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Engine oil cooler

7K views 12 replies 9 participants last post by  dhager4692 
#1 ·
Has anyone added an oil cooler for the engine??
I would guess to add an adapter at the oil filter and then pipe to a remote mounted heat exchanger.
Any ideas guys?
Thanks,
 
#2 ·
Dick,
For which engine or tractor are you thinking?
 
#3 ·
On What?
Today's oils withstand tremendous temperature ranges. The engine is designed to cool it self by either water cooling or air cooling and also the oil flowing through the engine. If everything is working correctly and clean, the engine shouldn't over heat with the help of the OIL cooling as it was designed. If I was to do anything, I would want an oil heater for the cold winter starts.
Transmission or hydro pumps usually don't have the cooling mechanisms an engine have so therefore sometimes an added cooler is warranted.
 
#4 ·
Dom,
I was thinking about the Onan B43 series or a P2... engine as in the 318 and 400 series tractors.

JDF,
I agree, and like you said: water or air and oil cooling is part of the total engine cooling. But high temps mean higher volatility (burn-off) causing high oil consumption. This is the component I am looking to reduce.

Thanks,
 
#6 ·
Did any other Onan applications using this engine use an oil cooler?
I know the Briggs Vanguards had an optional oil cooler that used hoses from the oil filter adapter to a small fin type cooler mounted on the shroud.

I would think if an Onan application used a similar setup, it could be adapted.
 
#8 ·
I would think before you did anything, you'd want to install temp. gauges to check how hot your engine oil is actually getting.

Air cooled engines do run hotter, that's why motorcycles went to water-cooled engines 30 yrs ago. The higher oil temps degrade the oil faster... not sure about "evaporating" it...warm oil will find it's way through small passages easier than cooler thicker bodied oil. The oil degrading is why you change oil in Kohler's & Onan's at 50 hours instead of 100 like larger water cooled engines.
 
#9 ·
My repowered Kohler Commands have them, but they came that way on the engines.

I suppose with ethanol fuels engines run leaner and hotter, but oil is getting better.

You may be opening your self up for leaks and other issues that you wouldnt have if you just left it as its been for 20 years.
 
#10 ·
Dennis,
I don't think a blanket statement that air cooleds run hotter is valid. Most air cooleds have no t/stat and are quite inefficient when running lightly loaded because they're not running hot enough!! You'll probably find that gov'ts wanted emissions lower on bikes plus the mfg, at the same time, could combine a much more efficient eng w/ temp being stabilized under all load conditions. Good quality air cooleds have t/stats. Oil needs to be at least 230F or more. I think you'll find that the frequent oil changes in most Kohlers & Onans is due to unburned fuel getting by rings and valves due to mixtures necessary to cover the wide operating temps they endure plus very poor combustion chamber shapes not much better than 100 yrs ago. DCD
 
#11 ·
DAVID - I did oil analysis on a K241 10 HP Kohler about a year or so after I rebuilt it. In the fall I changed the oil and put the snow blower on. Blew snow several times that winter... did three drives most times. That spring with maybe ten hours on the tractor I pulled the blower off and put the mower on and started mowing. Early-mid May I get a call from my buddy...."can you come over with your tractor?" He had a HAY FIELD for a back yard at his new house. He'd bought a repossessed house and they'd mowed the back yard twice with a farm tractor the year before, the clippings from that were still there plus the grass was already over a foot tall. Took me close to an hour to make the first round taking a full 38 inch cut... second round taking about 10-12 inch swath I started hearing a slight knock or ping. I stopped, idled the engine around 1800 RPM for ten minutes, no smoke, no more knock... went back to work with just a bit less vigor... took a 6 inch swath each pass. Finished up mowing and had TWO flat tires from junk hidden in the grass.

Called around and found a place that had used oil test kits, sent in a sample to the lab. The oil had about 20-25 hours on it. The results came back with No unusual wear metals (good news) but the amount of un-burned gasoline and water in the oil was off the charts. The un-burned gas from blowing snow in the winter and the oil not getting hot enough to boil the water condensate out of the oil. In cold winter temps an air cooled engine is over-cooled. But in hot summer (90+ deg F) with a full load an air cooled engine can get VERY hot, I'd expect to see 300+ degree oil temps. Dave Kirk rigged up an electric oil temp gauge for his Killer Kohler K301 (12 hp) and I forget exactly how hot he saw his oil get... I'll have to search another forum for that info... but it was more than 230 degrees... a LOT more.

Ha-Ha.... have to agree with the poor combustion chamber designs on these old Kohler & Onan's.

Yes, the Fed. gov't killed 2-strokes... I bought an RD-350 Yamaha right after I got out of college... REALLY enjoyed that bike... but street riding scares the heck out of me anymore. My Buddy had a Penton 125 with a European engine, DKW or Sachs? had HUGE cooling fins... he cold seized that engine twice while riding slowly around difficult terrain, then pulling out onto a road and running up to 60-70 MPH... it would seize by the time it got to 70. UNLESS you pulled the choke half way out to de-tune performance. The Honda's, Suzuki's, Kawasaki's, even my OSSA never had a problem like that!

A water-cooled 2 or 4-stroke wouldn't either.
 
#12 ·
Dennis,
Those examples in post 1567 corroborate my post654. These toy engines we have are built w/o regard for the extremes. One type fits all, well almost.When an eng gets hot enough the fuel will preignite. The shock will make the rings lose contact with cyl walls and the fuel goes into crankcase past rings, diluting oil. But you know that, thought some others would be interested. DCD
 
#13 ·
I agree with the comments both Dennis and David about the inefficiencies of the Kohlers and Onan. The extremes that these motors run at would have to be compensated for with the addition of an oil cooler. If used all the time it would keep the engine too cold. There would have to be a way to monitor how the cooler was used.

Just look at any modern automobile and all the monitoring equipment they have on them. My truck can tell me my average gas mileage. If all this was added to engines like the Kohler and Onan, it would result in a very expensive engine and unmanageable in lawn and Garden tractors. The other choice is just buy a new one at big bucks. Or repower with the newer and improved engines.
 
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