The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Neil_EngUK on 28.07. 2015 19:29

Title: 2 Oil Flow Questions
Post by: Neil_EngUK on 28.07. 2015 19:29
Can anyone tell me the 'ideal oil flow rate' from the oil tank to the oil pump please?

I am fitting a custom oil tank, with a tap in the pipe to the oil pump. (The bore of the oil hose is 7.8 mm diameter, the spigot internal diameter is 8mm but tap bore is 6mm diameter.)

I put the oil tank on the bench for a test, and was surprised how slow under gravity feed, the oil flows out. I am using 20/50 at room temperature, with only sufficient lenght hose.

Does the oil pump 'suck' the oil into itself, or does it just pump whatever oil it gets, to the big ends etc?

Many thanks as always
Neil

Title: Re: 2 Oil Flow Questions
Post by: Greybeard on 28.07. 2015 19:38
At the mention of ' tap in the pipe to the oil pump' I heard some sharp intakes of breath. I think you'll get a few replies to this question. I'd get ready to duck if I were you!  *fight*

Yes the pump sucks oil from the tank. If the pipe bore is no less than the tank outlet pipe bore and no longer than standard length then in my opinion it will be ok.
Title: Re: 2 Oil Flow Questions
Post by: duTch on 28.07. 2015 19:55

  *problem* *problem* *????* *dunno*....What GB said....! *ex*......"tap"

 The pump will suck it some, but it shouldn't have to, and in my opinion any restriction will risk having enough to pump...8mm should be enough for a short distance
Title: Re: 2 Oil Flow Questions
Post by: muskrat on 28.07. 2015 20:53
G'day Neil.
 *rant* *pull hair out* *problem* *work* re the tap. Found a Notrun Atlas on the side of the road last week. It had a tap and a hole in the crankcase.
just make sure the line is primed before starting.
cheers
Title: Re: 2 Oil Flow Questions
Post by: Neil_EngUK on 28.07. 2015 22:14
Thank you for your replies ;)

But, if you take off the oil line going to your a10 pump (and with your engine oil cold) how long does it take to fill a jug with a pint of oil?
Title: Re: 2 Oil Flow Questions
Post by: Greybeard on 28.07. 2015 22:35
 *conf2*
Title: Re: 2 Oil Flow Questions
Post by: Butch (cb) on 28.07. 2015 22:41
Thank you for your replies ;)

But, if you take off the oil line going to your a10 pump (and with your engine oil cold) how long does it take to fill a jug with a pint of oil?

That would depend on the size of the jug.
Title: Re: 2 Oil Flow Questions
Post by: Derby Rob on 28.07. 2015 22:59
a pint is a pint,no matter what the size of the jug is ? or am i confused again !
Title: Re: 2 Oil Flow Questions
Post by: Greybeard on 28.07. 2015 23:33
This is beginning to sound like; How many beans make five?
Title: Re: 2 Oil Flow Questions
Post by: duTch on 29.07. 2015 00:20

 Imperial or U.S pint. ..?
Title: Re: 2 Oil Flow Questions
Post by: muskrat on 29.07. 2015 09:55
Now, now children. *sarcastic*
Is your valve a ball and spring type or a ball cock? https://www.youtube.com/watch?v=UZDliLSCYAw
It may take a minute or two for the oil to reach the pump.
Cheers
Title: Re: 2 Oil Flow Questions
Post by: KiwiGF on 29.07. 2015 10:51
Hi Neil, I think I can see why you are asking the question but i doubt anyone would be able to answer your question without setting up a test.

In my opinion the biggest restriction to oil flow will be the pipes as they are far longer than the smaller diameter sections, so if you use the same diameter pipes as standard and no fitting with a really small bore and I think you will fine, the oil gets much thinner and flows much faster when it's hot of course.

The flow rate is not huge, it's not like oil is rushing through the pipes at high speed.