LArger oil cooler

[makenzie71]

My bike has an oil cooler on it...but it's a real dinky looking one. About 2" X 6" X .5". I'd like to have something a bit beefier on it considering the volume of oil running through it. How big would be overkill?

Also, what should the normal operating temp of the oil be? I'll be installing a gauge.

[Sunburn]

I'm sure someone could give you some input but that somone needs to know what you ride. Year, model and size please.

[chef1366]

The GS1150 oil coolers are a good size.

[makenzie71]

yeah guess I should have added that...it's a 1979 GS750E. It has an old school lockhart oil cooler kit on it. The cooler is actually 2 X 5 X .75...my earlier guestimate was a tad off.

I want to put something on it at least twice that in size...if not a little bigger. There's a lot of oil flowing through this bike. Seems like a cooler that small will heatsoak pretty quick and then be essentially worthless.

[Nessism]

I want to put something on it at least twice that in size...if not a little bigger. There's a lot of oil flowing through this bike. Seems like a cooler that small will heatsoak pretty quick and then be essentially worthless.

What do you mean by "heatsoak"? Never heard that term used like that. Regardless of how small the cooler is, it will transfer heat out of the oil. Maybe not enough heat to suit you, but it will continue to work no matter what.

If you don't mind spending some money check out the Earl's line of coolers. Super nice stuff, but not cheap. A cooler like you mention will cost about $80 - $100. http://www.anplumbing.com/shop/index...pt=Oil!_Cooler

[makenzie71]

Actually, it'll cost me about $25...but I know where to look. Those coolers are closer to the size I want, though.

A heatsoaked is when a cooler loses it's ability to transfer energy from the oil (in this case) to the outside air due to it's limited capacity. Essentially, the oil inside will be moving too fast to be affected after the bike has reached normal operating temperature. I know the math doesn't directly apply, but gearboxes for direct drive water wells use oil coolers to keep the temperatures down. According to the formula, the GS cooler, considering the engine's oil capacity, and if it had been a water well gearbox lol, the GS750 should have a 3-row core comprised of 3/8" ID tubing, with a surface area of approximately 35sqin with air cooling to maintain a 175*f operating temperature.

Of course that doesn't account for the fact that the motor will produce more heat...or that the cooler will see forced air while moving. But still...anything has to be "better" than the 10sqin single-row cooler it has.

[Shaughn]

Hey Mak,

Is that formula in a format you can share?

[makenzie71]

not that I can share...it's something the field guys at work came up with. I'll find out, though.

[makenzie71]

okay the formula they used was simplified...comes up with air cooled system that you need approximately 1sqin of surface area per 100cc of oil. That's assuming 3/8" ID tubing and 3/4" fins. And this was with forced air but the fans never see the volume of air you would running a bike 70mph down the road.

They work with gear boxes, though...they create a lot of heat but we don't see it creating enough heat to match what an internal combustion engine would do.

[TheCafeKid]

Now, when i say this, keep in mind that *I* am of the opinion that an oil cooler on ANY air cooled bike is a good thing. Most of the bretheren on here believe that an oil cooler on these motors is a bit of overkill. Frankly, they are probably right, as ive run the cafe at severe RPM for quite a while when i had that 52 tooth rear sprocket on it running it on the highway.. and NEVER had an overheat. (it redlined doing about 85, but DAMN that bike would rip your arms out of socket taking off) But, considering the low pressure system on your 8v motor, the oil will never likely move fast enough to suffer from heatsoak anyway. At fair RPM, say around 5-6k, my 1100G, also an 8v, rollerbearing low pressure oiler motor, only pushes about 3 -6lbs of pressure. At that rate, the oil will be pleanty cool coming out of the cooler. I assume that you are planning some head work and maybe a bore job on your bike, so you are looking to protect that. I would bet that just about any cooler you put on it would do the job fairly well, and as said, its not something that you should be overly concerned about. However, im all for an oilcooler, no matter the hive's concensus, as i am a firm believer that temperature moderated motor parts simply last longer since they are not subjected to wild temperature swings. Just my opinion tho.

[BassCliff]

If you don't mind spending some money check out the Earl's line of coolers. Super nice stuff, but not cheap. A cooler like you mention will cost about $80 - $100. http://www.anplumbing.com/shop/index.php?shop=Accessories&dept=Oil!_Cooler

Hey Mr. Nessism, is that what you have on your 850? Which one? I think an oil cooler would be, uh,...cool!


Thank you for your indulgence,

BassCliff

[TheCafeKid]

Hey Mr. Nessism, is that what you have on your 850? Which one? I think an oil cooler would be, uh,...cool!


Thank you for your indulgence,

BassCliff

Wow those ARE good prices, and some of those are fricken HUGE!!

[sharpy]

If you have a lot of spare cash a Earls setup like this would be ok, dont u think?

[Nessism]

Hey Mr. Nessism, is that what you have on your 850? Which one? I think an oil cooler would be, uh,...cool!


Thank you for your indulgence,

BassCliff

The cooler I'm using is not shown on the AN Plumbing web site, although that's where I bought it - Earl's store in Lawndale, CA. It's the smallest curved motorcycle model. Those regular Earl's coolers are quite thick so their is quite a bit of cooling capacity there. The motorcycle specific models are thinner. Fortunately for GS owners, there is quite a bit of clearance between the front wheel and the engine so the thicker coolers work well.

[salty_monk]

Personally I think with good oil (especially fullly syn) & regular changes you probably don't need an oil cooler on a stock bike mine has been ok so far even in heavy traffic.

I admit it would be nice to have one but I think the hose runs don't look nice on the bike.

Dan