Cause of this failure
08-12-2013, 11:08 AM
#1
Cause of this failure Hre is pic of a piston that failed. There are 4 others in this engine that are starting to crack also. The application is an endurance racing engine that runs at WOT for extended periods of time. The engine is an lsx454 620 hp crate engine. AFR was 12.2:1, timing 28 deg, air density 2500 ft, fuel was 100LL. We had two seprated engines have the same failure within 20 mins.
I believe that it was was light deto over an sustained time. The engine has 16 hrs on it.
Thoughts?
I believe that it was was light deto over an sustained time. The engine has 16 hrs on it.
Thoughts?
08-12-2013, 02:04 PM
#3
The fuel is fresh 100LL right from the airport but there could be a little something to that. the first 6 hrs of run time the fuel was 103.8 octane and the rest up until the last 1hr was 105.4 then it was 103.2. I think the timing was the major issue though.
08-12-2013, 04:08 PM
#5
It is just a factory gm crate lsx 454. Not even sure what the cranking compression would be 10.7:1 comp ratio. Peak tq@4900 and we were running it 5700
Last edited by allblowdup; 08-12-2013 at 05:27 PM.
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08-13-2013, 09:12 AM
#8
Found this PDF from Rockett Fuels, which corroborates this blurb from a pilot back in 2007...
We do data logg some things but we do not have any part throttle to speak of in our application (jet boat)
08-21-2013, 09:16 AM
#9
Found out some real interesting info regarding the pplugs in this engine. The plugs are ac delco 41-104 or ngk tr4ix. Friggen heat range 4 plug. I can not figure out for the life of me why GM would run such a hot plug in a hi performance crate engine. Does anyone have any insight into this?