When all eight cracked, were the bores factory? Studs? What type of nitrous setup? And how much total timing?
Piston Poll:
- Thread starter McRat
- Start date
Same main bolts too or are they studs? Reason I ask is because I used my stock main bolts.
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What the heck are you doing? Holey crap!
Either you are the most unluckiest guy here or others aren't talking about their failures.
The 4 stock pistons was at one time and the 8 mahle
Pistons was one time. Each set had over 300 1/4 mile passes
Not to sure. The stock pistons only had 10/15 nitrous passes. The mahles maybe 30.
Built motor 40 over bore. Head studs main studs and a cam. Block is half filled.
200 shot on a stock turbo with stock injectors 3000 pulse 32 degrees timing. Switched to 100 overs duel pumps and a S475 and put a whole in one piston and cracked the other 7. 2300 pulse 25 degrees timing.
The reason I ask is because there has been a trend in cracked and melted pistons vs. tight ptw clearance. it isnt dependent on just clearance, but also cylinder pressure, heat soak, and im sure casting flaws can't be ruled out either
My PTW clearance was not tight at all. I ruled it as shitty mahle pistons :roflmao:
I know of a truck lived at 800 HP for a few years, added nitrous and a bigger charger and probably would go 1000+ then. After the nitrous and charger upgrade and about 30-40 1/4 mile passes it cracked a piston. Upon tare down one piston was cracked all the way across and the other seven had small cracks where the valve reliefs and the bowl meet. These were cut and coated LB7's. My truck has been about 160k miles at 500 HP and 30k miles at around 600HP stock LBZ block and so far so good. Probably about 250 1/4 passes.
I've had other issues but no piston failures in 4 of my motors. 3 had stock pistons in different configurations and now I'm running performance cast
You atleast got new main bolts right ? Nothing wrong with running them same as Jeff said with his motor having stock bolts that's all I used in my build. My motor has SoCal cut and coated pistons, Crower rods stock cam stock heads build has 4 years on it now and 72k all but the last year and half was on the tune that ran 11.53. That was not the best tune but worked just had me into 6th at the 1/8 7.35 and lugged the Gt4202R to start pulling at the timing tower. Truck was on 4 M&H's dots and around 6,780 so Guess power was around 700 area Tune I'm running now is a Idahorob tune around 580 to 600 with the twins. Going to have Tony do tune for it and see what she will do with the twins.
Nope my stock bolts. I bought new oem bolts to use but the engine builder never saw them in the box. He said he wasn't gonna pull the bolts out and use the new ones after I told him about it. He said they will be fine, I trust him. I would have liked new ones but owell he's built some strong motors. And he knows what he's doing.
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cracked the skirts on 4 stock pistons, all the same bank. stock engine, bigger turbo. 600hp 80k ish.
They are, so are a lot of other bolts people reuse
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