Forum

[andyr]

Hi need some information I have a crankshaft that is fitted with a alpha big end assy in trying to check out the pressure relief valve to see if would work I found it had no movement in it so I had it stripped down to see what wrong and found that the relief valve had been removed and a blanking plug fitted I bought the parts fitted them so then used a oilcan to check on the flow to the big end the oil just came out of the relief valve so my question is do I need to use the relief valve or can I just use the blanking plug at least this way the oil got to the big end assy sorry its a bit long winded but its the only way to explain

Andy

[ric]

If it's a needle roller assembly, it's unlikely a pressure relief valve would ever open, but it could possibly fail, which is probably why it's been removed and blanked off.

[Tim NZ]

A: You dont need a OPR with a roller brg BE. Blank off the drilling.


B: The reintroduction of the timing side OPR by the factory in 2002 saw a massive jump in failed floating bushes.


C: IF one is to retain the post 2002 timing side OPR it is critical that it is CORRECTLY seated (Punched and Lapped) and a new Ball + Spring fitted: The Ball seat inside the timing shaft is frequently to be found in an 'As Drilled' (chattered) condition..


To date, EVERY new replacement crankshaft that I have inspected has had a leaky timing side OPR, and that lifted well short of the 35psi (nominal) of the original spec item. (Simply putting ones mouth over the shaft and blowing is often enough to confirm leakage!!)





Squirting an Oil can nozzle directly into the timing side shaft will cause the OPR to lift! Your oil can can probably attain over 100psi?


BUT the main question is did oil also pass through and out of the roller brg?

[andyr]

hi in response to Tim NZ
in checking out the oil flow to the big end assy there was more oil coming out of the prv than the main bearing this was just a little drop now and again so the prv has been removed the oil flow is now constant
regards
andy

[Lennie]

I may have got this very wrong but the PRV does not affect the oil flow to the big end does it? I thought it was in the scavenge pump discharge line, so a problem with it would starve the rockers of oil?

[Tim NZ]

No.


The rockers are fed by a different pump (return) and circuit

[Beezabryan]

I sometimes wonder if Alan (Hitchcock) was pissing in the wind by creating the helpful Technical Notes section to this illustrious website.
here in this very section is an explanation of the basic Bullet oiling system ie what goes where and why it does it - http://www.hitchcocksmotorcycles.com/pi ... cation.pdf - thoughj I do admit it does not cater for modified cranks the circuits are the same

[andyr]

in regards to beezabyran i am new to royal enfields so i am looking for information anywhere i can get it i did not know that there was this type of information to be found so the help i get here is great thanks to tim z i now have a way to move on with my bike
regards andy