Well, killed #7. Engine developed major crank case pressure, even at idle. Did a leak down, 90% on 7. All he plugs looked perfect, even 7, no metal or funny color. I will assume it has a broken ring land as the rear steam vents are blocked, although seems odd to have no signs of damage on the plug. Have to pull the motor to get the head off sadly. I plan to pull it out tomorrow, until then I'm hoping for the best.

99 LS1
Stock rebuilt bottom end with 15k
Eaton m112 blower
Alkycotrol injection

 

probably gunna see this

 

Do you have an intercooler under that eaton?

 

no, it does have a fuel rail under it with meth nozzles though. An intercooler would not fit using the stock hood.

 

in it for carnage pics! hey denmah? was that a 5.3 piston out of the notch stang with the 88?

 

Throw a 5.3 in there and let it rip again.

 

That's a 4.8 piston

 

What plug were you running, fuel, timing etc.?

 

pump gas?

 

Tr6 plugs @ .028
AFR's at 11.2-11.4
not sure on timing as I had it dyno tuned and never looked at it.

93 pump gas

Pulled the motor last night




Pulled the head at lunch today, cyl and piston look perfect. will pull the oil pan tomorrow and pull the piston out. Maybe a broke ring?

 

Next one you build run a non-projected tip plug in it at least.

Also verify the timing.

 

Probably crushed the ring land. Open the gap on the top rings to. 028" or there abouts when you go back together. It'll help it live. And get the rear steam ports working again.

 

Cyl is perfect. Its a good day.

 

Wow you got lucky.

 

I'm glad to see this. Both because it always sucks to have something break. And secondly because I was throwing around the idea of putting an Eaton blower from a Ford on my 5.3 and found you manifold thread today when I was researching it.

 

This is from #7 on an LS2 GTO engine with a rear mount turbo.
https://ls1tech.com/forums/forced-in...-piston-6.html

Looks like the rings butted/expanded and crunched the piston groove cracking it. Only had 46K miles on the shortblock. About 10K boosted. Bore was also fine luckily and simply honed all of them, ordered 1 new piston, and a set of Total Seal rings.

 

That looks familiar. Sucks, but thanks to a tight ring gap, lots of power, which equals heat, and the ring lands pop like that.