Topic: Oil cooler?

[Madman9050]

I wanted to ask if anyone had installed an oil cooler on a 750 is it worth it? how would you plumb it in?

[Danno]

generally speaking any air cooled bike will bennifit from oil cooling there are custom made oil tanks with fins that help a little but are expensive and there are kits that install with an adapter behind the oil filter most of them also convert the filter to a spin on type these work better and are easy to install with the cooler mount location being the hardest thing to decide about the kit some come specific for the model bike and have a set location for the cooler and all mounting hardware but most that can be found now are generic and for almost any air cooled bike generaly lowering the oil temp will prolong the life of the oil and help cool the engine plus it gives you a little bit of extra oil volume in the system there are a few nos kits still left around but they are rare and I could not tell you where to look for one

sometimes you can find a decent oil cooler at a motorcycle junk yard but if you do replace the hoses and verify that the cooler is not plugged up with sludge or anything else before you use it

[ekpent]

Do a search on that,quite a bit about it. You are almost entering 'popcorn' territory 

[TwoTired]

I wanted to ask if anyone had installed an oil cooler on a 750 is it worth it?

Not needed on a stock bike for street use.
Just do regular oil changes.

[Retro Rocket]

Depends where you live mate. Its quite warm all year round where i live and i use them on every bike i have owned, in saying that, half the bikes i have owned had them fitted as a stock item. I have NEVER had a problem with oil coolers and actually recommend them in moderate to warm climates. Regardless of what some will say, i have never seen an engine damaged from using one...

[jessezm]

If it makes you feel any better I spent about two entire days last month reading through the 37-page thread here on this topic and I'm not sure what I came away with!  I think I am going to use one on my cb400f but that's because I do live in a hot climate and am pushing a lot more horsepower than stock.

[CBNJ74]

My 73 CB750K came with one and I pulled it off after a line popped and sprayed oil everywhere. The bike has been fine ever since. I may sell it one day but for now I'm holding onto it.

[MCRider]

I wanted to ask if anyone had installed an oil cooler on a 750 is it worth it? how would you plumb it in?

Yes.
Depends on what constitutes "worth it".
Lots of adapter kits. Some made by forum members. You can buy complete setups from eBay, I bot a real nice unit from a forum member. Easy as add on accessories go. Adapter usually goes between the oil filter cover and the cases, uses a bolt extender. Racer guys get a little more into it and tap into various engine plugs to optimize cooling.

Its not necessary on the one hand. And it would be hard to quantify benfits even in a hot environment. Then on the other hand there is evidence Honda had one for the CB750s and it wasn't introduced on USA bikes. Since the 70s, virtually all aircooled bikes have oil coolers as well. So it became necessary I suppose you'd say.

Then again there is the coolness factor.        These are our toys after all. It if lights your wick, go for it.

[TwoTired]

I wanted to ask if anyone had installed an oil cooler on a 750 is it worth it?

O.K. I'll elaborate. 
All you will get on this forum is opinion based on "no hard facts" or supportable data.  In fact, supportable data is actually shunned and reviled by most, if not many of the oil cooler proponents, (including a forum member who profits from their sales).

The proponents like the "prove the negative" approach.  As in "prove that it doesn't help"  Which is like saying "see the president has short hair, so if you wear short hair you can be president, too."

But, given this topic is essentially a popularity poll, I'll introduce the wildly unpopular presentation of fact discovery. 

A. No one has shown evidence that adding an oil cooler has saved or helped an SOHC4 engine in any way (aesthetics not withstanding).
B. No one has presented any verifiable evidence that not having an oil cooler was a direct cause of engine failure.
C. No one has presented any (non-anecdotal) data regarding the engines that have survived long service lives WITH an oil cooler.
D. No one has presented any data regarding the engines that have survived long service lives WITHOUT an oil cooler.
E. No one has compared C with D above, to find statistical data supporting either.

I have 100,000-300,000 Miles distributed among my SOHC4 collection.  Only one of them has an oil cooler (which will be removed during it's restoration).  Some came from Arizona, noted for it's hot climate. (I certainly admit this to be anecdotal.  But, it is equally as valid as saying one never had an engine problem while an oil cooler was installed.  Meaning, neither is germane to the original question, and essentially strawmen.)

