Topic: Oil Cooler Thread

[Nate]

Does anyone know if the hose fittings on the 80-82 CB900 oil cooler are the same as the fittings on the 83 CB650 Oil Cooler?

I can't imagine they would be much different. They look the same, bolt on, not the newer style "banjo"(at least that's what i think they are called) fittings.

Any input is appriciated. I'm bidding on a cooler for an 83 cb650 cooler that matches the adapter plate i've got, but not sure if i'll be able to get the cooler at a resonable price. There are alot more cb900 coolers available at the moment, so...

[kghost]

No Idea.

Be hard to tell without the parts in your hand.

Maybe someone here will jump in with wether they have done it.........................

[Nate]

Yeah that's kind of what i was figuring. I think worst case scenario i'll have ot scrounge and find something to make it work.

[kghost]

I do my best work scrounging.....

Where you think my cooler came from? 

[mrbreeze]

Yeah...without having the part in your hand,how do you know if it fits?(shake the dice!) If you get it and it don't fit, you go for adaptors or mcgiver.I chose to know up front what size things are ahead of time.

[sparty]

Guys,

I am debating the install of an oil cooler on my 836CC '72 CB750.  I am also going to have a new higher HP engine built and was thinking of adding one to that mill as well.  Does an oil cooler help increase HP?  What are the real
advantages and disadvantages - other than the added weight?

Thanks,
Sparty

[hymodyne]

I'm planning to use a cooler on my 500 as it becomes a 605 cafe. the original motor configuration w/o a cooler meant that on long trips, I would start to have pressure issues at idle after a few hundred miles or so. this seemed to have mostly to do with viscosity and temperature, so my hope is that by lowering the  oil operating temp, I can diminish the pressure/viscosity issues.

the down side, besides weight, which is negligble, (I've removed more unecessary steel parts than the weight of the aluminium ones I'm putting on)
is whether or not the addition of a cooler is going to tax my oil pump to the extent that is cancels out any benefit from cooler temperatures and higher viscosity by increasing the distance that the oil flows beyond the pumps working limit.

By the way, as I reassembled my engine case this weekend, I attemptd to check clearances on the inner and outer pump housing as per the manual. the feeler gauge specified for a cb500K would not fit in either area that i was trying to check; it was way too thick. I have the Manual and the proper gauges, and would like to check these clearances properly before I reassamble. any suggestions as to how to check pump clearances properly would be appreciated.

Didn't want to hijack your link, just thought that anyone thinking about doing this should check oil pump first-correctly.

hym

[ProTeal55]

If you do a cooler on your ride, make sure it has a bypass valve so you can bypass the cooler when needed. These bikes are cold blooded to begin with - let along if you are cooling the oil you are trying to warm-up on a cold/cooler day...

Just my 2cents...

[hymodyne]

If you do a cooler on your ride, make sure it has a bypass valve so you can bypass the cooler when needed. These bikes are cold blooded to begin with - let along if you are cooling the oil you are trying to warm-up on a cold/cooler day...

Just my 2cents...

do the honda 650 coolers have this bypass?

I'm installing one with a base plate adapter purchased from terry on OZ

hym

[hopterfixer]

I had given thought to making a manual cooler bypass or a block off cover for mine but it warms up and runs fine.  I ride twelve miles to work in temps as cold as they get in northern Indiana, so it has plenty of time to get warm  

[Leino]

You can allways cover the oil cooler, when the weather gets cold. 

[Brunow]

If an engine is designed to ride without an oil cooler it is best to let it this way.
It is possible that your oil does not get at it's working temperature. So the engine will run worse...

[crazypj]

Stock engine doesnt usually require cooler, Big bore engines may find an advantage if your running at high rpm or stuck in traffic a lot.
As for the feeler gauge issue, its usually the max wear your checking. Make sure your not using metric spec with inch feelers.( or inch spec with metric )
PJ

[scondon]

Guys,

I am debating the install of an oil cooler on my 836CC '72 CB750. I am also going to have a new higher HP engine built and was thinking of adding one to that mill as well. Does an oil cooler help increase HP? What are the real
advantages and disadvantages - other than the added weight?

