Good Thing I Have an Oil Pressure Gauge!

Dan1950 said:
I apologize for the suspense. I have other things taking up my time so I am not able to post all of my observations.

I will say that once the bikes sits for a while it will start and run with adequate oil pressure for about 10 minutes. There are, nor had there been any suspicious noises coming from the engine.

Before the rebuild the engine would run at about 28 PSI oil pressure when at cruising speed.
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I am not in suspense but I do own the same model/year.
So your OP bottomed out (?) like near zero?
And, when you pull the cap to the oil tank are you seeing the obvious flow - pumping action, of is it just driveling out...
Same oil weight viscosity as previously used?
 
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Schwany said:
I was responding to Dan and you quoted my response to Dan to give me crap. I quoted your crap.
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Sometimes smug or snarky responses aimed at others mandate such.

Its an open forum , all are allowed and encouraged to participate.

Even those who freeload on the coattails of others and contribute nothing to its support.

See you around the campus.
 
Sounds like an oil temperature related issue. Perhaps the pressure release valve is malfunctioning, though that does sound counterintuitive.
 
lazyeye6 said:
Sounds like an oil temperature related issue. Perhaps the pressure release valve is malfunctioning, though that does sound counterintuitive.
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Had the same thought...oil viscosity (?) new camshaft just installed, need more info.
 
So, fitting an oil pressure gauge gives you useful information as you potter about?

Well I had mine fitted today on initial start up with fresh big end shells, which only got changed because the crank was apart! Removed items are good enough to re-use.

On the rollers at under 500 rpm with the plugs out, it gave over 20 psi.

Running and blipping the throttle to 3500 or so still only got 42, same as ever!

What do you think your OPRV is operating at?

(gauge comes off tomorrow!)
 
I could guess all day long. Might as well join in. I would think most of the closer guessing has been done though.

Drain the oil and look at it in the sunlight. You know what to look for.

Could be some silicon sealer moving around somewhere it should not be.

Big end rod bearings is the obvious place to lose oil pressure quickly. And the motor could remain quiet for a while, but it won't stay that way long if the big ends are going. Other options are missing or very cut seals in the timing cover.

I had JSM high compression pistons in my engine and it ran hotter than it did with 750 Commando flat tops. Oil pressure dropped from the heat at idle, but never to 0, so a simple to fix assembly error somewhere is also possible.

Were the crank rod journals reground next size smaller, or left alone with what seemed like the right clearance?
 
Could be the oil pressure gauge is leaking/malfunctioning and you are pulling everybody's leg about the value of an oil pressure gauge. :)

If that sounds snarky, it's not meant to be. It is supposed to be a humorous conclusion to the story.
 
Lineslinger said:
Had the same thought...oil viscosity (?) new camshaft just installed, need more info.
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Oil viscosity was a consideration. I had inadvertently put in Royal Purple 10w30 break in oil which was changed out for RP 20w50 with a new filter. Oil pressure was a bit better but the same problem persisted.
 
Are your rocker shafts oriented in the correct direction ? Correct crank end seal ? , sorry I'm not really up with the history on your motor , have you just fitted new bearings ? What clearance ? Too much clearance will lose pressure quicker as the viscosity thins , have you checked pressure just at timing chest only ? . Have you got the MK3 cover ? , isnt there a grub screw on the gallery , within the cover that must be there .Cheers.
 
I figured you had that aspect considered.
If the pressure only drops when oil/engine heats up and this problem only arose after the installation of your new camshaft maybe start there.
Did you by any chance take photos of the installation or were you furnished an installation guide, simply followed shop manual guidelines?
 
Did you take the sump drain out yet to see if the little brass filter is full of small pieces of silicon or other sealer?

I can't see how the oil in the sump could be whipped up into a froth and not scavenged unless there was some unusual build error. Somebody want to explain how that could happen and when they have had it happen? Not a lot of windage trays available for Nortons.

Hope it is something simple that you can figure out soon. Summer is winding down and taking that motor out of the frame and starting over is not that much fun.
 
Lineslinger said:
I figured you had that aspect considered.
If the pressure only drops when oil/engine heats up and this problem only arose after the installation of your new camshaft maybe start there.
Did you by any chance take photos of the installation or were you furnished an installation guide, simply followed shop manual guidelines?
Click to expand...
In all the years i have been building engines I cannot see where a solid lifter cam could affect oil pressure.
 

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