But, the anecdotal game is just too fun to play, I'll offer this.  The bike that came to me with the oil cooler installed, was on a CB750 whose engine had been replaced (clock said 68000 Miles).  So either:
A. The oil cooler didn't help save that original engine.
B. The oil cooler was put on to help save the replacement engine.
C. An oil cooler would have/may have kept the original engine in service if installed at the outset.
D. The presence of the oil cooler has no bearing or effect on the engine failure or it's replacement.
(Isn't all this speculation fun?) 

I may well be to only forum member here that has actual training or experience in machine thermal management.
I am slowly collecting test equipment to collect real heat data, from an operating SOHC4.
A. The equipment isn't cheap.  And I still need a couple of oil temp gauges. (Anyone want to donate $200-$300 for the "cause"?) 
B. There is a significant amount of engineering time and effort required to do objective testing (mostly thankless).
C. I don't feel that most of the forum actually wants an answer that doesn't fall in line with their preconceived opinion.
  (Realistically, many wouldn't be able to follow a complex dissertation on heat exchange pathways.  And, if it at all hints of "engineering", the mechanics here will immediately discount and attack it.)

So, I lack incentive to do the actual work.  Which, in fact, is also true for the rest of the forum members here, including the ones who make and sell oil coolers for profit.

Consider, if those who are making money on the sales of oil coolers can't show real data regarding their benefits, then the sales is purely marketing/profit driven, which needs no facts beyond keeping the account books in the black, (much like a carny).

From my thermal management experience, familiarity with, and cursory analysis of the SOHC4 design, an oil cooler is NOT worth it for a stock bike used on average roads.

If you have modified the engine and/or are using it near maximum HP 90% of the time, an oil cooler may well extend the oil service life (particularly with "cheap" oils), which indirectly benefits the engine.  Keep good oil in the engine, operate it normally, and an oil cooler is just a superfluous expense that increases mechanical complexity (aside from being something to just point at).

And THAT is my opinion.

Let the Pundits bloviate!

[TwoTired]

Then on the other hand there is evidence Honda had one for the CB750s and it wasn't introduced on USA bikes.

Hmm.  This is starting to sound like a perpetuated myth.  Can you please, substantiate this claim?

The only oil cooler I can track is the one which was part of the CR option. (replacement part on arace bike)  Yep, you could buy that part and install it. $$$  But, it wasn't an option readily available off the showroom floor in any US dealership, AFAIK.

Since the 70s, virtually all aircooled bikes have oil coolers as well. So it became necessary I suppose you'd say.

...In the same way that coffee mugs have "necessary" handles today when early ones didn't.  The handle-less" coffee mugs still do the beverage containment task just fine.

If monkey A has a nose ring and can run faster than Monkey B, it does not follow that simply putting a nose ring on monkey B will automatically make it faster.   

Cheers,

[dave500]

oil coolers,by two tired.

[heffay]

 Topic: Oil cooler?  (Read 158 times)

... or at least skimmed 158 timed.  can I get the cliffs notes?   

[MCRider]

Then on the other hand there is evidence Honda had one for the CB750s and it wasn't introduced on USA bikes.

Hmm.  This is starting to sound like a perpetuated myth.  Can you please, substantiate this claim?

The only oil cooler I can track is the one which was part of the CR option. (replacement part on arace bike)  Yep, you could buy that part and install it. $$$  But, it wasn't an option readily available off the showroom floor in any US dealership, AFAIK.

Since the 70s, virtually all aircooled bikes have oil coolers as well. So it became necessary I suppose you'd say.

...In the same way that coffee mugs have "necessary" handles today when early ones didn't.  The handle-less" coffee mugs still do the beverage containment task just fine.

If monkey A has a nose ring and can run faster than Monkey B, it does not follow that simply putting a nose ring on monkey B will automatically make it faster.   

