SRM oil system 'upgrades'?

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Fast Eddie

Fast Eddie

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Gents,

SRM in the UK sell a 'high output' oil pump for Nortons...

Has anyone on here used one? Are they really any higher output than standard?

Similar question for their pressure release valves, they claim super precession etc, seems a sensible upgrade on a 40 year old item of unknown PO history of interference to me, but has anyone tried them?
 
Yes, I got one, and converted it for use on a single cylinder (different orientation)

They are well made, machined from quality parts and do not have that mass-produced 'on the cheap' feel about them.

There was no slop between the gears and the brass plate, and when I stripped it down, nothing needed polishing (I usually use fine grinding paste and a sheet of glass)

Yes, I can recommend the SRM pump.
 
I have a stainless SRM relieve valve it is well made an came fully assembled though I have never tested the engine oil pressure I would feel confidant in the valve to work correctly as they are well respected firm.
 
Does SRM manufacture this oil pump or is it the same pump Andover Norton list ? (for some £25 less)
 
Time Warp said:
Does SRM manufacture this oil pump or is it the same pump Andover Norton list ? (for some £25 less)
Click to expand...
I was thinking the same question! Does anyone know??
 
Not sure, but my SRM one didn't come in an Andover Norton genuine parts bag, and wasn't marked up with part numbers.
 
I am using SRM pressure relief valves in both bikes .no problems and both have gauges .My hi output is from Norvil they all look identical.My oilpump does not wet sump either,it sat for a month and did not seep.I would bs interested to know if they all come from the same supplier probably.
 
Fast Eddie have a look at the Norton 905 at this website .I am sure these oil pumps will not read zero when they are hot at idle.They built my lightened crank I am using with JS gear.britishclassicbikes.de

SRM oil system 'upgrades'?
 
murraycod0 said:
Fast Eddie have a look at the Norton 905 at this website .I am sure these oil pumps will not read zero when they are hot at idle.They built my lightened crank I am using with JS gear.britishclassicbikes.de
Click to expand...

For a second I thought there was somewhere in NSW where you could get Norton reconditioning done,Germany typical.
 
murraycod0 said:
Fast Eddie have a look at the Norton 905 at this website .I am sure these oil pumps will not read zero when they are hot at idle.They built my lightened crank I am using with JS gear.britishclassicbikes.de

SRM oil system 'upgrades'?
Click to expand...

That looks impressive! I've emailed them to ask if they sell the pump.

I'm building my motor with JS rods & pistons and cams & followers too. I prefer to keep the crank at stock weight though.
 
murraycod0 said:
I am using SRM pressure relief valves in both bikes .no problems and both have gauges .My hi output is from Norvil they all look identical.My oilpump does not wet sump either,it sat for a month and did not seep.I would bs interested to know if they all come from the same supplier probably.
Click to expand...
That's yet more good feedback, thanks.
What does the pressure gauge show with this pump and pressure relief combo?
 
We (Andover Norton) have recently contemplated to offer the pressure release valve as a pre-set, pre-tested assembly. Experience of my engine man over many a rebuilt engine over the years shows, however, that a valve set to a certain pressure in one timing cover gives totally different readings in another due to slack in the threads etc. Hence we have, grudgingly, decided against offering the assembly.
 
Fast Eddie said:
murraycod0 said:
Fast Eddie have a look at the Norton 905 at this website .I am sure these oil pumps will not read zero when they are hot at idle.They built my lightened crank I am using with JS gear.britishclassicbikes.de

SRM oil system 'upgrades'?
Click to expand...

That looks impressive! I've emailed them to ask if they sell the pump.

I'm building my motor with JS rods & pistons and cams & followers too. I prefer to keep the crank at stock weight though.
Click to expand...

Their big super-duper doesn't fit standard cases. But they do offer a 25% improved output pump. I'll report back more details when I have them...
 
ZFD said:
We (Andover Norton) have recently contemplated to offer the pressure release valve as a pre-set, pre-tested assembly. Experience of my engine man over many a rebuilt engine over the years shows, however, that a valve set to a certain pressure in one timing cover gives totally different readings in another due to slack in the threads etc. Hence we have, grudgingly, decided against offering the assembly.
Click to expand...

That's a shame, but understandable. Perhaps you could sell one that is 'pre-tested to a match a nominal cover' or similar? At least it's some kind of datum point to offer customers.

