Two years ago I found an amazing deal on a new B&S 20hp V twin. It was just barely more that the parts would have been to fix the old one so I just swappped engines on my rider. I want to make it last as long as possible, so I’m wondering if adding an oil cooler would be worth the trouble and expense? If so, what parts do I need and is there a kit available?
I assume I just need some sort of cap that goes over the filter and diverts the oil flow, a couple of lines and a radiator? So really what I need is an oil filter relocation kit for a vehicle that takes the same size filter, plus a cooler radiator.
Waste of time and money. Millions of mowers out there don't even have oil filters. You want the engine to warm as fast as possible, be it car, truck or mower. These are low rpm Diesel like engines. If you did add a cooler you will risk losing an oil line like I DID on a new Jeep engine. My CJ-7 dumped all the oil out on the highway trashing a brand new motor. Had this "great idea" about adding an 800hp rated oil cooler and 2 Chevy two quart filters. Most expensive cooler I bought LOL. Leave it alone an mow with it.
Most people don't even check oil level. Lose one line and she is done. All the vibes bouncing around the yard. On a speedy 0 turn...... I sleep better with no oil filter at all.
I was taught that most engine oils are engineered to operate efficiently between 90-110 degrees Centigrade.
Also its good for the oil to go over 100C, for a sustained period (say 15-30 mins), so as to drive off volatile contaminants eg water, fuel, by products of combustion.
On engines fitted with an oil temperature gauge , I am happy for a nice constant 95-100C.
Air cooled engines are more affected by ambient temperatures than liquid cooled. So if you happen to be mowing in say 40C temps, your engine (oil) is not being as well cooled as say a nice 25C .
Add to the above the possibility that there is a bit of dust & chaff, restricting air flow and you have a recipe for an overheat.
The 724cc, B&S 25 hp Pro Commercial (comes with an oil cooler), that I recently fitted to a mower that had a 724cc B&S 22 hp with no oil cooler and ruptured innards, should handle higher ambient temperatures a lot better - hopefully will do a lot more hours than the engine it replaced.
Note: Running an engine/oil too cool is as bad as running it too hot.
