Forum

[Tim NZ]

The breather out the center of the crank into the chain case should be reinstated, it is located at the point of highest pressure inside the motor, and is also the place with the least amount of oil mist. It is a very primary good breather!


An auxiliary breather vent from off the top of BOTH exhaust rockers will take any blowby from the valves out of the motor at source...


That you have pre 1960 cases is not the best situation. and there are several modifications that have been done to the cases to improve matters. All of which is incidental, as for your motor to be pumping out over 1 pint of oil through the breather in under 100 miles, the oil return is NOT functioning correctly!
There may be a 'air' leak in the return suction?


There is too much oil running from the camshaft tunnels into the sump proper?


The crankcase screens/baffles are fitted?


The timing cover and or gasket are not correctly fitted?


The Rubber seal on the end of the Quill bolt into the crankshaft is damaged?


If so, then the ID of the bore it sits in is damaged too...


Focus on the timing-cover and reinstating the crankshaft breather.

[Norm]

Mike where did you get the high capacity scavenge pump. I didn't know they were available. Is this motor smoking badly, it should be if it has this much oil being flung up around the underside of the pistons to be forced out the breather

[Tim NZ]

You have not fitted a Bullet oil pump to the return, have you?


They have different port drillings and DONT work in the twins...

[Norm]

My thoughts exactly Tim

[Tim NZ]

If you are going to use the 1957 pattern breather/buckbill vent, it would advised to have the Bullet post 2004 Style Bullet catch can mounted somewhere slightly elevated, inside the tool box maybe?

[Connie 60]

Norm, High capacity scavenge pump as supplied by our hosts in 3 parts 43395, 43393,& 43396 is for the Enfield Twins.
The motor blows a puff of smoke, I assume when the oil in the cases reaches a critical level & then pushes up past the rings.
The breather has a continuous stream of smoke I assume from oil splashing on the hot cylinders

[Adrian]

I was embarrassed to be told I had the piston rings incorrectly fitted on my project bike a while ago, which I was assured by B.W. was the reason why mine was chucking so much oil of of the breather. Ahem... The rings were fitted correctly, and the scavenge oilways were treated to a good streamlining while B.W. was doing some tuning work, but I had also added the return from my (very non-standard) catch can to the oil tank filler neck for any excess to return to the system, the hopefully it won't needed as much. A.

[Norm]

All I can say is you have to split the cases and find out what is going on, continuous smoke out the breather means it is going past the rings for starters

[Connie 60]

No way am I splitting these cases again even though I could do it blindfolded by now as this must be strip down number 5 by now . There is nothing wrong with the cases they are NOS as supplied by our hosts and are identical to the old ones apart from the fitting into the oil tank roof.
I was careful when putting the top end back together and am trying not to be paranoid but it is unlikely that I botched it but never say never i guess.
I get it Tim about the crank breather, and some mods are stupid, but it seemed like a good idea at the time. But inefficient scavenge is the biggie and breathing comes next. I am sure I will only fill up the primaries with oil if I reinstate this breather at the moment.
I assume the standard oil pump can not supply too much oil and the pressure relief valve is fitted to spec, ie fitting screwed flush with case face,so I can't see how oil would spill over from the cam tunnels. There is no damage to the barrel bases where this would open the tunnel to the crank area as was the issue before rebuild. The drain holes into the timing chest from the tunnels are the same as the old cases also. My 53 meteor 61 SM and 60 Connie all had the breather into the tank roof. I assumed the spare SM cases without this fitting (and now the new cases on the Connie ) which also has the 6 bolt oil pump cover were later cases Tim?
Oil quill goodo and am sure there is no air leak on suction side. Baffles are in pace too.
My brain is starting to hurt so I shall sign off for now until I have a go at the timing cover. I might say these problems only occur when the motor is hot and running at high speed.

[Connie 60]

Barnes I would rather eat glass than replace the pistons again but just in case I do sprinkle some on my cereal one day where do i get JE pistons.