Oil Cooler

steveyacht · Jun 8, 2011

I found and installed an original Lockhart Oil cooler on my 1973 - 750 being as I now live here in South Carolina and often have traffic issues in the Myrtle Beach area. I am wondering if I should locate and put on a thermostat. If so, where should I look and what temperature range should I use. Currently I am using a "duct tape Thermostat" for cooler temperatures in the fall and winter.

(For What it's Worth: Using Silkolene 50w for break in and am planning on using a high quality Dino based 50w or 20w-50 after the first couple of thousand miles.)

Flo · Jun 8, 2011

Well, it is usually thinner oil to break in.
New motorcycles are called in at 600 miles to have the oil changed.
I use 10-40 semi all the time, motor seems free & easy to rev.

kraakevik · Jun 8, 2011

I run a Hyde bottle-brush cooler with thermostat--it doesn't open flow to the cooler below 165 degrees F. I'm out on the bike every day the streets are dry all through the year. Since I removed the oil-tank side cover I've noticed that the bulk oil temperature gets no higher than 80-100 F on freezing days--maybe 120 or so after a tollway run.

If you ride regularly in non-summer months you might consider installing a thermostat or bypass circuit. That Lockhart can dissipate plenty of heat--summer or winter.

Tim Kraakevik
kraakevik@voyager.net
'72 Combat, '74 RH10 850

steveyacht · Jun 8, 2011

kraakevik said:
I run a Hyde bottle-brush cooler with thermostat--it doesn't open flow to the cooler below 165 degrees F. I'm out on the bike every day the streets are dry all through the year. Since I removed the oil-tank side cover I've noticed that the bulk oil temperature gets no higher than 80-100 F on freezing days--maybe 120 or so after a tollway run.

If you ride regularly in non-summer months you might consider installing a thermostat or bypass circuit. That Lockhart can dissipate plenty of heat--summer or winter.

Tim Kraakevik
kraakevik@voyager.net
'72 Combat, '74 RH10 850

Any suggestions on what sort of by-pass or thermostat will work and not be so big as to be fugly?

JimC · Jun 8, 2011

I have a Lockhart thermostat that fits between the plates of the cradle in front of tranny. Hardly noticeable.

Hobot · Jun 8, 2011

A few things to consider. Nortons might get up to 6% of their cooling via oil. The bulk of this cooling is taking heat out of the tight shear spaces so little help in overall combustion cooling. Oil must get to about water boiling hot for the ZDDP to from a protective layer that wears off on each start up. Oil should get at least 165'F to evaporate moisture which is what creates the most corrosive products in oil and can eat up the hardest surfaces. Going slow on low throttle or sitting still at no throttle does not heat engine and oil up as much as 55 mph cruise speed. Humid air cools a whole lot better than dry air. Oil cooler on Nortons mainly only cool the oil to protect it. Oil coolers often have covers for cold conditions as well as thermostats. Going by 3 temp locations on Ms Peel I have collected materials to insulate her oil if it don't get higher than 160'F going illegal rates. Of course you know me I hardly strain at throttle so prolly don't apply to anyone else.

AussieCombat · Jun 8, 2011

Very interesting, thanks for asking Steve.
AC.

ashman · Jun 8, 2011

Hi All

I have been running a Lockhart oil cooler on my Norton for 36 years now summer and winter and have never worried about covering it up in winter, the bike runs the same all year round weather in traffic or highway riding, but when I first brought it new in 1976 for the first 6 months without the oil cooler on, it did run hot, the same lockhart cooler has been on it since then, I have never worried about the oil temp on my bike as I go by the way it is running, but I do like our winters here in Queensland, the bike does run better, so I wouldn't worry about a therostat myself, but it only gets down to about 6c here where I live in winter.

Ashley

Vertigo · Jun 8, 2011

I use the OT1 Mocal. It snuggles nicely between the front downtubes, and opens at 180 degrees which addresses the condensation concern of colder weather riding.
As I recall, it might even be made in England to boot.

http://208.109.215.220/files/thermos$.p ... nd+Pricing

Carey

comnoz · Jun 8, 2011

I have a large oil cooler in the fairing on my 880 along with a 180 degree thermostat. I have found it the only time the thermostat opens is on a long hard interstate run on a hot day. I rode my bike to NW Denver last weekend and after 150 miles of highway at 65 MPH two up and stop and go traffic through Denver the thermostat never opened.

That afternoon on the way home I ran 85 MPH on the interstate at close to 100 degree air temp and It opened after about 50 miles.

