Uh-oh!

That’s a bugger.

An oil pressure gauge would be wise in that case if you don’t already have one. But IMHO they are mainly good for understand trends, a catastrophic failure can easily still happen before you’ve glanced at the gauge. Well, it did with me once !

Plus, and this might be controversial for some: perhaps experiment having the ISO’s set a little tighter, just enough so they transmit a little more feeling from the engine, that way you may detect abnormal vibes, and if coupled with an oil pressure gauge, may give you more of an early warning ?
I have told this story before but it's still relevant
Many years ago I had a mk2a that I fitted an oil tap too (yep I know)
One morning late for work I forgot to turn the tap on
I got approximately 7 miles from memory before the engine started to rattle and pull back a little
Quickly realised I'd left the dammed tap off I reached down turned it on and pulled over
With the engine idling it gradually quietened down
And I rode to work with no further issues
I rode the bike for many years after that no problems
So there you have it 7 miles ish before disaster
I must have been right on the tipping point of destroying that motor
In this instance an oil light or pressure guage would have been helpful
The tap was swiftly removed after that
 
Larry, How many miles on the motor since the last rebuild? Was the bottom end inspected?
 
That’s a bugger.

An oil pressure gauge would be wise in that case if you don’t already have one. But IMHO they are mainly good for understand trends, a catastrophic failure can easily still happen before you’ve glanced at the gauge. Well, it did with me once !

Plus, and this might be controversial for some: perhaps experiment having the ISO’s set a little tighter, just enough so they transmit a little more feeling from the engine, that way you may detect abnormal vibes, and if coupled with an oil pressure gauge, may give you more of an early warning ?
I believe a pressure switch with VERY BRIGHT light may be the answer - a needle dropping low won't grab your attention.
I have a Don Pender switch plus the very brightest (8000 lumens) LED warning light. Also toyed with using M-Stop to make the light flash off and on.
Haven't fitted it yet - so my fault if disaster happens.
 
An oil gauge or idiot light will not indicate a blocked sludge trap as the pressure will not drop and the top end will still be getting oil.
But the photos appear to show RH big end - so not sludge trap related?
 
But the photos appear to show RH big end - so not sludge trap related?
In this case its before the sludge trap, just pointing out an oil gauge with the correct reading is not a 100% reliable indicator of oil getting to all the right places, neither is a good oil return to the tank.
 
An oil gauge or idiot light will not indicate a blocked sludge trap as the pressure will not drop and the top end will still be getting oil.
No but it shows the oil pump is making pressure and the relief valve works and the seals are in place and holding pressure and when the bike is cold it has a long slow drop off to zero when you prime the crank or do cold oil pressure checks. If you have one and are observant and open your eyes you could see differences in the reading you get. Oil pressure gauges" talk to you" if you are not deaf.

Years ago ,CAGO seals were sold by many shops and distributors and they would fail and look like you drove a screw driver thru it when you installed it. I had warned my parts supplier, but he did not listen or understand my the point I made = JUNK. Luckily when I met TC, I had read he had to come up with nitro proof seals to prevent the crank seal failing, but he said not really you just need a good quality seal. When I was talking to my parts supplier, he mention some one was complaining about a seal that failed and he thought the customer damaged it, and then I reminded him about the crappy CAGO seal. That ended his sales of them!

And the only reason I knew about it was I listened to my oil gauge when It gave a low # at idle after a hard ride. The pressure came up at revs , but not quite as high. I discovered the damaged seal. That is when I made a gauge to hook up on my customers bike and spent extra time to do the job to my CHR standards and test cold and hot pressure checks, sometimes twice to be extra nice.

But the Norton oil system must be very forgiving and robust because hundreds of bikes had those seals installed before I put a stop to the sales at my supplier. But I'm sure there are some NOS ones floating around and bikes with them in. Without a pressure checks you would never know.

You should learn to listen to the voice of experience, I know I listened to TC and all my other of my famous legend friends and all my HOL riders. What we know is priceless. And boy could they put the competition under pressure on my CHR street bikes.
The Fans saw what real Commandos can do in street trim. And the riders loved it. Don Emde said, he loved the Cadilac ride of a Commando and having a grand time away from the autograph table reliving the days of glory on good equipment that was professional built and finished strong.
 
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No but it shows the oil pump is making pressure and the relief valve works and the seals are in place and holding pressure and when the bike is cold it has a long slow drop off to zero when you prime the crank or do cold oil pressure checks. If you have one and are observant and open your eyes you could see differences in the reading you get. Oil pressure gauges" talk to you" if you are not deaf.

Years ago ,CAGO seals were sold by many shops and distributors and they would fail and look like you drove a screw driver thru it when you installed it. I had warned my parts supplier, but he did not listen or understand my the point I made = JUNK. Luckily when I met TC, I had read he had to come up with nitro proof seals to prevent the crank seal failing, but he said not really you just need a good quality seal. When I was talking to my parts supplier, he mention some one was complaining about a seal that failed and he thought the customer damaged it, and then I reminded him about the crappy CAGO seal. That ended his sales of them!

