[NeighborsComplaint]

Originally Posted by HWYSTR455

It certainly was caused by some type of bind in the valve train, and would have to say it was something overlooked by the builder. Rockers or not.

Let's see pics of the top of the valves and the springs on that cyl.

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X2 Underside of the rockers also.

[64speed]

Originally Posted by HWYSTR455

It certainly was caused by some type of bind in the valve train, and would have to say it was something overlooked by the builder. Rockers or not.

Let's see pics of the top of the valves and the springs on that cyl.

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I will take pics when I can but I promise you nothing looks amiss. It’s not Wayne’s fault it’s mine. I don’t think y’all realize how damn high I revved this thing.

[geeteeohguy]

Originally Posted by 64speed

I will take pics when I can but I promise you nothing looks amiss. It’s not Wayne’s fault it’s mine. I don’t think y’all realize how damn high I revved this thing.

When I was getting into GTO's in the '70's, most of the stick shift cars had replacement engines already at 10 years old or so. I ruined a 428 by over-revving and three of my friends blew up 389's by over-revving. The problem was, and is, is that a Pontiac will rev up like a small block Chevy, but won't handle it as well.
We didn't have rev limiters then. I still don't use one, but I drive like an old man now.
Rev-limiters are a VERY good idea when operating VERY EXPENSIVE equipment.

30+years ago I revved the 400 in my '67 so high that the lifters pumped up and I lost compression in several cylinders. Revved to the moon. I parked the car that night, thinking the worst, but when I started it up in the morning to begin my 51 mile drive to work, all was fine and they had bled down again. That engine, cam, and lifters is still in my '67 today, working fine. I got lucky, but also, USA made parts are good parts.

[Gach]

Don’t beat yourself up. Looking back at your pictures and seeing that roller lifter damaged. I now think the lifter went away, I doubt over reving had anything to do with it. Even though it says Lunati it’s made by Morel. Both have know issues. Didn’t see the damage on other roller lifter on the adjacent lobe. Which is no fault of engine builder. A good explanation, when the cam on base circle and moving up the ramp that lifter wants to turn the tie bar prevents that from happening. My guess is it started to bind and took out the lifter, so could be a combination of both weak lifter bore and lifter going bad. It’s hard to diagnose from those pictures but I’d like to see picture of the adjacent lifter. If your up to it. I’m guessing it’s the luck of the draw on weather or not you get a good set.

[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.

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[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.


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[64speed]

Just mailed a 200 deposit on a 455 block

[HWYSTR455]

Post pics of the tops of the valves/springs and the underside of the rockers.


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[Gach]

Originally Posted by 64speed

Just mailed a 200 deposit on a 455 block

That’s good news

[64speed]

I’m on the fence on what to do from here. To be totally honest that engine had great street manners but it was too much for a daily driver. I don’t think the BBC rockers had anything to do with it.I just looked the others and they still have perfect contact patterns. I don’t know if I will use this cam grind again. It’s a little much. Whatever I do it’ll have MSD

[geeteeohguy]

Originally Posted by 64speed

I’m on the fence on what to do from here. To be totally honest that engine had great street manners but it was too much for a daily driver. I don’t think the BBC rockers had anything to do with it.I just looked the others and they still have perfect contact patterns. I don’t know if I will use this cam grind again. It’s a little much. Whatever I do it’ll have MSD

Very sorry to see this. If it wasn't for bad luck, I think you sometimes would have no luck at all.

As a crotchety older guy, I prefer building my engines as drivers, not racers. I use factory parts and go pretty mild. So far so good....the 389 in my '65 is running strong 41 years after the rebuild and still leak free (plenty of seeps!) and the 400 in my '67 has about 90,000 miles on the rebuild I did for less than 2k 34 years ago. Still does not use oil, runs great. O68 cam, USA lifters, Forged pistons, iron Pontiac heads. Just get in and drive, no drama. These things get expensive and frustrating when you tweak them for as much power as you can get. You need to ask yourself if it's really practical.

[64speed]

No, going down there Monday, not his fault

[Lemans64]

Well that really sucks, I thought maybe you lost a camshaft to cause this, but this is crazy.
Sorry to hear about this.

[tom s]

Hyd rollers usually don’t cause lifter bore failure.Just not enough spring pressure.I suspect something broke and might have got caught and jammed the lifter in someway?Tom

[Gach]

64 speed. I’m on the fence on what to do from here. To be totally honest that engine had great street manners but it was too much for a daily driver.

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That’s reason I was asking for cam spec’s

[Gach]

I’m just saying it’s a good possibility that the very front lifter bore which just hangs out in mid air, was weak or my of had a hair line crack, that wasn’t detected. It finally let go taking the adjacent one out also. No fault of the builder or cam. Seen this in more then a few times. In that case not even installing lifter bored brace could prevent it.

[64speed]

Wayne has another block he is pretty sure. If so I will be transferring all useable parts and rocking on in a few months

[Gach]

Originally Posted by 64speed

Wayne has another block he is pretty sure. If so I will be transferring all useable parts and rocking on in a few months

Nice! Glad to hear you haven’t given up.

[64speed]

Well I have the heads and the forged rotating assembly. The cam is screwed. Paul Carter picked that cam specifically for my gear,trans,tire height, it was perfect….but it was rowdy. I think a rev limiter and this never would have happened unless it’s was a crack that would have eventually failed regardless. The car is/was outstanding and will be again. Isky is fixing the cam and Wayne will do his thing. Good thing we are friends and I can make payments