Wet dumping/crank oil seal?

Landspeedracer said:

How did you come to the assumption that I’d over pressurised the sump etc. that you’ve just mentioned?

if you read all of the words, you will see I said I came back to a small oil deposit ie perhaps 3cc/4cc under the bike, then I drained the sump of a normal oil tank’s worth of oil, then I removed the chain-case and wiped up another 3cc/4cc.

It is quite clearly engine oil, coming from the front end of the engine and black. Unlike the clear gearbox oil that I filled it with only recently, the gearbox doesn’t leak.


Perhaps in order to allay any more fears, I will put it all back together, then refill the oil tank and go for a ride. If I think the bike won’t move for any length of time then I will drain the tank and/or remove the sump bung.

Click to expand...

Because you "drained the sump of a normal oil tank’s worth of oil, " means you were cranking the engine, with all the pressure the descending pistons create from non-compressible oil where there normally would be air. That pressure reaches the crankseal and could have forced oil into primary. Either by damaging the seal or just seeping past it.
How else do you explain oil in a normally dry primary after a wet sump start?

Another problem with a fully wet sumped engine, there will be no oil in the tank above the oil screen, so little to no oil feeding to pump, so no or low pressure out of pump during initial cranks. Don't like that.

Landspeedracer said:

How did you come to the assumption that I’d over pressurized the sump etc. that you’ve just mentioned?

Click to expand...

That seems to be the common conclusion around here. Nobody can accept that a sump full of oil can find ways into the primary without being pressurized by a running engine. I had a profound revelation the first winter after my cNw e-start install. After about 5 months sitting in my basement I found a puddle of oil under the primary. Strip down revealed that the main seal was leaking where it fit into its bore, and 2 of the 3 bolts attaching the primary to engine were seeping. This ONLY happened after the sump became full. I have a working breather and there is NO oil leaking from the primary during the riding season.

Tornado said:

Because you "drained the sump of a normal oil tank’s worth of oil, " means you were cranking the engine, with all the pressure the descending pistons create from non-compressible oil where there normally would be air. That pressure reaches the crankseal and could have forced oil into primary. Either by damaging the seal or just seeping past it.
How else do you explain oil in a normally dry primary after a wet sump start?

Another problem with a fully wet sumped engine, there will be no oil in the tank above the oil screen, so little to no oil feeding to pump, so no or low pressure out of pump during initial cranks. Don't like that.

Click to expand...

He didn’t start it.

When he says he “drained the sump of a normal oil tank’s worth of oil” he means exactly that, ie that he drained the oil from the sump.

The leak happened whilst the bike was sitting.

IMHO the most likely reason for this is (as Maylar explains) that the seal is simply not designed to seal in a sump full of oil, sitting stationary, for an extended period.

Fast Eddie said:

He didn’t start it.

When he says he “drained the sump of a normal oil tank’s worth of oil” he means exactly that, ie that he drained the oil from the sump.

The leak happened whilst the bike was sitting.

IMHO the most likely reason for this is (as Maylar explains) that the seal,is simply not designed to seal in a sump full of oil, sitting stationary, for an extended period.

Click to expand...

Missed that in original post. Thx.

My experience is that oil seals seal best when the rotating assembly is rotating, NOT when it is stationery. Further, oil seals for rotating assemblies are not placed in a position where the seal is normally submerged in oil. The only time the oil seal in question is actually submerged is if sufficient wet-sumping has occurred to raise the level in the crankcase up to the level of the seal.

maylar said:

I thought I was the only one, brother.

Click to expand...

That's because there might be a really nice day for riding next week.

Fast Eddie said:

He didn’t start it.

When he says he “drained the sump of a normal oil tank’s worth of oil” he means exactly that, ie that he drained the oil from the sump.

The leak happened whilst the bike was sitting.

IMHO the most likely reason for this is (as Maylar explains) that the seal is simply not designed to seal in a sump full of oil, sitting stationary, for an extended period.

Click to expand...

Does this mean that the sump should be drained and left empty if the bike is stored for an extended period of five or six months?

You can just drain the oil tank after the last ride for the season.
That leaves the correct amount in the sump for startup in the Spring, provided the crankcase joint is good.
It's amazing how dry the bikes here stay when the sumps aren't overflowing!

Glen

well the oil has tobe somwhere.... if its in the sump it will at least have made its way along the oil galleys in the crankso nodry start up.. and how long does it take to undo the sump plug and refill the tank? Surelly not an issue now we are all non smokers and not getting engine oil on our not so lucky strikes ,john players or whatever yur favoured brand.
Must admit the crankcases do seem to hold the oil the ES2 is a different matter... its then down toalignment of crankwith the breather that existsunderneath the primary chaincase... always a sticky puddle underneath that

Thanks Fast Eddie.

I hadn't started it since it was parked up for about 4 months.

I still haven’t, and the oil tank is still empty while I do other jobs around the house, bikes, car, motorhome etc.etc.

oldmikew said:

well the oil has tobe somwhere.... if its in the sump it will at least have made its way along the oil galleys in the crankso nodry start up.. and how long does it take to undo the sump plug and refill the tank? Surelly not an issue now we are all non smokers and not getting engine oil on our not so lucky strikes ,john players or whatever yur favoured brand.
Must admit the crankcases do seem to hold the oil the ES2 is a different matter... its then down toalignment of crankwith the breather that existsunderneath the primary chaincase... always a sticky puddle underneath that

Click to expand...

Not that long to remove the drain plug, but it does take awhile to strain the oil before dumping it back in, if it's clean looking oil.
I used to just clean the area around the drain plug, drain the oil and , if still light and clear in appearance dump it back in the oil tank. After finding a tiny stone occluding the rocker feed banjo on my 650ss, I started straining the oil before dumping it back in.
This takes awhile but you should see the bits of road grit that show up on the strainer cloth.
If you are draining the oil from your sump and dumping it straight back in without straining through proper strain cloth, you aren't doing your engine any favours.
The next job is to clean the floor where the bike with the overfilled sump has been sitting. I sop this up with old rags then use some solvent and paper towel to finish.
The final job is to remove as much oil as possible from the tires as I always try to avoid the oil puddle but invariably move the bike for some reason and track right thru it!
Going for a quick ride on a bike that has wet sumped, nothing to it!

Glen