Forum

[Wheaters]

I agree, hydraulic tappet adjusters only need to be filled with oil to work. I’ve just rebuilt a car engine with a reconditioned cylinder head and fitted a performance overhead cam to it. The cam followers and cam went onto the head weeks ago; I had filled them up with oil at that time and have obviously not topped them up since. Yesterday afternoon I cranked the engine over using a spanner on the crankshaft nut with the cam cover off to check everything was in order before finally getting ready to start it. The tappets were fully charged and the valves opened fully. There was no oil pressure in the system at all at that time.

However, a couple of years ago this same engine suffered an intermittent failure of the pressure relief valve in its oil pump; it tended to stick fully closed when the engine was cold. The oil pressure intermittently went off the top of the gauge on start up (it reads up to 100 psi). I initially thought the gauge had begun to fail.....I soon realised this was not the problem, I was more interested in the severe misfiring which occurred at the same time. In retrospect, I think the reason for this was that the pressure was going high enough to pump a couple of tappet adjusters up so hard they held their valves off their seats. It misfired like mad - until the oil filter canister deformed enough to allow the sealing ring to the block to be blown out. The pressure went from off the clock to zero in about ten seconds because that’s how long it took for the pump took to empty the sump! It made a hell of a mess both inside the engine bay and on the ground.

[Huey]

Stored up a hornet's nest ?? .....well guessing it for our own good . Well as some of you have views on the bullet engines my thoughts are more about incorporating or moderfing the
G2 engine to better it's working . The alteration to the oil pump was done by me around 23 odd years ago and I think the floating bush seems to like it . As mentioned before the purpose of oil pressure is to keep the moving surfaces apart ( not touching ) which is not the case with rollers ." The rollers dont exactly make good big end bearings for the simple reason that the roller tends to skid around the top from around 30° BTDC to around 30° after due to compression pressure exerted on them " us what u read somewhere . The non return valve or relif valve fitted in the timing side shaft does nothing to the pressure as I have checked on hot and cold engines .Regarding the Ariel lubricating system ( a Red Hunter which I happen to own) it has a relief ball and spring preventing wet sumping as the pump is like the BSA and AMC singles situated below the crank in the sump . Rendering it useless will make the motor give off loads of white smoke on start-up .which of course go away soon .... But at the end of the day Gear pumps are a better bet . Shame about this timing covers Peace Out

[Wheaters]

Stored up a hornet's nest ??

I'd hardly say that is true. I did have to put my cup of tea down to type, though.

[Bullet Whisperer]

No hornets nest. As designed, the G2 Bullet engine and lubrication systems are fine, it is when people start messing with them that things go wrong. I stand by what I said about the Ariels and oil pressure, too. Peace off. I mean out.

[Bullet Whisperer]

The Ariel lubrication system discussed. Incidentally, I reverted back to the original gasket type after it turned out the blue one supplied with the new oil pump caused over oiling and excessive smoke - another reason not to mess with original designs.
https://youtu.be/ju2mAT-fppA

[stinkwheel]

The non return valve or relif valve fitted in the timing side shaft does nothing to the pressure as I have checked on hot and cold engines .

Others may correct me but my understanding of the function of the pressure relief valves on bullets is to overcome momentary spikes of severe high oil pressure that can be encountered. Especially if the engine is "blipped".

I'm sure I read an article by our hosts reporting pressure spikes in excess of 100psi on some motors. This puts an enormous load on the gearing in the worm drive system which can then strip the teeth.

I actually took the high flow pumps out of my 350 bullet because I'm convinced it was over-oiling the top-end to the point the oil couldn't get out of the rocker area quickly enough. Leading to a lot of oil finding its way past the valve stems.

Left them in my 612 because it has a roller bearing crank that could probably do with the extra oil flow and cooling, the afterload of the needle roller is almost zero anyway. It's a really noticeable difference if you prime the big end using an oil can through the end of the timing shaft. You have to give the floating bush type a fairly forceful pump, the roller bearing type offer almost no resistance.

