Oil cooler

[tomas_imp]

Having had a go at Tomas, I should be fair. I think his gripe is that he finds the oil cooler ugly not that it believes it unnecessary.

Correct Cormanus,
I would never go completely without a oil cooler on this bike. If it was a parallel twin with about 750cc and 60hp, I think one could remove oil cooling completely and be safe. Not on the CB though, but I do think a oil cooler about half the size of the original would feasible, without causing reliability issues. Honda has always over built its products (with is a good thing) which I think would allow some room for flexibility.

 

[jazzmans_imp]

The "13 service manual has an oil flow diagram on page 4-2. It looks as though there is a 2 chambered oil pump where one chamber pumps through the oil filter and into the lower engine (cylinders and below). The other chamber pumps oil into the cooler and from the cooler, into cylinder head channels around the spark plugs. From the cylinder head it flows through a channel with the EOT (engine oil temperature) sensor and then back into the sump. This design is consistent with the Honda engineers worry about high temperatures surrounding the spark plugs.

There is a high temp "idiot" light that comes on when the oil temp is too high. I wonder if our friends in Arizona or OZ have ever seen this come on when riding in stop and go traffic on very hot summer days?

You could try removing the cooler (I'm not recommending this) and then monitor the high temp light to come on under a variety of riding conditions like Pterodactyl suggested. A temp gauge would be more useful. Does anyone know of a gauge that can be wired into the EOT sensor?

Personally I don't have a problem with the looks of the cooler but as others have mentioned there are alternatives out there.

Earl's has a nice line of coolers that are designed to fit between the forks (2 different widths, curved vs straight, and variations in the number of "rows"). Mounting the coolers between the forks would involve moving the horns and also there would be a potential problem with the brake lines being just behind the cooler.

Japan webike sells Earls oil cooling kits designed for the CB750, CB900 and CB1000F. They are pricey though and you may be better off ordering the parts directly from Earls [url=http://www.earls.co.uk/earls100/earls_shop/index.php?main_page=index&cPath=14_38&zenid=32051fs1tutjtkm9711rapdke0](link).

Earls "curved coolers"



Another protector for the stock cooler that may be more visually pleasing.

I live in Las Vegas, where it's ~100 for six months out of the year, and I ride everywhere, and as of yet, I've not ever seen the engine overtemperature light go on.

I don't think I knew about the overtemp light.

p.s. neither of my DOHC cb750F bikes had oil coolers stock.

I still think it would be a bad, bad thing to remove the oil cooler.
fwiw.

 

[AzBob_imp]

I think its a poor design. They should have at least let you drain the cooler with a primer to refill. Leaving a full quart (20%) of dirty oil in the system just does not make sense. Remember this oil runs through the tranny collecting a lot of metal and brakes down much quicker. They would have been much better served to make a water cooled radiator the same size if there going to put it there at all, this would have allowed fresh oil changes.

I'm not 100%, but I'm relatively sure that an oil's ability to keep contaminants in suspension is unrelated to its sheer strength. Also, once you're past about 500 miles, your transmission really shouldn't be shedding any more metal than your engine, which is to say, nearly none.

Quote:They would have been much better served to make a water cooled radiator the same size if there going to put it there at all
And then they'd have had to put the overflow tank somewhere and run the giant coolant lines all over the place. A water-cooled radiator the size of the oil cooler we have now wouldn't be very performant. Much less so than the oil cooler. The oil picks up the heat of combustion by washing over the metal directly; the radiator fluid merely runs near the hot areas through the water jackets -- it's much less efficient at removing heat than directly cooling the oil.

"Then why are all modern automobiles liquid cooled?" Because you can only run so much oil in the engine before the crankshaft turns it into a frothy mess. You can increase the cooling capability of a liquid cooled automobile simply by increasing the capacity of the radiator. You can't increase the efficiency of an oil cooler by increasing its size because that would necessitate an increase in oil volume, which has an upper limit dictated by the needs of the engine.