Thanks,
Sparty

    Can't really see how a cooler would increase horsepower, but the advantage of having one on a 836 engine seem obvious to me. My 836 runs hotter than a stock engine and I'm always up high in the rpm range to take advantage of the power band of the megacycle cam. Since I stick with the 10-40 wt oil, so the engine spins easy, the cooler keeps the oil from breaking down too fast at high operating temps.

     Temp rarely drops below 30F overnight, 50F in the day during our winter(usually 40-60 degrees) so I run the cooler year round with no troubles warming up in the a.m.

[Leino]

For example, my -83 Suzuki GSX 1100 E, or GS as you US guys know it, after rebore to 1166cc and some headwork, done by the Master , warms the oil over 30C more than a stock bike in normal streetriding.I'm gonna use a cooler on that one next summer.Not necessary in drag racing, but I use it for some high-tech-bike-asskicking rides on the streets too 

I don't think that a stock CB needs a cooler, but I'm gonna use one on my 836cc, Megacycle cam, ported head etc. bike.

[Steve F]

I once had a 82 CB650C and rode it two-up for about 75 miles on the interstate.  When I pulled off at the destination, the bike was rattling so bad, I thought I had lost all oil.  Just turned out to be from the oil getting too hot and thinning out.  I asked the dealer about this, and they recommended an oil cooler for such type of riding.  I asked about changing the oil to something heavier, and they said it wasn't a good idea.  But I agree, that if you do use a cooler in the cold air, a cover for the radiator part will work if you don't have a bypass valve.

[kghost]

Some thing you may wish to consider as it relates to the 836 kit...........

The liners on your cylinder just got thinner and the compression ratio just went up.

Compression increase = more heat in the engine.

It has to go somewhere and as the fin area is fixed on the cylinder and head it goes in your oil.

There is a bypass mounted in the oil pump of the 750 engine. I have never seen a problem with warm up with a cooler provided that: When its cold outside DO let it warm up before applying RPM's to the engine. You know...let it idle until it is warmed up.

[sparty]

Some thing you may wish to consider as it relates to the 836 kit...........

The liners on your cylinder just got thinner and the compression ratio just went up.

Compression increase = more heat in the engine.

It has to go somewhere and as the fin area is fixed on the cylinder and head it goes in your oil.

There is a bypass mounted in the oil pump of the 750 engine. I have never seen a problem with warm up with a cooler provided that: When its cold outside DO let it warm up before applying RPM's to the engine. You know...let it idle until it is warmed up.

Yeah,

My biggest concern is overheating the engine at high RPMs.  I have been running in the higher rpms where my bike makes its power  (see my dyno chart) and it is getting really hot.  I don't want a meltdown.

Sparty

[kghost]

Yeah I used a J type thermo couple and my multimeter. Straight in the oil tank its reading 90 - 95 C after a hot run with the cooler.

That seems to be the perfect range for an air cooled engine. Hot enough to evaporate any water etc .

[Geeto67]

I ride in the city often and from april to september it is not uncommon for me to overheat my K5 in traffic. I have actually had it to the point where the fuel began to boil in the float bowls. Usually I can tell when she is overheating when she starts detonating. In july, In NYC, in traffic the street temp can actually really hot and moving with all those cages all I ever seem to be pushing is hot air across the cooling fins.

Over the winter, if I get finished with my cafe bike cb's I may install an old 811cc kit I have lying around. If I do this I am definatly going to put an oil filter on it.

[kghost]

#$%*.......

Try South texas in the summer...........

Think hell with the flames missing. 

[Bob Wessner]

Think hell with the flames missing.   

Hmm, you make it sound so inviting. 

[kghost]

Think hell with the flames missing.   

Hmm, you make it sound so inviting. 

Did I mention the humidity? 

Keeps out the riffraff.

(oh yeah it was 80 here today)

[eldar]

It all depends on your area and any mods. Unless it is always cool or below 90, an 836 pretty much needs a cooler unless you want to run heavier oil or a good synthetic.
A stock 750 usually does not need a cooler but if you are in a lot of traffic or in real hot areas, get a cooler. If I was going to go through Arizona or some other place like that, I would get a cooler even if the engine is stock.

One final thing about the 836, You removed material from the engine, which is used in the cooling process. So really, unless your temps are low, get a cooler, it cant really hurt things. If your pump is in decent shape, there should be no issue with that either.

[Terry in Australia]

Well, you all know what I think.................