Oil Pressure @ rebuilt engine

About None that I can remember reading about, which all seem
to be wet sump not dry sump like Harleys which commonly
have oil coolers added, but they also have rear barrel in
dead air.

So which is more important, oil temp or oil pressure?
Obviously they can't be separated. Thin oil carries more
heat away faster than thick oil. Thick oil makes more
pressure than thin oil. Proper single grade for ambient
temperature is better than multi-grade. Multi-grade
is better in wider ambient temperatures.

Engine efficiency goes up run cooler. Cooler oil
would help this - up to a point. But What Point?
There's some reports too cool oil wears engine more.

How much does oil actually help cool Commandos?
Boiling hot ain't really hot to oil with flash point over 400'F

hobot

What made me think of adding one: Utah Norton Rally 2007, Had the pleasure of meeting a guy from Canada (French Canadian) who was riding a 850 in the John player colors. Maybe someone knows him or maybe he's on this forum, He had over (I looked at his speedo and if I remember correctly) 70,000 miles on his bike and told me he had only done only one valve job on it and that the bottom end was never touched. He was running a Lockhart cooler on the front down tubes, I tend to think he was telling the truth as he seemed so proud of the high mileage he had done with little work on the motor. And he lived in cool Canada, As I live in Southern California and the heat here can get pretty high in the summer I have seriously considered one. The only thing that has stopped me was where to fit it, On the front just looks so out of place. If I could find a nice small one with a built in thermo control valve in it I would add it. I'm still looking, Not only does your oil last longer but your oil pressure won't drop as much when you ride on those hot days, This last part is from a good source who re-builds Norton's. :wink:

Oilcoolers aren't as efficient as one would like. It turns out that the hot oil has a channel down the center with cooler oil parked next to the wall of the tubing. They have tried ripples to get some turbulence going but I don't know if it works much better. Apropos of nothing, when the 911 first came out the ran a metal oil line up to a front wheel well for an oilooler. They found that there was no difference if they put an oilcooler in there or not, it was the line that did all the cooling. So they left out the cooler and just put a loop on there.
Eric Buell is a genius. He put the oil in an aluminum container that's in the airflow, and it's shaken, not stirred. It's cool

I have never considered an oil cooler but in light of all the reports of Commandos that have blown the engines due to overheating oil, it might be worth doing.

Oh, wait...there are no reports of such a thing...

Actually it's the engines that have quietly worn themselves out prematurely that I'd worry about. Maybe it would be a good idea to use a good class IV or V synthetic, then think about a cooler. Unless one thinks an engine overhaul every ten thousand miles is a fine way to have fun. I know these bikes don't get ridden as much as most but it would be interesting to find out what people are getting in the way of mileage between rebuilds.

Actually it's the engines that have quietly worn themselves out prematurely that I'd worry about. ("Amen to that")

Some people that don't think an oil cooler is needed are changing their oil way too soon, Why????? I can see why Ludwig don't need no cooler, WEIGHT. And he rides in the Bloody snow! I'm not saying that coolers are for everyone but they sure do keep the temp. down. I don't think you will see an engine "Blow up" because the oil is broken down, But it sure will wear a lot quicker. Now where can I find a nice looking oil cooler, LOL LOL. :wink:

YES! Let's see some pictures of some nifty oil cooler set ups!

ludwig said:

I have no doubt that for 90 % of the time an oil cooler is not neccesary , but the same goes for your front brake :
You do not need it for 99.9 % of the time you are riding , but would you ride without one ?

Click to expand...

Come on Ludwig you know that comparison sucks. No one would ride without a front brake because it is destructive to ride without it! But would no one ride without an oil cooler because it is destructive to ride without it?

Just saw your Reed Valve, very clean job!

highdesert said:

YES! Let's see some pictures of some nifty oil cooler set ups!

Click to expand...

Mine's in a box. It's dirty and I'm going to keep it there. If I think the bike is going to be run hot I'll use synthetic.

Hiding behind the footrest? Nice.

