Opinions on piston lubrication during assembly

[Belgian1979]

I have been trying to find out what the best way is about this. There seems to be a lot of opinions on this subject.

My previous engine scuffed the pistons during startup and I want to make sure this doesn't happen again.

Untill now there are people that say that you only lightly need to oil the pistons, walls and rings. Probably to have the seat fast. On the other hand reading D. Vizards book about rebuilding SBC, it says to really dip the piston in oil.

So what's the concensus here ?

[ClassicComp]

2 squirts of oil on the walls & spread it with my finger.
Pistons are only lightly oilled

[Keith Morganstein]

I have been trying to find out what the best way is about this. There seems to be a lot of opinions on this subject.

My previous engine scuffed the pistons during startup and I want to make sure this doesn't happen again.

Untill now there are people that say that you only lightly need to oil the pistons, walls and rings. Probably to have the seat fast. On the other hand reading D. Vizards book about rebuilding SBC, it says to really dip the piston in oil.

So what's the concensus here ?

Yes, lots of opinions and recipes. A few drops of oil on the rings and skirts is enough lube.

Most scuff / damage on start-up is because of dirt. Everything needs to be very clean.

[PWMAX]

Lightly wipe each cylinder with about a teaspoon of oil, then very lightly wipe a thin film on rigns, move them around a bit to distribute the oil around the rings, put a small dab of oil on each skirt, spread it around, and install. Just make sure you lube the wrist pin real good. DON'T use thick assembly lube on the rings, bores or skirts. Dipping the whole piston assembly into a bucket of oil is plain dumb and will make a huge mess, and is totaly a waste of oil.

Frank

[PWMAX]

To add, a lot of the scuffing on the 1st start up, is usualy a case of not having the block filled with coolant. Make sure to circulate coolant thru the engine before start up. Just as important as priming the oil pump

Frank

[Belgian1979]

To add, a lot of the scuffing on the 1st start up, is usualy a case of not having the block filled with coolant. Make sure to circulate coolant thru the engine before start up. Just as important as priming the oil pump

Frank

How do you do that ?

[Strange Magic]

Scuffing a piston on start up?

Are you actually tearing teh engine back down after the first few minutes to come to this conclusion? You would have to, to make a bold statement as such.

Do not mis-interpet a piston to wall clearance being to tight with scuffing a piston on start up. When you actually think about that staement, it's kind of rediculous. The piston manufactures recommended clearances are usually to tight and without the proper block prep and the correct piston to wall clearance, you will score and tear at the skirts.

[Belgian1979]

Scuffing a piston on start up?

Are you actually tearing teh engine back down after the first few minutes to come to this conclusion? You would have to, to make a bold statement as such.

Do not mis-interpet a piston to wall clearance being to tight with scuffing a piston on start up. When you actually think about that staement, it's kind of rediculous. The piston manufactures recommended clearances are usually to tight and without the proper block prep and the correct piston to wall clearance, you will score and tear at the skirts.

Actually yes, the previous engine scuffed on start up. Still unclear about what was all involved. One factor was that the block was not plate honed and the boltholes were showing. Possible fuel wash, dirt, I don't know.

Want to make sure it's not cause by oiling.

[Strange Magic]

I build engines with little to no oil on the pistons and have been doing it this way for years. I've never had an issue with scored skirts or tearing. If your cylinder walls are out of round in conjunction with being tight, you will have issues.

[panic]

WD40

[af2]

Vaseline is all that I use when wiping down cylinders and when installing pistons.

[needforspeed66gt]

Yes, lots of opinions and recipes. A few drops of oil on the rings and skirts is enough lube.

Most scuff / damage on start-up is because of dirt. Everything needs to be very clean.

Yep - chamfer and deburr the bottoms of the cylinders really well, aggressively scrub the cylinder walls with multiple cleaners to remove abrasive material and metal grit, a trip through the jet wash is not enough.

I squirt a couple drops of oil into each of the top ring lands and rotate the rings around, this puts a light coat on them but does not flood the land. Same thing for the oil control ring. The skirt then gets a layer of oil wiped on it and the piston is pushed into a bore that was wiped with oil so it has a sheen, but is not dripping.

[Caprimaniac]

Jeez. What Happened to my post?

I was gonna comment on the deburring! Done this mistake myself, although the pistons have survived well for 3 years or so.

And on the vaseline: The only lube you'll ever need....

[Blue Malibu]

I have always used Marvel Mystery Oil.
Keep a spray bottle in the engine assembly room just for it.
It smells good too

Andy

[jed]

x2