cylinder wall oiling

[wjli]

aside from engines with dedicated oil squirters, do all engines trust "splash" oiling from the crank shaft to provide oil to the cylinder walls?

I was just wondering because I know my engine (chrysler 3.7) has a built in windage tray/crank scraper.Im just a little confused on how oil reaches those cylinder walls consistantly.

 

[Steve S]

As the grankshaft rotates the oil of flung out of the rod bearings.Crankshafts of modern engines do not dip into the oil in the sump as a matter of design.

 

[Drew99GT]

I'd imagine the cylinder walls get some oil from oil splashing off the wrist pin from it's oil squirter.

 

[Steve S]

Originally Posted By: Drew99GT
I'd imagine the cylinder walls get some oil from oil splashing off the wrist pin from it's oil squirter.
The wrist pin is lubed br the squirter oil or by the oil flung off the rod bearings.

 

[punisher]

Squirters are mainly to control piston crown temps. Cylinder wall/piston ring lube is an afterthought of their function.

Wrist pins can be pressure lubed from the crank throws, from the back of the oil ring land, or from oil thrown off the crank.

 

[Kestas]

The design engineers told me those holes don't really "squirt" oil as much as they toss droplets upward. That, and the general misting in the crankcase is what lubricates the cylinder walls.

Toyota has come up with a true squirt design for cylinder walls on their NASCAR series engines.

 

[mechtech2]

Pistons are lubricated by splash - drops, mist, or liquid. Most wrist pins as well.

Oil squirters are to cool the pistons, and are common in turbocharged cars. The pistons can get REAL hot in them. they are not aimed at, nor can they lube the whole piston/cyl wall.

 

[Drew99GT]

I was under the assumption that most wrist pins in modern cars are somewhat pressure lubricated. There's usually an oil hole on the bottom of the rod with a drilled passage that goes up to the wrist pin bushing. The oil from the hole that lubricates the rod bearing will make it's way through the rod to the wrist pin.

 

[Drew99GT]

http://www.youtube.com/watch?v=SGB36DCkq6g&feature=channel_page

@7:30, our good friend Dave Rock explains things nicely.

 

[mstrjon32]

My LZ9 has piston squirters, which it claims are to cool the pistons and allow the engine to run on 87 despite increased compression. Between that and the VVT system, it seems reasonable enough for me to run synthetic in it.

 

[meep]

The old chevy SB V8s I used to tinker with had oil journals up the rods to the piston pins. I think even some of the tecumseh OPE engines I've torn down had that (they had pressurized oil in the vert-shaft engines)

M

 

[onion]

Originally Posted By: mechtech2

Oil squirters are to cool the pistons, and are common in turbocharged cars. The pistons can get REAL hot in them. they are not aimed at, nor can they lube the whole piston/cyl wall.


These are also common with industrial diesel engines- including but not limited to turbocharged diesels.

A couple months back, one of my co-workers found out the hard way just how important it is that the piston cooling nozzle is aimed correctly. He bent a nozzle when installing the piston in a Mercedes 4000 engine in a Freightliner. I ended up pulling that piston out a couple days later... in pieces.

 

[mechtech2]

Drilled through rods [to the pin] are very rare.

But people have found a couple of Coelacanths.