Quote:
Originally Posted by SurfDog
Well believe it or not after relashing the heads there was still some engine noise (less noise but still..) coming out of my motor so I tore it down again and found another problem. Can you friggin’ believe it!!?!
Z1s Short block is eating itself.
According to two motor builders who have looked at it, either the wrist pins are too tight or the pistons are a bit undersized (or a bit of both I suspect).
Anyhow after about 200 miles of easy break in (with break in oil) check out these totally trashed cylinders... the groves are deep enough to feel with your eyes closed. Definitely not normal at all. This motor wouldn’t last an hour at full power I suspect. The pistons are rocking with the wrist pins not “floating” in the cylinders on the oil as they should. Also notice the high carbon buildup from excessive oil blow by. That should not be there after only 200 miles of break in style driving.
     
Sooo... I’ve pulled the motor (again... 3rd time) and sent Z1 their block back.
They are deciding what to do about it. (They did send a shipping label so that a start)
In the mean time as the motor is again totally apart, I sent the heads to MA Motorsports. Daelen there looked em over. He says the lash and overall head condition looks good now. (After relashing them into spec here in Denver). I figured a second very experienced set of eyes could not hurt before I bolt this f-er back together... hopefully for the last time.
Ug. This has sucked. |
Had rebuilt a 400 ci Pontiac motor years ago. The cylinder walls looked like this after 500 mile break-in. Motor was making some weird noise. On tear down. Found that the ring ends was butting. And the ring coating was flaking off. Ring gap was set about .003" too tight.