And the only reason I knew about it was I listened to my oil gauge when It gave a low # at idle after a hard ride. The pressure came up at revs , but not quite as high. I discovered the damaged seal. That is when I made a gauge to hook up on my customers bike and spent extra time to do the job to my CHR standards and test cold and hot pressure checks, sometimes twice to be extra nice.

But the Norton oil system must be very forgiving and robust because hundreds of bikes had those seals installed before I put a stop to the sales at my supplier. But I'm sure there are some NOS ones floating around and bikes with them in. Without a pressure checks you would never know.

You should learn to listen to the voice of experience, I know I listened to TC and all my other of my famous legend friends and all my HOL riders. What we know is priceless. And boy could they put the competition under pressure on my CHR street bikes.
The Fans saw what real Commandos can do in street trim. And the riders loved it. Don Emde said, he loved the Cadilac ride of a Commando and having a grand time away from the autograph table reliving the days of glory on good equipment that was professional built and finished strong.
Well said Carl.
 
I don’t wear earplugs and/or listen to music when riding. I am practically deaf in my right ear and have trouble hearing in my left. Because I only hear in mono and not stereo, I can’t even tell where the sounds are even coming from. That is if I hear anything at all.
I'm pretty deaf too, but I still wear ear plugs on the basis that they might just help me hang on to what hearing I have!
 
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Well said Carl.
For Clarification, I write/ talk in my style. Deaf is not to mean hard of hearing, To put it politely,= Not Observant. I looked in my defective show and tell bag. I Have 2 different brands of junk seals one has GACO and much of #s on it and another with a bunch of # on it. If you get the new different brand like Andover ones, you should be ok. I also have plenty of L/S bearings one with the cage just broken around 1 ball = I saved the customers ass and a slew of money. On warrantee I split the case on my new MK2a in half and the dealer fixed it all and I got a Quaife shell= bullet proof after thousands of all out hole shots and lots of blow gears and shafts.
 
Larry, is the Mk3 anti-drain plunger (circled) fitted because none of your rebuild thread pictures shows the plunger in position inside the Mk3 timing cover although of course it could've been fitted but didn't get into any of the pictures?
Without the plunger, the relief hole that vents the plunger cavity would be an open 'hole' in the timing cover oil feed gallery and although small in diameter, once the oil thinned out there would perhaps be a significant loss of feed/pressure without the plunger.

Uh-oh!
Plunger and spring are both fitted.
 
Matt Spencer told me that the top part of a 1950s Triumph oil pressure indicator will screw onto the botom part of the Commando relief valve. That way, you would know if you have oil pressure when the engine is running, without running a line to a gauge.
 
Matt Spencer told me that the top part of a 1950s Triumph oil pressure indicator will screw onto the botom part of the Commando relief valve. That way, you would know if you have oil pressure when the engine is running, without running a line to a gauge.
But then you need someone running alongside the bike to look at the telltale as well as it can't be seen from the seat.
 
And one last nail in the coffin, If you were to prime a Commando crank like I do, a gauge could also tell you if you have a plugged sludge trap and if the rods shells/ inserts are being supplied. But it would be very, very hard to fill one enough. Unless you so much debris in the oil, you'd have to be blind not to see it. Over and out.
 
And one last nail in the coffin, If you were to prime a Commando crank like I do, a gauge could also tell you if you have a plugged sludge trap and if the rods shells/ inserts are being supplied. But it would be very, very hard to fill one enough. Unless you so much debris in the oil, you'd have to be blind not to see it. Over and out.
Not sure I understand how that works? Do you mean you are priming the crank with oil in normal use of a high mileage engine?

I sometimes prime the crank after a rebuilt, but to be honest not every time. I do use Graphogen paste on mating surfaces on assembly, which I feel does more than the priming and begins to get washed out with oil flow! I fit a gauge temporarily for first start up, if I start up on rollers, which is mostly, I am going to run it without plugs in until I get oil pressure.

Of course, in this case, I know the state of the sludge trap. Seriously, I have no idea what indication a gauge might give in normal start up use to indicate a sludge problem.
 
I believe a pressure switch with VERY BRIGHT light may be the answer - a needle dropping low won't grab your attention.
I have a Don Pender switch plus the very brightest (8000 lumens) LED warning light. Also toyed with using M-Stop to make the light flash off and on.
Haven't fitted it yet - so my fault if disaster happens.
I have both.
 
Add the warning buzzer like on the turn indicators...but then most of us won't hear it at road speed anyway I suppose.
You know it may happened that some sludge breaks away and suddenly plugs an oil way or even doesnt plug but finds
it way into the bearing surface and that causes some metal erosion and it just snowballs from there.
 
Regardless of what early warning apparatus a rider relies apon ...none of them caused this issue...

💡.... So you are blasting along at 70 mph + and your psi gauge drops to zero or your light comes on and you shut the engine down and save a potential catastrophic failure of the engine cases....in my mind a tear down will be required at some point.🤔
 
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