The "13 service manual has an oil flow diagram on page 4-2. It looks as though there is a 2 chambered oil pump where one chamber pumps through the oil filter and into the lower engine (cylinders and below). The other chamber pumps oil into the cooler and from the cooler, into cylinder head channels around the spark plugs. From the cylinder head it flows through a channel with the EOT (engine oil temperature) sensor and then back into the sump. This design is consistent with the Honda engineers worry about high temperatures surrounding the spark plugs.

There is a high temp "idiot" light that comes on when the oil temp is too high. I wonder if our friends in Arizona or OZ have ever seen this come on when riding in stop and go traffic on very hot summer days?

You could try removing the cooler (I'm not recommending this) and then monitor the high temp light to come on under a variety of riding conditions like Pterodactyl suggested. A temp gauge would be more useful. Does anyone know of a gauge that can be wired into the EOT sensor?

Personally I don't have a problem with the looks of the cooler but as others have mentioned there are alternatives out there.

Earl's has a nice line of coolers that are designed to fit between the forks (2 different widths, curved vs straight, and variations in the number of "rows"). Mounting the coolers between the forks would involve moving the horns and also there would be a potential problem with the brake lines being just behind the cooler.

Japan webike sells Earls oil cooling kits designed for the CB750, CB900 and CB1000F. They are pricey though and you may be better off ordering the parts directly from Earls [url=http://www.earls.co.uk/earls100/earls_shop/index.php?main_page=index&cPath=14_38&zenid=32051fs1tutjtkm9711rapdke0](link).

Earls "curved coolers"



Another protector for the stock cooler that may be more visually pleasing.

I've ridden my CB in extended 120*F heat in stop & go traffic where I was CERTAIN the overheat lamp would light, but it hasn't, so far.

 

[Pterodactyl_imp]

+1 to all of the above.

If my bike had a lot of metal in the oil I would be seriously worried. If there is any, and unless a failure has occurred there shouldn't be, the filter will trap it. There must be some very fine metal breakdown from engine and transmission (after all metal parts do wear despite lubrication) in oil, but that is not the prime reason oil must be changed. It is the "products of combustion" that need to be removed. This is mainly scoured from the cylinder walls and piston sidewall surfaces and due to its qualities causes degradation of the oil itself. If oil is never changed ultimately it will loose its ability to lubricate. Expensive racing quality, synthetic, oils resist this better than cheaper products. But if any approved oil is changed on schedule then, whatever the brand or approved grade, it is still doing its job. The only time oil is completely removed from engine parts is on a complete strip down and wash. If you are worried about the dirty, filthy oil in the cooler consider the oil that adheres to the crankcase surfaces, the bearings and galleries, in fact anywhere that is lubricated. This is particularly true of synthetics which, thankfully, have high adherent properties. That is why they work well.

Water cooled? Not for me. "Oils is oils", but water? Wow that stuff can vary from mildly clean to highly toxic. If I need a remote area top up of oil almost anything will do. Even some diesel oil will do. But some of the water available in remote areas is highly acidic, alkaline, full of dissolved contaminants ranging from rust and corrosion accelerators to dead kangaroo. That is why Cormanus (and others) boil it and add tea before consuming it, and I drink beer as a healthy, natural, hydration fluid.

Does the cooling system on the CB work effectively in all the ambient conditions likely to be encountered? Well, like AzBob, I have ridden mine in very high temperatures and not had the oil temp light come on, even after extended periods of idling or low airflow. I think someone on the forum fitted an oil temperature gauge. Their observations would be interesting, particularly in conjunction with reducing oil cooler effective area.

Cheers

 

[Jim21680_imp]

What a crazy thread....how did that little black oil cooler work up such a discussion? It's hardly noticeable!

 

[Frulk_imp]

Jim... people on this site sweat the details. We have hundreds of posts on RLETS alone. It was only a matter of time before somebody noticed the oil cooler.

 

[kmoney_imp]

What a crazy thread....how did that little black oil cooler work up such a discussion? It's hardly noticeable!

I guess it's not just oil threads, but oil related threads that do it...

