N. Ohomo
Registered user
MAC offers a +2 qt. deep sump. So if I put some aluminum tubes thru it length wise that should cool the oil nicely at speed. How would that compare to a proper oil cooler? TIA
Engineering opinions please
- Thread starter N. Ohomo
- Start date
If you put the tubes within the sump I cannot see how they would have any cooling influence. Maby I've missed something in your post. If the sump reduces ground clearance I'd be worried about that. JJH
I think he's talking about tubes lengthwise (front to back) which will allow air to pass through them.
It seems like a reasonable idea to me. I would imagine you'll have issues with welding onto the cast alloy material though.
How far does the rotating assembly drop down into the sump?
It seems like a reasonable idea to me. I would imagine you'll have issues with welding onto the cast alloy material though.
How far does the rotating assembly drop down into the sump?
N. Ohomo
Registered user
Yes front to back. Pictures show the MAC sump pretty deep and that stands to reason with +2qts. They provide a pick up extension which could be shortened if need be. The tubes would be at the bottom of sump. Air would flow thru. In my readings I'm lead to believe a sump like this used to be available but no more. Welding should not be a problem granted we're not F1 central but we get around ok.
If you've a higher capacity of oil will that not add to the cooling. I like the idea but is it needed, and will it over cool the oil (will it introduce a fail point where it's not easily fixed) if an oil cooler fails you can by pass it and take it steady.
Beemerboff
Registered user
Ground clearance simply isnt an issue on a Airhead - if you need more you need a bike 120 kg lighter , with twice the suspension travel.
It is hard to over cool oil - if you look at Robs color gradient pics on the other thread you will see that the oil radiator is self regulating, the hot oil flows at one end and the other is almost stone cold until needed. Rob might have to post a few more pics to fully demonstrate this-----.
The same would happen with these tubes, the cold oil would stick to and below them and only the hot stuff at the top would circulate, then as the oil warmed up more would start to circulate, but not any more than necessary.
Motern Israel might still have the sump, or spacer, with the tubes.
I was as surprised as anyone when I saw how easy it is to weld extruded to cast aluminum, but it does not appear to be a problem - quite a few superbike frames are made with castings at the pivot points and extrusions welded to them and forming the rest of he frame.
It is hard to over cool oil - if you look at Robs color gradient pics on the other thread you will see that the oil radiator is self regulating, the hot oil flows at one end and the other is almost stone cold until needed. Rob might have to post a few more pics to fully demonstrate this-----.
The same would happen with these tubes, the cold oil would stick to and below them and only the hot stuff at the top would circulate, then as the oil warmed up more would start to circulate, but not any more than necessary.
Motern Israel might still have the sump, or spacer, with the tubes.
I was as surprised as anyone when I saw how easy it is to weld extruded to cast aluminum, but it does not appear to be a problem - quite a few superbike frames are made with castings at the pivot points and extrusions welded to them and forming the rest of he frame.
I think you are creating a problem in your own mind that really doesn;t need that difficult a solution
If I remember correctly You talk about off roading Well in that instance once the tubes are covered in mud and crap they no longer will work Fit a deep sump and move the Rad off the Crash bars and up below the head stock (Fit a bigger one if you wish) and all should be fine
Simple is best Trying to ensure a seal between your tubes "through" the sump would be a headache
If I remember correctly You talk about off roading Well in that instance once the tubes are covered in mud and crap they no longer will work Fit a deep sump and move the Rad off the Crash bars and up below the head stock (Fit a bigger one if you wish) and all should be fine
Simple is best Trying to ensure a seal between your tubes "through" the sump would be a headache
fayeslane
Registered user
I agree. There are and have been plenty of bog standard airheads circulating around Oz in 40C + temps, overloaded to buggery, without dying from oil temp issues. One that passed through my shed was a standard R80, 750,000kms, one engine /drivetrain rebuild, ridden all over Oz in all conditions. No oil cooler.
If it worries you bung on a deeper sump or extender, change the oil regularly and turn your attention to brakes and suspension where upgrades can significantly improve the performance of your bike.
solidstate100
Registered user
I agree. There are and have been plenty of bog standard airheads circulating around Oz in 40C + temps, overloaded to buggery, without dying from oil temp issues. One that passed through my shed was a standard R80, 750,000kms, one engine /drivetrain rebuild, ridden all over Oz in all conditions. No oil cooler.
If it worries you bung on a deeper sump or extender, change the oil regularly and turn your attention to brakes and suspension where upgrades can significantly improve the performance of your bike.
^THAT^
Seriously, the solution to your "problem"already exists, and is well proven. Nothing you will come up with will regulate or control oil temps as well, and simply, as an oil cooler.
Another thing to consider is there was simply not the spec of oil around when the airhead was designed as there is now
Put a modern high quality oil in the bike and you won't get it hot enough to be a problem
Put a modern high quality oil in the bike and you won't get it hot enough to be a problem
Bugger all. Oil coolers have many small tubes to increase the surface area, plus the matrix inbetween to conduct the heat away.
A few tubes passed through the sump will have a negligible cooling effect.
Add the fact that you're introducing a potential weakness into a critical component and I think it's a no-brainier.
Agreed - it all about surface area, and you wont be adding nearly as much as with a small oil/air radiator.
