The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: a10 gf on 13.06. 2013 20:46
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Adm edit: post split from http://www.a7a10.net/forum/index.php?topic=7010.msg50526#msg50526 (wardleyrob).
Would be very interesting to know how to access the spring\ball without engine strip\case split !
Thanks
edti: seems a mod is possible.
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G'day wardleyrob, twin brother of wardleybob *????*.
I would imagine to do the job insitu you would drill out the oilway till the orig ball & spring come out then modify the hole to go al la A65. Would this not make the new oil way too large or do you plug the hole and re drill *????*
Cheers
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Would this not make the new oil way too large or do you plug the hole and re drill
I've only seen a pic of this SRM mod Musky, I presumed that the ball seated against the pump body (, the pump body being chamfered to suit and a longer spring and larger ball)
Can't recall where I saw this, bound to have been an article in one of the mags, jeez if I had a memory I'd be dangerous
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Hi , I've had the SRM mod done about 8 yrs ago and because of another similar thread re wet sumping , as a result I had to ring them as I seemed to rememeber the ball being against the pump and thought bingo it's slipped off hence my sumping problem but no on checking ball goes against the crankcase spring against the pump as per so I'm told A65 so it would be easy ...if you've had the conversion done , regards BobH.
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Hey Bob,
I am in the process of working out a procedure to convert A10's to the superior A65 arrangement, and will post details when I am happy with it (keeping it in the family!).
I think it might be possible to do the mod without splitting the crankcases.
If the spring is placed against the oil pump, and the ball is on the timing bush side, then it is likely to block oil flow to the bush.
Richard
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Richard ,shown up again ! You are quite right and I did honestly mean the other way round but fingers and mind not in unision yet again , think of the engines I could have ruined Regards BobH.
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hi guys/orabanda, i have an idea myself, have a look and make comments,cheers
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As I read the first posts, I had a similar idea to kiwipom (your credit, I'm not stealing your thunder), using a 'grub-screw' from a LPG fitting. There is a variation I recently discovered that has a replaceable rubber seal tip, held in place via a screw in plug with ~5mm bore,and ball and spring behind (I expect for using two+ bottles to a system- irrelevant).
It's a bit chunky but maybe enough material to slice a different thread and trim to length so to not block the bush oil feed and use whichever spring most useful....or whatever??
Come to think any Allen-head grub screw could be drilled through but steel ones maybe a less satisfactory seating medium, or could maybe even make your own from Ally bar(drill and press in a hex before threading o/s)?
It needs to be simple and easy to service. I don't think locktight necessary, as 'where's it gonna go to?'
Hope that makes sense, it took a while! cheers, duTch
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Good move making this a separate topic!
I will have info to contribute soon.
I am hoping to use A50 / A65 ball, spring and gasket, because they are available, cheap, and they work!
The A50 spring is much heavier than the existing A10 arrangement (which is why the A10 doesn't work).
Bear in mind that when the ball is moving back into the casing, it could block off the oil hole (at 90 degrees) linking into the timing bush, if the drilled depth of the hole is incorrect!
Richard
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Hi guys, yes Richard as you say of blocking the oil hole, but my idea was basically using the same ball and spring and simply making a removable seat which could be accessed from the pump side, the ball seems to be back about 20mm but an exact measurement would have to be made so as to manufacture the removable seat. Dutch the insert seat would need to be sealed in some way or oil could pass around and down the insert bypassing the ball and spring, (my opinion)cheers
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Oh yeah K-Pom, yer right, I stand corrected- I'm a dumbass, was forgetting that this is all about the wet-sump issue in a dormant engine , when running I think it wouldn't matter.
Loktite and Selleys(?) do a couple of products that's used on hydraulic threads, I used one on my sludge trap plugs, may be the go?
Cheers
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the ball and spring...very interesting as i am sure SRM just told me to drill thru with a 5/16 bit..and drop in the a65 ball and spring...
have to go back thru my correspondence...see if i missed something.. the sleeve idea looks easy enough...as long as it doesnt slide a bit further down the hole...
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hi guys/shuswapkev, yes i may have `over engineered` my idea but keeps the brain active,cheers
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Hy kiwepom I have done the conversion without spliting the cases. You drill a 5/16 hole tease the original ball and spring out.
Make sure you put a stronger spring back in.
