Cooling the Harley Milwaukee 8 Engine!

BY: Gabe Carrera, Esq.
February 19, 2023

I ride long distance in Iron Butt runs and the Hoka Hey Motorcycle Challenge so keeping a cool engine benefits me greatly. The Milwaukee 8 engines to comply with woke EPA standards run super lean creating a hot engine. I ride through hot parts of the country and my legs roast on that Mustang seat stuck in traffic. It got so bad that a few years back Harley got sued for having an engine too hot.

The motorcycle engine defect class action lawsuit asserts that Harley-Davidson was aware of the engine defect and had a duty to warn about the dangers associated with it. However, the plaintiffs claim Harley-Davidson failed to address the engine defect and failed to adequately warn consumers about the issue.

“Like the earlier Twin Cam engines, the Twin Cam 103 is ‘air-cooled,’” the Harley-Davidson class action lawsuit says. “That means that the engine is, b design, cooled exclusively by the flow of air. Simply put, if there is no or little to no airflow, which is caused by moving the bike to allow air to flow over the engine’s fins, the engine is not cooled. As Harley-Davidson is aware, air-cooling as a method of keeping and maintaining a safe and efficient heat level has limited effectiveness.”

https://topclassactions.com/lawsuit-settlements/lawsuit-news/harley-davidson-class-action-says-engines-unreasonably-hot/

Protect You Gasoline From Heat!

So the engine is hot and your cookie cutter Harley dealership shrugs its shoulders that they can’t help you. You have arrived at the right place so that I can throw together some videos on how to cool that HOG engine under your ass. I came across a Design Engineering Inc guy back during Daytona Beach, Florida Bike Week. He was pushing some heat shield inserts to cool your legs from the HOT pipes. I sent him my heat shields to Ohio and upon return he threw in some heat reflector stickers to protect my gas tank from the extreme heat to keep the gas cooler.

Reflect-A-Cool™, constructed of fiberglass material backed with a layer of aluminized reflective foil to handle direct continuous temperature of 400°F has many uses such as covering firewalls, marine engine compartments, RVs, in the tub of a race car where typical mechanical fasteners cannot be used and has many industrial uses. Reflect-A-Cool™ can be trimmed to fit just about any shape. Just measure, trim, face reflective side towards source of radiant heat and remove self-adhesive backing. It’s that easy.

You can take this stuff and wrap the bottom of your seat to keep your bum cooler. Use your imagination in wrapping other components on your bike with this to reflect extreme heat.

My M8 engine is water cooled but that does NOT cool worth a shizzle! My mechanic says all it does is reduce the noise of the engine. In fact if you spring a leak and empty the cooling fluid you can keep going with no problem cause its mainly an air cooled engine. The fluid paths in the engine does it no justice thus there is not enough space for the fluid to flow to cool the engine. It does cool a little but not like a truly water cooled moto engine.

Reflect-a-Cool Tape

Motorcycle Heat Shield Liner Kits

Heat from the exhaust system can become uncomfortable, especially riding in slow traffic. This issue really comes into focus for those with shorter legs. Not wanting to disrupt the attractive lines and appearance of the exhaust, DEI’s Heat Shield Liner Kit insulates the outer heat shield, without disturbing the looks of the bike. Each piece is precision cut to fit in-between the exhaust pipe and the heat shield, blocking heat transfer and lowering the surface temperatures of the outer shield. Easy to install, with no permanent modifications needed. The Heat Shield Liners are dual layer constructed of Aluminum and our proprietary Dura 2000™ insulating material and offer over a 60% reduction in heat.

I installed the shields and then went on a 15K mile run to test the shield inserts. If my legs roasted I was going to ROAST DEI, but that’s not happening today. DEI passed the test and my right leg was happy as pig in doo doo going down the road in death valley at 114 degrees heat! Only tip I can give ya is use brand new hose clamps when putting them back on your bike. I had a defective clamp worn out by usage that vibrated too much. This caused 15% of one insert to get destroyed due to the flapping or vibration. Still works but I might just send that one back to be refitted.

Air Cooled Engines Need AIR!

A long time ago, in 2015 in fact, when Love Jugs first came out I was amazed at how good they assisted in cooling my 103 Harley Twin cam engine as I rolled 5-10 miles per hour on I-95 to Miami. Steve gave me a box to raffle off in the Keys for the Peterson’s Poker run. I immediately fell in love with the jugs! What a way to cool the engine when you bike is air cooled…..solution = MORE AIR!

Love Jugs are by far the most powerful and effective cooling system available. There are some that say that Love Jugs’ superior power is overkill, nothing could be further from the truth. Don’t believe me, here is what the Buell engineers quote in their US Patent application for a forced air cooling system. “The higher the volume of air flowing over an air cooled motorcycle engine, the more effective the cooling fins are at transferring heat from the engine to the air.”

The bottom line is that the more forced air that you can direct at the heat source, the more dramatic the cooling results will be. More powerful streams of air will always cool substantially better than a lesser volume of air. Although this fact is inarguable, some proponents of competing systems will allege that a greater amount of forced air doesn’t really matter. The truth is that nothing matters more. The greater the volume of forced air – the greater the cooling results will be. THIS IS AN INDISPUTABLE SCIENTIFIC FACT!

“I endorse Love Jugs big time. I have ridden them over 45 thousand miles of the toughest riding possible. Through all terranes, weather, and conditions. I’ve beaten the hell out of these babies and they stand up to every challenge I’ve thrown at them. This includes my record breaking ride from Tierra Del Fuego to Alaska. Gabriel Jose Carrera, Esq. Attorney At Law Holds hemisphere distance record – Tierra Del Fuego to Alaska. More to come 01/10/17 stylized, stainless steel engine cooling system. You can install the Indian Cool Master in less than 15 minutes and it’ll prolong the life of your engine.”

https://love-jugs.com/the-attorney-that-rides/

DK Custom Products Help Cool Your M8

I found these guys on YouTube when I was researching ways to cool my M8 rebuild. On my 2019 Road Glide Ultra my flywheel bearings took a shit, thus I had to split the cases to get to them. Mike my mechanic suggested building it to a 117 from its stock 114. I wanted to keep my gas mileage so I purchased a bolt in cam thats a hair above stock giving me more passing power. DK Custom made several suggestions on products that i have ordered like my tank lift brackets. I raise the tank 3 inches away from the engine and with the DEI wrap I keep the gas cooler and allow more wind to flow to the top of the engine.

It is Getting Warm again in parts of the world. Heat can be Uncomfortable, it will accelerate Wear on the Engine, and it Robs Power. Don’t Fall for the “It’s Normal, they All Do That” lie that is perpetrated by many Dealerships & well meaning HD Owners.

Gabe’s Final Thoughts and Videos!

Two years ago i made a video of the goodies I installed on my bike before competing in the Hoka Hey Motorcycle Challenge. At the time I had heat issues but I was limited in my knowledge on cooling the bike down. My 2019 HD RGU is almost completed. It should be ready for the spring time to work out any kinks and then I plan on doing a summer Harley Adventure!

Lastly, I want to thank you all that support and follow me on these runs I do and my Screaming Thunder Blog! Without you referring your friends and family members my law firm would not survive. As you know I only advertise in the ABATE magazine the rest is word of mouth. I work hard with the cases that are referred to me. I thank you for referring those cases or by you hiring me to handle the difficult situation you find yourself in whether its a motorcycle accident or a family law issue. Either way I wanted to say thank you and I hope you find this engine cooling post valuable.