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I think we have to remember that the oil system is a closed circuit---the oil "starts" at the tank, is pumped through the bearings, is scavenged by the return side of the pump, goes through the thermostat (if fitted) , through the cooler (to a greater or lesser extent depending on whether a stat is fitted) and then back to the tank---where the cycle starts over again.
If a stat is not fitted (the standard configuration) then at constant operating conditions (constant speed, throttle opening, ambient temperature) the temperatures in the system will stabilize. Different points in the system will have different temperatures but the equalisation temperatures will be basically at a level where heat into the oil from the engine equals heat out of the system via radiant heat from engine, convect4ed heat from engine, cooler, oil tank, connections etc etc.
If a stat is fitted then this is the control point in the system. Generally the temperatures will run higher so the heat losses from the oil tank, connections, radiant and convected heat from engine etc will be higher than if the stat was not fitted. However we must have equalisation of heat into the oil with heat from the oil so this is achieved by modulating the effect of the cooler by restricting the flow through it.
If the stat is set at say 185F then the return flow from the scavenge pump to the stat will equalize to be at 185F. Other oil temperatures in the system will be at a lower temperature than that.
Just my two cents worth of course.

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I finished assembling this bike 4 years ago. Completely rebuilt engine using alot of used parts. New bearings, crank ground, and new steel H beam rods. Many annoying problems and a whopping 300 miles since. Took out today for 21 miles. Need to get back at clutch.

Oil pressure on start - 80 psi

Oil pressure hot:

3K rpm - 42 psi
4K rpm - 55 psi
5k rpm - 70 psi
idle - 10 psi

Works for me!

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Very nice. The Suzuki 4-leader in the OIF forks looks interesting. Are the triple clamps standard OIF disc brake ones? Is it OIF frame, as it is well hidden?
Tom


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Nice bike Dick!

Regarding your numbers, how hot is "hot"? Do you run a thermostat in the loop?
Not far from the pressures I record when I ride moderately hard with the thermostat fitted. The temperature will typically be around 65 C or 150 F at ambient temp at some 10 C/50 F. As the spring rolls on I'm going to see higher temps and lower pressures.
If I ride very hard the pressures drop even further of course.
With the thermostat removed I'm seeing pressures of over 20 psi per 1000 rpm, dropping to under 20 psi/1000 riding hard.

I have reason to believe my oil pump is below par, I hope to come back with some more information on that later.

SR

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Originally Posted by Tridentman
I think we have to remember that the oil system is a closed circuit---the oil "starts" at the tank, is pumped through the bearings, is scavenged by the return side of the pump, goes through the thermostat (if fitted) , through the cooler (to a greater or lesser extent depending on whether a stat is fitted) and then back to the tank---where the cycle starts over again.
If a stat is not fitted (the standard configuration) then at constant operating conditions (constant speed, throttle opening, ambient temperature) the temperatures in the system will stabilize. Different points in the system will have different temperatures but the equalisation temperatures will be basically at a level where heat into the oil from the engine equals heat out of the system via radiant heat from engine, convect4ed heat from engine, cooler, oil tank, connections etc etc.
If a stat is fitted then this is the control point in the system. Generally the temperatures will run higher so the heat losses from the oil tank, connections, radiant and convected heat from engine etc will be higher than if the stat was not fitted. However we must have equalisation of heat into the oil with heat from the oil so this is achieved by modulating the effect of the cooler by restricting the flow through it.
If the stat is set at say 185F then the return flow from the scavenge pump to the stat will equalize to be at 185F. Other oil temperatures in the system will be at a lower temperature than that.
Just my two cents worth of course.
This is a "must read" on thermal equalization! I've saved it for future reference.
I take from this text that the desired 185 F pertains to the bulk of the oil, not taking into account the "hot spots", as I somewhat optimistically suggested.
From this it follows that we're fortunate to have a means of controlling, to some degree, the temperature of the bulk of the oil, and hence the engine operating temperature. None of the other air cooled engines I've ever owned had this feature. However, it does mean that for the most part, most of my bikes have run for years and miles being way too cold! Makes me wonder how much of the wear and tear issues we've seen have been due to this? Things like camshaft wear for instance, or cylinder and ring problems?

SR

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Quote
Regarding your numbers, how hot is "hot"? Do you run a thermostat in the loop?

No thermostat, and no temp measurements. It was as hot as 20 miles riding on an 85F day would make it. I did take several pressure/RPM readings and they did vary a little. Always 10 psi at idle. Oil pump is unknown used. Wasn't pushing, just tooling around on the rural back roads of the Blue Ridge.

Quote
Are the triple clamps standard OIF disc brake ones? Is it OIF frame, as it is well hidden?


Yokes are T150 disc brake. Lower is slightly different from OIF. Frame is standard 73 Trident with oil tank.

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Originally Posted by koncretekid
Is it OIF frame, as it is well hidden?
Tom
Except for Dave Madigan's special the Trident was never made with a wet frame. It did share forks and brakes with the OIF twins however.


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Here's some new oil temp/pressure info.
This mornings 110 mile ride was with a bunch of modern bikes. It is still cool but the speeds were much higher and the last 40 miles or so was mostly 70-80 mph freeway stuff. The old nail survived it just fine though I'm sure it guzzled another quart of oil. Exhaust smoke was seen and reported (complained about) by other riders. The vintage guys are so much more tolerant of things like that.
[Linked Image from i.postimg.cc]

My oil cooler is still blocked with cardboard.
[Linked Image from i.postimg.cc]
And the oil temp was just over 180.
I went with the wife's cooking thermometer because infrared temp guns are not very consistent.
[Linked Image from i.postimg.cc]
So the results are....
1200 rpm idle oil pressure=30 lbs
5500 rpm highway OP =65 lbs
And remember, this is with the cooler blocked by cardboard. I mentioned in an earlier post that I may just leave it blocked for most riding and this seems to confirm my thoughts. It appears a triple really only needs a cooler for seriously high speed running or in really hot weather.
I hope this helps reassure other anxious triples owners out there.

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