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hi guys/wardleybob,so does the ball seal against the pump? cheers
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Hi Kiwi, thats a yes ,look at orabanda's reply to my earlier incorrect post above , regards Bob
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Just for the sake of variation, instead of making a liner for the hole you could install the tube inside the spring so as to limit the travel of the ball but leaving enough space for the pumped oil to get past.
My twopence worth would be one of two ways.
1 - similar A65/50, drill out just big enough to remove existing ball and spring, then drill out larger from pump to just short of oil feed to bearing, (larger being large enough for ball and flowing oil), then drill for smaller holes at the periphery of the bottom of the larger hole so that the ball could not block oil flow, counter sink the pump to accept the ball.
2 - fit the Bri-Tie non return valve that I have lying in a box in the shed as neither bike wet-sump to any extent after rebuilds, not popular with everyone but worked for me just fine and has the same components as your about to retro fit
PS I'm not good with apple carts
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Im not sure of its effect on the design but the std a65 pump has a bigger supply hole to suit it's revised spring/ball arrangement?
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Hy guys you drill a 5/16 hole from the front .tease out the original ball and spring.I put a 6mm ball in and a stronger spring.
The ballseats against the oil pump. I counter boar the back of the pump slightly. All done without spliting the cases
Make sure you get all the crude out. Ps it will still wet sump if the pump is worn. I put a sump plug in and if I am not useing
The bike I let it drain out.
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hi guys, wardleybob says(Ps it will still wet sump if the pump is worn) so a worn pump will let oil track from the cogs that supply pressure, to the return oriface and back into the return pickup,is this correct?cheers
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Hi All
Kiwi, the worn pump will let oil leak out along the drive spindles, out between the end plate and casing and some will leak straight through the porus alloy *eek*
Bill, the difference between the britie and standard or A65 is that the oil is sucked through the britie valve and pumped through the standard valve
If the pump body is counter sunk or the ball tapped into the alloy body the pressure the spring exerts is lessened as the seating area becomes wider !!!!
Just rotate the ball against the pump body till you see a continuous shiny line, that will be enough !
Beware of gasket fibres near the seating or spring as these will prevent the ball from seating
HTH
John
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hi guys/chaterlea, it must be quite tricky making sure that the ball stays in place while fitting the pump,also i read somewhere that the A10 pump was not designed to `create a vacuum`so a valve on the oil feed would presumably lessen it`s capability,cheers
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Bill, the difference between the britie and standard or A65 is that the oil is sucked through the britie valve and pumped through the standard valve
Yep that's all true John, but I don't altogether go with the pump is not designed to suck theory, fair enough it's a gear pump as opposed to a type with pistons which might shift air more efficiently, however the return side of the pump is just a slightly larger version of the feed side and the return side is constantly sucking and sucking a mixture of oil and air and also having to suck open a ball valve, the feed side has an advantage in that there is a weight of oil ready to be sucked in in normal circumstance.
I imagine the fear is the pump wont prime, but again the return side manages to do this in circumstance where it constantly loses oil and has to pump air
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hi guys,some pics of A10(on left) and A65(on right) oil pumps. virtually the same apart from rotation in opposite directions hence A65 drives from the upper cogs and A10 from lower. O-ring on A65 to stop oil flowing through to the drive cog which could be applied to A10 after a bit of modification, i dont see any advantage in the A65 apart from that. Cant see much of a chamfer for ball-spring oil control, cheers
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hi guys,just seen that the last pic is A65 on left and A10 on right,cheers
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Hi kiwipom - I have an A65 pump that I thought I might use but noted that it is a tad longer than an A10 one so it still lives in the shed.
do you know if it is possible to swap the drive end and shaft between the two pumps, I didn't try with mine as I thought I'd mark the cogs before dismantling (pangs of conscience since I did not do this with either of my other bikes pumps)
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hi bill,no i have tried switching top and bottom set of cogs on the A65 pump which you would have to do to get the drive in the lower position which would then pump in the correct direction as you have to switch the rotation, but was not possible due to too tight/slight difference in cog housings, there does not seem to be any point in pursuing the exercise as the pumps are almost identical apart from the small o-ring which could be made to fit on the A10 pump,cheers
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Cheers for that Kiwipom
Looks like I'm going to have to resurrect my sellers account, to much stuff lying around doing nothing but taking up space
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Bsa bill, i have an a65 pump body with a10 drive shaft casting/shaft, works fine, gears are wider than a10 so more flow, my bike does not wet sump even though i do not recall seeing an o ring inside it.
It took a bit of filing of the holes in the drive end casting to get it to spin freely.
So dont sell your a65 pumps!