Oh REALLY? Then we need to see pictures of these devices please. It's funny you say that because I have some copper tubing and some stainless sitting on the work bench as we speak, I just need to figure out where to place the cooler and then design it for that location. I plan on using the Lockhart thermal valve which is small and compact. With this it won't take any longer to warm up the oil. Seriously do you run a cooler? I kinda figured you would have to warm your oil, LOL. :wink:

I can't help but once again go back to the fact that a production Commando lapped the IOM course at over 100MPH without having to rely on any of these "must upgrade" things that seem to be "required" now. In general these bikes never see 1/3 the stress that they did back in the day when we were young and rode the s#$t out of them and none of these "upgrades" even existed. Yet now we seem to believe they are going to fall apart unless immediate steps are taken to "fix" them...

Adds weight, more plumbing leaks possible, looks ugly and is plain unneccesary. Unless you live and ride regulary at high speed in an equatorial climate, i.e. North Africa, Central America, or Northern Australia there is no need for an oil cooler on a Commando it carries enough oil and has enough exposed surface area to dissapate engine heat. An oil cooler carries only a small additional volume of oil. High ambient temperature will eventually heat all the oil to the same temperature. If your engine got so hot as to breakdown the oil and cause metal to metal contact, the pistons would be shot already. The only way to reduce engine temperature effectively is to either decrease the energy i.e. slow the revs or increase the dissapation from the head i.e. water cooling. The small amount of oil circulated to the rockers is simply inadequate to compensate.

Mick

Going by various reports I worked out the oil contributes about
5% of total cooling of engine.
BY Far hottest place is oil passing exhaust side head where
some probes showed almost 450' F. Only more flow can
lower that.

There is no guide leak issue on exhaust side as guides
only see hi pressure outward from chamber when un sealed, no suck.
Also the push rod tunnels and pair of liter grooves
can drain more oil than tiny intake side drain path.
So I'm going to experiment in Peel by creeping up on opening up
rocker face to see if helps head temps or oil endurance.
The factory spindle notch looks like it'd just flood area though.

hobot

Just to let you know Mike the JPN production racers did have oil coolers, At least in 72 they did. But I want to thank you and Mick for your opinions, I appreciate them very much, Chuck. :wink:

Did the Manx engines that dominated world road racing all those years employ oil coolers?

LOL LOL LOL

I don't believe they did!

Then again, how frequently are race bike engines rebuilt?

highdesert said:

Did the Manx engines that dominated world road racing all those years employ oil coolers?

Click to expand...

Last time I checked race bikes don't do much puttering at low speeds where the engine can cool fast enough.

Hortons Norton said:

Just to let you know Mike the JPN production racers did have oil coolers, At least in 72 they did. But I want to thank you and Mick for your opinions, I appreciate them very much, Chuck. :wink:

Click to expand...

True and as well the Triumph 500 twin class racers at Daytona in '67 and '68 had oil coolers too. But look at the size of them! A pair on either side holding about half a gallon each! Also the Tri-BSA triples had them for racing and as stock. The issue for the Commando is its overall efficiency at dispersing heat under normal road conditions in comparison to race conditions. The race bikes had eveloping fairings, road bikes are open. Race bikes are built for speed not for beauty contests and carry as much lubricant as possible and may have extensively modified internal feeds. The JPN's had if I recollect correctly, 6 start worm drives, that helps when running near the red-line for a couple of hours. Get as much oil in and out as insurance, more importantly get as much air flow to the top end of the motor.

These dinky little after-market motorcycle oil coolers for road bikes don't add much to heat dispertion where it matters and that is in the cylinder head. The best example of an oil cooler actually doing its job on a road bike was Suzuki's first GSXR750 of 1986. This had a purpose designed oil cooled motor with air assisted cooling. Many fine pitched fins on the top end, copious oil feeds and a massive oil radiator. Our Commandos have a purpose designed air cooled motor. Tacking on a cute little oil cooler is just cosmetic, particulary if you really only ride on the road in blissed out Commando cruising.

Mick