https://forums.maxperformanceinc.com...d.php?t=855698

I had a Rhoads lifters failure.

Roller in now

Yeah Bill but you also found springs that only had 80 lbs. on the seats. I wouldn't call that a cam and lifter failure, that was just the result.

What likely happened, and I posted in your thread about this, because I tore down a pontiac engine with a similar issue that had the same spring pressures you found, is those weak springs were causing all kinds of ugly harmonics, valve seat bouncing and not really controlling things well at all. Couple that with what ever lash you dialed in with the lifters there would have been all kinds of lifter bounce and other weird things going on. Not good for camshaft life at all and will eventually cause wear and tear.
The engine I tore down only had a few thousand miles on it which is basically nothing, and it was already eating at the retainers and locks pretty severely as the springs rotated under the retainers. That's just the first sign of springs not doing their job and it leads to other issues that eventually turn catastrophic. You're lucky it was just a cam that went flat and not a dropped valve.

Unfortunately that thread was closed over some chest beating before you really got any chance to explain much more and possibly put a lid on it. Well maybe I shouldn't say that, after all the thread was 2 years old before all that got out of hand but that part is pretty damn funny though LOL

What are you building?

A 1968 400 YC engine with a little over 40k original miles. I’m replacing the cam, lifters, valve springs, timing chain & oil pump. The stock 15 heads have pressed in studs so probably an 068 cam.

I agree with you that is most likely the assignable root cause of my cam/lifter excessive wear.
I definitely searched out and found a very reputable engine builder to go through my heads and setup the valve spring pressure for my roller cam.

I wonder how many cam / lifter failure were the results of weak / improper setup springs ? Usually the blame goes to the wrong oil and break in process.
My springs did not have many miles, but I understand the concept of fatigue and thermal cycle impact.

That's a good question Bill. I would say likely a lot more than we hear about as most of these threads go unresolved or people are reluctant to admit any fault and blame the cam and/or lifters. Typically there is a root cause and yes sometimes lifters and cams can have issues, but I think that number is skewed a bit when it comes to the internet.

That's a good question Bill. I would say likely a lot more than we hear about as most of these threads go unresolved or people are reluctant to admit any fault and blame the cam and/or lifters. Typically there is a root cause and yes sometimes lifters and cams can have issues, but I think that number is skewed a bit when it comes to the internet.

You're one of the few that actually posted other issues with the engine that were likely the cause and I thank you for being honest.

Spring surge and improper distance from coil bind can also be a factor on some occasions.


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Interesting videos....

https://www.youtube.com/watch?v=adYrRk22GDQ

https://www.youtube.com/watch?v=cfGg15WgSEU

"A valvespring sees two times the stress of a connecting rod, the next mostly highly stressed engine part."

Billy Godbold, Comp Cams


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I tend to think your failure was from something else. I recall 20 plus years ago I helped friends put SPC-8s in two different engines that both had completely stock original valve springs. Lots of trouble with the valve floating, and no cam trouble. A couple other non Pontiac engines I worked on were terribly abused, when I took them apart you could see abuse everywhere on the valve terrain and nicks on the pistons from the valves hitting them, but the cam’s were fine. I would think any of those could have had bad enough harmonics to get back to damage the cam, but none did. I can definitely visualize issues with harmonics creating cam trouble, but on the other hand, it is a mild HFT cam, just turns half of engine speed, and it likely is not real easy to get bad harmonics down that far with both the Hyd lifters and the rockers softening the harmonics from where it starts at the valves. But who knows, bad valve float is never good.

540RAT’s oil testing does nothing to replicate how a lifter scrubs itself over a cam lobe. My guess is you had two things happen, 2 lifters were not machined all that well, requiring more of the oil, and the oil ended up not doing it’s job. Instead of the lifter scrubbing over the lobe it slid it over the lobe. Eventually the taper was gone and the lifter quite spinning. My guess is those 2 lifters had a problem with the finish, and oil with more zddp wouldn’t have hurt, it would have helped. Quaker State 5w30 synthetic is a decent oil, outstanding for some things, but it is also known to have a fairly weak detergent package for some applications. It doesn’t seem to hold on to it’s Viscosity very well with extra use. I don’t think you can totally rule oil as not being one of the causes.

It seems like there are about seven different issues that cause failures with flat tappet cams, which is worse than ever…it is getting harder and harder to not get hit by one of them. With that in mind, and Vmax lifters now over $300, it doesn’t seem like a bad time to go roller.

I don’t think Rhoad’s or HLJ are immune to trouble right now. But either can be successful yet, I set up a Vmax lifters that had the superlube option for a friends 455 and a 60919 cam that has over 20K mile on it now. I know it has been past valve float several times. It just got refreshed and put in a different car. All the bearings were trashed, so they were replaced, but the cam looked like new and is still in it, operating again. The superlube option should extend service life, but if there is machining or lubrication problem the super lube option is not going to make much difference. All you can do is to try to stack your odds and run the best parts available.

I probably wouldn’t have thought to mention the info in my last post. Except our most recent engine project here was replacing a bone stock flat tappet cam on an engine that lost two intake lobes and the rest of the cam looked fine. I don’t know the engines full history, but it sure appeared like it could trace back to something similar, it was industrial engine that spends most of it’s life at 2000 RPM.

It’s because Pontiac racers use their brains first and their wallets second. Chevy guys just call summit and say what’s the flavor of the week send it over

Yeah Jay, oil is always a weird subject with people. Someone on the internet always says this or that is better yet almost no one even sends off a sample to see what their oil is doing.

I will say this, plenty of oil testing done with very expensive equipment that has shown too little and too much zddp can be harmful. What's the right amount? Only an oil analysis will tell you what your engine likes.
The other thing to watch for is the lighter weight oils. Another weird subject with people that isn't cut and dry. Everyone wants a lightweight oil but you have to be careful as the API ratings don't allow as much zddp in these 5-30 and 10-30 oils. Some have more than others but the API puts a cap on the amount allowed in the light weight oils, some dont even have 700 ppm. Not to mention the zddp today is different than it was just 15 years ago as several regulations were passed to make it more compliant with cat converters, but that's another subject.

How much do you want? Again you need an oil analysis to tell you that, every engine is a bit different.

Not sure if anyone really answered your orginal question. They are still in business, none of the speed shops stock them. Order from Rhoads direct, they will ship in a few days.

https://rhoadslifters.com/Shop/

Ran Rhodes lifters years ago in a 400 at the suggestion of Ken Crocie and Nunzi. They worked great.

If Rhodes lifters have been proven to be bulletproof. And so many are having troubles with hft cams.
THERE is your answer.
Just but a cam a little bigger than you need and run some Rhodes.
Besides, its a PONTIAC and we like our cams BIG.

This is something that I’m considering personally since I’m concerned about installing a HFT cam in the engine I have on a stand currently

They are available and are for the cam that you want, but that cam iss 10-15 degrees bigger than you think you should buy. The Rhoads are magic in my opinion. I put them in everything I can. Including the rollers. Even put a set of rollers in a 393 stroker 318 Mopar recently. The sound is similar to a perfectly lashed solid cam. I know they go to 7100rpm with enough spring. Buy the cam that is "too big" install the Rhoads and enjoy. BTW the Pontiac community is a fraction of total Rhoads sales.