Re: Explain to me again, please
 

There you go again putting your spin , I never said 1500 racers want rule changes , I am sure have none of the changes on your car that have moved us closer to Super Stock !

Re: Explain to me again, please
 

No, they haven't run mushroom tappets in the Cup series for at least 30 years.

Larger diameter cam cores are used to reduce flex and produce better valvetrain stability, especially in engines with splayed or canted valve heads. They are widely used, even in Super Stock.

Cam tunnels are used primarily to reduce windage on the rotating assembly.

You're right about one thing, though. NASCAR is very different from NHRA Stock Eliminator.

The point, however, is that if a 750-850 HP, 358 CID, canted valve, flat tappet engine in a Cup car can run 500 miles at over 9000 rpm with a stock diameter solid lifter, then it's hard to imagine why it can't be done in a stocker that doesn't anywhere near that RPM and is raced a quarter-mile at a time.

Re: Explain to me again, please
 

You're correct about their ability to properly check Cam Duration and shame on the N.H.R.A. for that. Greg Xakellis had a great team then and it was not a D1 issue and I doubt it was a D3 or D4 issue either as they also had great teams as well. But the Valve Springs? Come on man, anybody can check spring pressure.

Re: Explain to me again, please
 

Put the "stock" back in "stock".... good start would be Pressure on valve springs.

Re: Explain to me again, please
 

The point, however, is that if a 750-850 HP, 358 CID, canted valve, flat tappet engine in a Cup car can run 500 miles at over 9000 rpm with a stock diameter solid lifter, then it's hard to imagine why it can't be done in a stocker that doesn't anywhere near that RPM and is raced a quarter-mile at a time.

You're still comparing apples to grapes...

The technology used to make a NASCAR engine live is so for advanced it makes a SS engine look like a high school mechanics class project.

Re: Explain to me again, please
 

You are probably correct... But it's going to be awful hard to stuff that genie back in the bottle...

Re: Explain to me again, please
 

It's simple, NOT GOING TO HAPPEN.

Re: Explain to me again, please
 

You're batting a thousand on being wrong. Apparently, you haven't seen the inside of a well-developed Super Stock engine. By the way, I have several Cup engines, so please stop embarrassing yourself.

Re: Explain to me again, please
 

Don't know who you are... don't care...
I know what I've seen...
I'm not interested in getting in a pissing match on the inter web...
I have more important things to worry with...
Have a nice day...

Re: Explain to me again, please
 

I worked for a period of time for the former engine shop director for Robert Yates, Penske Racing and later on, Richard Petty. He spent lots of time sharing tidbits of the technology used in NASCAR on racing engine building. The only aspects that I see are advanced in NASCAR is the machining processes, equipment and materials used in the parts for longevity. Of course, they also spend millions on R&D and testing, and yes, we run more radical camshafts. Nevertheless, some of the qualifying engine cams have radical profiles and spent lots of hours and days doing Spintron testing, learning to control the valvetrain that is one of the main keys for making power.

As regards to camshafts, the cores are billet and treated. The camshafts are not broken in th engine. Every camshaft is broken-in by installing the cam in a specific machine the simulates the lifter contact and load, and different RPM levels and temperatures, being sprayed with engine oil during the operation. After the camshaft was broken in, then it would go into the assigned engine. The choice of hardened steel solid lifters made by either Trend, PPPC, Isky and Crower.

The other key for making power in NASCAR is sealing the engine, spending lots of time testing hone finishes and piston ring materials and configurations. All the torque plates we had in the shop, were custom made. The thickness of the torque plates mirrored the height of the actual cylinder head, with all the fasteners and hardware having the same length and diameter as the ones used in the engine. They were not the normal thickness of torque plates used by most shops, and many of the torque plates had provisions for hot honing.

There is more to building a fast engine than putting a big cam and stiffer valve springs.

Re: Explain to me again, please
 

Just talking about valve train today at shop. What was done to control valve train when using a Spintron?
Pushrod deflection, particular valve sping pressure ect.

Re: Explain to me again, please
 

Jeff,
Valvetrain behavior is affected mainly by the dynamics of the camshaft lobe and rocker arm and pushrod deflection. As a result, Spintron testing has helped with the reduction of spring pressures, the use of stiffer pushrods and many have switched from aluminum rockers arms to CNC machined/profiled steel rocker arms with Jesel shaft rockers. Like my friend Robin Wright says, the key is to control a "pissed off" valvetrain.

Re: Explain to me again, please
 

Ya know, I think readers will find (and I hope that someone will add to this or correct me) that the major issue with 21st Century Tech (and late 20th) is that (probably) 20 or 30 years ago the Government (you all remember them, the guys looking after our best interests) "forced" NHRA to start treating Tech people like employees and paying them accordingly. Until that time, many Tech people volunteered their time or were paid a token amount. When NHRA was "forced" to pay, they just cut back the number of Techs to an absolute minimum (and beyond).
OBTW, ANOTHER reason to appreciate those "old" Tech guys!

Re: Explain to me again, please
 

I for one have had, lifter problems both ceramic and steel, cast core cam failure, and an oil pan full of steel shavings from a ceramic lifter failure on a steel cam. Each time a failure occurred we lost everything but the heads, intake, rods, and sheet metal. I put eight sleeves in a block, the block broke after a few runs. So we , a bunch of smart people that have helped me, have attained a small amount of reliability with the six pack car.

The cam is factory size journals and lift

I know the other shoe will drop sooner but I hope it later.

Re: Explain to me again, please
 

What do you feel are the major contributor to these failures? I'm just curious, but have these motors always had these problems, or did they surface due to any particular enhancements?

The demand for roller lifters seems to be presented as a way to cut costs. Could the same argument be made to take a step back to simpler times?

