1958 G11 - Wet Sumping

Information relating to the Matchless G11 or AJS Model 30 600cc twin
starfield181
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Joined: Wed Aug 18, 2010 11:56 am
Location: WILTSHIRE UK

1958 G11 - Wet Sumping

Post by starfield181 »

quote:

quote:
Thanks for various replies and it seems that I have probably confused people over my 'methodical' approach to measuring the degree of wet sumping. The table of events is as follows:

1st Drain of crankcase yielded 175ml. Not sure how long it had been standing at this point but the bike had done a run the previous day so not more than 24hours.

2nd drain yielded 75ml which was immediately after the engine was stopped having been run for 10 minutes or so. The crankcase was empty at the start of this test having just done test 1 and it was meant to establish the amount of oil in the crankcase during normal running,

3rd Drain yielded near 200ml after a period of 30hours. The crankcase was empty at the start of this period having just done test 2. Engine was not run between test 2 and 3

4th drain - today yielded 50ml after a period of 24hours. The crankcase was empty at the start of this period having just done test 3. Engine was not run between test 3 and 4



5th Drain (Tuesday 11th Sept) yielded 25ml. Engine still has not been run. Giving it one more day then going to take the bike for a run and repeat the tests.



6th Drain (Wednesday 12th Sept) yielded about 15-20ml. Rate of loss is definitely slowing. Rained today so aborted the proposed ride. Maybe tomorrow. Still confused.

Peter
cbranni
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1958 G11 - Wet Sumping

Post by cbranni »

Maybe its slowing because the quantity of oil in the tank is getting less, less oil = less pressure or head of oil to force oil through pump into sump...............just a thought
Colin
only dead fish go with the flow
cbranni
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1958 G11 - Wet Sumping

Post by cbranni »

quote:
Maybe its slowing because the quantity of oil in the tank is getting less, less oil = less pressure or head of oil to force oil through pump into sump...............just a thought
Colin

PS if you are returning the measured oil back to the tank then the above thoughts are load of rubbish
only dead fish go with the flow
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paul knapp
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1958 G11 - Wet Sumping

Post by paul knapp »

You are not the only one starfield181, my old girl drains the mono SAE50 oil in 7 to 10 days into the sump, depending on the weather temperature. I checked the pumps and found that the pump gear spindles to be a good fit in the end plates, they, which in turn had no signs of wear. I then noticed the pump gear wheel teeth had plenty of back lash, so I guess that is where the oil is finding it's way through.
Now to over come the wet sumping dilema, I always drain the oil tank within a day of having the bike out for a run. I use a 2 liter Coke bottle to hold the oil, screw top on, and place it next to bike under cover......This gives me time to worry about other things.

When you finish doing all this fiddling about, daily measuring ETC, the 'bottom line' will be that you still have a wet sump problem!........join the club.

Paul.
___“As a hobby for the technically minded, motorcycling provides great scope.”

J.B.Nicholson

Don't worry about the world coming to an end today. It's already tomorrow in Australia!


_____________________________________________



starfield181
Posts: 114
Joined: Wed Aug 18, 2010 11:56 am
Location: WILTSHIRE UK

1958 G11 - Wet Sumping

Post by starfield181 »

quote:

When you finish doing all this fiddling about, daily measuring ETC, the 'bottom line' will be that you still have a wet sump problem!........join the club.

Paul.


Sad but probably true. However, I started, so I will finish even if the outcome is already known.
ghost123uk
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Joined: Sat Nov 26, 2011 12:07 pm
Location: CHESHIRE UK

1958 G11 - Wet Sumping

Post by ghost123uk »

quote:
quote:

When you finish doing all this fiddling about, daily measuring ETC, the 'bottom line' will be that you still have a wet sump problem!........join the club.

Paul.


Sad but probably true. However, I started, so I will finish even if the outcome is already known.



~~~~~~~~~~~~~~~~~~~~~~~~~~~

John, with a G12, near Chester in the UK
starfield181
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Joined: Wed Aug 18, 2010 11:56 am
Location: WILTSHIRE UK

1958 G11 - Wet Sumping

Post by starfield181 »

Thank you all for you words of wisdom on this post. The second round of measuring has produced identical results to the first and establishes that the bike is only dropping about 20ml of oil a day; possibly less. Quite low compared to some figures that were mentioned.

My main concern is to avoid getting engine oil into the chaincase with a slipping clutch as collateral damage. I reckon the crankcase should hold at least a pint before leaking into chaincase so I have made up a dipstick calibrated in 1/2lt increments. During the riding season, each time it drops by 1/2lt I will run the engine to get oil back in the tank. Reckon this will be no more than once every two weeks so not really a big deal since with luck the bike will get used more often than that anyway. Come the winter I will simply drain the tank completely along with the carb.

Once again thanks for the input but I think we can close this thread now.

PeterEdited by - starfield181 on 16 Sep 2012 4:11:35 PM
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