29-11-2020, 04:32 PM
(This post was last modified: 29-11-2020, 04:35 PM by Nick Turley.)
Hi Mark
I ran my Speedy sucessfully until recently for many years and I would like to suggest that your oil pressure is a very risky low !
Remembering that you have to get the oil to number four big end all the way from the front - a big ask at high revs.
Centrifugal force is fighting you !
My opinion is that a happy Speedy reliable engine in it's original condition would show 50/55psi cold reducing to about 30psi when hot. That is totally OK and safe.
If not, then I would look firstly at the seals at the front. The originals were leather (sprung loaded) - not very good !
I found it was a good to modification to have modern lip seals in the nose.
Having the nose properly centred on the dog is essential.
The surface of the dog has to be spot on.
Once in position I found it a good idea to put a couple of small locating pins into the nose/crankcase flange joint.
This of course keeps the nose in position and ensures that if it is removed in the future it goes back centrally.
Quite a bit of faffing about involved but well worth it.
In this original format I would use a good non detergent 40 grade oil as Austin recommended.
With this setup I changed the oil very 500 miles.
If you want to "improve" on that, I would fit a filter into your oil system. Should you go down this route you must have a better oil pump (more flow is what is needed not just pressure) and an adjustable relief valve.
The great thing about this set up is that you can then use a full Silicon oil like Mobile one for example.
It can then stay in the engine for a good length of milage (say 2000).
Also the pressure can then be set a lttle bit higher.
Mine with this set up was set to cold (mobile one oil) 55psi and dropping to 40/45 psi hot. This is plenty enough pressure don't go for more, it does not need it, and you would be putting unnecessary strain on the camshaft drive gear.
With this set up you finish up with a very reliable engine that you can drive hard without worry.
Good luck, if you are not sure get expert help - your engine is not replaceable.
I ran my Speedy sucessfully until recently for many years and I would like to suggest that your oil pressure is a very risky low !
Remembering that you have to get the oil to number four big end all the way from the front - a big ask at high revs.
Centrifugal force is fighting you !
My opinion is that a happy Speedy reliable engine in it's original condition would show 50/55psi cold reducing to about 30psi when hot. That is totally OK and safe.
If not, then I would look firstly at the seals at the front. The originals were leather (sprung loaded) - not very good !
I found it was a good to modification to have modern lip seals in the nose.
Having the nose properly centred on the dog is essential.
The surface of the dog has to be spot on.
Once in position I found it a good idea to put a couple of small locating pins into the nose/crankcase flange joint.
This of course keeps the nose in position and ensures that if it is removed in the future it goes back centrally.
Quite a bit of faffing about involved but well worth it.
In this original format I would use a good non detergent 40 grade oil as Austin recommended.
With this setup I changed the oil very 500 miles.
If you want to "improve" on that, I would fit a filter into your oil system. Should you go down this route you must have a better oil pump (more flow is what is needed not just pressure) and an adjustable relief valve.
The great thing about this set up is that you can then use a full Silicon oil like Mobile one for example.
It can then stay in the engine for a good length of milage (say 2000).
Also the pressure can then be set a lttle bit higher.
Mine with this set up was set to cold (mobile one oil) 55psi and dropping to 40/45 psi hot. This is plenty enough pressure don't go for more, it does not need it, and you would be putting unnecessary strain on the camshaft drive gear.
With this set up you finish up with a very reliable engine that you can drive hard without worry.
Good luck, if you are not sure get expert help - your engine is not replaceable.