When I put my new motor in soon I am going to remove the thermostat and re-plumb the oil cooler into the supply line for the cylinder head. The small amount of oil that circulates through the head seems to be the only oil that gets too hot on my bike. Jim

steveyacht · Jun 9, 2011

hobot said:
A few things to consider. Nortons might get up to 6% of their cooling via oil. The bulk of this cooling is taking heat out of the tight shear spaces so little help in overall combustion cooling. Oil must get to about water boiling hot for the ZDDP to from a protective layer that wears off on each start up. Oil should get at least 165'F to evaporate moisture which is what creates the most corrosive products in oil and can eat up the hardest surfaces. Going slow on low throttle or sitting still at no throttle does not heat engine and oil up as much as 55 mph cruise speed. Humid air cools a whole lot better than dry air. Oil cooler on Nortons mainly only cool the oil to protect it. Oil coolers often have covers for cold conditions as well as thermostats. Going by 3 temp locations on Ms Peel I have collected materials to insulate her oil if it don't get higher than 160'F going illegal rates. Of course you know me I hardly strain at throttle so prolly don't apply to anyone else.

Thank you sir! This is a VERy informative post with some details I was not aware of. Now all I need to do is find a Themostat or manual by-pass valve that I can fit to the bike without looking totally out of place. That or the black ductape thermostat will continue to suffice until I can actually see one of these valves in person. Hate to order one, pay for it then get it home and hate it.

Thanks Again.

kraakevik · Jun 9, 2011

I have the AOT1 Mocal thermostat mounted on the old air-filter backplate, close to the supply and return lines. The Hyde cooler, thermostat and additional piping hold about a tumbler's worth of oil--the aluminum bracketry also stiffens the downtubes.

On hot days the Hyde's return outlet feels about 20 degrees F cooler than the inlet. Even with weather in the 60's the thermostat often opens after a blast on the expressway--I sit at the four-minute stoplight at the exit ramp with my finger on the inlet, and before the light changes the accumulated heat load actuates the cooler. A mile or two later the thermostat closes again.

Tim Kraakevik
kraakevik@voyager.net
'72 Combat, '74 RH10 850

Torontonian · Jun 9, 2011

Steve , up here in the Dominion of Canada I/we have never ever discussed the need for cooler oil. Crazy is loaded up with camping gear and DEET (the world's longest word ) ready for the 3 1/2 hr. drive up to the cooler Meaford Georgian Bay Rally with a View , in the mornin'. Cool , chilly forecast = normal. Just for fun could you post a photo of the black duct tape arrangement thermostat thingy.

Foxy · Jun 9, 2011

Hers a pic of my Monster's oil cooler and a bypass tap they use instead of a thermostat.

Also a pic of a oil cooler and possible placement on my Featherbed 920's build.

pelican · Jun 9, 2011

i thought we came to the consensus in the other threads that oil coolers are not needed and serve little purpose on a commando

steveyacht · Jun 10, 2011

pelican said:
i thought we came to the consensus in the other threads that oil coolers are not needed and serve little purpose on a commando

As I have not been an active member of this site until recently, I had no knowledge of other oil cooler threads

pete.v · Jun 10, 2011

pelican said:
i thought we came to the consensus in the other threads that oil coolers are not needed and serve little purpose on a commando

I never voted on that. What was the out come of yea's vs nea's?

I think an oil cooler would be ok as long as a thermostat is employed. The oil must come up the temp.

Hobot · Jun 10, 2011

Best I've gleaned over the years is the only place Norton oil gets too hot is the tiny trickle passing the exhaust side of head draining down lifters. Reports measured up to 500'F. No matter how cold you get the oil it will not be enough for matter in this area. The famous zinc/phos metal additives we must have for push rod flat lifters must get to ~200'F to form the nano-pads that wear off on each start up. I'm with Jim on this, my Peel plan is only cool the head supply. More oil heat cooling might be gained by increasing the exhaust side oil flow if extra drainage could be made to handle it and not pile up on lifters. I can notch the rocker spindle to up flow some but not sure how to do the drainage side.

JimC · Jun 10, 2011

I measured the oil temperature in the tank. If memory serves me correctly it was in the + 220°F range. This would be after a 75mph extended run. Running a Lockhart cooler, the temperature was reduced about 20°. I spoke to an engineer from Spectro Oils and he thought +220°F in the tank was too high. Considering that the tank provides some cooling, the actual oil temperature was in excess of 220°F, probably 240°or better. The engineer also warned of the danger of too cool oil. Moisture being the culprit. Hence the need for a thermostat.

Considering that the life of the Norton Commando engines is a bit on the short side, I think an oil cooler is a good thing. Personally, I wouldn't run without one. Especially if you are doing sustained highway runs. If you have an oil pressure gauge you will see the effects of too hot oil. Pressure at idle will drop off to nearly zero after a highway run.

pelican · Jun 10, 2011

pvisseriii said:
pelican said:

i thought we came to the consensus in the other threads that oil coolers are not needed and serve little purpose on a commando

Click to expand...

I never voted on that. What was the out come of yea's vs nea's?

I think an oil cooler would be ok as long as a thermostat is employed. The oil must come up the temp.

basically it came down to 1. they don't really reduce the temp enough to be of value 2. plenty of people use for extended periods in hot regions without a cooler, and their bikes run fine.

Oil Cooler

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