Oil pressure gauge, Yay or Nay?

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One thing an oil pressure gauge will do is disclose how poor of job the Norton oil pump does delivering oil at idle when the oil is real hot. It ain’t peace of mind, at all. That being said, I am definitely for an oil gauge and warning light combination.
 
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Hehehe in case some don't know, Norton pretty early on fitted some Commandos with OP gauges for immediate many freaked out new owners and dealerships, so Norton quickly removed that option and put out official notice not to install them. Why did this happen - It would take a few pages of crank sling and size of rod journals per rpm and load to explain but boils down in air cooled clunkers and lawn mowers its more a temperature meter to judge which grade 'wieght' of oil to use. duh. Once ya understand the fluid physics then won't freak out like newbie 70's teenagers. IIRC first Nortons required a stroke of pilot power oil pump every 25 telephones at cruise and 15 on the boggie.
 
I do not believe pressure gauge much use to protect engine as loosing enough oil to show on meter on the fly will be revealed by the mess/smell/smoke or squirrely traction to alert ya. Even the long term dropping reading would not stop from using - until bottom noises or seizures force ya too.
bottom or engine noises can also come quick & sudden, at cruise in a car one time, i had an oil line blow, my first clue was a change in the tone of the engine,

i then looked at the oil pressure gauge that read zero, shut it off right away but ended up with a knock
 
These bikes have survived since the beginning without Oil Pressure gauges. I see no reason to add something to worry about on a street machine. Racing? Well that's different but other than that, an OP gauge serves the same purpose that it did from the factory. So I use the same one that they equipped my '73 (and my original '71) with! ;)
 
These bikes have survived since the beginning without Oil Pressure gauges. I see no reason to add something to worry about on a street machine. Racing? Well that's different but other than that, an OP gauge serves the same purpose that it did from the factory. So I use the same one that they equipped my '73 (and my original '71) with! ;)


Actually, quite a few didn't survive. I lost one due to no oil pressure. No gauge either.
 
Personally I would prefer an OP indicator light. I have run OP gauge's on my HD Shovelheads and they aren't worth a pinch of crap. If I had an oil pressure indicator lamp on my Commando, I wouldn't be re-building it ATM. (Don't ask)
JUG
 
I did a couple of hundred mile round trip. Next day jumped on the bike to head to work, in a rush, oil pressure was good on start, 2 miles down the road the gauge was flicking between 0 and about 40 psi. Fortunately there was a garage about a mile ahead. Checked oil tank, just about empty, disaster averted!
 
Personally I would prefer an OP indicator light. I have run OP gauge's on my HD Shovelheads and they aren't worth a pinch of crap. If I had an oil pressure indicator lamp on my Commando, I wouldn't be re-building it ATM. (Don't ask)
JUG
Ok I gotta ask,
Why are rebuilding your motor??
 
Indicator lights often hard to see esp on a hot bright summer day just when you need to see it. I know we put indicator lights right under
the gauge on aircraft. Nothing wrong with belts and braces now is there?
 
"Even the long term dropping reading would not stop from using - "

Um, yes...
 
Most practical protective would be low oil shut off switch -with say a 5 sec delay- so would allow a few kicks to start and keep running at hot idle or creeping in parking lots yet shut off faster than human might notice on the fly. Could still add light and gauge too. Its pretty taboo risky slackness not to check oil after every other shut down or so when wet sump not a factor to guesstimate before start. One my best labor saver mods was attaching clear hose to tank drain to let down tooless/dripless for changes then tucked up back up behind tank/frame tube for a sight tube oil gauge. Plug end with pourous material or tiny orifice to keep out bugs and equalize pressure.
 
Had a ball valve fitted to oil supply hose to stop wet sumping while sitting idle. You only gotta forget to turn it on once. Once. :(


How many times have you kicked yourself in the ass for that costly mistake? I had a valve in-line for a very short time. Until I asked myself if I trusted my memory that well. Tried the spring loaded valve. Found 0 psi at idle with hot oil. Finally went with the AMR mod. No more wet sumping, no more worries about a memory fart.
 
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I know it’s been said before, but I’ll repeat it for those that missed it...

If you fit the Comnoz / cNw breather at the back of the case, or even easier, if you fit the Comnoz sump plug replacement reed valve breather, these will rapidly return access oil in the sump back to the tank. By rapidly, I mean within a few seconds of starting up.

It’s not a cure per se, but it removes the symptoms of the problem.

The only time you need to intervene is when it’s been stood so long that the entire tank has emptied into the sump (ie, if it’s stood over winter).

For me, its a much more comfortable, and simple, way of living with a Norton than putting anything in the oil feed line.
 
The
I know it’s been said before, but I’ll repeat it for those that missed it...

If you fit the Comnoz / cNw breather at the back of the case, or even easier, if you fit the Comnoz sump plug replacement reed valve breather, these will rapidly return access oil in the sump back to the tank. By rapidly, I mean within a few seconds of starting up.

It’s not a cure per se, but it removes the symptoms of the problem.

The only time you need to intervene is when it’s been stood so long that the entire tank has emptied into the sump (ie, if it’s stood over winter).

For me, its a much more comfortable, and simple, way of living with a Norton than putting anything in the oil feed line.

The reed valve doesn't require any mods right?
 
The screw in sump plug type requires no mods. But it doesn’t fit with the early frames as there is a cross tube in the way. I believe a 1972 frame is OK.

The bolt to the back of the cases type also requires no mods IF your bike already has a breather there (and I believe a 1972 DOES have a breather there).

So, I think you can decide betweeen both.
 
The screw in sump plug type requires no mods. But it doesn’t fit with the early frames as there is a cross tube in the way. I believe a 1972 frame is OK.

The bolt to the back of the cases type also requires no mods IF your bike already has a breather there (and I believe a 1972 DOES have a breather there).



So, I think you can decide betweeen both.

I have the front left breather. So just unscrew the current valve and replace with the breather? No need to take anything apart ?
 
You mean on the end of the cam?

I thought 1972 had the breather on the back of the case? Have your cases, or whole engine, been swapped for and earlier one?

No, neither Comnoz breather will fit end of the cam. Blanking that off and using his sump plug version would be my choice (I use that on mine). Assuming you do not have the early frame (‘68-‘70 I believe).

This is the early frame:
https://andover-norton.co.uk/en/shop-drawing/457/early-commando-frame-repair-items

This is the later frame:
https://andover-norton.co.uk/en/shop-drawing/464/1971-on-commando-frame-repair-items
 
Interesting. Andover Norton show this as the ‘72 spec: https://andover-norton.co.uk/en/sho...rankcases-crankcase-breather-tachometer-drive

I’m guessing your may have been made in the 71 build season, but sold and registered in 72?

If I were in your shoes, I’d go for the Comstock sump plug version. It’s simple to fit. It works flawlessly. And it’s a great wet sump ‘cure’ too!

There are other options though, from JS, and ultra cheap ‘in line’ versions, etc. But I do not believe they have the added wet sump cure abilities.
 
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