odd one this

[wadsapple]

Compression test done on the Chevrolet all ok ,Leak down test done showed up two cylinders that were 15% down passed the rings so it was decided to strip the engine and have a look see what was what. We have been chasing a misfire on the car since it was built, so it was a no brainer to do some looking as I wanted to look at my camshaft anyway as part of this missfire. It is getting new rings because of the suspect cylinders on the right bank, what I wasn't expecting was to see this on the back cylinder on the left bank where all the tests said it was ok.It has been like this a few races as there is carbon build up on both edges. We are guessing detonation.

[Guillotine]

Looks like its eaten the top of the piston, about 10 oclock?

what compression are you running, what fuel?

Finally, is hat the pistion that broke at BHI?

A

[Graham]

which pot number is that. Andy H had a lot of problems when they first ran the ls, kept doing the same piston. The ls is very picky about its coolant system and really doesnt like any detonation.


re-reading that you do say back cyl on the left bank fairly sure that was were andy had issues.

[teamHOLDENracing]

That is detonation. Cylinder no 7?

You need better cooling and or a safer map. I'd also recommend Evans Coolant to prevent localised boiling and det on that pot.

[wadsapple]

yep will look into that cheers andy x 2 and graham number 7 it is . Lucky for some they say

Edited by wadsapple on Wednesday 12th February 11:45

[Keithyboy]

"7 out" new thrower!

[wadsapple]

Keithyboy said:

"7 out" new thrower!

translation anyone

[sarbec]

You running a thermostat or some restrictor so the rear cylinders have a good flow of coolant ?
and not starved

[Keithyboy]

wadsapple said:

Keithyboy said:

"7 out" new thrower!

translation anyone

Lucky for some or not as the case may be. It's the call the boxman on a Dice (Craps)table makes when a 7's thrown after a point's already been made. Generally a losing roll and the dice are passed to the next thrower. Lesson over!