I suspect my newly rebuilt ES2 has an oil flow problem.
It was rebuilt with an overhauled oil pump, new spring and plunger in the timing cover. It was resleeved and of course new bearings and gaskets throughout.
The crankshaft was not split, big end bearings were fine.
Oil flows back to the oil tank, there is very little wet sumping.
Oil oozes out of the connection to the valve gear at the head, more slowly than I would have expected.
But, I want confirmation that oil is going to the internals and not just going from the pump into the crankcase bottom and being sent back to the tank. Running it for about 10 minutes in the garage, there is no increase in temperature of the oil going back to the tank. This is what is making me suspicious.
How can I confirm that the flow is correct? Can I fit a pressure gauge anywhere? What is the purpose of the small screw under the timing cover, at about 7 o'clock, can it interfere with the oil flow in any way if it is not the correct item? It is not shown in the AN exploded view.
In addition, looking in the valve cover on the side of the rocker box, there is no sign of any oil, it is dry. The oilways in the rocker box were cleaned out in the rebuild.
How is any oil expected to get up to the head when the the tank is at a lower level?
I have only done about 10 km on the bike slowly without loading the engine.
Any advice please.
The. es2 oil system is fairly bullit proof, to check that oil is going to the rocker box, cover the return hole in the oil tank with your finger, when running for a short while ( 20 - 30 secs max) all the returning oil will then be diverted to the rocker box, If the rocker box cover is then removed, and no oil still shows, the problem can be solved by removal of the rockerbox,
Sometimes a restrictor is fitted before the oil gets to the valves, check you don't have one, remember the top end only relies on oil from the return pipe ( just before the oil tank) and is not a positive feed.
Regards John O
Did you do the rebuild yourself or get someone else to do it ? If you think the oil is taking a short cut, there could be a few reasons for this. Is the pump bolted firmly in place, if it has been accidently left un-tightened this could be the reason. Was the fibre washer fitted to the oil pump to seal against the inside of the timing cover and to the correct thickness ? Has the pressure release valve in the timing cover been damaged or missing ? Does the big-end oil feed jet have the correct size hole, too big will flood the big-end bearing.
Have you checked the rockerbox feed pipe is clear as there should be sufficient return pressure to pump to the rockerbox and if you remove the banjo fitting you should get an egg cup full after about 2-3 minutes at a fast tick-over. This amount doesn't feed into the box this quickly as it is restricted by a jet hole in the banjo bolt for the correct amount. The oil enters via the rockers so is not really visible straight-away. I think the screw you are referring to is to blank a machining operation access hole.
Thank you both for your advice and assistance.
John, that is a good idea to block the oil return hole, I’ll do that this morning.
Richard, I did the rebuild myself, resleeve, new gaskets, and seals throughout. New timing case jet/plunger and spring, new washer on pump outlet – all from Norvil.
The pump I reconditioned myself by dressing the worn plates on an oilstone.
If no other factor still does not satisfy me, I check that the pump is firmly in place.
I did get a new ball and spring for the timing cover pressure valve but checking the old one with compressed air, it seemed ok so I left it. Anyway, it seems that to get the old one out could lead to damage of the case. If I can think of a way to change them I will do it.
Some oil did ooze out of the valve feed pipe union at the rocker box when I checked, but I’ll do it again and measure it.
I’ll check these thing today.