Baffled, confused and covered in oil!!!!!!

[chaterlea25]

Biker Boy,
I cannot remember if I mentioned this before or not? 
If there was a loose lump floating about in the return system it could restrict the return at odd times ?
I once found a lump of silicone stuck up at the top of a return pipe in the oil tank, it was right at the top where the pipe is crimped off, the only way I found it was using a lengthof inner cable, winding it up through  the oil pipe
The only other suggestion, is the oil pump and its seating area flat, undamaged and level with the 3rd screw mount
I often thought that using a fibre washer at the front screw was not a good idea, who knows what thickness the washer is compared to the gasket?  I make my own oil pump gaskets and extend it to the 3rd mounting
or use one of SRM's one piece gaskets

John

[limeyrob]

I think at this point I would sit down and make a lit of every bit that has been changed and every bit that has not and look very closely at those.  I number of us running old Land Rover have had really hard to find problems with the inner linings of fuel pipes becoming loose and causing restrictions leading to carb rebuilds that don't fix the fault.

[JulianS]

Over the years I have had banjo bolts with varying sized holes and non caused any oiling problems. The first photo is of a "Eddie Dow" rocker feed manifold and its supplied banjo bolts, see the size of the exhaust rocker hole, quite large. 

Second photo shows the Webco version, which takes original pattern bolts showing smaller holes. This one been fitted to my A10 for years again no oiling problems.

Like John experience I also had a problem with an obstructed return pipe in the oil tank itself. Back over 10 years ago before I realise there was a problem, the oil tank blew its contents out of the breather during a 20 mile run.

A further problem came when the SRM end feed conversion was damaged, this caused a build up of oil in the sump which then sprayed from the breather. A new seal sorted that.

[BagONails]

... at no time does the oil not pump back to the tank and it does not appear to splutter at any time. The time I got it to happen in my workshop and not on the road I was alongside it watching the oil circulation none stop.

I had a long re read of this tale of woe and picked up on BB's comment above.

Maybe I'm taking you too literally but do you mean the oil return remains at a constant smooth full stream flow? i.e. we normally expect full flow from cold start after being left for a week or two then as the residual over filling of the crankcases is cleared the return starts to splutter and gout as the scavenging pump (should) always beat the supply side.

If your return stream stays a constant flow say more than two minutes in after start up then over supply, rather than poor scavenging would seem to be the issue here. 

[bikerboy]

Firstly thank you for all your suggestions and ideas regarding this P.I.T.A. problem

I decided to go back to basics and check absolutely everything.

Without the engine in the bike getting at the pipes to the tank is easy so I blew the return line out and can poke a bit of cable up it easily actually being able to see the end of the cable coming upp the return pipe in the tank. I also blocked of the return in can the tube in the tank was cracked low down, stuck at airline on it and am totally confident that there is no blockage or restriction of any kind.

Next I checked the bolts that hold the rocker box feed to the head, the flow holes in the bolts actually seem to be slightly smaller than 1/64 so I know its not getting too much oil up to the rocker box and consequently flooding the sump that way. I am unsure if I should actually drill them out to 1/64 I am still thinking on that one.

There are very few oilways in the crankcases but blew them all through thoroughly, again no sign on any restrictions. Having removed the scavenge pipe that is also clear and good. Blow one way and the ball seals blow the other and there is no restriction at all. I even heated it with a blow torch to make sure there were no cracks that I could not see that might cause the problem.

The oil pump I have sent away to be tested and I am waiting for an update on this.

The oil pump gasket is an SRM one so it does not need the washer under the pump at the front but when the pump returns I will be checking the seating of it. I aim to bolt it on the right hand case so that I can blow all the oilways when it is in situ to check that it is seating correctly.

The next stringent check will be to make sure that it in engaging correctly with the crank and the worm drive.

I have also extended the breather pipe coming out of the crankcase so that I can actually put a rubber pipe on it and wedge it into a container, just so that I dont get covered in oil again and if it does pump out I will at least be able to measure the flow coming out of the breather.

Once all these tests have been performed and hopefully passed I will bolt it back together. Should it pump oil out of the breather AGAIN I will then have a full ceremony where I will douse it in petrol and happily set the damned thing alight. 

I will be purchasing a few things off Andrew at Priory, new PRV ball and spring, gaskets etc etc.

 

[bikerboy]

If you can think of anything I have forgotten please shout very loudly at me 

[berger]

bikerboy don't open up the banjo bolt holes i got told off for wanting to do this over 40 years ago by a chap who worked for classic mechanics. i think you should scrub out all the breather channels with little spiral brushes, i did this on worty's engine build and masses of crud came out. i also remember a piece on different timed breathers regarding the position and timing of the different holes. maybe someone could show the different timed breathers? good luck.

[bikerboy]

Hi Berger

I did wonder if possibly I had the wrong breather part, as in the holes in a different place to what they should be. Does anybody know eactly when the breather should open as in at BDC or whenever.

All the breather spares I have the holes are in the same places so I assume they are right. Did any engine use a different breather top hat to the A10?

[bikerboy]

Just to add to that berger every oilway, gallery etc etc has been cleaned completely including the breather route. I can honestly claim that there is no oilway that has not been blown out or had a wire or brush pushed down it to ensure it is clean and clear of any restriction

[bikerboy]

Maybe I'm taking you too literally but do you mean the oil return remains at a constant smooth full stream flow?
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Yes I think you may be taking me a bit literally, The flow increased and decreased as I used the throttle but at no time did it stop or splutter or give any indication that flow had stopped due to the oil pump or a blocked oilway.

[berger]

bikerboy the oil return to the tank should blow a bit of air with the flow once it has scavenged any surplus from the sump on start up. i have a clear plastic line on the feed up to the rockers and always see air going up the pipe and splutters of oil into the tank, not a continuous stream .

[chaterlea25]

Hi BB,
A forum search should show posts on the breather sleeves
Something tells me that there is a difference somewhere in the gear train between the plunger and swing arm engines.
While you have the engine all apart plug up the main bush where the crank fits,
Use a pressure oil can to pump oil from the pump face hole through to the prv and crank bush. This should reveal any leakage between the bush and crankcase or at the PRV.
A hydraulic test is much better than compressed air, you would be surprised at the pressure a pump oil can can make.
Juliana post reminded me of another  case
where  leakage at the end feed block on a SRM converted engine made the owner and me to tear out the remining grey hairs..
I'm thinking leakage at the main bush could cause similar to Julian's and my friends Bikes symptoms?
I figured that excess oil in the timing case was carried up by the gears and flooded the breather!
Heat up your crankcase and check for leakage as above

John

[KiwiGF]

If you can think of anything I have forgotten please shout very loudly at me 

The ball and spring in the crankcase to reduce wet sumping?

[bikerboy]

The ball and spring in the crankcase to reduce wet sumping?
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Done it does not wet sump at all ever

[bikerboy]

I'm thinking leakage at the main bush could cause similar to Julian's and my friends Bikes symptoms?
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I will check it but it was ground until it was round and then a new bush line bored as is the norm nowadays. It seems to fit fine, definitely no play for sure