Author Topic: My Totally Weird Oil System  (Read 385 times)

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Offline peterg123

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My Totally Weird Oil System
« on: April 16, 2019, 07:51:56 am »
Here is a pic of oil pipes for newly acquired C10L. I have just noticed that the feed and return pipes are looped together.

When I got the bike, which had stood for a year,  she smoked like heck. This was due to wet-sumping so I drained the sump. Smoking vanished and there was a return oil feed but pretty weak. Now I know why! I never noted the oil feed loop until someone on this forum spotted it yesterday, so I have done a better pic.

My questions are

1) What is the effect of this weird looped oil pipe system on the lubrication theoreticals?

2) What was the likely cause that the previous builder did this bodge? Faulty pump or what?

Offline Donald

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Re: My Totally Weird Oil System
« Reply #1 on: April 16, 2019, 08:35:34 am »
Hi there,
1 , unfiltered oil circulating engine
2 , don't know why,
If you are getting a return of oil back to the tank, pump should be ok, I would  take the loop out and all should be fine

Offline timsdad

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Re: My Totally Weird Oil System
« Reply #2 on: April 16, 2019, 09:34:32 am »
I'd think it's just down to someone not knowing what they're doing.

The main point of oil going back to the tank, as well as the filtering, is to give it a chance to cool down a bit before it gets pumped round the hot engine again. The air is cooling the outside but the oil is cooling the inside.


Ray
Just a motorcyclist.

Offline MilitaryRon

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Re: My Totally Weird Oil System
« Reply #3 on: April 16, 2019, 09:50:55 am »
Well since the scavenge side of the pump moves more oil than the feed side, it might be someones daft idea to increase the feed pressure. I can't see any point in it and would remove the loop toot sweat!  Ron

Offline peterg123

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Re: My Totally Weird Oil System
« Reply #4 on: April 16, 2019, 11:14:11 am »
Except the scavenge sucks at a larger rate than the feed feeds...so IMO all it would do is starve the big end!

Offline peterg123

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Re: My Totally Weird Oil System
« Reply #5 on: April 16, 2019, 11:15:44 am »
The guy who rebuilt this bike that has landed in my lap is a well known re-builder of classic cars and bikes....that's what makes it more amazing, given the differential between feed and scavenge rates!

Offline ThomasC11

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Re: My Totally Weird Oil System
« Reply #6 on: April 16, 2019, 12:20:43 pm »
Hm, I don't know whaa a well known re-builder of classic cars and bikes is. But this construction is nonsense.
1946 BSA C11
1937 Sunbeam Model 9
... and a dented Opel