Where has all my oil gone (Part 2)

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Reworking the end plate affects the pressure side. The scavenge side normally wears the gear teeth and the pump cavity, which cannot be repaired.

There's no aftermarket upgrade that I'm aware of.
 
maylar said:
Reworking the end plate affects the pressure side. The scavenge side normally wears the gear teeth and the pump cavity, which cannot be repaired.

There's no aftermarket upgrade that I'm aware of.
Click to expand...

Unless Comnoz decides to make his pump.
 
Hi Lads,

As usual many thanks for all your helpful advice. I've had a good read of all the posts on all things oil pump related so I think I have a good angle on what to do.

I was thinking of splashing out on a new pump consider it could be referred to as the 'heart' of the engine pumping all that lovely oil throughout the engine.

Maylar's comment about the new pump he got has me worried, it does not sound like the new pump he got worked out? any chance of explaining what the issue was?

Does anybody know if all the new pumps available are NOS or re-manufactured originals?

Kevin
 
I wouldn't use a new pump, unless I knew the gears had too much clearance between themselves (not the end plate).
 
swooshdave said:
I wouldn't use a new pump, unless I knew the gears had too much clearance between themselves (not the end plate).
Click to expand...

Hi,

Interesting, why would you not use a new pump, do you feel there is quality issues?

Kevin
 
click said:
I was thinking of splashing out on a new pump
Click to expand...

Both feed and scavenge pump gear end play can be reduced to back to zero end foat by lapping-in the end faces of the pump body.

Occasional lapping of the pump to remove end play should be considered a service task, as finding end play doesn't automatically mean you to need to buy a new pump.

http://britmoto.com/manuals/Manuals/850_man.pdf - Section C25, "Servicing The Oil Pump"
 
click said:
swooshdave said:
I wouldn't use a new pump, unless I knew the gears had too much clearance between themselves (not the end plate).
Click to expand...

Hi,

Interesting, why would you not use a new pump, do you feel there is quality issues?

Kevin
Click to expand...

I wouldn't use one unless I was 100% assured that all the clearances where very tight. I would never make that assumption without validation.
 
L.A.B. said:
Both feed and scavenge pump gear end play can be reduced to back to zero end foat by lapping-in the end faces of the pump body.
Click to expand...

Yes, but the scavenge side typically does not benefit from that. Scavenge problems arise from metal shavings getting drawn into the pump and scoring the gear teeth and pump cavity. Lapping doesn't help.

Click, my new pump is way better than what I had. It just annoys me that it's not perfect, considering the cost. My buddy replaced his pump last year and it scavenges perfectly, so I guess there are tolerances. Difficult to measure and validate before installing tho.
 
maylar said:
L.A.B. said:
Both feed and scavenge pump gear end play can be reduced to back to zero end foat by lapping-in the end faces of the pump body.
Click to expand...

Yes, but the scavenge side typically does not benefit from that. Scavenge problems arise from metal shavings getting drawn into the pump and scoring the gear teeth and pump cavity. Lapping doesn't help.

Click, my new pump is way better than what I had. It just annoys me that it's not perfect, considering the cost. My buddy replaced his pump last year and it scavenges perfectly, so I guess there are tolerances. Difficult to measure and validate before installing tho.
Click to expand...

Hi Maylar,

Thanks for the extra info. from what you are saying it sounds like a bit of a lottery regarding how 'good' a new pump you get. I agree they are very expensive, it would be good to know if you are getting a 'good' one before you shell out the dosh for one :D

When you say your buddy's pump scavenges perfectly how can you tell, is it to do with the flow of oil coming back into the tank or how little oil there is in the sump after a run or both?

Kevin
 
maylar said:
Yes, but the scavenge side typically does not benefit from that. Scavenge problems arise from metal shavings getting drawn into the pump and scoring the gear teeth and pump cavity. Lapping doesn't help.
Click to expand...

I think click has yet to ascertain if there is an actual problem with the scavenge side, and at this stage I'm not entirely convinced there is?
 
L.A.B. said:
maylar said:
Yes, but the scavenge side typically does not benefit from that. Scavenge problems arise from metal shavings getting drawn into the pump and scoring the gear teeth and pump cavity. Lapping doesn't help.
Click to expand...

I think click has yet to ascertain if there is an actual problem with the scavenge side, and at this stage I'm not entirely convinced there is?
Click to expand...

Hi L.A.B.,

I agree, it's early days yet, hope to clock up some miles this week & keep an eye on levels / oil usage etc.

I've come across lots of posts on this forum & others from lads who have stripped various parts of their engines only to find nothing wrong, or buying expensive parts & then realising the one part they did not purchase is the part they need :mrgreen:

I have basic motor & mechanical skills & I know my limitations, hence ALL my annoying questions.

More anon.

Kevin
 
click said:
I have basic motor & mechanical skills & I know my limitations, hence ALL my annoying questions.

