Assembly oil

[Homemade]

What do you guys for assembly oil on bearings, piston skirts, rings and so on? I’ve used straight 2cycle oil. I know it won’t harm anything and will burn off cleanly. On four cycle engines I’ve seen everything from 5w30, to grease, to royal purple engine assembly lube.

I would not think the specific assembly oil would be needed for a saw?

The argument for the grease was that it will last longer during start up and provide better initial lubrication.

The 5w30 guys say the oil will last long enough and will not cause oil starvation when the grease washes off and plugs the oil filter.

Should consideration be given for needle bearings vs roller ball bearings to what kind of lube they get?

 

[Cut4fun]

I use straight kl200 and if not on hand straight other 2 stroke mix in synthetic. Just the way I do it, right or wrong no clue but works for me.

Rod and crank bearings I squirt some mix on them

 

[Stump Shot]

I use two stroke oil in a squirt can. Most any oil will work as it will be expended out the exhaust in short order after firing. The new fuel/oil charge coming in taking over.
Also this is more oil than the engine has in it after it is turned off, so to my line of thinking is more than adequate for the first fire.

 

[huskihl]

There's actually quite a debate on motorcycle forums as to whether the new piston, rings and cylinder should have any oil on them at all. Some claim that it breaks the rings in faster and does no harm to the piston and cylinder. That being said I always squirt a small amount in the cylinder and smear it around a couple times with my finger. I also use a tiny bit on my fingers and spin the rings a couple times before installing them. I don't put any on the piston because it'll end up on the base and I don't want that hindering the sealant

 

[3browns]

There's actually quite a debate on motorcycle forums as to whether the new piston, rings and cylinder should have any oil on them at all. Some claim that it breaks the rings in faster and does no harm to the piston and cylinder. That being said I always squirt a small amount in the cylinder and smear it around a couple times with my finger. I also use a tiny bit on my fingers and spin the rings a couple times before installing them. I don't put any on the piston because it'll end up on the base and I don't want that hindering the sealant

Kind of OT but I have also heard the "synthetic vs non-synthetic oil for ring/engine break in" debate for years in the 4 stroke world

The claim is that synthetic is sooooo slippery it wont allow rings to break in and seat correctly and all new engines should be broken in with dino oil for good ring sealing

I am sure that's why Porsche and other top tier car makers fill new $100-200,000 cars with Mobil 1...

So their engines don't break in correctly...

 

[huskihl]

Kind of OT but I have also heard the "synthetic vs non-synthetic oil for ring/engine break in" debate for years in the 4 stroke world

The claim is that synthetic is sooooo slippery it wont allow rings to break in and seat correctly and all new engines should be broken in with dino oil for good ring sealing

I am sure that's why Porsche and other top tier car makers fill new $100-200,000 cars with Mobil 1...

So their engines don't break in correctly...

There are just so many variables that I doubt it matters. I would think a lean tune/mix of synthetic oil would break in a set of rings quicker than a blubbering rich saw running on cheap dino.

 

[3browns]

There are just so many variables that I doubt it matters. I would think a lean tune/mix of synthetic oil would break in a set of rings quicker than a blubbering rich saw running on cheap dino.

Good point

Food for thought...

 

[Steve]

I use 30w in an oil can. Some on the crank and rod bearings. Some on the piston and cylinder. Smokes for about 2 secons on start up and good to go!

I'd imagine any oil for assembly would be fine. I dont like the grease because it takes up clearances. I believe it also can carbon up rings because it wont flow like oil will. Just my opinion, no lab testing science to back me.

 

[drf256]

Any good 2 stroke oil in a pump can. Usually the stuff I’m not sure I’d want to run all the time in a saw but is of good quality.

 

[Hinerman]

There's actually quite a debate on motorcycle forums as to whether the new piston, rings and cylinder should have any oil on them at all. Some claim that it breaks the rings in faster and does no harm to the piston and cylinder. That being said I always squirt a small amount in the cylinder and smear it around a couple times with my finger. I also use a tiny bit on my fingers and spin the rings a couple times before installing them. I don't put any on the piston because it'll end up on the base and I don't want that hindering the sealant

How do you get your finger in the cylinder? Do you use a special lube for that too?

 

[Brush Ape]

Think of it two ways. First think of it as a pressure pyramid, tackier more viscous stuff at the base on your mains drippier stuff with a more uniform molecular structure toward the top. Also consider how long things will sit before they get fired up. Are you building a pair of 440 heads to put on a shelf in plastic bags until you get the block back from the machinist? I'd want a tackier film on those. (I like compression rings, pushrods and roller rocker arms with Royal Purple running throughout who wouldn't..??) Or are you building something very simple with fixed valves which theoretically will fire on the first pull? Are you a cowboy with a ketchup bottle of discarded two-stroke oil or a scientist? How long are you gonna crank on something before you realize the distributor is 180 out of phase? With your confidence and experience level as a guide you may use a combination of assembly lube on one job.

