Engine Block Epoxy

[Dadandson]

I am almost ready to start the assembly of my motor. I noticed that some motors I have seen, I have been doing research for months, have a paint or epoxy on the inside of the block. I would think it would help keep the oil cleaner. Is this something I should do or just leave it raw cast iron? If I do it, what kind of coating will withstand the heat and oil and not come off in the oil pan in chips?

 

[Sarastro]

I've seen this too, and it's always mystified me. I have a hard time seeing how it would keep the oil cleaner. And, yes, it seems to me that the chance of it peeling is a serious drawback, especially on a surface that has had oil on it continuously in the past.

Maybe it's some other kind of surface finish?

In any case, I can't see how you would need anything like this.

 

[Dadandson]

Cast Iron is very porous and allot of dirt is in these pores. Oil will flush this dirt out over time. By sealing in epoxy, the dirt will not be flushed out. I am worried that the coating will come off and cause problems later.

 

[MikeP]

There are special paints for doing that sort of thing, I'd suggest checking with a place like Jegs or a racing engine preparer. My understanding is that it isn't really to keep the oil cleaner but to create a slicker surface so that it runs back into the pan quicker and should decrease the ppossibility of oil starvation in corners and such.

 

[bill_young]

The most common product used (and has been for years) is called Gylptol and is commonly used for electrical insulation but works great inside blocks. Eastwood has it available. https://www.eastwoodco.com/jump.jsp?itemID=2298&itemType=PRODUCT
A lot of racers use it to promote oil flow back to the pan.