Flat tappet lifter failure

[Terry Cain]

Originally Posted by bubski

Bubski is thinking like OK let's go roller for all !! Since this is "stock" wouldn't it be in the best interest of the rules to stay "stock" ??? So !! Ffford n Chevy "stock" rollers have a .700 lifter wheel diameter !! Every aftermarket roller is .750,.760 not really "stock" where you're supposed to abide by the "stock" rules !! Such as lifter diameter which is enforced but cam bearing diameter is a gray area !! Let's get even more into it !! .250-.280 lobes are not in every cam companies master list !! But Bubski's sure for a few bucks more they'll make a few concessions !! Sooo !! Now you can have a universal roller cam rule and make everyone with a roller go to stock roller diameters and spend some more cash on a set of lifters that are now legal !! However Bubski doesn't know of any race lifters at stock roller wheel dimensions !! However Bubski is sure a few will step up to the "cause" and kindly beat YOU over the head with a "stock" diameter roller lifter and accompanying valve train package !! Maybe it's time to break out the "lifter tru" and reevaluate your camshaft and valve spring choice !! SS has unlimited cam lift and the like !! Show Bubski a 305 with 1.250 lift !! It's not feasible and a BBC with an unrealistic camshaft is also unfeasible !! Sometimes you gotta work within the parameters you're given !! Cheers !!

Damn, I thought stock DID have a lift rule. That's why this stocker has .460/.480 lift. Wish I could and (I'm sure others do too) rule more lift. Good point on roller diameter as I'm sure all the later model stockers with rollers (and others) are aware of it.

[Stan Weiss]

OK the spring pressure needed is a result of lobe profile (yes there are also some other factors). Do all brands have this same problem to the same degree, or is it more a function of lifter diameter? The larger the lifter diameter the greater the max velocity the lobe profile can have. If this is the case then MoPars would have less problems than GM with Ford in the middle.

Stan

[Dwight Southerland]

Originally Posted by Stan Weiss

Isn't the class you are running called "Stock". So if manufacture "F" used a better valve spring than manufacture "G". That might have bin a reason to maybe run manufacture "F" engine. At some point it seems people who run manufacture "G" felt entitled to be able to run manufacture "F" type springs. Before you ask, no I don't run a car in stock and have not for over 45 years.



Stan

Yeah, well, there will always be somebody who figures out something to whine about the competitors having an advantage. That's what started this thread.

Doesn't that all get worked out in AHFS and HP factors? That is the assumption with all rules changes that affect engine performance.

The main reason they don't check valve spring any longer is that it takes too long, the expense of the tech staff, the risk of being sued, and the expense of equipment. So the racer is paying for the decision again, and it still is not "fair" for everybody.

[Terry Cain]

Originally Posted by Dwight Southerland

Doesn't that all get worked out in AHFS and HP factors? That is the assumption with all rules changes that affect engine performance.

ASSUME. Dwight, I'm sure you know how to break that down.
AHFS doesn't work.

[Alan Roehrich]

Roller cams will not solve the problem, and will not make it cheaper. It will only make it more expensive, change the failure mode, and cause more problems. It will create another R&D expense. It won't make anyone any faster, except maybe someone who has unlimited funds to invest in camshaft and valvetrain testing.Roller cams will simply cause more problems, and make nothing cheaper.


What will people cry about tearing up next? What rule change will they demand? How much will it cost?


Where will it stop?

[john ancona]

Originally Posted by Alan Roehrich

Roller cams will not solve the problem, and will not make it cheaper. It will only make it more expensive, change the failure mode, and cause more problems. It will create another R&D expense. It won't make anyone any faster, except maybe someone who has unlimited funds to invest in camshaft and valvetrain testing.Roller cams will simply cause more problems, and make nothing cheaper.


What will people cry about tearing up next? What rule change will they demand? How much will it cost?


Where will it stop?

All this type of unfounded information ,that is just flat wrong again ,and again is not welcome by many ,simply put we are already using billet camshafts ground for solid lifters, that are DLC coated in order to run valve spring pressures well above the limits of a solid lifter at what is already what many say on this site as expensive , so maybe the uninformed may want to go do some of there own research as to the cost before they make false statements , I have said this before many times on this site since 1985 car manufactures have went to roller cams , and before all you opinionated racers express your own views telling others to run a car with roller lifters from the factory ,you may be better served by understanding there is a reason as to why many like running the older cars

[Billy Nees]

Originally Posted by john ancona

All this type of unfounded information ,that is just flat wrong again ,and again is not welcome by many

you may be better served by understanding there is a reason as to why many like running the older cars

Now there's some real funny s**t right there!
I'm quite sure that Dwight and Alan are very well aware of the cost of running flat tappets vs. rollers.
YOU may be better served by understanding there IS a reason as to why many like running older cars that came equipped with flat tappet cams in an Eliminator called STOCK!

[Billy Nees]

Ya know, you can just never have enough "roller cams for the masses" discussions!
Deja Vu?

https://classracer.com/classforum/sh...ad.php?t=60886

[Alan Roehrich]

Originally Posted by john ancona

All this type of unfounded information ,that is just flat wrong again ,and again is not welcome by many ,simply put we are already using billet camshafts ground for solid lifters, that are DLC coated in order to run valve spring pressures well above the limits of a solid lifter at what is already what many say on this site as expensive , so maybe the uninformed may want to go do some of there own research as to the cost before they make false statements , I have said this before many times on this site since 1985 car manufactures have went to roller cams , and before all you opinionated racers express your own views telling others to run a car with roller lifters from the factory ,you may be better served by understanding there is a reason as to why many like running the older cars

Really?


And you have how many class wins with your big block Stock Eliminator engines? Because I have more than 1-2.


Oh, and I have a 9500 RPM+ 396-375 Super Stock engine as well.


Maybe YOU can't make a flat tappet Stock Eliminator engine run. That does not mean the rest of us can't. There are a ton of VERY fast big block Chevy stockers out there running flat tappet cams and having zero problems. Maybe you should ask yourself why YOU can't.

[john ancona]

Originally Posted by Alan Roehrich

Really?


And you have how many class wins with your big block Stock Eliminator engines? Because I have more than 1-2.


Oh, and I have a 9500 RPM+ 396-375 Super Stock engine as well.


Maybe YOU can't make a flat tappet Stock Eliminator engine run. That does not mean the rest of us can't. There are a ton of VERY fast big block Chevy stockers out there running flat tappet cams and having zero problems. Maybe you should ask yourself why YOU can't.

Maybe you ,and others would have some creditably if you replied with facts rather to what YOU wrote that is flat wrong , maybe you should check your facts as to if I can make a flat tappet run in stock with zero problems ,I have had not one problem in well over a dozen years running my 396 375 hp in stock @ 8200