A10 Wet Sumping - other fixes ?.

[wilko]

Wont help, all gear type pumps will pass oil. Some more than others.

[Brian]

I wouldnt entirely agree Wilko.

Your right that gear pumps will seep oil but it can be minimised. With the A10 pump there are basically three escape routes for the oil. Past the in built anti drain valve, back out through the pick up and out through the drive spindle. If the balls are seating properly on both the anti drain and pickup and the pump is in reasonable condition the seepage should be very little.

Most A's wet sump because the anti drain valve is not seating correctly due to it not getting any attention because BSA chose to put it in such a lousy unaccesable location. Even when you have the engine apart they can be very difficult to get out.

Its hard to give an exact time that one should be able to sit before the sump needs draining, mine will sit for about 6 months before it needs draining. I've had others that will only last a couple of months though.

The tap or valve in the delivery line subject has been done to death so I'm not going to go there except to say I would never put anything in the delivery side. One thing to bear in mind is gear pumps are designed to have a flooded suction so if you do have a anti drain valve fitted pray it never fails. If you have a tap I would recommend turning it on a few hours before you go for a ride so the suction side has time to "prime". And yes, I have seen the result of someone forgetting to turn the tap on.

Just for interest here is a pic of how the pumps in our A's work.

[duTch]

Hoo Boy,
            A few points to address here. I have no intention of adding a fed line valve, even thinking about it, before I heard of others doing them I discarded the idea- nuff said.
     I had a feeble effort at removing the grub screw but gave up without a replacement on hand, having flushed the ball & spring with petrol and poked and prodded, blown air though, and sucked back on with resistance, I'm ok with it, will do for now, but have reinforcements on the way.
 Will run the breather pipe into a bottle of some kind just in case.
  > TT, I know you not condoning it, but that idea of 'lever on the kick starter', may work except for when people like me get lazy and decide to occasionally bump-start..!!!

 Musky, thanks for that sump plate offer, will keep it in mind, have also been considering an alloy plate, as the steel one is a bit prone to distorting. Where did you get yours, or make them??
 Also, off topic, but I don't actually have a Dutch bone in my body, except maybe a knuckle-joint, throw-back from when some French rellies had to pretend to be Dutch(anything but french), back in the revolution!!!
     I do have Scottish heritage though, which could incite 'frugality'..!!!!

 Cheers, un-duTch-able

[alanp]

Dutch, don't worry about expecting to feel the urge to be frugal anytime soon, the myth about Scottish frugality has been blown apart by recent revelations concerning the RBoS bank(ers).

[duTch]

Thanks Al, Not sure on the details, but get the drift- Banker$ and I are world$$$$$$(£££in your lingo) apart, believe me...! I'm frugal-ie stingy, I guess Musky was right (but then, I did lash out earlier and bought my mate a dads' day beer=meltdown!!) and it is noted that he didn't reciprocate.

    Cheers 'n happy days ta all tha dads

[JulianM]

Just thought.

How about fitting a sump plate with a drain plug,
When you park it for a longer period, just pop out the plug, put a container under it and leave it.
When you come to ride it again, just pop the plug back it, re-fill withthe container, and ride!
Can't be that hard can it?

Julian

[duTch]

   A half good idea, but unless the transition from the plug hole to the container is a fairly sealed operation, I'd have to fish out lizards and things and gum leaves before putting it back in....
 
   Actually funnily enough, the plan is to use it on a regular basis,why I started building it in the first place. After spending so much time playin' around with it, I don't plan to park and polish...or keep draining oil. 

cheers,duTch

   on the other hand, I could fit an 'auxillary' oil tank,via a special sump plate, to catch the wet sumping and fit a 'lectric oil pump back to the tank...?

[bsa-bill]

Ah now Julian you haven't factored in the old farts memory thing, it's a good idea for robots but not for us less than perfect humans, this is also my opinion on the various taps and switches plans, given a thousand starts and journeys I bet the human would fail more times than a non return valve.

I'm with Dutch - the best cure for wet sumping is a frequently warmed sump

[duTch]

 But then, I don't have super-cold and snow to deal with.!

[stu.andrews]

Being an old fart, perhaps I am missing something. Looking at Brians diagram, the gears seem to be rotating the wrong way for it to work, or do they work that way in OZ?
This subject is interesting in that when using SAE 40, virtually no wet sumping occured on my A7, but since using 20/50, it does, a bit, obviously due to being thinner when cold.
This forum is excellent, keep it going guys!

Regards

[orabanda]

Stu,
Confirming that Brian got it right (as is usually the case!).

This type of gear pump is known as an External gear pump, because the oil flow (path) is around the exterior of the gears (in other words, between the housing and the outside of the gears).

There is also another style of gear pump, called an  Internal gear pump, which has a sun and planetary gear arrangement, which features a crescent (quarter moon) segment between the sun and planetaRY GEAR.

Richard

[stu.andrews]

That's logical- why didn't I think of that. As I said, old fart & a senior moment to boot!

[RichardL]

Based on Brian's drawing, why is suction faster than supply?

[MG]

Because the cogs are wider, ie more volume between two adjacent tooth flanks. The secret is in the third dimension 

[duTch]

 Can't wait to hear about dimensions 4 & 5...?