 

[the Ferret]

Jim... people on this site sweat the details. We have hundreds of posts on RLETS alone. It was only a matter of time before somebody noticed the oil cooler.

:rofl:

 

[Pterodactyl_imp]

What a crazy thread....how did that little black oil cooler work up such a discussion? It's hardly noticeable!

I guess it's not just oil threads, but oil related threads that do it...

I guess it's not just oil threads, but oil related threads that do it...
Very true mate. Oil is the "precious bodily fluid" of our bikes.

We cannot allow anyone to sap and impurify all of our precious bodily fluids. When did that come to me? Well forum decorum does not allow me to go there .

Cheers
And Jim, I'm not crazy. It's everybody else. Heeeeeeehaaaaaheeeeeeeee........

 

[kmoney_imp]

What a crazy thread....how did that little black oil cooler work up such a discussion? It's hardly noticeable!

I guess it's not just oil threads, but oil related threads that do it...

I guess it's not just oil threads, but oil related threads that do it...
Very true mate. Oil is the "precious bodily fluid" of our bikes.

We cannot allow anyone to sap and impurify all of our precious bodily fluids. When did that come to me? Well forum decorum does not allow me to go there .

Cheers
And Jim, I'm not crazy. It's everybody else. Heeeeeeehaaaaaheeeeeeeee........

Love DSL. Somehow that movie has become our family "christmas movie" that we watch together every year.

 

[flynrider]

I've ridden my CB11 on dozens of 110+ days here in Phoenix. Can't avoid that if you ride everyday. I've never seen the oil temp light, but if I did, I'd be seriously concerned. The manual states that it will light at a frighteningly high temperature ( I think it was something like 340F). Most oils are already starting to break down at that temp.

I have managed to overheat the CB750 (also equipped with an oil cooler) on two occasions in the last 20 yrs. Both times involved standing still while idling for 20-30 minutes in 100+ temps. Now that I know better, I just shut it off if I'm not going to be moving for a few minutes.

 

[Pterodactyl_imp]

I've ridden my CB11 on dozens of 110+ days here in Phoenix. Can't avoid that if you ride everyday. I've never seen the oil temp light, but if I did, I'd be seriously concerned. The manual states that it will light at a frighteningly high temperature ( I think it was something like 340F). Most oils are already starting to break down at that temp.

I have managed to overheat the CB750 (also equipped with an oil cooler) on two occasions in the last 20 yrs. Both times involved standing still while idling for 20-30 minutes in 100+ temps. Now that I know better, I just shut it off if I'm not going to be moving for a few minutes.

Once or twice I've considered shutting down but wonder if that might lead to an initial rise in engine temperature as the oil stops circulating. On other engines, fitted with temperature gauges, I've observed this. With the CB as long as the warning light doesn't come on then I guess all is well.

Cheers.

 

[Cormanus]

Quote: curlyjoe said—

There is a high temp "idiot" light that comes on when the oil temp is too high. I wonder if our friends in Arizona or OZ have ever seen this come on when riding in stop and go traffic on very hot summer days?
Like others, I've ridden on some hideously hot days and the oil light has not come on. Most has been in the country but some in the city.

 

[Southwend]

What a crazy thread....how did that little black oil cooler work up such a discussion? It's hardly noticeable!

I guess it's not just oil threads, but oil related threads that do it...

I guess it's not just oil threads, but oil related threads that do it...
Very true mate. Oil is the "precious bodily fluid" of our bikes.

We cannot allow anyone to sap and impurify all of our precious bodily fluids. When did that come to me? Well forum decorum does not allow me to go there .

Cheers
And Jim, I'm not crazy. It's everybody else. Heeeeeeehaaaaaheeeeeeeee........

I guess it's not just oil threads, but oil related threads that do it...
Very true mate. Oil is the "precious bodily fluid" of our bikes.

We cannot allow anyone to sap and impurify all of our precious bodily fluids. When did that come to me? Well forum decorum does not allow me to go there .

