'57 Huntmaster - Ball Valve

[roger.attwood]

Hi Everyone. I'm back again for more advice. I've split the crankcases for examination, and I have been checking the oilways are clear. I put a tube against the holes where the oil pump is mounted and blew through them. One of them was clear if I blew gently, then stopped up if I blew hard (but not completely!). I traced the path through to the pipe that hangs down in the oil sump. There is a ball bearing in a housing at the end of the pipe, and it closes off the oilway when I blow hard. I've been trying to trace the oil flow, and I believe this pipe is used to scavenge the oil in the sump and return it to the oil tank. I'm presuming the ball bearing is to stop the flow of oil from the tank to the sump (wet-sumping) when the engine is stopped.

View is from below the engine with sump cover removed.

1. Am I right in my supositions so far?

When the ball bearing blocks off the pipe, I can still get air past it. Therefore, it isn't seated properly in the housing. I believe it can be seated by giving it a tap with a hammer to re-seat it.

2. Again, am I right?
3. How do get at the ball bearing? It looks like the top of the housing unscrews (screwdriver slot?), but it's so tight the pipe starts to move/twist. Can the pipe be removed easily so I can hold the housing firmly.

4. Lastly, can the indicated screw be removed? It has been centre-popped, but I've cleared that. The screw undoes about 2 turns, then stops. I'm not sure if it is fouling on the bush, or there is some other reason? I pushed a bit of wire down the hole from the other side (under the oil pump) and the wire got caught/trapped. Is there something in the oilway that can trap the wire (another valve of some sort?).

Thanks again for any advice.

[roger.fellows]

Hi Roger, I expect somebody with specific knowledge will answer you, but in the meantime have a look at the topic 7 or 8 items below yours in this section of the forum. This is a regular sort of question.

Roger

[johnwalsh]

Hi Roger, the small screw in the case that you can move a few turns is a small bung below which is a spring and ball bearing. Worth removing, cleaning and re-seating the b/bearing as you have described. I would carry on removing as you have described, but try removing any of the centre punch marks if you can. The steel screw will cut through the alloy casing material anyway. I did mine recently and it held a small quantity of gritty oil!
The return pipe in the sump does hold a b/bearing which is not sprung loaded, only held in place by gravity. I didn't bother removing mine as it was very tight. You could try holding the union with some grips but I preferred to leave well alone. I can't confirm whether the pipe is removeable from the casing but I would imagine it is. I believe the small screw ( bung ) is the main anti syphon. Hope this helps.
John

[Simon.Gardiner]

I think the ball in the return pipe must be just to stop oil draining from the actual return pipes, I can't see the tank draining by that route (and like John I've just been doing my oilways and as the bottom screw was very tight I too didn't bother removing it).
It's that small screw in the crankcase that has the anti-drain spring and ball behind it, that trapped the wire when you pushed it in.
I ended up using an impact driver (carefully) to get the screw/bung out, even after drilling out the centre punch dimples.
If you feel yours end ups being too mangled Drags have them in stock!

SG

[ColinPeck]

A word of warning with regards to the blanking screw behind the oil pump. I bought my Huntmaster with a con rod through the crankcase, the cause? This screw had come undone so the oil from the feed side of the pump was going directly into the crankcases with little or nothing going through the crankshaft to the main bearing or big ends.
The strange thing was I never found the spring, ball or screw when I stripped the engine, the hole in the case was on the drive side so it seems almost impossible for all three of them escaping from the engine?? The bike had 3000 miles on it from a total re-build "supposedly" done by a professional for the previous owner at the cost of over £10,000 (I have all the bills). Could the engine have managed 3000 miles with these missing from the re-build? I wouldn't have thought so but they were nowhere to be seen and I was the only one to touch the bike after it went bang.
When I re-built the engine I used loctite both to seal the threads and help hold it as well as some decent centre punching!
Colin

[pete.collings]

I agree with the above comments, but would add that the fit of the sump pipe into the crankcase should be good, or it is possible to suck additional air into the return line, with a possible buildup of oil in the bottom of the crankcase.

I have a return pipe available (removed from a damaged crankcase) should it be needed, this and other Huntmaster parts are available via my web homepage, link as below:

http://homepage.ntlworld.com/pete.colli ... T_PAGE.htm

[roger.attwood]

Again, thanks for the advice/comments. I managed to get the small screw out - it was jamming against the bush. The spring was a little gritty. I reseated the ball, and I staked the screw twice. As for the ball in the tube - I tried again to remove it, applying some heat to the housing, but it just won't move. I'm going to leave well alone. I noticed that a bolt holds the tube to the wall of the crankcase, and the end of the bolt actually protrudes a smidge to the outside of the case. Has anyone come across any leaks from here?

[johnwalsh]

I've not owned a running Ariel twin long enough to say so, but I would imagine its highly unlikely to leak. I would be careful of disturbing the pipe as it is very close to the crank flywheel and you don't want it chafing.

[Simon.Gardiner]

That bolt always seems to protrude and I've never seen one leaking (so far anyway )
(My early crankcases have been modified to take the later crank, which involves getting that pipe slightly deeper, and I've just finished filing the end of the bolt back level with the outside of the cases as it was a tad too prominent for my liking. Pity I've only got an early small bearing crank to use in it!)

SG