Wet sumping
-
- Member
- Posts: 83
- Joined: Fri Sep 16, 2016 7:51 am
- Location: QUEENSLAND AUSTRALIA
Wet sumping
Hi,
This morning when I went to start my bike, which has now done 250 miles from rebuild, it billowed blue smoke. Upon checking the oil reservoir it was substantially lower than usual. I then drained about 300 ml from the sump. Is this wet sumping indicative of a worn pump. I am asking this as I replaced the plunger on rebuild and this is the first time it had happened to me. The pump is still pumping to the head and to the oil tank.
Regards
Chris
This morning when I went to start my bike, which has now done 250 miles from rebuild, it billowed blue smoke. Upon checking the oil reservoir it was substantially lower than usual. I then drained about 300 ml from the sump. Is this wet sumping indicative of a worn pump. I am asking this as I replaced the plunger on rebuild and this is the first time it had happened to me. The pump is still pumping to the head and to the oil tank.
Regards
Chris
- Rob Harknett
- Member
- Posts: 11236
- Joined: Mon Jan 01, 1990 12:00 am
- Location: ESSEX UK
Re: Wet sumping
The sump does retain a certain amount of oil, not sure how much in ml. As you have done work on the pump. Perhaps someone will suggest you may have done something wrong and advise accordingly. I have never had a pump problem, so do not have any experience to pass on. Except having to except, when standing for a few weeks, my bikes will sump oil. So all I do is drain and re start.
-
- Member
- Posts: 8542
- Joined: Wed Sep 01, 2004 1:00 am
- Location: WEST SUSSEX UK
Re: Wet sumping
How long had it been standing since last run?Chris Berry wrote:Hi,
This morning when I went to start my bike, which has now done 250 miles from rebuild............,
'There is a tide in the affairs of men
Which taken at the flood............'
Which taken at the flood............'
-
- Member
- Posts: 83
- Joined: Fri Sep 16, 2016 7:51 am
- Location: QUEENSLAND AUSTRALIA
Re: Wet sumping
No more than 24 Hrs as I was working on it the day before. I've checked the pump operation which seems OK. Tonight I drained the sump completely and I'll See how much is in it tomorrow morning (Australian time)SPRIDDLER wrote:How long had it been standing since last run?Chris Berry wrote:Hi,
This morning when I went to start my bike, which has now done 250 miles from rebuild............,
- Rob Harknett
- Member
- Posts: 11236
- Joined: Mon Jan 01, 1990 12:00 am
- Location: ESSEX UK
Re: Wet sumping
If you refilled with oil, upon starting the sump will first fill to the required level, so oil level in the tank will drop a bit. The bike should not smoke a lot. Need to know the history, perhaps oil circulation is actually OK and some thing else done when you worked on the engine is causing the engine to smoke.
-
- Member
- Posts: 8542
- Joined: Wed Sep 01, 2004 1:00 am
- Location: WEST SUSSEX UK
Re: Wet sumping
Hmm, that's a bit quicker than it 'should' be after only 24hrs.Chris Berry wrote:I replaced the plunger on rebuild and this is the first time it had happened
Your new pump plunger for the '48 should have the 1/4" annular groove for the plunger guide pin. A 3/16" groove was used in the earlier (up to '46/'47?) engines.
I suppose you haven't re-used a 3/16" pin in a 1/4" plunger, thus reducing the pump throw and therefore its efficiency?
Otherwise check that the pump end plates are sealing 100%.
'There is a tide in the affairs of men
Which taken at the flood............'
Which taken at the flood............'
