Discussion in 'Norton Commando Classic Motorcycles' started by scotnort75, May 11, 2018.
I have an oil temp gauge and thermostats fail
That’s a good thing, but I don’t think any manual valve is as handy, nor worry free, as a thermostat. Just sayin’.
If the thermostat is a failsafe system where thermostat failure is just like not having it in the first place then ok. Not sure how it would all work out (though I'm sure it's been tried umpteen times succesfully in the past). In the engineering literature they state that it is flow that also affects cooling. By reducing the oil temperature perhaps (I'm saying perhaps because it is a question for which I don't have a solid answer) you would need to reduce the upper viscosity number by using a lower viscosity grade oil. There must be a balance point between flow rate and the cooling effects of colder oil. Both for lubrication and for engine cooling. Once again, an accurate oil pressure and temperature gauge set could answer some of this. If for a warmed engine with oil cooler you can't achieve the correct flow rate (see previous posts) then you must make an adjustment. This one thing further, and this questions the use of an oil cooler except when using your bike for a tractor pull contest, I don't know at what temperature modern oils begin to be destroyed and stop working even at the correct flow rate -- but I think it's a bit higher than thrashing your bike up the mountain. But I don't really know for sure.
No measurements, just empirical evidence:
I ran a 900 Nourish kitted Triumph that got over heated to the point that it melted the soldered joint on the head steady mounted earth point!
It missed and popped and banged badly if kept in the warm up area for too long, but cleared within a lap or two once let go.
Fitting Morgo rotary pump improved things a lot. Fitting a Trident type cooler in the head feed solved it completely.
As a side note, I ran this on R for a bit cos all the ‘old boys’ said I should. On start up the oil gauge seemed to go backwards, blip the throttle and the pressure dropped! My conclusion was that the pump just could not drag the straight 40 through fast enough. I concluded that this must be creating horrible cold start wear, so flushed it and reverted to my ‘standard’ choice of Redline 20w60 and problem solved!
Not according to what a petroleum engineer from Spectro Oils told me. When I told him the temps in the tank, ~ 220 F as I vaguely recall, he recommended an oil cooler with a thermostat.
I don’t see why anyone would consider an oil cooler not necessary when you consider the exceptional high wear rate on the Norton of valve guides, valve seats, rings, and everything else that would benefit from a lower operating temperatures.
Soft solder has no business anywhere near a Triumph head.
I’ve had same pressure experience as you, but with cold SAE50.
Surely not on a Commando... Mine on cold start goes straight round to 70lbs on straight 50
How does one determine that oil pressure goes to 70 lbs. if the OPRV has a set point of 50 lbs.? Just curious.
Because it doesnt have a setpoint as such , depends on the shims ... they vary.
Dump pressure is adjusted by shims.
I’ve seen more than one on this forum who think the low oil pressure at idle can be increased by shimming the OPRV. Oh well!
So, I searched the internet again for proper idle oil presures at proper oil temps. And it took me ..... right back to access Norton. 2011 I believe. Well, better late than never. Same discussion. But it does bear repeating. Surely Norton must have studied this issue inside out. What are their conclusions, where's all their wear data?? Or was it the bikes were never meant to last that long anyway. Bike blows smoke buy a newer model (with that girl lounging across the seat).
“ Surely Norton must have studied this issue inside out.”
I doubt that. The multitude of issues that Norton failed to address suggest to me little if any time was spent on oil pressure at idle.
I doubt that. The multitude of issues that Norton failed to address suggest to me little if anytime was spent on oil pressure at idle.[/QUOTE]
I believe that. What I should have asked was, for the bearings and clearances involved with an air cooled engine, I'll bet the answer is "textbook" mechanical/automotive engineering. The answer has probably been common knowledge among those at, well, name your famous mark for years. What they didn't have a while back was synthetics and multi grade and all the additives we have now.
Yes I can't afford a Commando!
When I first posted a reply to this I screwed up the "reply" mechanism and it sounded at first as if I was disagreeing. Actually agree with what you said about Norton and it's issues at that time.
Thomas, where are you sourcing this from? All I could find available locally was Lucas Synthetic Straight 50W
I get it at Crescent Oil in Hamilton which I buy by the case. Crescentoil.ca
Talk to their sales rep. They ship to areas. They have a sale on the oil now.
Not saying one brand is better than another because I really don't know, but on Amazon, Mobil 1 synthetic 0W-50 is available. There are others, it's just that I was looking for 0W-50.
i'd think that if it was a necessity here, or even just a clear cut benefit or improvement, it would have been widely adapted, cos going there isn't even a big deal,
wouldn't consider going there a big deal cos oil coolers/vernatherms are widely used in air cooled aviation piston engines, however,
adding something even with benefits also introduces new failure modes,
read in another thread about "correct zinc additive" ?
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