Shane I'm really sorry to hear about your engine, I just heard this morning from Cameron, (I figured Friday had been rained out) With my broken arm I have been laying low.
It's funny to read everyones speculation on what happened, what part failed, and why... Unfortunatly we probably will never know exactly what failed first,
It could have just simply been just a part failure, It happens. Something we unfortunately have to live with in this game....
Was It leaning out? By the color of the valves I would say no, When Turbo motors lean out they melt Aluminum, Very fast, the Hottest area is the deck around the exh. valve and that would go first I see no signs of that, or a hole melts in the top of the Piston the motor looses power and has Shit loads of Blow by, but usually not a catastophic failure like this.
Also note than a rich running motor can still detonate if the Octane of the fuel can not handle the Cylinder pressure.
As Jim Martin recommends an LM1 withdatalogging would tell us alot.
I know that was used during it's original tuning.
My guess is another Piston faiure, But not bacause of using Cima Pistons at 15 Lbs boost but perhaps some undetactble detonation was happening
that finally took it's toll on the P/C,
I know that detonation is very hard to detect sometimes especially in a car going 120 + and soo many things happening soo fast.
I ran well over 100 passes at 22-25 lbs boost on the old Turbo car and never changed the Cimas, I Tried 30 lbs once leaned it out and melted a ditch in one head. (I consider myself lucky on that one) But the Cima's lived on.
I never asked you what grade of race gas you use and that could also play a roll, It may be best to go to higher octane fuel regardless of what boost you run. the Slowest burning fuel available is made by Trick Racing, it is called Trick Turbo and it's motor octane is 119, That is what I reccomend that you run in the future.
Always remember that the combustion temps on an aircooled engine especially turbo are higher than a water cooled engine and what works for them may not work for us.
We can also put a tell tale on the rising rate fuel pressure regulator to track what your peak fuel pressure is under max boost.
The heads look saveable, and hopefully the crank is too.
Anything ya need don't hesitate to ask.
I hope to get out to Airspeed tomorrow and if it's all right with you I will take a look at it.
Darren
