“That hot-Harley syndrome doesn’t have to be permanent. There is a cure. There are number of them actually.”
“We hear it all the time,” Jamie Hanson says. “Riders rolling up to the Speed’s Performance Plus mobile shop come in sweating bullets, pleading for help. Thankfully they can get it. That hot-Harley syndrome doesn’t have to be permanent. There is a cure. There are number of them actually.”
The first thing to do is get that bike tuned right. “Late-model Harleys are calibrated way too lean.” A richer, cooler-running fuel mixture can go a long way towards beating the heat. So can something as simple as an oil change. “If you haven’t already made the switch to synthetics, now’s the time,” Jamie goes on. An air-cooled engine is also oil cooled and running a full synthetic can drop temperatures in the range of 15 to 25 degrees. Not insignificant. “Another good move,” Jamie adds, “is to use one of those cleanable and reusable metal-mesh oil filters; the ones with a finned aluminum canister.” Not only is this the last oil filter you’ll ever buy (and those disposable/synthetic-compatible filters aren’t cheap), there’s that finned aluminum canister effectively turning the filter a combination oil filter/oil cooler. The ones SPP offers even include rare-earth magnets in the spin-on base to further trap metallic particles.
Making those moves, the tune-up and switch to synthetic oil with a finned filter goes a long way toward controlling the heat problem on a Harley. That isn’t the end of things, though. There’s more that can be done here, on a bagger especially, and with just a few more steps the SPP techs have found that you can pretty well beat that heat into submission. The first of these is increasing oil capacity, and since we’ve just been talking about oil, that’s a good place to start.
More oil onboard means more oil available to remove more heat, adding up to an even cooler-running motorcycle. “And that Baker Drivetrain ‘Plus One’ oil pan kit works great,” Jamie explains. It’s available for all the ’93-later FLs and as the name implies it adds 1 additional quart of oil, which can drop oil temperature by as much as another 10 degrees. It’s become a regular in the SPP bag of tricks. Besides adding that extra quart of oil, the Plus One (available as either a one-piece cast unit or a two-piece billet assembly) relocates the feed port to the rear of the pan for more complete circulation, and inside there are multiple aluminum baffles. As a bonus there’s an integral boss for easy installation of the most popular track stabilizers, but that’s a whole different subject. Right now we’re talking about added cooling and that Plus One pan is another tool in the arsenal.
We’re not done. “The right set of pipes,” Jamie concludes, “can be a huge help here.” The aftermarket hasn’t turned a blind eye to this hot-Harley situation, responding with reconfigured head pipes aimed at cool running and added performance. There are some great choices, especially for the baggers. “And we’ve had great luck with those new S&S Power Tune Duals,” Jamie says. More than just adding a true dual-pipe look to a dresser, these S&S pipes feature a hidden crossover to balance the flow, 2-into-1 style, a clever design good for an additional 8 horsepower all by itself. But more to the point here the header for the rear cylinder has been relocated to move that pipe far away from the passenger to significantly reduce the radiated heat. “And it works like a charm,” Jamie says, “in both its performance and ability to cool things down.”
Late-model Harleys run hot. They don’t have to stay that way. You can start small with that tune-up and the switch to synthetics and then move up to the other steps as needed. Or bite the bullet and tackle it all at once. Next time you see that big black SPP truck at an event, stop in and have a talk with the guys. You’ll leave a much cooler customer. The full SPP tour schedule is on the website.
Speed’s Performance Plus
speedsperformanceplus.com (605) 695-1401 – MN (605) 695-2272 – SD