 

[Steve]

Think of it two ways. First think of it as a pressure pyramid, tackier more viscous stuff at the base on your mains drippier stuff with a more uniform molecular structure toward the top. Also consider how long things will sit before they get fired up. Are you building a pair of 440 heads to put on a shelf in plastic bags until you get the block back from the machinist? I'd want a tackier film on those. (I like compression rings, pushrods and roller rocker arms with Royal Purple running throughout who wouldn't..??) Or are you building something very simple with fixed valves which theoretically will fire on the first pull? Are you a cowboy with a ketchup bottle of discarded two-stroke oil or a scientist? How long are you gonna crank on something before you realize the distributor is 180 out of phase? With your confidence and experience level as a guide you may use a combination of assembly lube on one job.
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Very true. Good information there! So many variables to such question. I suppose if there was only one correct oil/method to assembly pre-lube there would be a ton of parts saws in the for sale adds.

 

[Homemade]

I know there is no correct answer (see every oil thread ever created). But I just wanted to see what you fellas like to use and why. I’m putting together a 090g and seeing needle bearings apposed to ball bearings, makes me want to use something thicker then two stroke oil cause of the wider tolerances between needles and cage and bearing surfaces. Otherwise it’s two stroke oil rubbed in with an acid brush.

 

[Steve]

I usaually pack roller bearings with grease durring assembly.

 

[huskihl]

How do you get your finger in the cylinder? Do you use a special lube for that too?

Some times I have to push really hard, but it always fits

 

[MustangMike]

I use 2 cycle oil on the cylinder and generally spray some WD-40 in the bearings mostly to flush any grit out. As long as they are not dry before the mix hits them, you are fine. I have yet to have a failure, so I'll keep doing what I'm doing.

Before synthetic oils, which seem to cling to parts, most engine wear was on start up, before the oil hit the parts. Cars, etc last much longer now mostly due to synthetic oils and lubricants. (oil does not break down, anti freeze does not go bad, etc).

I believe synthetic oil is better at 15,000 miles than conventional oil was at 3,000 miles. If you were a high mileage driver (like I was), oil changes were a real PITA! 36,000 miles / year meant changing oil every month!

 

[DrewUth]

Two stroke oil for me. I have a few old pull-tab cans of Evinrude oil laying around from my grandfather that I wont burn in fuel for the outboards, but with a brush or in a squirt can the stuff is great for assembly lube, plus I use it on the lathe and I have been known to pour some in with the bar oil to thin it out as well.

 

[Marshy]

In a chainsaw I would stick with 2-stroke oil only on roller bearings. I personally would not use WD on them or grease. The problem with grease is it captures contaminants really well and keeps them there. Also, if the oil wicks out the thickener is left and hardens and can cause issues. The WD is not a lubricant, it a solvent. It likely gets washed fairly easily and shouldnt cause a problem buy I have seen bearings "lubricated" with WD fail prematurely. Also, the viscosity of WD is too light to provide proper fluid film IMO. I'd rather just use 2-stroke oil and know that there wont be an issue. As far as rings go. I've used a light coating of 2-stork oil also. There are many recommendations on the internet that a light oil is recommended on the rings to help them seat. They even recommend a light spray of WD. I've never tried it but I would give it a try.

 

[Steve]

In a chainsaw I would stick with 2-stroke oil only on roller bearings. I personally would not use WD on them or grease. The problem with grease is it captures contaminants really well and keeps them there. Also, if the oil wicks out the thickener is left and hardens and can cause issues. The WD is not a lubricant, it a solvent. It likely gets washed fairly easily and shouldnt cause a problem buy I have seen bearings "lubricated" with WD fail prematurely. Also, the viscosity of WD is too light to provide proper fluid film IMO. I'd rather just use 2-stroke oil and know that there wont be an issue. As far as rings go. I've used a light coating of 2-stork oil also. There are many recommendations on the internet that a might oil is recommended on the rings to help them seat. They even recommend a light spray of WD. I've never tried it but I would give it a try.

Didnt think about the grease keepin in contamination. That makes sense.

 

[Leafy]

For cylinder walls Wd40, it's really just to keep from rust flashing on them during assembly (on car motors) and give enough to stop a scuff on startup, but it'll be covered with plenty of whatever is supposed to lube that engine by the time it gets hot enough to need it.
Roller bearings in a saw just get wd because they'll get 2 stroke oil no later than they would after the saw was sitting for months. And roller bearings work fine at low rpm, loads, and Temps dry.
Journal bearings get thick assembly grease because they don't work without lubricant and sometimes it can take a while to build oil pressure on modern cars, especially ones with gearotor pumps around the crank that have a hard time priming when just cracking.