Sludge !?!?!?

[79XS11F]

I have the oil pan off my hop-up engine so I can remove the internal kick start assembly and ...
HOLY CRAP ... I can't believe how much sludge there was in the oil pan. It was about 1/32 of an inch thick. The entire oil pan surface was covered with this thick BLACK sludge. I had completely cleaned this engine inside and out when I had it apart for the 1179 kit. Is this normal for a rebuild break-in? I only have about 700 KM on this rebuilt engine?
Rob

[Crazcnuk]

As long as there are no BIG chunks, yes, it would be normal.

You get a lot of ring wear with new rings as they seat in. Also if you put in new bearings, there is a fair amount that scuffs off them in the first few hundred miles.

This is why they tell you to change the oil more than usual for the first while.

[mitch]

Yup

What he says but you should change the oil on a new or rebuilt engine at 500 klms starting out. I do 500,1000,1500 then every 3000, clean oil is the life of most motors IMHO. Have a great day
Doug

[randy]

And drain the oil HOT, that will keep the solids in suspension so most of it drains with the oil.

If you let the oil cool, the sludge will settle to the bottom, then, when you drain, the sludge remains.

[79XS11F]

No there were no metal bits to be seen ... I was just surprised to see that much crap in there. I guess I now have the opportunity to clean that out as part of this job. I also always do my oil changes HOT.
Rob

[Crazcnuk]

Essentially, for the first few hundred kms your actually forcing the rings to wear to the cylinder walls. That's what that whole x-hatch hone thing is about. The hone makes a dedicated 'wear-off' zone to speed up the break-in process.

Makes for a real fine sludge.

[prometheus578]

Expect to see shiny oil for the first few changes.
Shimmer-y.. like black, metal flake paint.
Real black, too, as the rings haven't set all the way, a lot of combustion carbon and such gets into the oil.
All normal, like everyone said.

[79XS11F]

Yes in deed the oil was BLACK as BLACK gets and did have that "shimmer' as you call it on the surface. Makes me wonder why I bothered to do such a complete cleaning job when I did the hop-up work.
Another thing I noticed while I had the pan off was that the oil pump pick up screen was about 1/3 covered with lint. I am guessing it is lint from the cheap rages I used to clean parts and stuff into holes while doing ring clip's etc. So in the future i will be paying the extra for the "lint free" shop rages with the edges sown.
Rob

[DiverRay]

The ONLY lint free shop rag is compressed air! I'm rebuilding a '68 Datsun 2000 Roaster engine, and I DO NOT use any rags. If I do need to wipe something, I'll go back over it with a degreaser and then use the compressed air to blow=dry the parts.

[prometheus578]

Very good point made by 79XS11F and Ray.
Not too many people consider that issue when building.