N. Ohomo
Registered user
Thanks people, I appreciate the input. I don't have much experience with the airhead yet, reading everything I can, I hope I'm not being too grating 
I should add that the frame has been modified to lift and cant the engine back a bit. This was done by cutting 1.5in. out of the front down tubes. I'm mentioning this to indicate no clearance issues with filter cover. So I'm looking at a deeper sump and pick up as safety feature. Was hoping to roll that into an oil cooling solution 2 birds with one stone etc. This bike, like everything else I ride, will be 50/50 gravel roads/pavement. No hardcore off road.
I should add that the frame has been modified to lift and cant the engine back a bit. This was done by cutting 1.5in. out of the front down tubes. I'm mentioning this to indicate no clearance issues with filter cover. So I'm looking at a deeper sump and pick up as safety feature. Was hoping to roll that into an oil cooling solution 2 birds with one stone etc. This bike, like everything else I ride, will be 50/50 gravel roads/pavement. No hardcore off road.
Beemerboff
Registered user
Nothing wrong with your idea, at one time it was possible to buy a sump which had tubes in it.
But you are asking in the wrong place if you want an informed engineering opinion, no engineers here and most seem to know so little they think they know everything.
On a Air cooled bike oil plays a vital role in cooling the highly stressed engine components, and it cant do that if it overheats.
If you speak to professional BMW mechanics they will tell you that blown engines are not rare, and the cause is almost always overheated oil, or little or none due to a leak.
You have a 1000 cc GS to keep cool but the OEM cooling equipment is similar to much less powerful road only bikes. In fact it is sometimes less - my clamshell air cleaner R75/7 draws air in from the bottom of the front cover , over the rectifier and engine and into the air cleaner, but my GS doesn.
If you do a decent amount of slow speed off road work on a fully laden bike in hot conditions the oil will overheat, and the oil pressure will drop, and you will put the life of your moter at risk.
This problem has existed since the introduction of the / series and improved equipment has always been available for those who ask a bit more from their bikes.
If you dont want to take the risk of damage to the oil cooler and pipework you simply cannot safely remove it if you intend any more than modest low speed work, and every BMW specialist sells equipment which will improve the cooling an let you use the full potential of your bike, and every bike taking part in any sort of competition has it.
The jackasses are braying loudly on this one, but dont let it stop you doing the right thing.
But you are asking in the wrong place if you want an informed engineering opinion, no engineers here and most seem to know so little they think they know everything.
On a Air cooled bike oil plays a vital role in cooling the highly stressed engine components, and it cant do that if it overheats.
If you speak to professional BMW mechanics they will tell you that blown engines are not rare, and the cause is almost always overheated oil, or little or none due to a leak.
You have a 1000 cc GS to keep cool but the OEM cooling equipment is similar to much less powerful road only bikes. In fact it is sometimes less - my clamshell air cleaner R75/7 draws air in from the bottom of the front cover , over the rectifier and engine and into the air cleaner, but my GS doesn.
If you do a decent amount of slow speed off road work on a fully laden bike in hot conditions the oil will overheat, and the oil pressure will drop, and you will put the life of your moter at risk.
This problem has existed since the introduction of the / series and improved equipment has always been available for those who ask a bit more from their bikes.
If you dont want to take the risk of damage to the oil cooler and pipework you simply cannot safely remove it if you intend any more than modest low speed work, and every BMW specialist sells equipment which will improve the cooling an let you use the full potential of your bike, and every bike taking part in any sort of competition has it.
The jackasses are braying loudly on this one, but dont let it stop you doing the right thing.
In addition, the rate of heat transfer to the air is proportional to the temperature of the oil. An oil cooler normally takes the oil at its hottest.
In the sump its at its coolest.
So even less cooling will take place.
Speak for yourself fucknuts. Some of us are Chartered Engineers who have experience designing, amongst other things, heat exchangers.
Others on here can build a fucking bike from old tin cans and string.
Bikes are designed for a wide range of operating conditions.
Its perfectly possible that the OP will be able to run his bike without an oil cooler.
You saying "Oh BMW know best" is showing yourself up for your lack of engineering ability or knowledge.
So feel free to have your own opinion but please don't slag off our engineering knowledge without knowing what you're talking about.
We all have something to add.
Or, are you saying we should all come grovelling at your feet when someone has a technical query.
You do seem to know your stuff judging from your previous posts but your last thread just came across as being an arrogant prick.
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solidstate100
Registered user
Beemerboff,
Speaking as as an apprenticed and time serviced automotive engineer, with amongst many other things, being responsible for dealing with engine cooling for project vehicles for clients of Lotus (the sports car manufacture) i find your comments somewhat arrogant and ill judged.
The OP asked for engineering opinions, which he has received. Or are only yours the valid ones?
Speaking as as an apprenticed and time serviced automotive engineer, with amongst many other things, being responsible for dealing with engine cooling for project vehicles for clients of Lotus (the sports car manufacture) i find your comments somewhat arrogant and ill judged.
The OP asked for engineering opinions, which he has received. Or are only yours the valid ones?
N. Ohomo
Registered user
Dry your eyes mates, I ordered the MAC sump from Niche Cycle Supply and an Emgo airfilter. I hope I didn't screw up too badly. Discuss amongst yourselves
fayeslane
Registered user
Spot on.
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