Engine oil weights & running temps

[Pancakes]

Ok, so understanding oil weights and the ratings in relation to their thickness and surface tension at different temperatures is easy, they are made to known standards and most manufacturers have comprehensive info on their products.

The hard part; what temperatures do bikes run at? What runs hotter, water cooled, oil cooled or air cooled? could an air/oil cooled bike (in my case) run cooler than a water cooled bike if I don't warm it up for long and am riding at 100+ early in these winter mornings. Do I need to use a winter oil maybe down to 5w with the cold mornings and would a cooler oil handle the conditions on the same bike at midday sitting or riding slowly?

Has anyone got a pyrometer/temp probe and multimeter that they'd like to do some testing with. I'm thinking a few bikes of different types and establishing baseline temps at different speeds (and loads?) and mayme see if they hit different max temp's with no air movement?

There are probably 200 threads with all my answers already so I'm kinda waiting for the links to start coming in but fire away if you have ideas or info on this.

Thanks

[xwhatsit]

This is just what I've gleaned from me asking similar questions on KB, so it may not be quite correct.

Water cooled bikes run far cooler than hot. They are designed to do so. Oil cooled and air cooled are the same thing, oil cooled mostly being a marketing strategy to seem less old-fashioned. But they do run hot, and the engine likes to run hot.

Your bike should not be running any cooler than a water-cooled bike in the same conditions. This is bad, you should always warm your bike up properly even if you have to wait around for a bit. Taking a cold bike with cold oil and then winding it up to 100kph isn't very good for it.

I wouldn't worry about winter oil unless it's ridiculously cold. I've noticed that for any given oil on the shelf, it nearly always only comes in one weight (e.g., my tipple of choice, Delo 400, I've only ever seen in 15W-40. You could probably buy a different weight if you made an effort to track it down, though). I think this is because across the board, temps in NZ (or at least Auckland) only ever cover a certain range, which one oil weight covers OK. I think the only reason you'd go out of your way to get a particular weight would be if you have an old engine with the rings on the way out and the seals don't hold much in anymore.

I'd just buy the oil you prefer in the weight it's provided in. If you've got a choice then go with wintery stuff for winter and summery stuff for summer. It's unlikely to be horribly wrong.

[Motu]

Air cooled and liquid cooled bikes run at the same temp,but a water cooled bike will run at a constant temp,an air cooled bike will have a wider temp range in it's running....that's the main advantage with water cooling,the consistent temp means less tuning problems.Oil will run between 70 and 120 deg C....85 C is pretty normal.Normally engine temp,but a turbo will put more heat into the oil - my Pajero on a big climb (say over the Bombay's) will run the oil to over 100C,with the cyl head at 85C....it has an oil/water heat exchanger on the block and an oil/air heat exchanger in front of the radiator,thermostatically controlled.No problems running oil to that temp.Get a non contact thermometer,they are pretty cheap now - and just check points on your engine when you stop,that what I do.

[Pancakes]

Yeah I don't just jump on and go, I let it idle, sometimes with the choke out if it idles too low or rough until it is running smooth and quiet (once it's warm it seems to quiet down?) kinda the time it takes to put gloves on in summer or helmet, gloves and kiss the family goodbye in winter but definatly notice more low power and top end when it's a really cold day. Thanks Motu, I gave you rep for straight tech answers and thats more of the same, I wanted to know the tested running temps to match them up with the oil weights. Good stuff, I had thought 1) more access to cold air may actually let an air cooled engine (and the same engine w/ an oil cooler must give of more heat, same heat generated-more surface area and time exposed to cool airflow) or 2) must run hotter with the less advanced cooling system, no thermostat/fans etc or 3) must just have a bigger range of running temps which is what I think your saying? Maybe on the odd accaison could be colder but generally hotter and bigger fluctuations.

Any more thoughts anyone? Does anyone else think about this or nah?

[slowpoke]

Sounds like you are putting way too much effort into something that chemists, engineers and phycisists have already spent millions of dollars and millions of man hours perfecting.