-
- Member
- Posts: 83
- Joined: Fri Sep 16, 2016 7:51 am
- Location: QUEENSLAND AUSTRALIA
Re: Wet sumping
Another lesson i guess. I have just reused the old guide pin but it did seem to fit well in the groove of the plunger. The engine in my bike is actually a '51' but i'm not sure what difference that makes to the oil pump. On a better note I checked the oil tank this morning and there was no appreciable drop in oil level and the sump was empty (I drained it last night). When I started the bike there was no smoke so who know what it was. Maybe the pump plunger was in such a position that the oil was allowed to run through the pump into the sump.SPRIDDLER wrote:Hmm, that's a bit quicker than it 'should' be after only 24hrs.Chris Berry wrote:I replaced the plunger on rebuild and this is the first time it had happened
Your new pump plunger for the '48 should have the 1/4" annular groove for the plunger guide pin. A 3/16" groove was used in the earlier (up to '46/'47?) engines.
I suppose you haven't re-used a 3/16" pin in a 1/4" plunger, thus reducing the pump throw and therefore its efficiency?
Otherwise check that the pump end plates are sealing 100%.
- Pharisee
- Member
- Posts: 1126
- Joined: Tue Mar 15, 2016 8:51 pm
- Location: Lincolnshire UK
- Contact:
Re: Wet sumping
There was popular myth that you should leave the engine at TDC on the compression stroke to avoid wet sumping but when you think about it, with eight revolutions of the crankshaft for one cycle of the pump, you've only got a one in eight chance of it being the 'right' TDCChris Berry wrote:Maybe the pump plunger was in such a position that the oil was allowed to run through the pump into the sump.
I'm from the Fens.... Gimme six.
- Expat
- Member
- Posts: 1033
- Joined: Thu Nov 12, 2015 2:22 pm
- Location: Tennessee, USA
Re: Wet sumping
Mmmm.......didn't think of that. Still, it is possible to relax the valve springs at TDC on the firing stroke, eh?
Luckily wet sumping is not a problem for me, yet anyway!
Luckily wet sumping is not a problem for me, yet anyway!
Keep shiny side up.
These are my principles, if you don’t like them, I have others. (Groucho Marx)
These are my principles, if you don’t like them, I have others. (Groucho Marx)
- clive
- Member
- Posts: 5657
- Joined: Mon Jan 01, 1990 12:00 am
- Location: LONDON UK
Re: Wet sumping
Unless your 51 engine has been bodged it must have had the later pump and hence the later guide pin. My usual advice at this point is did you disassemble the guide pin? It has one end which is relieved and smaller than the other. That end must go into the pin holder, although it looks like it should be the other way round. If in the wrong way it will be a loose fit in the pump groove and will substantially reduce the effectiveness of the pump. I am just wondering if instead of wet sumping the reduced effectiveness of the pump meant the return side was not coping quite wth the supply and hence the sump filled gradually over the 250 miles of use.Chris Berry wrote:Another lesson i guess. I have just reused the old guide pin but it did seem to fit well in the groove of the plunger. The engine in my bike is actually a '51' but i'm not sure what difference that makes to the oil pump. On a better note I checked the oil tank this morning and there was no appreciable drop in oil level and the sump was empty (I drained it last night). When I started the bike there was no smoke so who know what it was. Maybe the pump plunger was in such a position that the oil was allowed to run through the pump into the sump.SPRIDDLER wrote:Hmm, that's a bit quicker than it 'should' be after only 24hrs.Chris Berry wrote:I replaced the plunger on rebuild and this is the first time it had happened
Your new pump plunger for the '48 should have the 1/4" annular groove for the plunger guide pin. A 3/16" groove was used in the earlier (up to '46/'47?) engines.
I suppose you haven't re-used a 3/16" pin in a 1/4" plunger, thus reducing the pump throw and therefore its efficiency?
Otherwise check that the pump end plates are sealing 100%.
So is it possible you have it in the wrong way? If you are going to check you will have to drain the oil tank as the pump body will tend to slide forward as soon as you take the pin out. You need the end plates off to relocate the pin in the groove. Still after 250 miles on a rebuilt engine an oil change would not be a bad thing.
clive
if it ain't broke don't fix
if it ain't broke don't fix