787 Munches & Crunches Metal

[chrisny454]

Bought a dead 1996 GTX with low compression in one cylinder. (i knew this before I bought it - so you dont think I am an idiot :ack: ). Bought it to use as a parts machine for my other 1996 GTX and my 1997 GTX. ANYWHOO... Took the Head off and found something rather interesting. One cylinder clean, the other looked like the piston was munching on something metal. Left divots in the top of the piston and the head. The piston itself is "loose" - meaning that it seems to be disengaged from the crankshaft to some degree. Nutherwords it moves semi-freely from the shaft, but will go up and down just not fluidly like the other piston does. Here are some pics below. What is your opinion as to what happened and what are the chances of doing a top half rebuild and being successful or is the bottom half likely toast as well. Lastly, for my worst case scenario, what are the chances that SBT take this in on a core without charging me bookoo extra for damaged parts?

Damaged Cylinder

Good Cylinder (Head Side Only)

 

[rookie101]

If i took a guess I would say either the wrist pin or crankshaft bearing came apart and some of the shrapnel ended up in the combustion chamber. Pretty sure you will need a bottom end rebuild at this point, but to be sure just pull the jug off.

I don't think this is the kind of damage that SBT cares about, but your best bet would be to call them.


Aaron

 

[derek]

SBT throws away pistons. the jugs look ok. they completely redo the cranks. only possible core back-charge would be the head. call them and discuss it. they will always speak to potential buyers, no runaround. worst case scenario; buy a decent head on ebay for 30 bucks.