Regarding the oil pumps that you sell, can you advise how they fair, do they flow more or leak any less than the originals?
 
Both Gauges run between 50 & 60 psi .Both have the SRM relief valves.Oil pressure does drop when bike is hot but not to zero .About 20 to 30.
 
Regarding the oil pumps that you sell, can you advise how they fair, do they flow more or leak any less than the originals?
Click to expand...

The Andover Norton oil pumps are to original specification, assembled and then tested. I should think with today's manufacturing methods and with our careful assembly they are better than the average procdution pump used to be. A certain amount of leakage when standing still is practically impossible to stop completely considering the construction of the pump. Certainly not a problem on a bike ridden on and off during the summer, but I tend to drain the sumps of my Commandos (and OHC singles) before I start them up in spring or for the first race of the season.

Never had engine problems caused by underoiling even on my Commando race engines or the other Commando racers of my friends over the 20-odd years I was involved in vintage racing. In my humble opinion a bigger pump is the answer to no real question. But I am happy to ask Peter Williams if, and if so why, he may have a different opinion.
 
Fast Eddie said:
Fast Eddie said:
murraycod0 said:
Fast Eddie have a look at the Norton 905 at this website .I am sure these oil pumps will not read zero when they are hot at idle.They built my lightened crank I am using with JS gear.britishclassicbikes.de

SRM oil system 'upgrades'?
Click to expand...

That looks impressive! I've emailed them to ask if they sell the pump.

I'm building my motor with JS rods & pistons and cams & followers too. I prefer to keep the crank at stock weight though.
Click to expand...

Their big super-duper doesn't fit standard cases. But they do offer a 25% improved output pump. I'll report back more details when I have them...
Click to expand...

I said I'd report back on the high output oil pump that these guys do. Well, they modify the customers existing pump to increase the flow by 25%. They do this by "fitting the larger return gears". What is the accepted wisdom here gents, is this a good idea?
 
ZFD said:
Regarding the oil pumps that you sell, can you advise how they fair, do they flow more or leak any less than the originals?
Click to expand...

The Andover Norton oil pumps are to original specification, assembled and then tested. I should think with today's manufacturing methods and with our careful assembly they are better than the average procdution pump used to be. A certain amount of leakage when standing still is practically impossible to stop completely considering the construction of the pump. Certainly not a problem on a bike ridden on and off during the summer, but I tend to drain the sumps of my Commandos (and OHC singles) before I start them up in spring or for the first race of the season.

Never had engine problems caused by underoiling even on my Commando race engines or the other Commando racers of my friends over the 20-odd years I was involved in vintage racing. In my humble opinion a bigger pump is the answer to no real question. But I am happy to ask Peter Williams if, and if so why, he may have a different opinion.
Click to expand...

You make good points there sir! I guess all on this forum would be very interested to hear what PW has to say on the matter though... Please...!
 
If one "fits the larger return gears" on the feed side without also increasing the return side the effect is that feed and return side are of equal pumping power.

The intention behind making the drain side gears wider was to make sure the sump gets fully drained because what goes back is potentially more than what goes in. Hence you find froth coming back- oil and air, because there is not enough oil in the sump for the pumping abilities of the drain side.

Now if the pressure side is of equal pumping power ideally this evens out. In practise I doubt it however, because the oil only gathers in the sump after a while and in the meantime more and more oil was pumped into the engine. If, then, too much oil gathers in the sump this can not be pumped back into the oiltank because new oil is coming in at the same rate. Result- wetsumping.
 
ZFD said:
If one "fits the larger return gears" on the feed side without also increasing the return side the effect is that feed and return side are of equal pumping power.

The intention behind making the drain side gears wider was to make sure the sump gets fully drained because what goes back is potentially more than what goes in. Hence you find froth coming back- oil and air, because there is not enough oil in the sump for the pumping abilities of the drain side.

Now if the pressure side is of equal pumping power ideally this evens out. In practise I doubt it however, because the oil only gathers in the sump after a while and in the meantime more and more oil was pumped into the engine. If, then, too much oil gathers in the sump this can not be pumped back into the oiltank because new oil is coming in at the same rate. Result- wetsumping.
Click to expand...

I already put that to him, but having never looked inside a Norton pump, I'm a bit green here, anyway his response was:
"The scavenge side is way larger than the feed side in the pump. I am only reducing the ratio a bit but the return is still bigger than the feed after my mod".
 
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