I have always used assembly lube on cyl.walls when doing a rebuild,but have seen where some prefer wd40 or equivalent.What are your thoughts?
Use the thinnest oil. The thicker lubes will not let the rings seat fast and will allow glazing. WD-40 isn't a lubricant. It was designed as a "W"ater "D"ispersant and last for 40 days....hence the name. If the cylinder walls glaze over then you'll have trouble getting the rings to seat. You want the rings to seat as quickly as possible.
It was designed as a "W"ater "D"ispersant and last for 40 days....hence the name. so very close. it was the 40th attempt, not designed to last 40 days. but i don't know that i'd use WD-40 as a long term preservative either. it is prone to evaporation. http://en.wikipedia.org/wiki/WD-40
Its water displacement but anyway...I use assembly lub on the cyl walls and rotate as often as I'm at my weekend house.
Great tips,thanks-forgot to mention that the engine will be sitting for a whlie(possibly a couple months before startup,if this would make a difference as to what type lubricant to use)
I am curious about this too, I may not be running My engine again till next spring. I was told to use a mix of engine oil, and trans fluid, pour it down carb while engine is running, until it stalls.
If you are going to rebuild it and let it sit for awile, I would use assmbly lube or Lucas oil. Lucas oil is pretty thick and in the long term wil mix into your engine oil. I have done the same thing on a racing engine and had good success with it after letting it sit for 3-4 months. Our friend WD will just run off the walls. Great for rusted fasteners, not a great assembly aid.
Doesnt sound like a good idea to me, liquids dont compress, so pouring it down the carb would bump compression and possible cause detonation. I put assembly lube on mine, but reading above, i think ill wipe them when i switch the heads, and put a light ATF in there.
Some ring manufaturers adamantly specify "assemble dry!" As has been mentioned, dipping pistons ina can of oil and such are "old-school" and may not be the best idea if you don't want an oil-burner. My last engine, per Total-Seal Rings' instruction, was assembled dry. I did spray the piston skirts with dry moly-lube. Some builders recommend using WD-40 and a clean towel to scrub the cylinders of honing abrasive after honing. Continue spraying and rubbing until your towel is no longer blackened.
The oil will be a lubricant to the rings, allowing them to slide over the cyl. walls and not seat as quickly. While the rings are moving over the cylinder walls heat is built up, this heat and movement will promote glazing, especially if the rings aren't being forced against the walls and instead are sliding over the walls with less friction. When the rings are already broken in it won't matter as much. WD40 isn't a lubricant. And while trans fluid is a lubricant it also has cleaning solvents. You can wash the grease right off your hands with trans fluid. You want the rings to seat to the cyl. walls as quick as possible. That's why Total Seal recommends dry. I've used both WD40 and trans fluid and then an aggressive break-in cycle. NO idling, lots of high and low vacuum situations (aggressive throttle thru the gears and compression back down to lower gears) to work the rings in and out of the ring grooves of the piston, watch the engine temp closely so it doesn't get too hot. If you're going to let an engine sit for long periods depending on your climate you can fog the engine down before you put it away. If its a new engine thats going to sit I'd use trans fluid on the cyl. walls and not assy. lube or oil. If its an engine thats been run over a period of time I'd drain the oilpan (to get rid of acids and contaminents) and fill with fresh oil and then spray a light oil or better yet trans fluid on the walls. I've never fogged the engine til it quit with oil. I can only imagine the smoke you'd see. I think they make a product just for that.....probably just a light oil in a can.
I have always used a light coat of engine oil on the cylinder walls and on the piston/rings. No dipping!!
I, too used to use engine oil on the cylinder walls, now considered a no-no for proper break-in. I only oil the wrist pins, while the cylinders just get the no-lint cloth cleaning with solvent. I don't stop cleaning until the white cloth stays white. Devon
Great, that means i have to clean the assembly lube off the cyllinder walls before i put on the TA heads (way later) oh well, at least i know its not going to rust how it is now.
One of the list members has built hundreds of engines over many years-he liberally parges on white grease to the pistons/rings at assembly and has had no issues. I don't do it this way, but often there are a number of OK ways to do a job-
