Back in the late winter / early spring, before the time of the Corona, I chatted up adding an oil cooler to the old Road Glide after some engine work added some heat to the system. At the time a couple of the brethren asked for a heads-up later on how well (or even if) it worked. Here goes (so bored right now I'm talking about oil in a thread -- but it is NOT an oil thread):
Baseline is a 98" first gen Twin Cam with just a little over 10.25:1 and TMan 625 cams, 2-1 pipes, on a Road Glide.
After the engine was re-done I noticed more heat in the system than there had been before. Not unexpected at all. On several warm spring days with temps in low to mid 80s the in-dash oil temp gauge would show 230. Not worrying at all. But it would climb from there when coming back through town and I'd not yet seen hot summer temps. Wanting this to be the last time I ever went inside that engine for the entirety of my riding lifetime decided to add a pound of caution (oil cooler) to the system.
I liked the UltraCool tank and fans system better. I wasn't wild about their filter adapter. It was open to allow oil through the cooler all the time. Summer or winter. Their solution was a little magnetic vinyl sweater to cover the cooler with in lower temps. That bugged me.
However....
I had one of the old oil HD filter adapters that were stock from the 03-04-05 vintage 103" CVO engines. They're thermostatic. So mounted that, added some AN fittings in place of the nipples, made up some AN lines to plumb it all together. And life is (should be) good.
The housing had a slight leak at one of its service points. Service kit on backorder with no ETA. Crap.
The other guys in the oil cooler world (JAGG) have a thermostatic filter adapter that plumbs to the cooler. So it will shut oil off to the cooler at lower temps. That would do what I wanted.
So my hybrid final solution was the UltraCool tank and fans system and the JAGG thermostatic filter adapter on the stock oil filter mount. The fans are wired to the accessory switch on the dash. The AN lines that come with the UltraCool kit plumb directly to the other company's adapter. Only thing had to do was swap out the NPT fittings on that adapter made for 3/8 rubber line to fittings for 6AN line. Then it was just a bolt on and I don't have to mess with the silly cooler sweater when the temps are lower.
I also did not wire the fans for automatic thermostatic control. They're not helping at highway speed anyway. I did manual control of the fans via the accessory switch on the dash so they're on and off when I want them. And, in a win-win, that damned accessory switch now finally does something.
So how does it work? I'm actually quite satisfied. Perhaps even more than expected.
This morning it was mid 80s. Same temps I'd see the oil temp climb to and run about 230 on a highway run before the cooler was installed. I'd see above that loitering in town traffic once the engine was warm or in slower traffic noticing it climb a bit if traffic speeds dropped to 45mph-ish and below.
This morning I paid close attention to oil temps just so I could drone on here about how it was doing. Highway cruising at the same ambient conditions I'd previously see a solid 230 on the oil temp gauge I'm now seeing 200-210.
Lower speeds riding 40-45 see oil temps begin to climb a little. Turn on the fans and within about three minutes it's back down to the 200-210 indicated and just stays there.
Then the biggest surprise. Farting around in town for 20 minutes or so. Stop signs. Slow traffic. The normal crap. Fans on the entire time. Gauge stayed indicating in the 200-210 range.
So it's doing everything I could ask. The couple times I've been out in on hot days, 95 or better, the system has kept the oil within completely manageable levels then too.
The only difference between the UltraCool filter adapter and the JAGG adapter from a hardware installation perspective was that the UltraCool had 1/4" NPT for its fittings while the JAGG had 1/8". That little difference in and out would allow for some small difference in both volume of oil going through the cooler and how long the oil is in the cooler during each circuit. However those volumetric and heat transfer calculations work out (and I didn't even try to do the math) this particular combination works like I want it to and is doing a good job. So I declared victory and rode on.