Cheers,

I'll retract the "evidence" word. Replace it with "a rumor". I did specifically say it was not on US bikes. I also said results of using a cooler are hard to quantify.
As to coffee mugs and nose rings, I have little to add.   

[raymond10078]

I look at oil coolers as insurance - meaning you may not need it, or ever benefit from it.  It may be wasted money, and its benefit is only to make you better protected.

Generally, I agree with TwoTired - that stock bikes don't need an oil cooler.  When the power output starts growing beyond stock, I believe (without emperical evidence) that it is a good idea, if implemented correctly.  Honda must have thought so too.  The F2 is the only CB750 SOHC bike that I know of that included an integral oil cooler.  Honda did it for a reason, most likely power density and/or leaner mixtures (EPA regs).  Granted, the heat shedding ability for that factory cooler isn't much, but "Mother Honda" didn't do it for looks.

[MCRider]

Here's a link slightly less than anecdotal, yet not quite scientific.

http://board.mcnews.com/Topic38001-9-1.aspx

This guy was doing it right. He has a temp gauge. And when the oil temp got below 180°, the cooler was turned off. He said this would occur at about 55° ambient, he usually carried a good load. It would not be good to run too cold.

Seat of the pants will work. I'd say if its cold enough to dress warmly, you should turn the cooler off.

There are various methods. Cover the radiator like you see on some trucks. Some have a simple on off bypass in the line. Some have a thermostat.

[TwoTired]

I find it interesting to compare oil cooler threads to the threads asking about the brown mayo found in the crankcase.

See, the brown mayo results from an emulsion of water mixed with oil, and the inability for the engine to generate enough heat and transfer it to the oil to evaporate the water in the oil.

Clearly, the fixed capacity cooling system found on the SOHC4 is often too much for even a street bike.   Certainly at some higher temperature point, the reverse could be true.  But, we don't know if that's at 100F, 150F, or 200F ambient.  What IS known, is that the heat generated by the engine is shed into the surrounding air.  So, another factor is how often that air is replaced.  The faster the air flow, the faster the heat shedding occurs due to the replacement of lower temperature air.
Because of the myriad physical dynamics involved, many just throw up their hands and form opinions, rather than educate and decide based on a known and quantifiable balance sheet, which would account for both the heat input and the heat receptacle capability, as well as the means to convey that heat in between input to output.  I've done this balance sheet many times in my career on other equipment.  The physics principles are exactly the same.  It takes time and careful consideration.  But, after you've done 10 or more of them, you can get pretty close with an eyeball or back of the envelope quick assessment.  You do have to get the foundational data and assumptions correct to have any success, though.

Cheers,

[TwoTired]

oil coolers,by two tired.

And if that document proved conclusively that oil coolers were superfluous, would you even consider it, or anything in it?

[Gordon]

Here's a link slightly less than anecdotal, yet not quite scientific.

http://board.mcnews.com/Topic38001-9-1.aspx

This guy was doing it right. He has a temp gauge. And when the oil temp got below 180°, the cooler was turned off. He said this would occur at about 55° ambient, he usually carried a good load. It would not be good to run too cold.

Seat of the pants will work. I'd say if its cold enough to dress warmly, you should turn the cooler off.

There are various methods. Cover the radiator like you see on some trucks. Some have a simple on off bypass in the line. Some have a thermostat.

I won't be installing an oil cooler on my bikes, as, IMO, in all but the hottest climates on a mostly stock and street sohc4 they're just added bulk and work for very little if any gain, but if I were to do it this is the only way it would be done.  Not having a bypass for warm-up time or cold weather seems counter-productive. 

[MCRider]

" if that document proved conclusively that oil coolers were superfluous, would you even consider it, or anything in it?"

and if the inverse, would you?

[TwoTired]

" if that document proved conclusively that oil coolers were superfluous, would you even consider it, or anything in it?"

and if the inverse, would you?

Of course.  That's why I'm collecting test equipment to gather data.

I think that document in the picture might actually be the tax code, though...
 /2 

[FuZZie]

I find it interesting to compare oil cooler threads to the threads asking about the brown mayo found in the crankcase.

