Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Wet Sumping

While doing my oil tank cap mod, I happened to notice that the oil level was down to the minimum. This was a surprise since on every previous occasion it has been indicating full.
So I removed the crankcase sump plug and, sure enough, out it came - I'd guess about a litre and a half.
Maybe it has always leaked and I have not noticed before, but this seems a lot of leakage to me. The car had been standing for only about 10 days.

Any views?

With a dry sump setup oil can drain down when the engine's not running.

As soon as you start it up the oil's pumped back up into the tank.

That's why you need to check the oil level straight after the engine's been run - or even for some cars whilst it's still running.

My M3W tank oil level seems to be maintained for several weeks of non running but I don't think that a drop in oil level over several days is a problem. There is possibly a slow leak down through the oil pump into the sump, there doesn't appear to be a non return valve in the line to prevent this. As long as the oil level is checked a few minutes after running, that should give a true level. The oil in the sump will soon scavenge back into the tank after start.

Triceratops, that is why it is so important to check the level with a running engine after your filling up. Eventually you filled up too much and then you will have a problem when cruising with oil blowing out, be careful

Achim

Wet sumping..something I thought was a speciality of old parallel twin Triumph motorcycles.

If too much oil drains into the sump if can cause major problems, on a Triumph.

The cause was normally a faulty non return valve in the crank case oil pump. The answer was either an engine strip down to repair the pump valve, qite costly, or put a stop cock valve in the oil return.
The latter solution was cheap and worked well, as long as the owner remembered to turn the oil on before starting.
Failure to turn on the oil alse resulted in an engine strip down, but in this case a rather more comprehensive and expensive re-build.

I don't know anything about the S&S Oil system, but I suspect it shouldn't wet sump.

Peter, wet sumping hasn't really been an issue on modern engines since the 1970's. My BSA Rocket Goldstar used to suffer from this but not any Harley I've owned and the S&S is a similar type of set- up to the Harley.

You can get a non return valve for the oil feed line (a lot of people fitted these on British bikes, not me though) these, if they seize up or block will obviously starve the engine of oil - Not something to look forward to.

On the English engines sumping would come to light when the bike was kicked over and it dumped it's now siphoned black load all over the block paving. - Trust me her who is really the boss went absolutely ballistic -
I guess running it regularly is the answer.

.l

It is indeed.. We never had wet sumping issues when our bikes were everyday transport. It's putting them in garages for weeks on end that starts the trouble.

It says on the s&s x wedge manual. Section 6 page 2.
I paraphrase:
Do not test the oil level if the engine has not been run in the last 30 mins.
run the engine for at least 1 min then turn it off for 30 seconds to check the oil level.

(Keep the oil cap on while the engine is running and remember yo check the state of the oil cap seal... but you know that already)

Thanks all for your advice.

I am now sure that I have a problem. On recheck, the oil level has dropped from 'max' immediately after a drive to 'min' 24 hours later.

That just can't be right.

Wet Sumping - Solved ?

I had my M3W for a year with no wet sumping issue - at this stage it was running the oil used by the supplying Morgan dealer and was serviced before purchase (second hand at 7000 miles).

I serviced the car myself after the first year having done another 3000. I used Motul fully synthetic V twin oil of the correct grade. After not using the car for a couple of weeks I noticed a leak and initially panicked but having read the threads on here realised this was simply a wet sumping issue. The oil level in the tank had dropped by a litre or two but on starting it was back to normal.

Ever since then if I leave the car for over a week, the leak returns - which is the sump filling up and leaking through seals/gaskets somewhere. No oil leaks in normal use and if run regularly.

My theory is that the new oil has some slightly different properties that either allow it to leak back down the line into the engine (through the oil pump in reverse?) or the sumnp fills up anyway and the new oil is better at getting past seals etc. Either way it is a nuisance.

Maybe a change of oil to another brand would fix it ?

The solution I have now adopted is to drain the oil from the header tank if the car is not going to be used for a week or more. Initially I did this with a manual pump of the type used over here for filling paraffin stoves from a big container. But I have now purchased a small 12v oil pump from LIDL 15 Euros which is meant for doing car oil changes. This makes it quick and easy to drain the oil into a bottle ready for re-use. I wouldn't use the pump for a normal car oil change as I think it is important to get any rubbish out of the borrom of the sump, but for this job it's perfect.