Cheers
And Jim, I'm not crazy. It's everybody else. Heeeeeeehaaaaaheeeeeeeee........
wow one of my all time favorite cinema moments.

 

[Southwend]

At the risk of beating the dead horse, I was in my garage staring at the CB last night. For me the whole 'oil cooler thing' for me is to allow a better view of the engine. I do not want to shortchange the engine's cooling or ignore the engineering of the design. So how about this. If the oil cooler stayed in place, but was angled out say 20 degrees or so at the bottom only so it would clear the front fender on rebound. If you picture this when you are looking at the bike, it appears that it would really open up the front of the motor visually while keeping all of the design characteristics unchanged.

 

[Jim21680_imp]

Hmm...if I'm imagining this right, you're thinking of rotating the cooler out into a vertical position (out away from the normal frame-mounted angle)?
I think that would undoubtably draw more attention to the cooler instead of the engine, as if something was broken off or bent, etc.

It could probably be mounted to the lower fork tubes, either in front or behind the stanchions. I don't think you'll do better than that.

 

[Frulk_imp]

I'm only posting here because #77 is my lucky number

 

[Southwend]

Hmm...if I'm imagining this right, you're thinking of rotating the cooler out into a vertical position (out away from the normal frame-mounted angle)?
I think that would undoubtably draw more attention to the cooler instead of the engine, as if something was broken off or bent, etc.

It could probably be mounted to the lower fork tubes, either in front or behind the stanchions. I don't think you'll do better than that.

not rotating, not moving, just changing the angle, away from the frame at the bottom of the cooler stiil at the frame at the top of the cooler.

 

[dsinned_imp]

Very interesting . . .

Here's an update to twist this subject into the extreme opposite direction. Yesterday, I was in my garage with a box full of various sizes of fans and the idea of mounting one to the front of the oil cooler entered my mind. It would be easy to do, although a pusher fan would not be as beneficial as a puller (mounted "behind" the cooler). With the elongated rectangular shape of the cooler it might even be feasible to mount TWO fans side by side.

First, I'm planning to install a thermocouple sensor with a handlebar mounted temperature meter to measure the EOT at the stock cooler. The delta T across the cooler also would be of value to measure, but more complicated in favor of just the temperature at a single fixed point. Then, repeat the same measurement, under identical test conditions, with a fan mounted. This answers the question, would there be any benefit with the addition of the in lowering EOT?

I suspect there would be especially at relatively high OAT, stop and go riding conditions, or making the engine work harder riding continuously uphill for several miles at a relatively slow speed.

A good candidate for a fan - one with an integrated finger guard for added personal safety - is one made by the Italian automotive grade fan manufacturer, SPAL. They have a relatively low cost, 5.2" diameter pusher fan suitable for this application. (They have smaller sizes, but their CFM ratings are much less than the 5.2" fan.) It's a bit oversize, but should do good a job helping to further air cool the oil flowing thru the cooler on the CB1100, without causing the 12V battery and alternator to be overloaded.

I'm going to take on this project mainly to gain a better understanding of the OEM oil cooler and how it can be made to look even uglier, but more efficient, without major modifications, at the same time.

P.S. There is another recently started thread on the subject of measuring EOT, so I will resume posting my findings over there since I think we have already established the importance of keeping the oil cooler, so this thread should be considered closed.

 

[Noleshot_imp]

My 1980 GS1100 did not have an oil cooler, made 105hp at the crank and survived many years in TX and FL with no mechanical issues. Nobody has mentioned the richer fuel/air mixtures then as a possible means to keep the engine running cooler. Leaning the mixture out to where they are today in a 1980 engine would cause heat related failure, detonation/holed pistons very quickly. So, why not find a way to make the mixture richer, change the spark plug heat range, etc? With the modest output of the CB, that could possibly substitute for the oil cooler, not to mention the fact that metallurgy and design are now worlds better. I also like the thought of working around emissions-related gear (we don't have emissions inspections here in Florida). Besides the clear view of the front of the engine, one could again inspect plugs and exhaust openings for the proper color left by unburnt hydrocarbons.