melt down

jdcrzy · Post by **jdcrzy** » Sat Dec 20, 2008 11:37 am

pics of the cylinder and piston on the PTO side of 80 trailfire. engine has new gaskets and seals, idled great ran fine and then down it went. is it just the age or what should i look for. didnt notice anything while jugswere off during rebuild but i guess i didnt look to close either

any insite?

thanks

Joel

Attachments:

big danno 1970 · Post by **big danno 1970** » Sat Dec 20, 2008 12:00 pm

Which side of the piston is that intake or exhaust?

jdcrzy · Post by **jdcrzy** » Sat Dec 20, 2008 12:02 pm

exhaust side

big danno 1970 · Post by **big danno 1970** » Sat Dec 20, 2008 1:17 pm

How tight is your fan belt?Looks to me like it was over heated.

jdcrzy · Post by **jdcrzy** » Sat Dec 20, 2008 1:19 pm

new belt, tension good

jdcrzy · Post by **jdcrzy** » Sat Dec 20, 2008 4:05 pm

after looking at slid found the needle all the way down, so probably running lean. will make adjustment when getting it started again. im runnung 40 : 1 premix will premium gas.

thanks

joel

Miller Motorsports · Post by **Miller Motorsports** » Sat Dec 20, 2008 5:09 pm

It looks to me like the piston got burnt from lean mixture or severe detonation. I had a 6.5 turbo bus that did that to a pair of lungs 2 times. Active engine said it was lean out from the oil pressure sending unit trying to shut the engine down while the driver pushed it harder the ECM was cutting fuel to shut down. The flame wants to burn something and in low fuel lean out it gets super hot and will actually burn the piston. Anyone who has fooled with nitrous oxide has a set of pistons that look like this 'cause if they lean it at all it will burn down.

Joliet Jake · Post by **Joliet Jake** » Sat Dec 20, 2008 7:41 pm

I might jump in here and post:

I bet it wasn?t the a signal from the oil injection to the ELICTROIC CONTROL UNIT that the oil pressure wasn?t sufficient and this then resulted in the ECU sending a signal to lean out the fuel to that cylinder to shut it down and with that subsequent leaning of the mixture lasted long enough to result in the burn down.

But what the heck do I know :lol22:

Sorry for being a wise ass!............looks like somehow that cylinder got very lean
Now the fun begins!

JDT · Post by **JDT** » Sat Dec 20, 2008 7:51 pm

Could have been one of those super-mod Trailfires with 200 hp that were all dream about....