Kevin
Click to expand...

Pretty sure you don't have the market cornered on annoying questions. :mrgreen:
 
hi click,going back to the title of this thread[where has all my oil gone] i dont think it accumulating in the pump,and i dont think the pump is the problem,you would,nt have managed a 200 mile ride and getting up to 90 mph [on that private road ]if the feed side was,nt pumping the motor would have gone bang,if the scavenge side was not scavenging, you would see blue smoke pouring out the exausts, next time you start up observe the return pipe in the top of the tank,at first there will be a steady uninterupted flow of oil till the pump clears the crankcase,then it will be intermitent,if my memory serves me right i can remember a road test of a commando back in the day and the oil consumption was stated at 300 miles per pint,but with modern pistons,rings and closer bore tolerances i would expect it to be a bit better than that
 
chris plant said:
hi click,going back to the title of this thread[where has all my oil gone] i dont think it accumulating in the pump,and i dont think the pump is the problem,you would,nt have managed a 200 mile ride and getting up to 90 mph [on that private road ]if the feed side was,nt pumping the motor would have gone bang,if the scavenge side was not scavenging, you would see blue smoke pouring out the exausts, next time you start up observe the return pipe in the top of the tank,at first there will be a steady uninterupted flow of oil till the pump clears the crankcase,then it will be intermitent,if my memory serves me right i can remember a road test of a commando back in the day and the oil consumption was stated at 300 miles per pint,but with modern pistons,rings and closer bore tolerances i would expect it to be a bit better than that
Click to expand...

Hi Chris,

After draining the sump, and keeping the bike at tickover, approx. 1Krpm, I observed the return pipe in the oil tank, it took a few seconds and the oil started to appear, a very healthy continuous flow. The return pipe splits the return into two steady streams. I observed this for at least 4 minutes.

The oil consumption figure is VERY interesting, a pint of oil every 300 miles!!! that seems like a lot of oil? I've heard of guys doing 3000 mile trips on their Commando's that would work out at 10 pints of oil, if your running a type of oil not commonly available like me i.e. 40wt you could be badly stuck unless you bring a lot of oil with you.

Overall the bike is running really well & very strong, it's just the owner has all these questions & should just get on the bike & ride it :roll:

Thanks for the reply.

Kevin
 
hi click,i agree it does sound high consumption,do your level checks and go for a long ride,and report back what you find regarding consumption
 
I have a set of later cases for a 72 that appeared to have lost a piston at high speed. I was able to pull about a teaspoon of mangled oil ring bit along with regular ring and piston bits out of various nook and crannies of the cases. The majority was dug out of the oil channel and oilpump hole. Pulling the oil feed manifold and grub screws, I was able to shine light in there and push a wire and the like to get all the crap out.
Where has all my oil gone (Part 2)
Where has all my oil gone (Part 2)



My point is, if you pull your pump, pull the feed manifold and anything else (grub screws) so you can inspect the oil holes and tunnels as well as posible. You just never can tell.

Your problem seems a little Symptomatic as a blockage.
 
hi again click,i managed to find that road test i mentioned,it is in GREAT BRITISH MOTORCYCLES OF THE SIXTIES, BY BOB CURRIE,and is taken from the motor cycle,11 september 1968,its one of the first fastbacks,and to quote a paragraph it says,oil consumption was 300 miles to the pint.this is thought to be higher than average but there was no obvious explanation.the exhaust was not smoky and the engine remained free from serious leaks. un quote,however this is probably not relevant to your later bike with more modern pistons,rings and closer bore tolerances
 
chris plant said:
hi again click,i managed to find that road test i mentioned,it is in GREAT BRITISH MOTORCYCLES OF THE SIXTIES, BY BOB CURRIE,and is taken from the motor cycle,11 september 1968,its one of the first fastbacks,and to quote a paragraph it says,oil consumption was 300 miles to the pint.this is thought to be higher than average but there was no obvious explanation.the exhaust was not smoky and the engine remained free from serious leaks. un quote,however this is probably not relevant to your later bike with more modern pistons,rings and closer bore tolerances
Click to expand...

Hi Chris,

I really appreciate you finding the road test you mentioned. I've been running mainly modern motobikes over the last 15 years & I'm 'slowly' getting back into the frame of mind you need to to run old brit bikes! (Some might say a state of insanity :mrgreen: )

Minor update:

Did 25 miles today, before run I checked the level after bike was ticking over for 3-4 mins. Checked level just after run, NO change. I'll keep running the bike this week & keep an eye on the levels.

More Anon

Kevin
 
click said:
Minor update:

Did 25 miles today, before run I checked the level after bike was ticking over for 3-4 mins. Checked level just after run, NO change. I'll keep running the bike this week & keep an eye on the levels.

More Anon

Kevin
Click to expand...

That's perfect. I'd say you're good to go.
 
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