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Tech Installation Handled by Two Experts in Two Hemispheres

Text and photos By Rogue and Doc Robinson

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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.

1 After removing the tank and the stock horn SuperKalb cuts a hole to give access to the main wiring loom and smooths the edges.

2 The top mount is readied.

3 As is the lower mount.

4 SuperKalb puts the unit in place and now tightens both mounts to specifications.

5 He solders a couple of wires and then uses heat shrink to insulate the soldered joins.

6 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).

7 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.

8 By 2.35pm the front head temperature was reading 177°C (351°F) and I used the manual switch to activate the ForceFlow.

9 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.

10 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!

By Rogue
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?
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.


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Reader Comments

A Super write up Thank You! I was in the pondering state of oil cooler choice. I am now not any longer pondering. I am just going with the JIMS unit! Even though there are other options the JIMS looks good and above all it works!!!!!

Thank's Again

Fountain Inn, SC
Wednesday, July 8, 2015
So, I posted this below review on my Amazon account, which is where I bought this from.
Thought I'd share it here, as when I was looking, didn't find to much info from actual buyers of this. Bought it *because* of the BikerNet test/review.

Yep...It works...let me get that out of the way first. It works, and works well.

After building up and Hot Rodding my 2007 Twin Cam Road King, (Feuling Oil Pump, Billet Cam Plate, Woods 55 Cams, Fuel Moto Push Rods, Feuling Lifters, head work and 103ci top end, PV1 Fuel Management) , my bike, which had always run hot as it was, (Stock 96ci) became pretty unbearable. Routinely hitting 300 degrees + temps, hitting the oil breakdown point more than once.

(Red Line 20/50 and even 20/60 Synthetic)

I wasted time and money doing the Jagg Fan Assisted Oil Coolers. First one was the one low mounted. No air flow and no way to keep it from leaking...no room under there...so I then went with the Side-mount. Aside from it was fugly it also had issues with leaking and I also never understood how the fan would point forward into the wind and then when I was going at speed how that was supposed to work, etc.

They maybe reduced the temp 10 or so degrees...which really didn't help all that much.

So, after looking at the reviews for the Lenale and also the Wards Fans, Love Jugs, etc...was a little concerned when I didn't see too many reviews for this JIMS Flowforce, but this one on your BikerNet was pretty detailed, so gave it a shot.

Fairly easy installation, if you know your way around a wrench, should be able to do this, no issues.

Then went for a ride....around Chicago...in almost stopped dead traffic. I usually hit the shoulders or bicycle lanes (have too, can't sit in traffic in Chicago on a Harley), but always have to keep an eye out for the law.

This time, just stopped, go, stopped go etc... Fan kicked in the way it was supposed to and I kept checking my oil temp gauge. 10 miles of this and usually my EITMS kicked in, and usually pushed 320 degrees or so like this....this time, with the fan running...only hit like 220. Thinking maybe this was a cooler day or something...took it back to the shop...unplugged the fan, and hit the road again...let it hit 300...stopped, plugged it back in...sat there...not moving. Watched it steadily drop until it hit like 240 or so in just about 5 or 6 mins...then rode it some and it dropped back lower to the 220 range... so I have to give it its props.

So, for less than the $450 cost of the Jagg Fan-assisted oil coolers, which only give me maybe 10 degrees off (they *say 20) this whacked approx. 80 or so off my oil temp gauge.

Buy it. It works.

Chicago, IL
Monday, October 6, 2014
Editor Response Thanks for taking the time to send us a report. Perfect!
This appears to be a awesome product w/ a lot of thought going into the cure for a real problem. I would really like as much info. as you can send. My service manager & lead tech are very impressed with the idea. Thanks

Frankey Walker
Union City , TN
Friday, June 7, 2013
Editor Response I'll put you in touch with the JIMS team.

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