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[Barryeggs]

How much oil should come from the rocker banjos at idle, i get a fair bit if i rev the engine
But just the odd drip at idle. Pumps seem ok, filters clean, pipes free of blockages,
Also had rocker lids off and seems to be fair bit of oil up there, am i being paranoid?

[stinkwheel]

A slow ooze at idle seems to be pretty standard.

If in doubt, you could flush/replace the oil feed pipes and pull the timing cover to inspect the worm gear for signs of wear but yes, I think you're being paranoid.

[Wheaters]

I was more used to gear and rotary oil pumps until I became acquainted with Mr Enfield's finest..

When I first took the oil pump of my iron barrel 350 apart as part of my "settling it in" service and for a serviceable exhaust valve seat to be fitted I was quite taken aback by how basic a system it is and how little oil it must flow even at "high" revs.

I lapped in the discs (they needed doing, even though the bike only had 3,000 miles on it) so I could be certain it was as good as it could be.

Seems to work alright, at least my engine hasn't seized and it certainly gets some "stick".

[Barryeggs]

Thanks, I think I will fit new discs on the next oil change just to be sure

[Wheaters]

I'm sure the Hitchcock parts are better than the OE ones. The originals might well need quite a lot of lapping in, even from new.

[Leon Novello]

It doesn`t matter how much oil is slopping around, it is the thin film of oil between the moving surfaces that counts.
As long as there is that film of oil, any extra is superfluous except where oil is also used for cooling.

[stinkwheel]

In fairness, they are probably at more risk of problems from oil going over pressure than under. If they go over pressure, the worm drive wears/breaks and if that goes, you have no oil at all. Given the lack of pressure relief, the ability of the pumps to come away from the face in an overpressure situation is quite important. For that reason I've made sure my feed pump has a weak spring and two cover gaskets. I fitted a scavenge side pressure relief valve.

It does make me wonder just how thoroughly the discs ought to be lapped in?

It's amazing how slowly oil clears from the rocker area anyway. Try pouring some in there around the exhaust valve area and see how long it takes to find its way out through the narrow channel past the rocker posts and down the pushrod tunnels. I'm fairly convinced one of the reasons for my high oil consumption on my 350 was that the oil couldn't get away quicker than it was being pumped up there resulting in it sitting higher than the valve guides. It certainly went down after I changed back to standard pumps from the high flow ones.

[Wheaters]

I have a tuned Reliant 850 that used to power my trials/sports car. These engines can be prone to smoking on the over-run and I realised when rebuilding it that the small oil drainage/return holes in the cylinder head casting were also where crankcase pressure vents up to the engine breather in the rocker cover. Oil would be trying to drain down to the sump as gases were blowing upwards through the same small holes.

I fitted an external crankcase vent pipe up to the rocker cover from the aperture where the mechanical fuel pump used to sit (I had an electric fuel pump fitted elsewhere).

Might it be worth doing the same on a Bullet engine? Don't know, not investigated that because my 350 doesn't smoke.

[Barryeggs]

So Stinkwheel, you think the Hitchcocks pressure relief kit is a wothwhile investment?

[stinkwheel]

So Stinkwheel, you think the Hitchcocks pressure relief kit is a wothwhile investment?

Not really sure. I fitted them to both my bikes. Perhaps paranoia too? Although scavenge-pump overpressure is a well known issue and a reason for a lot of pump drive/engine failures. I believe the original design had an internal relief valve fitted.

I'm also running samrat rockers as pressure fed, unmodified with the O-rings in place meaning there will be a much higher tendancy for the scavenge side to overpressure. Standard rockers are more leaky and effectively volume fed. The oil is being forced out through a pretty small gap on the samrat items.

Proof of the pudding? My 350 motor did over 80k miles before catastrophic engine failure due to a snapped valve through an apparent fatigue fracture at the friction weld. I did not give that motor an easy life, towing, motorways and protracted runs at full throttle. The original floating bush big end is fine, no perceptible play. The crank is scrap but due to a loose drive shaft, nothing to do with an oiling issue. I'm rebuilding it now. It will have standard oil pumps and the scavenge-side pressure relief again. I'm using a needle roller big end so the pressure on the feed pump is now negligeable.