Editor's note: We are very fortunate to have two of our top techs tackle this installation. Each one brings a slightly different direction to this tech, and both thoroughly tested the Force Flow from JIMS.
By Doc Robinson
Summer is here and engine heat once again becomes and issue given that Twin Cam engines run hot. Often, very hot. And, as you hot them up to produce more horsepower, they run even hotter again. Which is where this JIMS innovative product comes in. The patent pending JIMS ForceFlow literally forces the heat away from your engine by pushing high velocity air through the cylinder fin pack in a wide flow pattern, directed at the head gasket surface.
Powered by a cooling fan that was designed to cool brakes in NASCAR, it is claimed that the JIMS ForceFlow can lower head temperatures up to 100 degrees. The ForceFlow can either be activated by a thermostat (included), or wired through a manual on/off switch, or both.
This unique design also includes a horn inside the ForceFlow’s streamlined housing, and thus gives the horn mount, or left side of the bike, a new look. The ForceFlow comes with all necessary hardware and wiring. Now there are way too many overblown claims about various aftermarket products for American V-Twins so I wanted to give this unit a thorough test.
My ForceFlow was installed at an authorised Harley-Davidson dealership by tech Adam Kalb, better known as SuperKalb due to his predilection for bolting superchargers and turbochargers on anything that comes within his reach. This is an overview of the installation process.
After removing the tank and the stock horn SuperKalb cuts a hole to give access to the main wiring loom and smooths the edges.
The top mount is readied.
As is the lower mount.
SuperKalb puts the unit in place and now tightens both mounts to specifications.
He solders a couple of wires and then uses heat shrink to insulate the soldered joins.
Now he replaces the tank and we’re almost good to go.
In order to test the unit thoroughly I waited for a hot day to be forecast and held off the testing until 2.00pm when it was due to record a temperature of 34°C (93.2°F). In fact it reached 34.1°C.(93°F).
In order to be able to monitor the time and temperature of the front head during the testing, I plugged in my Power Vision unit and rested it on a plastic storage container and was able to place a wristwatch next to it. The bike was then started and left idling in order to reach a temperature suitable for testing the ForceFlow.
By 2.35pm the front head temperature was reading 177°C (351°F) and I used the manual switch to activate the ForceFlow.
By 2.42pm, despite continuing to idle in the hot sun on a cement driveway, the head temperature had already dropped to 143°C (289°), an impressive reduction for a stationary idling bike.
At 2.44pm – a mere two minutes later – the temperature had further reduced to 130°C (266°F) which was even more impressive. And for me, more than enough proof of the efficacy of the JIMS ForceFlow and, well, it was time now for an icy cold beer and a dip in the pool.
Twin Cam Harley-Davidson engines run from hot to very hot for all sorts of reasons,
including the need to meet EPA regulations, and while legislation may dictate this it is not so nice for the rider on a hot day. And once you modify the engine with higher compression pistons and bigger capacity, to name two common power upgrades, you are going to generate even more heat. So any product that can significantly reduce heat, is worthwhile both from the point of view of rider comfort and engine wear. The ForceFlow scores brilliantly in both areas.
And if you are concerned that the hot air blowing across the engine might make the inside of your right let uncomfortable, don’t be. While riding this air is dissipated into the airstream and at the lights, with your feet down, you will find your leg is behind the airflow.
The ForceFlow unit is available in Black or Silver for $420.00 MSRP, or Polished for $450.00 MSRP. Your local dealership or aftermarket shop can source this product for you or you can contact JIMS at www.jimsusa.com
. Highly recommended!
JIMS “FORCEFLOW” CYLINDER HEAD COOLER
Most of the Harley Twin Cam owners I meet complain about the heat of the engine. Even with oil coolers I see oil temperatures of 270 degrees and engine head temps of 380-400 degrees.
JIMS has designed a unit called “FORCEFLOW” which uses a cooling fan that was designed to cool brakes in NASCAR racecars, to force cool air between the cylinders thus cooling them by 80-100 degrees.
The unit mounts on the left side of the engine where the factory horn is. Because of that they have also included a horn in the Forceflow.
The unit is easy to install but as with all installations I recommend reading the instructions prior to starting the job. You will also need basic wrenches and sockets, Ft-lb torque wrench; cutter for the wiring trough, blue thread locker, tie wraps and a H-D service manual is recommended.
This installation took place on a 2009 Harley FLHTC and there may be slight differences with other models.
Remove the saddle bags, side cover, main fuse, battery cable and fuel tank. Remove the horn assembly leaving the bracket and rubber isolator.
Cut a notch in the wire trough and position the wiring harness in position following instruction from Jims. Locate and mount the thermostat to the front rocker box using the supplied bolt and spacer, torque to 15-18 ft-lbs. The thermostat will activate at 140 degrees.
Remove the center case bolt and replace it with the one in the kit. Add blue thread locker to the end without the slot in it and using a screwdriver tighten it snugly. Follow instructions to mount the lower bracket. Check that the shifter rod does not make contact with the bracket.
Follow instructions on hooking up wiring and temporally install the cooler assembly on the two runner isolators. Recheck wiring for clearance and that it is not going to touch anything like the fan blade and or cylinders.
Once clearance has been confirmed remove the mounting nuts one at a time, add blue thread locker and torque to 7-9 ft lbs.
Following the instructions route and hook up the wires to power. I used the factory Deutsch Data Link Connector as recommended.
Reinstall the side cover, saddlebag, fuel tank and seat.
The switch on the “FORCEFLOW” allows you to turn it on or off. I started by starting my engine and then turning it on. I used an infrared thermometer to measure engine temps and the fan started at 110 degrees at the rocker box and 270 at the head with a oil temp if 110 degrees.
I shut the cooler off and I rode the motorcycle until the oil temp was 200 degrees, the rocker box 124 and the head 360 degrees.
I then turned the “FORCEFLOW” on and rode the same route. The oil temp dropped to 185 degrees, the rocker box to 104 and the head to 280 degrees.
I rode from Florida to Alabama in the rain recently and ran the “Forceflow” to see if water would affect it and it worked fine.
I can hear the fan and motor running quietly while at a stop but not while riding. It can be shut off, but that sort of defeats the purpose.
Some in-the-field heat testing, or is he taking a photo?
I am pleased with the “FORCEFLOW” and it will remain on my motorcycle.