Oil cooler and Gauges on JD Z320m

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Jun 28, 2003
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Illinois
I took the gauges and oil cooler off the old JD F510 and transferred over to the new JD Z320m mower. It has a v twin Kawasaki 21.5 hp FR651V. Last summer I was consistently getting oil temps around 250F after a hour and a half mow in 80-90F temps. This was measured via the fill tube immediately after shutting off.

The old cooler which is a Hayden transmission cooler with 3/8" hose inlets. Has a self restricting orifice for cold oil bypass. I put in a bypass ball valve too. It's mounted on top of the air cooling intake screen on top the flywheel. I used some 1.25" foam backer rod and mounted that over the screen. Then cable tied the cooler to that. We will see how it holds up.

The gauges were pretty straight forward . Just needed a good mounting place visible when using. And rerouting, securing the wire.

Probably too big now as it has air forcibly draw trough it. The old mower it was just mounted in front and the F510 doesn't move very fast. But it did the job on it for 20+ years.

It all added 450 mL oil capacity. I used a bigger filter too. The two adapters, one for cooler and one for the gauge ports and the extra length of the new filter added about three inches total. But still plenty of room.

Adapters senders and filter mounted.jpg

Gauges dr view.jpg

Wiring.jpg


Oil cooler hoses.jpg


final mount from side.jpg
 
Ingenious. However might you be pulling a lot of grass and dirt into the oil cooler fins via the draft of the flywheel? Some type of pre-filter now may be required.
 
Ingenious. However might you be pulling a lot of grass and dirt into the oil cooler fins via the draft of the flywheel? Some type of pre-filter now may be required.
Yes the OE grill would get leaves built up. More than likely it's way overkill for an oil cooler. So watching oil temp would indicate a need for clean out. If the oil cooler is too big, then I plan on cutting out some of the foam backer rod sections. I could probably just use some stand offs but that's more work. Maybe when I take the shroud off for cleaning.

I think a prefilter would restrict the air flow for the engine cooling too much. This cooler on the other mower did an excellent job and really didn't have great airflow. It also shared the oil with the drive unit. Would get to 300F+ on hot days when I first got it. With the cooler it ran 230F max.
 
Yes the OE grill would get leaves built up. More than likely it's way overkill for an oil cooler. So watching oil temp would indicate a need for clean out. If the oil cooler is too big, then I plan on cutting out some of the foam backer rod sections. I could probably just use some stand offs but that's more work. Maybe when I take the shroud off for cleaning.

I think a prefilter would restrict the air flow for the engine cooling too much. This cooler on the other mower did an excellent job and really didn't have great airflow. It also shared the oil with the drive unit. Would get to 300F+ on hot days when I first got it. With the cooler it ran 230F max.
Yeah I have found pressure washers and riding mowers run really hot oil.
 
Had a minor oil leak. That's what the cardboard under the filter is about. I feared te old oring on the first adpter for the cooler. But turned out to be a aluminum 3/8" threaded tapered plug. I didn't want to originally tighten it down too much being aluminum but was easy to access.

85 psi on cold 5w40 and max speed. Just about what my Gen Coupe runs on cold oil and pump bypass.
 
I noticed when checking for oil leaks that under the filter there is a nice lip that catches any drips. You can place a small pan there when changing the filter. Though when I took the filter off nothing spilled anyway. I'll have to cut up the OE JD filter.

There is also two allen head plugs there. More than likely a good place for a gauge sensor. or a cooler loop.

JD Z320m oil gauge ports.webp
 
Did my first mow with the cooler. 1.5 hours, 55F out and windy so not much heat load. The oil ran 160F or so at 60 lbs of pressure. Did not take long time to get there. This is with the cooler bypass loop valve open, it still goes though the cooler though. I don't know the specifics but it's a Hayden Rapid Cool 679 stacked plate type.

Going to cut out some of the foam backer rod so air bypasses the cooler. Right now all the air for engine cooling also goes though the cooler.


oil cooler with leaves.jpg
 
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Did my first mow with the cooler. 1.5 hours, 55F out and windy so not much heat load. The oil ran 160F or so at 60 lbs of pressure. Did not take long time to get there. This is with the cooler bypass loop valve open, it still goes though the cooler though. I don't know the specifics but it's a Hayden Rapid Cool 679 stacked plate type.

Going to cut out some of the foal backer rod so air bypasses the cooler. Right now all the air for engine cooling also goes though the cooler.


View attachment 215069
impressive results, should help the engine live a much longer life.
 
I took it off. It was running tooo cold at 160F IMHO. And I wanted to see if indeed it did run at 230F which it does. I had previously measured the temp in the sump after shut down with a regular temp probe. They match pretty close I suppose. The gauge is deliberately vague but does have numbers....

And ordered a smaller one that I am going to mount to the frame under the fender. I figure there's a enough air blowing around to keep temps above 200F or so. Made for ATVs up to 250cc.

s-l200.webp
 
I took it off. It was running tooo cold at 160F IMHO. And I wanted to see if indeed it did run at 230F which it does. I had previously measured the temp in the sump after shut down with a regular temp probe. They match pretty close I suppose. The gauge is deliberately vague but does have numbers....

And ordered a smaller one that I am going to mount to the frame under the fender. I figure there's a enough air blowing around to keep temps above 200F or so. Made for ATVs up to 250cc.

s-l200.webp
Many of the commercial zero turn engines (Kohler Command Pro, Briggs Vanguard, etc) come with oil coolers that size.
 
Here's a guy putting the OE Kawasaki oil cooler on. Originally for 25 hp and above but it would be a direct fit.



s-l1600.jpg
 
Where/how are they mounted?
On my 28HP B&S Commercial Turf engine, the OEM oil cooler is mounted to the side, it is designed so that the flywheel fins pull air through it, the oil filter is right below it and it just has a couple of lines that run to the cooler.
 
The engine cover must have some vent slots behind the cooler?
Yes, a lot of air gets moved across that cooler, although I don't know that they are necessary on OPE. I've got a Kawasaki FH500V (17HP twin) that is on a Wright Stander mower that has 1600 hours on it and it doesn't have an oil cooler at all.
 
I got the eBay cooler and it has too small of fittings. They appear to be a straight M12 x 8mm hose barb. I would need a M12-1.25 x 12mm hose barb. I could go to 10mm hose I suppose.
 
Any updates on the cooler? I like the idea of the Kawasaki cooler as it is a simpler design. I wonder if it would fit on a Briggs 24hp engine?
 
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