweeper.

In an effort to understand how we ended up as some on here would let you to believe
we are only a few rule changes away from super stock , we have to go back to the spring rule ,in the 80's NHRA decided to do away with the spring rule , I ,and others asked what the reason was ,and as always I, and others were told the racers wanted it , so this is the way I ,and (I am not speaking for other racers ) , this rule change was so NHRA did not have to check the springs , again I asked why ,and in NHRA's way of keeping the racer informed they said the racers wanted it ,the canned answer , it was not long after that the cam was no longer checked for duration , these two rules opened the door for Schubeck to manufacture a ceramic lifter , maybe at the start it looked great ,but when the pucks started coming off, maybe not , now before others start getting on here saying I have been running them for year's I also have been running them for years , with a lot of attention paid to the valve lash ,and the valve springs , why because if the lash get's to big or the spring fails the lifter will bounce on the cam lobe ,and those that have had the misfortune of the puck breaking off the lifter body know all about it ,and what happens next , so Schubeck disappears for what ever reason ,and Smith starts making the same lifter with still the same results , and disappears ,at this point you have to think the spring rule started this , and you can not blame someone that try's to help like Schubeck . So fast forward to 2016, I for one ,and others talked to the Tech department ,and showed them the failures from the lifters ,I asked to put the rule back at that time to stock springs like the in the past the answer was we will put it under consideration ,good enough, so while they have it under consideration the tool steel lifters become an option , no puck to come lose off or break in a million pieces
if you bonce it on the cam lobe ,just the cam starting to frett ,and lifter wear , but not to worry the too steel lifters can be resurfaced ,but through away the cam , so next a billet cam is needed ,and coated tool steel lifters , to work with the billet cam , so here we are today $ 2100 dollar lifters for a Chevrolet a $ 650,00 steel billet cam not to mention months to get the lifters like to set I ordered six months ago . I like many I talk to are trying to to make the cam ,and lifters work as the rules are at present ,it's not that we necessarily want roller lifters , but at this point after fifty years of racing stock and super stock ,I see for myself that super stock is the place for me as I only have a few years left ,I hope NHRA and stock /super stock is around at least until I quit for good !

e vassar 01-07-2022 10:41 PM

Re: Explain to me again, please
 
Quote:

Originally Posted by Billy Nees (Post 655153)
Ya know, every time "we" get an enhancement, "we" have to go running back to the dyno to figure out just how "we" can exploit it.
Well, maybe it's time for the Tech Dept. to give an un-enhancement a try. Put a "valve spring rule" in place (200# sounds good) and watch how fast "we" go about figuring out how to make it work. I'll bet it will fix the AHFS in a hurry too!
If ya think about, it's kinda funny how a rule change can have the same effect but in a different direction. Instead of giving us roller lifters that "we" will spend loads of time and money figuring out, take away the big valve spring pressures that let us over rev our "Stock" engines and watch how quickly "we" will figure it out.
And maybe, "we" won't have to spend stupid money on aftermarket rods, cranks and blocks that "we" can't get anyway.

Rules are a funny thing!

Nah just a NHRA issued rev limiter. I vote for 7800

SSGT Mustang 01-07-2022 11:59 PM

Re: Explain to me again, please
 
......

GTX JOHN 01-08-2022 03:58 AM

Re: Explain to me again, please
 
Originally the Schubecks were interference fit and I believe he heated
and pressed them together.

Then that became too much trouble as his volume increased and he then just did not keep the tolerance
as well controlled and he simple started to glue them together.

That is what I surmised after hanging around there.
But I believe that is a pretty good guess about what happened!

Terry Cain 01-08-2022 06:41 AM

Re: Explain to me again, please
 
Quote:

Originally Posted by SBillinson (Post 655112)
Excellent explanation.

It bears mentioning that there can also be issues with pushrod angularity. Steep angles between the lifter and pushrod will cause bias pressure on the lifter.

AND on a stocker we're (correct me if I'm thinking wrong) not allowed to change that and it does come into play on a BBC.
200 lbs might work on a small valve motor.


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