See, the brown mayo results from an emulsion of water mixed with oil, and the inability for the engine to generate enough heat and transfer it to the oil to evaporate the water in the oil.

Clearly, the fixed capacity cooling system found on the SOHC4 is often too much for even a street bike.   Certainly at some higher temperature point, the reverse could be true.  But, we don't know if that's at 100F, 150F, or 200F ambient.  What IS known, is that the heat generated by the engine is shed into the surrounding air.  So, another factor is how often that air is replaced.  The faster the air flow, the faster the heat shedding occurs due to the replacement of lower temperature air.

You can find the temp info @ http://www.thelubepage.com/learn/lube-notes/lube-notes-synthetic-versus-petroleum-oil?showall=1 the chart shows the oil failing before the boiling point of water.

[heffay]

I've purchased an oil cooler from one of the members on this site that profits from the sale of said oil coolers.

I have not installed it on the bike, do you think I may have done harm by not installing it?  Should it have been installed or would it be best to leave it in the box? 

I fear that I may have a performance and longevity issue now that I have not give my motorcycle that added protection.

[azuredesign]

Thank you for this article, I have been looking for something like this for a while. I assisted(or hindered, depending on who is telling the story) a 836 high comp build that I am now running with an oil cooler and fittings purchased from Earl's, with one of Terry's ( member Terry in Australia) tapped spin-on oil filer adapter. I have been running a Daytona oil temp gauge. In the summer it's possible to see temps close to 200F, which is just at the high end of the range of petrolium based oil efficacy, based on the oil temp chart in the article. I'm running about an extra quart of oil with the cooler, which probably also doesn't hurt. I was out in low 50(f) weather on Sunday and ran in the 145-165f range. I have not run the bike without the cooler so I don't have a means to compare temps with and without the cooler, but I'm running in a temp range that is comfortable based on the aforementioned oil temp chart as is.
Time will tell whether I accumulate the sludge Two Tired speaks of.

I find it interesting to compare oil cooler threads to the threads asking about the brown mayo found in the crankcase.

See, the brown mayo results from an emulsion of water mixed with oil, and the inability for the engine to generate enough heat and transfer it to the oil to evaporate the water in the oil.

Clearly, the fixed capacity cooling system found on the SOHC4 is often too much for even a street bike.   Certainly at some higher temperature point, the reverse could be true.  But, we don't know if that's at 100F, 150F, or 200F ambient.  What IS known, is that the heat generated by the engine is shed into the surrounding air.  So, another factor is how often that air is replaced.  The faster the air flow, the faster the heat shedding occurs due to the replacement of lower temperature air.

You can find the temp info @ http://www.thelubepage.com/learn/lube-notes/lube-notes-synthetic-versus-petroleum-oil?showall=1 the chart shows the oil failing before the boiling point of water.

[TwoTired]

You can find the temp info @ http://www.thelubepage.com/learn/lube-notes/lube-notes-synthetic-versus-petroleum-oil?showall=1 the chart shows the oil failing before the boiling point of water.

Water does not have to boil to evaporate, only be exposed to air at less than 100% humidity/saturation.  The emulsion does have to reach a temperature that allows water separation from it's trapped position in the viscous emulsion.

Temperature - An elevated temperature accelerate the water separation by increasing the probability of the water droplets to collide and decreasing the viscosity of the continuous phase.

Oil viscosity does thin with raised temps and this helps allow the tiny water bubbles to collect into bigger ones that can rise to the surface for evaporation, rather than be completely surrounded by the oil.  Higher temps, thinner oil, more water droplet movement to where it can evaporate.

An emulsion is water frothed into a viscous oil, where it becomes trapped and unable to move.  In the SOHC4 this looks like brown, tan or white mayo, (which is also an emulsion).

[TwoTired]

Time will tell whether I accumulate the sludge Two Tired speaks of.

What is oil sludge?

Oil sludge is the breakdown product of over-stressed oil in your engine.

The water/oil emulsion I mentioned is not defined as sludge, and I haven't addressed sludge in my posts.  However, if the engine is developing sludge, it may well be overheating the oil.

Just trying to get the terms straight.

Cheers,