C15 oil pressure relief valve spring

[rhyatt]

Good evening,
Working on my pal's SS80 and cleaning out the oil ways.
I see the spring has a slightly larger diameter  at 1 end, which way round does the spring go 0lease , large diameter towards the ball or outwards please?
Thank you

[JulianS]

Like this.

[rhyatt]

Perfect , many thanks

[rhyatt]

Hi again,
Just got round to installing my new correct shape spring in the big hexagonal plug.
BUT
The bore of the hex plug is only the diameter of the narrow end of the spring, on the picture above , it does I dicate that the bore should accept the bigger end of the spring, my bore seems smaller than the picture certainly (allowing for drawings etc)

The old spring was the same length but a uniform shape that corre tly and snugly dropped into the hex body.
Bike is a 1965 SS80, maybe there were 2 different bodies?
At the moment, it is "wrongly" installed, but the ball does sit comfortably in the larger end of the spring for sure.
What fun.

[JulianS]

See attached. They changed the spring no doubt to avoid confusion.

Was there something wrong with your uniform shaped spring so that you could not use it?

[rhyatt]

Ah, spot on,
There was nothing really wrong I could see with the old spring obviously. It wasn't deformed.
It was just that I was assuming a million previous owners may have fiddled and I wanted to be sure of known quantities in the rebuild.
I think I'll either leave it as it is or put the 9ld spring back.
There is plenty of oil in the engine moving around, so not worried on that front.

Thank you

[JulianS]

There was obviously some confusion about the spring, resulting in this USA service bulletin.

I would not risk using the earlier spring the wrong way around.

[rhyatt]

Thank you again,
The only solution for me(bearing in mind the bore diameter of my body which will not accept the other 2 dia spring) is to revert to original parallel spring in its body

[rhyatt]

Whilst digging around cleaning things on my pal's SS90 , I discovered poor scavenging of oil.
I removed the sump plate cover and discovered that it was fitted back to front, thereby the pick up pipe was too close to the metal cover not allowing oil to be scavenged,
Easy fix , turn the cover round so the pick up pipe was in the deeper end.
But I also noticed there was no ball valve in the pick up pipe as indicated in books, it scavenges fine but is this ball necessary please?

[idie]

The ball is to stop oil draining back to the sump.

[rhyatt]

"To stop oil. Draing back to the sump"
OK, so it is on the scavenge side of the pump clearly, and it is there to prevent the oil in the scavenge side right up the return pipe into the oil tank running back into the sump when the engine is stopped,
This would give me a bit of delay in oil appearing in the tank on start up.
Looking at parts books and diagrams, it looks like this pipe is part of the pump cover plate, can I remove the plate and pipe from the pump whilst in situ please? Or is it a total strip please?
It looks like someone in its life has dug out the ball looking at the shape of the end of the pipe!
Or is it something I can live with for the while
Thank you

[idie]

I would live with it. It has run without it up to now.

[rhyatt]

Fair enough
Thank you.

Exploring deeper, if I did want to do something about it , it looks like you can extract the pump downwards through the sump cover

[Stubaker58]

Going by my B40 I think it is possible that the oil pump can be removed after the sump plate is taken off. However re-fitting and checking for an oil-tight seal would be a challenge. A strip down of the timing side is not too arduous (but may reveal unwanted additional work!)
On the pumps I've got the ball is very much internal, I was only convinced it was there when I sucked and blew on the scavenge pipe!

[rhyatt]

Thank you for that advice,
As it is currently whatever oil drains back is quickly returned on start up, he's using sae40 oil , so the gear pump picks that up quickly on starting