Piston Slap?, Advice Please Options

[solex]

I recently performed a top end rebuild on my engine with:

• NOS Mahle pistons and cylinders
• rebuild heads from HAM
• Rebuild Raby rods
• New Rod Bearings

During the break-in period everything was going well, using Brad Penn break-in oil, performed a tune up with new oil at 100 miles.

At about 150 miles I started to hear a knock at idle, sounded like it was coming from #2. The sound seemed to be some what reduced when the plug wire was disconnected.

At 200 miles I decided to do some more investigation; during oil change I noticed that there was a sludge / silvery substance on the oil strainer plate and decided to tear it down, thinking that there was a problem with a rod bearing.

The first thing I noticed was some rubbing on the #4 exhaust push rod.

I removed the heads and noticed that there was cylinder scoring on the tops and bottoms, remove the cylinders and saw the tops and bottom were worn... this must be the source of the silvery sludge. Attached are some pictures.

No what do I do? Any advice would be greatly appreciated... (IMG:style_emoticons/default/sad.gif) (IMG:style_emoticons/default/sad.gif)

Dan

[Jake Raby]

Looks like the cylinder/ piston wasn't cleaned well enough prior to assembly. That looks like a lot of wear for only 150 miles... Did you check the cylinder/piston clearance before assembly?
I have heard some complaints that the new Mahle sets are too tight out of the box, but since we don't use these I have not experienced it.

It takes quite a bit of an issue to create an audible slap from a piston/cylinder....

Those case through bolts don't look like they have been removed in a looooong time.. I would imagine that you snuck in a set of rods and rod bearings without splitting the case, based on your post and the pics.

This is quite risky, as you can't mic the rod journals for size or ovality..

I'd be puling those rod bearings, especially #2... I'd be willing to bet thats where the sludge came from and where the noise is coming from.. I have seen instances when a rod bearing was going south and fed dirty oil up the bore, resulting in the type of wear that you have pictured.