Had a good LOL on the comfortable seat!!!!! a mod as in oversizing pistons and other things then sure and some more cooling is a good thing for the most part. But if I put a a oil cooler out I must be sure that it could be hit with a rock ever feel one of them on your face I bet you have or you lucky. Think that seat hurts LOL please read that as bad pun. Any time you put your oil out you have to get it back and if it springs a leek well..... The bullet hit it....wargoth wrote:If an oil cooler is not needed on a bike, why have so many manufacturers (honda included) put them on so many models over the years? A comfortable seat is not needed, but my ass gets sore after a couple hours in the saddle. Having the timing perfect isnt critical, but I still do it.
Example: Yamaha XS750 triples did not come with an oil cooler, and had issues with big end bearing failures. Yamaha added the cooler to the XS850 triple stock, and improved the oil ports to big end bearings. Fixed that problem.
Oil coolers are also an excellent idea if you are oversizing pistons, since the reduced cylinder wall has less mass to soak heat.
I prefer to mount the cooler high to keep it away from the road. If you dont like how it looks, build an aluminum sheetmetal shroud to help hide it and paint it. the shroud will help baffle air through the cooler. Plus the shroud is a good place to put custom owner logos.
It can also be a way of adding a spin on filter to the oil system.
For any dry sump engine the simplest bolt on upgrade usually is a larger oil tank.
What makes for a bullet proof engine?
1974 CT90
1964 CA77  the same can be said for a liquid cooled MX'er too, but never have broke or been riding with someone who broke one of those radiators. water pump housing, yes. radiators no. Regardless, my XS750 (with an 850 motor) and the oil cooler, has run over 77,000 mi without any major problems, not even a dent in it.
'61 CB77, '72 TC125, '72 CB350F, '73 CB350G, '76 CB400T, '79 XR80, '79 XS750 (850), '83 CB650S, '84 KDX250,'91 YZ 250
Logic is a little flawed here. Firstly I never said that an oil cooler is NEVER needed, just that they are not necessary on a CB72. Oversized pistons make no measurable difference to engine or oil heat unless we are talking 3mm plus oversized as in 350 kits. Simple overbore will make an insignificant difference in oil temperatures. The mass of material is relevant to the time it takes to heat up but the heat transfer rate will remain the same - no difference. The rate of heat transfer is related to the temperature differential and is different for different materials, but the mass of material is no a variable. Anyone who has measured oil temperatures and component temperatures has the facts to determine whether or not they wish to fit an oil cooler. We did and decided they were unnecessary on a street CB72. Your results may vary.
Good debate, so far, guys; and all data obviously comes from valuable perspectives leading to one being able to make an informed decision.
I agree that a cooler should be mounted high, but to where do I then relocate my little air horn? And, in any case, on our bikes an appendage is always an appendage. I don't even like the air horn, as discrete as it is, but it's a very necessary warning device for my Wacky Races riding environment where human beings -- their semi-intelligent ancestry notwithstanding -- become totally selfish, monstrous Neanderthals (and that's just the women!) piloting their prized weapons of choice. I'm off on one again, aren't I? It's not representative of all of Spain; just this island, it seems. Sorry for the digression; but a problem shared...... Ok. Without empirical data this is all speculation. The only way I can think to solve this digression of opinions would be to get data from some source that has done tests on the oil after a specific amount of use in specific conditions.
The extra cooling provided by the oil cooler really IMO is to extend the time it takes for oil to be broken down thermally. The tranny does a ton of damage to motor oil, due to the shear forces between the teeth. Then there is the contamination provided by the wet clutch in the motor oil too. An element filter seems in order for all the clutch crud. Probably true that using high quality synthetic oil is probably more effective than the cooler, but even better with both. No moly base synthetic either, my understanding is this will ruin the fiber clutch plates. Just note that all of he big 4 use coolers on their race team bikes, and the oil is changed after every run on those. Actually maybe someoe here who has race history has an opinion, remember a cooler adds weight to the machine, and racers are crazy for less weight. They would have to be able to justify any additions? I am pretty sure that the engineers never expected people to be riding these after 45+ years '61 CB77, '72 TC125, '72 CB350F, '73 CB350G, '76 CB400T, '79 XR80, '79 XS750 (850), '83 CB650S, '84 KDX250,'91 YZ 250
Wargoth,
Jerry has successful (very) race bikes and uses a cooler. I have built several race bikes and I have two coolers - neither fitted. Our analysis says coolers are not needed. Other people have other data and believe they are a good idea. Jerry made his decision based on his analysis of the situation and I made mine. His bikes make more power so maybe his need them. His riders ride harder than I do, so there we have another variable. Use good oil and set up the bike correctly and go ride. Others who know what they want are capable of making a decision that is right for them. For you to make a decision, you have two choices. Go without like 99% of the bikes out there (CB72 77 we're talking) or gather enough data to make a sound decision. Or you could just fit one as insurance I suppose. Just make a decision and life with it. Whatever you decide will be OK
Mr. HONDA did.
Until his death there were spares for all the bikes he designed/produced. ......lm
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