I suppose that is another consideration, if there is little to no resistance to the oil flow, there wont be any measurable pressure. So even if the pump is capable of building up a very high pressure, it won't happen. I don't think so anyway? If I had a pressure gauge in a garden hose and turned it on, there wouldn't be a particularly high pressure to measure but if I stuck my thumb over the end and just let out a thin squirt, there would be? Any physicists on here?...

[Bullet Whisperer]

The non return valve or relif valve fitted in the timing side shaft does nothing to the pressure as I have checked on hot and cold engines .

Others may correct me but my understanding of the function of the pressure relief valves on bullets is to overcome momentary spikes of severe high oil pressure that can be encountered. Especially if the engine is "blipped".

I'm sure I read an article by our hosts reporting pressure spikes in excess of 100psi on some motors. This puts an enormous load on the gearing in the worm drive system which can then strip the teeth.

I actually took the high flow pumps out of my 350 bullet because I'm convinced it was over-oiling the top-end to the point the oil couldn't get out of the rocker area quickly enough. Leading to a lot of oil finding its way past the valve stems.

Left them in my 612 because it has a roller bearing crank that could probably do with the extra oil flow and cooling, the afterload of the needle roller is almost zero anyway. It's a really noticeable difference if you prime the big end using an oil can through the end of the timing shaft. You have to give the floating bush type a fairly forceful pump, the roller bearing type offer almost no resistance.

I suppose that is another consideration, if there is little to no resistance to the oil flow, there wont be any measurable pressure. So even if the pump is capable of building up a very high pressure, it won't happen. I don't think so anyway? If I had a pressure gauge in a garden hose and turned it on, there wouldn't be a particularly high pressure to measure but if I stuck my thumb over the end and just let out a thin squirt, there would be? Any physicists on here?...

[/quote]
With you all the way there, Stinkwheel. And it's funny, I could have sworn I have made those relief valves in the timing side shafts open when a certain oil pressure is reached!

[tribonnie]

Well if you think discussion of Enfield oiling system is full of panic, rumour, facts and non facts you should look on a Triumph T150 forum. Of the literally 1000s of post on the subject there is a 50/40 split on crap/brilliant. As with Enfield all sorts of weird and wonderful solutions to a perfectly adequate system. Richard

[Wheaters]

I actually took the high flow pumps out of my 350 bullet because I'm convinced it was over-oiling the top-end to the point the oil couldn't get out of the rocker area quickly enough. Leading to a lot of oil finding its way past the valve stems.

Looking back to earlier designs, engines such as the Matchless V twin fitted to Morgan three wheelers had no built-in provision for top end oiling and the valve gear was open (as in open to the elements).

John Rowlands, who was for many years the head chemist for Silkolene and later Fuchs Oils, lived near me in the late 1960s and used to drive his Morgan to work at the Belper oil refinery, which was next to our school (my grandmother also used to work there). John used to stop at the end of our road, get out his oil can, give a few squirts from it to the valve gear then roar off again. I think he still owns and races the car, so it seems to have lasted well enough. A few years ago I was in contact with him and told him I blame him for my interest in quirky vehicles!

[Huey]

Damn ....looks like a few ruffled feathers ... Well let's start with ' spikes ' ....at 1/12 th engine speed with or without a relief valve attaining a 100 lbs pressure .....amazing. .....' Over oiling ' with the valve guides way above the return gutter getting oil into the valve stems .....amazing ......
All that was altered to the standard pump was reduce the size of a hike which seemingly has no consequence to oil pressure as enlarging Piston diameter would .It's not rocket science .
But then again I realise why Egli refrained from educating the masses ....but as long as the sheep go through the gate .
Guessing that " Peace Out "is rather old-fashioned and mainly used by Pat Condell I'd prefer to go the modern way " Peace Off"