Oil Pressure Sensor (2016)

lutewizzard said:

The proposed switch IMHO will only indicate oil pressure (or lack thereof!) to the rocker gear. At best it could be an indication of wear in the rocker/spindle area wouldn't it?

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No, it wouldn't, as the crank and rockers are fed from the same source (the gallery in the timing cover) oil pressure will be the same throughout the system, it can't be lower in one part than it is in another, so it shouldn't matter where the sensor or gauge take-off is.

lutewizzard said:

I like Madass's idea very much but wouldn't it be wiser to have a sensor/switch between oil pump and crankshaft?

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Theoretically, it is, as the rocker feed is already situated "between the oil pump and the crankshaft".

L.A.B. said:

re; "Theoretically, it is, as the rocker feed is already situated "between the oil pump and the crankshaft".

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Excuse me for butting in, if this is installed on the rocker oil feed, isn’t that on the RETURN oil tank pipe :?:

Bernhard said:

L.A.B. said:

re; "Theoretically, it is, as the rocker feed is already situated "between the oil pump and the crankshaft".

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Excuse me for butting in, if this is installed on the rocker oil feed, isn’t that on the RETURN oil tank pipe :?:

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No. :wink:
https://www.oldbritts.com/oillines.html

Don is doing a great job and service in this effort, many of us prefer the simplicity and cost efficiency of an idiot light vs. a gauge. The principle is sound, I mocked up a banjo fitting with a standard triumph OP switch (hamfisted and ugly), and tested the rig at the timing cover/rocker feed junction with a double banjo bolt... worked a treat. Key on = light on, kick over = light off. Simple. It's a one wire hookup (with the triumph switch), so I just ran the wire up to the high beam indicator light in the headlamp shell.

An idiot light would require a low cost OP switch. An OP gauge would require a more expensive OP sender unit. It is possible the oil pressure at the rocker feed is lower than that at the crank because of the longer smaller pipe connecting them. May not be much difference though. Haven't had time to measure it. As far as the Triumph OP indicator is concerned. Could be a WOT . Who is going to be bothered looking down at their engine all the time. I'd rather keep my eyes on the road.
I am for the idiot light [ LED variety] . The KISS principle is best. I have read stories about commandos not having much oil pressure. A lot of the older op switches of old, shut off at 7 1/2 psi.
Dereck

kerinorton said:

An OP gauge would require a more expensive OP sender unit. It is possible the oil pressure at the rocker feed is lower than that at the crank because of the longer smaller pipe connecting them.

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I don't think so, however, as Don originally said in his first post: "A small oil pressure switch/sensor, I imagine taken off the rocker oil feed banjo at the crankcase" (timing cover).

thats correct off the timing cover, the switch will be facing inwards at about 45 degrees down , so I dont think it will be to obtrusive.
Don

madass140 said:

thats correct off the timing cover, the switch will be facing inwards at about 45 degrees down , so I dont think it will be to obtrusive.
Don

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Is there significant difference in the pressure, measured at the timing cover vs at the rocker spindle?

Fritz

Is there significant difference in the pressure, measured at the timing cover vs at the rocker spindle?

Fritz

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No, oil is effectively incompressible so the pressure is the same inside a long chamber regardless of position.

I havent measured that but thats irelevant to this issue. the pressure switch acts like the one in your car, either you have pressure or you dont.

The pressure in a pipe does decrease as you move away from point of origin (pump) This is due to friction losses with the pipe wall and friction within layers of the fluid itself.
Engineers have all sorts of methods to calculate this, but it is a tiny effect within a small system such as our Commando lube system.
If you are shipping jet fuel from Calgary to Vancouver via pipeline, you would need to make the calculations. And build some compressor stations along the way to boost pressure back up.

For an on/off oil pressure switch on a Commando, as Don says, not gonna matter.

Glen

worntorn said:

The pressure in a pipe does decrease as you move away from point of origin (pump) This is due to friction losses with the pipe wall and friction within layers of the fluid itself.
Engineers have all sorts of methods to calculate this, but it is a tiny effect within a small system such as our Commando lube system.
If you are shipping jet fuel from Calgary to Vancouver via pipeline, you would need to make the calculations. And build some compressor stations along the way to boost pressure back up.

For an on/off oil pressure switch on a Commando, as Don says, not gonna matter.

Glen

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+1 : The pressure difference will be insignificant .... probably not measurable.

Slick

An idiot light would require a low cost OP switch. An OP gauge would require a more expensive OP sender unit. It is possible the oil pressure at the rocker feed is lower than that at the crank because of the longer smaller pipe connecting them. May not be much difference though. Haven't had time to measure it. As far as the Triumph OP indicator is concerned. Could be a WOT . Who is going to be bothered looking down at their engine all the time. I'd rather keep my eyes on the road.
I am for the idiot light [ LED variety] . The KISS principle is best. I have read stories about commandos not having much oil pressure. A lot of the older op switches of old, shut off at 7 1/2 psi.
Dereck

I am in favour of taking the OP of the timing cover. Less heat to stuff up a switch maybe, and less risk of false readings due to low oil pressure at high temp and pressure drop from resistance????
There was a thread on this forum describing the OP readings on a gauge, and an instance , because the readings were often so low, the owner removed the gauge. [ saving paranoia ] How many of us might remove the light because idle pressure was down below 7 1/2 psi????????. Not me though if I had a warning light. If I thought it was super necessary to have a warning light I would have fitted one years ago, but I have had other projects which have taken up my time. Anyone who has a manual tap on their oil pressure supply would be recommended to have an OP warning light installed. I have an ignition cut out on mine to prevent starting with the valve turned off but I should take my own advice and fit a warning light. Must do it before I do the Cape Reinga to Bluff ride in January.
Enough rambling on. Time to just DO IT.
Dereck

Well it didnt end up like the one we envisaged for different reasons. but this is what I ended up with. it uses an automotive type switch, special 5/16" BSF
Titanium banjo bolt and a couple of special fittings. My bike hadnt been started for a week since I was out testing the Lansdownes, I hit the starter (Alton) and the motor turned over about 3 or 4 times before the light went out. It held pressure for about 5 seconds before the light came back on.
Second time to wind the engine over now that the oil system was primed, the light went out after the first revolution. Well its not rocket science , just an automotive oil pressure switch, but it does the job. I'm sending one unit off to one of our good members here for his evaluation then if his evaluation is positive then I'll get some together for whoever wants one. It will come with 2 Dowty seals and if I have stock 1 x 5/16" sealing washer , if not use one of your existing ones. I was going to supply a length of wire but probably wont bother. $30 + $6 shipping by normal post office air mail to the US will be the cost. other places on the planet maybe slightly more or less. probably a few weeks for me to get organized, been a bit busy of late
Don

Looks great, I like the simplicity of the standard OP switch, easy to replace if need be.

I'm definitely interested in one. I assume you will make an announcement when they are ready?

Me too.

Simplicity! Sign me up

Apologies in advance for the simple(ton) question

What do you connect the switch to, I presume you need to supply a warning light & mount it somewhere?

Any neat solutions, pictures, of a MK3 with an extra oil pressure warning light?

Add me to the list, always wanted something to indicate oil pressure like I have on my Triumph but didn't like the extra plumbing required for the dial gauge solution, this is an elegant, simple solution, add me to the list :mrgreen:

Are you going to rebuild your engine when the light flickers on at idle after a decent run on a warm day?