I'm not picking. I respect you and know that you work hard.

Re: Explain to me again, please
 

I would like to see valve spring pressures for "stock" to be set at 200#'s , unless OE was more , then set at factory specs. Should remove the need for all the enhancements requested for more exotic valve train.

In my opinion , opening up the spring rule (or lack of a rule) started all this rule changing requests.

If you want a jessel , roller cam , lighter this or that , then Super Stock or comp , or? Is the Class is for You

NOT STOCK!!!

Re: Explain to me again, please
 

Darren,

The biggest contributor of failures is dissimilar materials, finishes, treatments, changes on the engine oil additives/composition and break-in process.

The camshaft lobes and lifter surfaces are high load contact areas, and although they may be considered highly polished contact areas, immersed or sprayed with oil, there is still some surface asperity or roughness and the reason why many engine blocks have enclosed camshaft tunnels and many enclose the camshaft tunnel area.

Flat tappet camshafts and flat tappet hydraulic and solid lifters, also need to have a specific taper on the lobe and lifter crown. I have seen too many aftermarket camshafts and lifters that have been ground without enough taper, preventing the lifter to rotate, especially with high pressure valve springs. Many of the ceramic flat tappet lifters that I have seen,do not have any taper on the crown, therefore, you have a very high contact area that eventually will wear, causing a catastrophic failure. When you have the proper taper, the engine will require a camshaft thrust plate or stop to control its movement. Nevertheless, when you have a thrust plate or stop, you also need to have the appropriate clearance because being too tight, will also prevent the rotation of the lifter.

Material compatibility between the camshaft and lifters is also a big source of failures and also the lack of Zinc and other oil additives are also a culprit. My preference of break in oils is Maxima or Joe Gibbs.

For roller cams, I recommend the use of a Calcium Sulfonate based grease or lubricant such as Lubriplate 130-AA Multi-Purpose Calcium Type Grease. Calcium Sulfonate based grease is designed for high contact areas and I apply it to the roller camshaft lobes only.

Re: Explain to me again, please
 

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.

I have offset lifters on my modified engine to try to compensate for the difference in width between the lifters and the rocker arms. They are top-shelf lifters but even with 50 passes on them, you can see the wear pattern from the pressure bias.

The fix is to machine the block so the lifter bores align with the rockers, side to side. That way the pushrods will be straight without using offset lifters. With the splayed head, the bore angles also need to be changed front to back to remove the angularity caused by the valve/rocker placement.

The lifter bores for my application need to look like a standard BBC.

Re: Explain to me again, please
 

I'm not sure which changes you would be referring to, but both of the combinations that Todd has built throughout the past 20+ years have not been given a great deal of the "enhancements" that combinations in the same classes have been given. Ok, maybe the 12 bolt rear in place of a 10 bolt is one, but I can't imagine that rule change having a similar reaction than allowing anyone to run a roller lifter in there engine.

Re: Explain to me again, please
 

Ceramic lifters failure seems to start the snowball rolling for engine destruction. We brake the cam in on a fixture, run it on a dyno, race it with break in oil and then the ceramic lets go and it’s back to square one.

Re: Explain to me again, please
 

Despite the disagreements of the subject matter this discussion of Valvetrain Geometry and how it legally applies to the rules of Stock Eliminator is fascinating.

Re: Explain to me again, please
 

My understanding is the cam lobe does have a taper. The lifter bottom has a radius to it. The size of the radius depends on how the cam lobe has been ground. I believe from the factory Ford has uses a different size radius on their lifter bottom than GM does.

Stan

Re: Explain to me again, please
 

My bad. You are correct Stan.
The lobe taper has a taper across the face and the lifter faces are ground spherically with a crown in the center. Also, when the camshaft and lifters are installed, the lifters are offset by a small amount from the cam lobes.

Re: Explain to me again, please
 

Ceramic materials were never intended for the dynamics and type of surface contact of a camshaft lobe and lifter crown. Ceramics are polycrystalline materials joined together, in layman terms, all ceramics are multiple crystals joined and formed together.

Although they are used in high impact applications such as ballistic armor, ceramics are brittle and have poor impact strength. When ceramics are used as ballistic armor, they are also surrounded by or encased in Kevlar material and replaced after receiving an impact.

Re: Explain to me again, please
 

Never should have been allowed in Stock in the first place.. Remember, about the same time..We've got to stop the use of "space age " materials in PRO STOCK !

Re: Explain to me again, please
 

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

Re: Explain to me again, please
 

We changed to solids in the LT1 car because the hydraulics we're getting tired. Went from 10-30 to 5-30 and had rockers coming loose. Car is no faster with solids... however..if we ever get it to the point we can win a heads up race. A zero weight will probably work a little better with solids.

Re: Explain to me again, please
 

Concerning cam and lifter wear issues with flat tappet cams, I was looking at my old Isky Cams catalog, and they offered some special "Hardface overlay" application on the lobes, which were meant to be used with their "Chilled Iron" flat tappet lifters. My catalog is from the 80s, so no idea if Isky still offers this stuff, but curious if anybody has any experience with these, in either a Stocker type engine, or anything else.

Re: Explain to me again, please
 

Rory,
Some NASCAR teams ran the Isky solids with the hard face overlay.

Also, although not mentioned often, Crower makes some great solid lifters with lots of options, including lightweight and billet steel lifters.

Re: Explain to me again, please
 

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. .

Re: Explain to me again, please
 

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!

Re: Explain to me again, please
 

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


Stan

Re: Explain to me again, please
 

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.

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

Re: Explain to me again, please
 

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

Re: Explain to me again, please
 

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 !

Re: Explain to me again, please
 

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

Re: Explain to me again, please
 

......

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!

Re: Explain to me again, please
 

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.