The whole point of todays multigrade engine oils is that they will work over a wide range of conditions. The manual you receive for your bike if purchased in Dunedin is the same manual they receive in Alice Springs, Australia and chances are they'll recommend the same oil.

If you are curious, sure go ahead and test your heart out, but bear in mind that the conditions will be totally uncontrolled as compared to the incredibly complex and repeatable test scenario's the boffins will have dreamt up.

So, short answer long, I wouldn't waste time thinking about something that somebody smarter and with far more resources than us has already bent his/her brain over. Just use the recommended grade....unless you are racing in which case you could choose a higher spec lighter oil for less drag and a poofteenth more hp....which is gonna make SFA difference for the average club racer.

[Pancakes]

If you are curious, sure go ahead and test your heart out, but bear in mind that the conditions will be totally uncontrolled as compared to the incredibly complex and repeatable test scenario's the boffins will have dreamt up.

So, short answer long, I wouldn't waste time thinking about something that somebody smarter and with far more resources than us has already bent his/her brain over. Just use the recommended grade....unless you are racing in which case you could choose a higher spec lighter oil for less drag and a poofteenth more hp....which is gonna make SFA difference for the average club racer.

If I thought I was smarter than a petro-chemist or whatever they are I'd go for the job and ask for more money or at least be just writing answers here, you might see I asked a question in the first place, not an answer. That would incinuate I don't know the answer already so I don't know who told you I was a boffin! heheheh

Your right, they are all the same manual and your right, my riding conditions are not controlled by my supposed boffin friends, I was thinking of keeping an eye on my engine temp and asked if anyone had previous info on the same thing. IE, Motu is a mechanic and has and did list the answers so seems to get the point of my thread,

Oils are different and the w ratings relate to viscosity at various temperatures, thats the part those geniusses list freely, what I couldn't get hold of was running temperatures, not for lab test bikes (anyone see the Hyundai engine running for XXXX hrs on that ad, wonder if it has any load applied? doubt it or that room would have fans all over).

Your right, the same manual is given to owners in hot and cold places, you seem to be someone who is happy to do as your told and that it may not interest you to monitor your equptment for your own curiosities sake so I wonder if you think that they have the same manual because thats the best thing for your machine or because they didn't want to pay to print 20 differert runs of the same thing and get the legal team to proof read the whole lot? I recon they will give you the very best advice not matter what, even at the expense of their bottom line, I mean, really, thats what companies do isn't it?

Hey, no hard feelings, I just wonder why you question something that is interesting, relevant and useful especially given this is a motorcycle tech forum?

PS, you could probably run a modern engine on the shittest cooking oil money could by for quite some time, doesn't mean it's a good idea!

[gambit]

i had many air cooled bikes and yip they ran better when it was colder my bikes with oil coolers didnot like riding around town too long the temp would hike up,my gsxr was full oil cooled ran down to welly and back thru hot n cold and didnt miss a beat in the one day but difinitely ran better in the cold my vtr is water cooled and gets hotter faster the radiators are on the side which means city running the temp rises faster not enough air flow. all of them running on 10w40 castrol or motul , mate done the oil in a fryin pan trick which ever oil took the longest to boil that was the one he would use lol

[Motu]

If he really did the frying pan test then he would be using castor oil.....all oils run away from heat,castor oil moves towards heat.The reason air cooled bikes run a bit ratty around town is the heat sinks into the carbs sitting at lights,then cool down as you ride,then heat soak again.The water cooled bike maintains that constant temp and so has less heat soak.And your Suzuki is not ''oil cooled'' - all internal combustion engines are oil cooled,it's one of the major functions of oil....heat transfer.Suzuki just made more use of the heat transfering and then called in the advertising guys.

[Brian d marge]

If he really did the frying pan test then he would be using castor oil.....all oils run away from heat,castor oil moves towards heat.

Could you enlighten me on this .. heat move across a temp gradient ,, not being funny or anything , genuinely curious

That caster oil had something going for it !!

