EOT meter for OEM oil cooler

[dsinned_imp]

Thanks for your comments.

First, let me just say, I did a similar project already on my 2015 Triumph Bonneville T100. It was the same idea except on that bike, there is sufficient room behind the oil cooler for a fan. Also, on the Bonnie, I was able to gather EOT data directly out of the ECU and it was based on INTERNAL oil temperature readings. I was shocked to find out how extreme the EOT got; very nearly 300F WHILE RIDING THE BIKE! But not riding across the Mojave Desert in the middle of Summer. I had EOT excursions that high from riding during mild Springtime days with OAT only in the mid 70s. Of course, stop and go exacerbates engine temperature on ANY air cooled motorcycle. The Honda CB1100 is no exception.

Long story short, I was able to reduce EOT significantl, especially during adverse riding conditions, with just the addition of a retrofitted EOC fan. In fact, it is exactly the same fan I'm using again on my CB, except it's a pusher not a puller. I am using an Italian made Spal 5.2" fan in both cases. This particular fan is quite powerful for its size and does a good job flowing air thru the oil cooler especially when riding at relatively slower speeds. At higher speeds, obviously a fan is not really needed, and can be turned off, but does not create much of an obstacle to natural air flow.

As you have rightfully pointed out, what is undeniable in the design of ANY air cooled motorcycle engine is the importance of MOVING AIR! However, we cannot control everyday riding situations and sometimes stop and go traffic is unavoidable. This is where a fan provides supplemental cooling benefits to an air cooled engine. Understandably, they are commonly used on dirt bikes oil coolers.

What I was shocked to read on this forum was from a fellow member who claimed the only overheating protection we have on our bikes is a little idiot light that illuminates at 340F! A warning at that point, is too late IMHO! Thus, this is the reason I began this project with an inexpensive temperature monitoring mod, which I have already validated its effectiveness this afternoon.

Unfortunately, there are no OEM "fan kits" for the CB1100. Nor for the Bonneville either. I don't know why as there are appropriate fans available - fairly inexpensive - well up to this task that can be easily mounted either behind or in front of the EOC "as is". Mounting the fan is easy to do merely using tie wraps and a pair of wires to the 12V battery. With the addition of a simple SPST switch to the handlebars, the fan can be operated by the rider as necessary, and certainly of usefulness while stuck in stop and go. All the parts needed for this DIY mod don't even add up to 100 bucks. Managing to keep the oil cool(er) will also pay big dividends with respect to the overall reliability of the bike (e.g. keeping rubber and plastic hoses and oil seals from wearing out and leaking).

The fan mod turned out very successful on my air cooled Triumph, so it might be just as worthwhile to try out again on my Honda. No guarantee, of course, but that is what I am trying to determine and the rationale for this project.