[HWYSTR455]

Too many misconceptions regarding over-revving, it's basically folk lore.

First, 'back in the day', when you heard people 'over-revved an blew up an engine', was due to cast cranks, rods, and pistons. The engine in question is not a stock engine.

A lifter pumping up doesn't destroy an engine, period. If that were the case, what about solid lifters?

Generally, over-revving causes valve float. There are other factors, such as weak spring etc, but valve float, worst that can happen is a piston contacts a valve. If that happens, it bends the valve stem and/or the pushrod. That's it. It would take a lot more to break off the lifter bores.

Think about it, the valve goes into the chamber at an angle, the piston would hit the edge of the valve, the valve would take the hit, not the block. A valve bends before the lifter bore breaks.

If it's a cheap 2-piece valve, the valve head can come off. If that happens, it falls into the cyl and beats the head/piston causing damage, maybe block damage, but not the lifter bores.

If a valve bent, it wouldn't close all the way, and you would be able to tell by the spring not being at the same height as the rest.

MAYBE the block already had a weakness, but that would usually get picked up in a sonic or magnaflux check.

MAYBE the piston to valve clearance was close, and the valve/lifter floated, which could have struck the piston. But then again, it would bend the valve, not break the lifter bore.

The ball broke off the pushrod, that takes considerable force. It's more likely there was critical bind in the valve train, which caused that, and if the valve isn't bent, the bind happened before the tip of the rocker on the spring side.

You go to your builder and tell him it was your fault because you over-revved the engine, he's going to leave you believe that, and you will be responsible for repair. (And him off the hook of responsibility)

My guess: Incorrect rocker geometry caused bind, due to using the incorrect rocker.

As another posted suggested, a pic of the rocker underside will show a witness mark.

.

[Gach]

Could very well be, not being there to see and assess the damage in person like also head being off to check valves and rockers makes the diagnose kind of hard. But I’m sure the advice helps him and makes him think.

[HWYSTR455]

Post 1232 shows the bar still on both lifters.

.

[Gach]

Yeah I notice that but look at the bottom of the lifter, looks like wheel completely gone. But doesn’t change your assessment of what might be.

[grivera]

Excellent points Mike - as has been stated in the past, the BB Chevy rocker is suspect as the geometry could be jacked up and the 7K rpm helped it be known. I still don’t understand why that was used when there are off the shelf quality Pontiac rockers. I wouldn’t be so quick to blame the high RPM as cause of the carnage.

[64speed]

Across from each other. You gotta remember my car is LOUD. After the rev disaster I did not immediately hear anything so I coasted the roughly 500 yards to my house all the while those lifters beating the hell out of their bores. I thought I was fine because I had good oil pressure….for a little bit.

[tom s]

I have never read about lifters loosing a wheel let alone more than one with so few of miles.JMHO,my engine would not be going back to that builder.Tom

[Gach]

My opinion lifter failure, most likely took out weak lifter bores. Them baby’s were trying to turn which put a tremendous amount of pressure on lifter bores.

[Gach]

Tom if I remember right a while back he mention having a couple of noisy lifters.

[Gach]

Tom, there’s a chit load of hydraulic roller lifters that have lost wheels. There’s been two other pictures posted of different failures.

[tom s]

Yes Lou but have not seen any with virtually no miles on them!Unless a error on assm.Tom

[Gach]

My brothers made a few miles, I’ll bet less then 15 and I know for a fact it had nothing to do with valve train.

[Sirrotica]

FWIW, back in 1970 I was working at a Pontiac dealership in my final quarter of my senior year on COOP. There was a RA IV block that had been changed under warranty sitting in the warranty parts pile that also had one broken lifter bore same as the OPs block. Now that was with a .520 lift at the valve camshaft with 1.65 rockers. and of course a hydraulic flat tappet cam and lifter.

It's always been a weak point in Pontiacs engine design, accentuated by quick ramps, and high lift cams. I've run my share of both solid, and hydraulic, flat tappet, and solid roller cams, without any lifter braces, and been lucky that I never had a lifter bore break. But as I said, saw a bone stock RA IV break out the bore.

Being both bores broke with the same pair of lifters, my guess was they turned sideways because of link bar failures. 2 bores breaking on the same pair of lifters is too much of a coincidence. That coincidentally is the first time I have seen 2 adjacent bores fail in a Pontiac at the same time.

Assessing blame is going to be tough sledding, No one is going to step up and take all the blame, and liability that goes with it, too much money is involved.

In this type of situation there is plenty of blame to go around, but everyone has pulled their shoulders in as close as they can.......

The primary reason so many high performance engine shops get reputations is they don't get rich doing the work, and there is a ton of liability involved.

Example: a 410 sprint car engine can easily be $50,000, they do fail, and when they do there is likely not much salvageable. It's a cost of running a 410 cubic inch engine on methanol to the ragged edge, best parts, best builders but nearly 2.5 HP per inch, and they do go south. No bitching about what failed, they get a new one, and go on.

On someone's own car that they invested their own money into, they can't finance engine after engine out of their own pocket, so they want someone to stand behind the parts, and labor, there isn't enough money being made to warranty a piece that you know is going to get thrashed, and you have no control over it after it leaves your shop.

On another example of another RA IV. I set the tune up on it, the car was sold to a new owner, and he had someone work on it from a Fiske auto store, affiliated with K Mart. The guy thought that he heard a lifter tick, turns out it was a header leak. That didn't stop the inexperienced fool from tightening the intake valve down, over, and over, until he ran the valve into the piston, breaking the valve head off and punching a hole through the piston. It scored the cylinder too. Oh yeah, I got a call because I set the engine up, but I had no fault in the demise of that engine whatsoever. I probably got $75 to set that engine up after they got it fired up, but I could have been in line for the whole boat without some good detective work. The reason many shy away from high performance engine work.

If you never heard of Ron Hutter, he lives up in the northern part of Ohio (Chardon), and has been a premier engine builder for many Busch cars and drag cars, as well as late model stock cars. Has his own engine dyno, flow bench, been doing it for decades, very good reputation. A friend of mine bought a high dollar SBC for his late model stock car, put the engine in, and his crew forgot to put water in the engine. You can surmise what happened. The guy wants Ron Hutter to repair the engine ASAP, as it's during the race season.

Ron Hitter tells him that he won't do any more work for him, period. The guy says why is that? Hutter tells him you made me look bad in front of a lot of my customers, and I can't afford a bad reputation.

If the car runs good, and for a long time, you're a hero, if it ends up in a pile of broken parts you're a zero. Lots of times it was out of my control, and months later, never stops someone from pointing a finger at you.

[Gach]

Look at this picture the wheel came off, my guess it was putting pressure on tie bar, but look at the lifter bore it’s attached to, that lifter bore isn’t hanging out in mid air. At first I thought tie bar had let go. Hey I could be wrong but I’m betting not

[64speed]

I’m just glad Isky can save the cam because that is an awesome grind.

[Gach]

Yes it is makes good power.

[Tom Vaught]

Sorry to read about your Engine Failure. Hang in there.

Tom V.

[NeighborsComplaint]

Check out the brand new pushrods. I spy a clearance issue in the heads from the rockers too.

[HWYSTR455]

Wow, I didn't catch before that it was multiple lifters that the wheels came off. I would accept maybe one or two lifter failures, but a handful really makes me think it was a clearance issue.


.

[64speed]

Just mailed a 200 deposit on a 455 block