Ransomes MG2 Oil Pump…squirt or ooze?

[vhgmcbuddy]

Hi All

Thanks to help and advice from many on this forum, especially Neil Jarrett (many thanks Neil), I have my MG2 running. Before going for a run I checked oil flow among other things, it seems very slow, but without a frame of reference I can not tell if this is normal or not.

On tick over oil oozes very slowly, with what appears to be air ‘gulping’ it out like a slow heart beat. On mid revs it is same but with a bit more flow, and occasional 2 or 3 seconds oozing flow without the gulping. Even this seems a little slow to me, but what should it look like? I will try to post short video on site or YouTube with link…..need kids tonight to help with that however 🙂

Scale
0 – no flow
1 – gulping flow, trickle into filter box……THIS IS WHAT I HAVE
2 – constant trickle without gulping
3 – constant weak but full slow flow
5 – strong full flow
6 – squirting strong flow

Any indication on what is normal from above scale would be very welcome.

Cheers
Graeme

[expeatfarmer]

Graeme the way you describe your oil flow sounds just the way it should be, what you are seeing is the return flow from the galleries. If you are concerned about oil pressure/ flow, slacken one of the pipes next to the starter dog when the engine is running.

[trusty220]

It sounds like your engine is running on the dry sump principle very much like the Norton engine that I’m doing on the Steed. The oil pump that pushes oil to the engine is in two parts (on the Norton at least); the first part is the pressure pump which lubricates crankshaft and big end and the second part (which has twice the capacity) is a scavenge pump that sucks up the oil from the bottom of the crankcase once the engine has finished with it. It then pumps this into a separate oil tank ready to be used again.
The reason for the scavenge pump to be twice the capacity is to allow for the tendency of the engine oil to drain into the crankcase when the engine isn’t running. At least when you start the engine up after lying idle for some time the scavenge pump will clear the excess oil out quite quickly. This would also explain why you are seeing a poor flow mixed with air bubbles when you look at the return flow- obviously the scavenge pump is doing it’s job and the crankcase is empty periodically (hence the air bubbles).
From what you describe is happening to your engine I agree with Jonathan- it sounds perfectly normal, and when my own Norton engines are running they also show quite a slow flow with air bubbles.
To put your mind at rest the only true way is to measure the flow going into the engine, but the fact that the scavenge pump is finding oil in the engine would point to the fact that the pressure side is working as it should.
I hope that helps!

[vhgmcbuddy]

Hi Both

That is very useful info. I think the machine is 1941, which would make it a ‘TB’ and not a ‘T’ engine, but both are, as you say, dry sump. I read that there were two pumps, but without the good explanation on how they worked I was a little concerned, but now as you have explained it does seem all is as it should be.

After first post on this subject I took off all the new looking oil pipes, filter, and looked inside the holes. All clear, and when I got the machine I used a flushing oil to clean the internals, so new oil just fitted is also running clear, so no signs of grunge.

So I think she is ready for a trip to the Forrest to pull a log or two….thanks, I am not sure how I would manage without this forum, not knowing what to expect is a challenge sometimes.

PS, you have a Norton? I have a Triumph Trident, still in renovation, built like a tractor, hope it handles better when I finish it! 🙂

Graeme

[trusty220]

Don’t get too excited, the Norton isn’t in a bike. If you look under Trusty Steed Engine Rebuild in the Projects section you will see what I mean.

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