Britbike forum Forums British motorcycles in general British motorcycles in general Testing Oil Pressure…..

…. On a motor that has no OEM oil pressure switch or test port.
David Madigan made the banjo fitting with an oil pressure relief valve internal, and AN3 fitting for a gage line. It replaces the stock relief valve. This guy is amazing.
Put it on my A65 for a check. At initial start cold oil, 90 psi, after warm up then rode around until hot, 50wt oil, 75psi at 2,500 rpm and up. 55psi at 1,000 “idle” rpm. Good to see this pump makes enough oil!

That is a good idea.

Your A65 looks fabulously shiny!

Dave

I wouldn't mind one of those for my A65 is David Madigan selling them?

I know this one is the first put into use, and was given as a test process. I did fwd this post to David so he would know I shared the info. I can’t speak for him but he’s on the board and surely you’ve seen some of his other work, contact him by PM should work: DMadigan

Hi D Madigan; as you know, is not possible to communicate with you via messages due to always over the limit.

Do you fabricate one of these but for Triumph and to connect also the light? so 2 connections on the part. 27 threads
Also; now after months I can measure under the 79 to see if I can modify the center stand to make space for your external oil filter.

Thanks

Hi Reverb, I was thinking about the possible warning light addition also. It occurred to me the pressure line to the gage could instead go to a Tee. Both the gage and switch off the tee. That might make for a cleaner setup, with several possible locations instead of all down at the engine case.
BTW,….. I believe David has posted his direct email in his profile….. ;~)

It is possible to put both the female thread for the switch and the male thread for the hose connection but I am not sure it would not leave one in a vulnerable place. Making a new dual port banjo would not be cheap for only a few and I am not sure there is much of a market for it.
Since the gauges are usually 1/8 NPT, the switch is 1/8 NPP and the hose is AN03, a special tee would be needed. Even if the switch was somewhere in the line, an AN03 - 1/8NPP - AN03 tee is needed which I do not think anyone makes. Plus it would depend upon the metal braid of the hose for the ground connection. There probably is an AN03 - 1/8NPT - AN03 tee and a switch with both contacts could be used. I would have to search for one.

So, KC, what oil pump are you using to get that pressure?

The straight 50 will have a big impact on that. Too viscus would lead to more oil blowing off and less going to the crank.

I use the SRM pump on my bikes, when I spin the pump up with a drill, it doesn’t take too much speed to blow off to return with either the 50 or the 70 psi Oprv units.

Forgot to hit POST the first time……..
Anyhow, just the best looking one I had in a collection. Not a cast iron, and Not a DD pump, as I didn’t have any at that time. Also FWIW, I only take the shaft top housing part off the pump and replace the shaft O-Ring in there. I don’t take the pump apart “just cause” or to do any lapping etc. I flush the pump clean with a drill motor in oil, and call it good. Most pumps I tried to make better, were worse than when I started in the end, maybe just me, Dunno.

I have a piece done by PO where he put ON the external filter (Norton style). There, is a connection for both; the gauge and the light wire using the original style switch (Triumph) but I removed the filter so I want to put that in the timing cover.

KC, what is exactly your idea?

Thanks

Sorry reverb, I’m not understanding the whole question. To answer,…. What is your idea?
At the top: “ Put it on my A65 for a check. At initial start cold oil, 90 psi, after warm up then rode around until hot, 50wt oil, 75psi at 2,500 rpm and up. 55psi at 1,000 “idle” rpm. Good to see this pump makes enough oil!”
I was just testing, not intended to remain hooked up. Will put the warning light switch back on soon.

Hi KC, just see; may be I confused the situation when you mentioned in the other comment about possible light and Tees etc. Yes, I will put a device to receive the light wire and the gauge cable to the timing cover in a 79 Triumph. I will try to communicate with DMadigan but I cannot send a message and cannot see his profile so I do not know.

Hi Reverb, you already have a port for a light on a '79. If you exchange the switch with a NPP - AN03 fitting you can run a braided line to the pressure gauge.
On a twin there is a problem on which direction to point the AN fitting as the switch is outboard of the OPRV.
You can contact me direct by [email protected]

If you had an end-feed crank, you will have likely flipped the oil seal with that pressure. If thats what your seeing then you probably want to switch to a 20-50 or a straight sae 40.

Problem with having too much pressure is it also means you could have a restriction in flow! - a lot of people forget about that.

Why use a non multigrade oil?
I can understand it on a manx norton or similar but these days ........ especially on an a65
flow with cold oil is important, that's when most wear takes place. beezer were advocating
20-50 oil in the 60's.Pumping glue around will give great pressure but little else.

Definition of pressure is the resistance to flow….

Not really.

Definition of Pressure is Force per unit area,


Resistance to flow is covered by fluid friction, not the same thing. Fluid friction is affected by many things, surface finish , pipe area, number and type of bends, viscosity, Renaults numbered . its how pressure losses in pipework are calculated.

Measuring oil presure from the OPRV chamber does not give true pressure at the big end, fluid friction depends on the square of the fluid velocity, as pump out put increases with revs, fluid friction losses rise exponentially. The high numbers seen on the gauge are not what the bearings get.

Agreed to all the details brought up in the thread. The rest of the engine is quite an important factor in how any oil works to keep it alive. It was only “ …Good to see this pump makes enough oil!” After the OPR valve, who knows…? I have a test rig to bench check the pump for Sumping leaks, but no way to see the operating output, other than installed. Trap is clean, clearances as close as I can get them in my hobby shop, filter added, calling it good.
Satisfied my curiosity, and taking it off this bike. My build goal is “resto-mod” looking, reliable mods added but not easily visible on the outside! Hopefully will last as long as my 75yo body will need! Thank you David! 🏍