S475 TCT single
- Thread starter zf>allison
- Start date
The same thing happen to me on an engine I bought, but it knocked a hole in the water jacket. The guy that orginaly pulled it out of the truck said it ran fine. 
I don't know how it didn't finish blowing out the block.
I don't know how it didn't finish blowing out the block.
The same thing happen to me on an engine I bought, but it knocked a hole in the water jacket. The guy that orginaly pulled it out of the truck said it ran fine.
Well like I said I wasn't nailing it when this let go. I had just put it in third gear and was coming back on the throttle. No where near the rpm that turbo was spooling at with exhaust leaks. But u would still think it would have flung the rest of the way apart i guess the wrist pin still being on there kept the rod from going as far sideways, held it straighter anyway. Makes me never want to buy a "ran when pulled engine"
We just fixed a truck that did the same thing as yours, had head gaskets done and the bridge between the two valves was not on all the way on one valve. Ran for several thousand miles till the keepers came off and valve dropped!
Mine were on, i was pretty strict on putting the valve bridges on and adjusting the valves. As a guy I know slapped his back together without even adjusting the valves and it would make a weird almost underwater sound. But he fixed it before he drove it. I am thinking I floated the valves, but I want to pull the driver head tomorrow and check that side out before I make to many assumptions.
Got the driver head off. Every piston in the engine but one had at least one valve tap groove. Some worse than others. I think she floated the valves.
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What was your rev limiter and when did you shift? I flogged the guts out of my zf/lb7. I can't remember if it was limited at 4200 or 4400 rpm but it saw the limiter frequently. Mine was stock air/fuel though.
I'll have to ask tony what it was set at. I know it was higher than 4200. That's what duramax tuner had it set at. It might have been high. I never intentionally over revved it but it broke loose a few times and rapped up pretty fast and I let out of it.
Crank pin is fine. Haven't checked the cam. If that happend would it have started and ran to load in on the trailer?
Well the balancer pin was good haven't checked the gear pins l, I guess that's what would count?
I'm not 100% sire if it would run but if all the valves smacked pistons it seems more like it would be a cam or crank pin. I can't see all the valves floating. I had my truck to 4600 rpm with 60#'s boost multiple times when I was having trans problems and never floated them.
Well it didn't hit every valve. And some were intakes and some were exhausts. And one piston wasn't hit. And I ran it to load it on a trailer if it jumped time by bending a pin or shearing one I think it would have hit every single valve.
Wow. Sucks to hear! That is some serious damage!
I totally called this. Post #168. Do i get a prize?
I totally called this. Post #168. Do i get a prize?
you made me do the same thing. Im sorry to hear this happened if it were my truck I would be tempted to light the whole damn thing.
Im very surprised it even attempted to turn over thats just unreal. But thats the reason we own these things. Dropped a valve f it, it'll run. I have dropped valves in many race quads due to valve seats coming out. Last one happened after sending the head off to get new seats put in. In fact completely rebuilt motor. This is also the reason I will never buy stainless valves ever again. First race dropped the seat and grenaded the head. It was a nightmare like this must be.
Anyways, what are your plans? I know you have some kind of idea going through your head.
Im very surprised it even attempted to turn over thats just unreal. But thats the reason we own these things. Dropped a valve f it, it'll run. I have dropped valves in many race quads due to valve seats coming out. Last one happened after sending the head off to get new seats put in. In fact completely rebuilt motor. This is also the reason I will never buy stainless valves ever again. First race dropped the seat and grenaded the head. It was a nightmare like this must be.
Anyways, what are your plans? I know you have some kind of idea going through your head.
GMC_2002_Dmax
The Still Master
Each tune has the "Throttle Table" set to a different RPM, your three smallest tunes are limited to 4K rpms, the two bigger tunes go to 4200 rpms and that is the ecm REV LIMITER setting.
I would guess weak springs or incorrect spring height, revving it to 4200 would not be an issue IMHO.
I would probably bet that a valve dropped as others have suggested, the tuning you have I ran in my LB7 from 2005-2014 when I sold the truck.
It sucks when stuff breaks.........
Each tune has the "Throttle Table" set to a different RPM, your three smallest tunes are limited to 4K rpms, the two bigger tunes go to 4200 rpms and that is the ecm REV LIMITER setting.
I would guess weak springs or incorrect spring height, revving it to 4200 would not be an issue IMHO.
I would probably bet that a valve dropped as others have suggested, the tuning you have I ran in my LB7 from 2005-2014 when I sold the truck.
It sucks when stuff breaks.........
Hm. I'm pretty damn sure I've looked down and it's been close to 5k. Not at it but close cuz I made this face
would something that was failing let if rev higher than that?