Stephen

[Motu]

Just what I've been told and read - castor oil can withstand far more heat than mineral oils.And it can take far more pressure to - for a long time it was the only oil that could handle worm final drives.Even the thickest most fortified EP oils fail in a worm drive truck diff (and Peugoet 404's,but let's not go there),but plain old straight 30 weight castor oil does the trick.

[Pancakes]

Motu's right you know (again!). Been doing tons of reading about oil lately and drag cars, circuit sprinters and heavily boosted boats seem to all be running CASTOR OIL!! it seems to be because it has mad surface tension or it's viscosity and helps the rings and plain bearings do their job without the engine tolerances being too tight, race motors are built looser because the resistance robs power and they are run to way shorter service intervals. It does however "gum up" (the things that different oils do poorly are gum up (some organics with castor being the worst by far), "oxidise" (mainly organics to varying degrees), "airate" (all oils carry air bubbles to different degrees, this causes minor drops in oil pressure from the air compressing and means the oil can't carry heat away from hot spots and moving parts as well, some oils will have added stuff to stop this, will edit when I remember what it's called). And "varnish".

So far I can see with bikes your looking for an oil with added detergent to keep gunk suspended in the oil so the filter can catch it and no added friction modifiers. Other than that I haven't finished learing yet so will hold off saying anything else. Oil volume increase will also help lower running temps, like enlarging the sump on a car but there's not much room on most bikes for this type of mod, have also seen mentioned that while a "cold start" oil (for want of a better term) may become more fluid faster it also adheres to engine parts less well while the vehicle is off, the oils that go thick faster when the engine is turned off stick thicker around the rings, valve guides etc better so I'm gonna have to stick to my current regeime for now. OEM filter and Semi-Synthetic every 5000kms, I remove and clean the base plate thing with the gause filter each time too, fuel & air filter every 10000kms. I just use name brand middle of the price range oil. Whatever known brand the shop is stocking.

[gambit]

the original gsxr were oil cooled ie oil jacket not watercooled and stills runs better than the vtr as for the frying pan trick it makes me mate happy and thats all that matters to him didnt mean to upset anyone just wanted to share , what oil do you use in your bikes? as another mate has just scored an old tt500

[Pancakes]

I've been using 20w50, castrol as it was $5 cheaper at the time. I haven't seen yet a doubt the manufacturers would release the info you'd need to make a choice between the main brands. I'd love for someone to start an ethical oil company, " not from a war torn country!". Fat chance. I did have a look in the back of a manual in the garage and found the chart in the pic below, the writing above says "If SAE 10w30 or 10w40 motor oil is not available, select alternative using the following chart". Thats the homemade mexican bean pizza I'm eating and the beer I'm drinking right now too.

[Motu]

I usually use Silkolene,these are ester based synthetics - esters were developed to lube jet engines,they can handle far more heat than other oils.They also cling to metal,make cold starts no problem.But I have no lost my trade accounts,and Fuchs no longer bring in Silkolene,only 3 litres left of my stocks.

I also use diesel oils - the stuff I use is long life stuff,able to go over 70,000km between changes.Diesel oils have a similar additive package to motorcycle oils,and them some.Most are rated for Allison transmissions,so no worries with wet clutches.

Oil threads are a lot of fun - but whatever the views,in 37 years working on engines,I've never seen one fail because the oil wasn't up to the job.Any damn oil changed regually is good enough for any engine.

[Pancakes]

Can you recommend any other ester containing oils? A guy I know is a diesel mechanic and I get (remulux? something like that) diesel oil off him for the car, didn't know if it had friction modifiers so didn't want to put it in the bike. I totally agree with your last sentence Motu (not that with my level of experience I'm in a position to disagree) If people ask me (car owners) I say to use the best oil they can while keeping the changes regular, theres no good in using Mobil 1 or anything like that and not being able to afford to change it for another 20,000k's! With all my other cars I'd just look out for specials at the Warehouse and do the change often with whatever was going.