Harley-Davidson Water-Cooled Heads Patent

The next 3 years are going to be very interesting. How Harley-Davidson, and other brands, are going to adjust to the very stringent US EPA emission regulations to kick in in 2013? A liquid cooled engine? Almost certain. When? Harley 2012 new bikes about to be unveiled seem to keep the V-Twin air-cooled engine with an extension of the 103” to more models. And after that?

A certain Charles, one of my readers who animates in France a  website called Info-Motos, unearthed from the US Patent & Trademark Office, a patent filed by Harley-davidson 1 1/2 years ago showing a V-Twin cylinder head cooling system. As you can see on the drawings, a cooling liquid passage runs through the cylinder heads to reduce their operating temperature. The cooling system seems to be made of 2 radiators, fans and hoses hidden within the fairing of a touring model with an electric water pump located at the bottom of the frame. It looks like a very simple simple system, something that Harley-Davidson could put in production very fast. But let’s remember that brands filed multiple patents and don’t use them all, and that this system may be modified if used. One thing for sure. Harley engineers demonstrate in which direction they are going. No ugly radiator hanging in front of the frame. Relief… Enjoy all the drawings.

42 Responses to “Harley-Davidson Water-Cooled Heads Patent”

  1. 1 S. Bradek Jun 21st, 2011 at 8:22 am

    Here we go. Easy solution. Harley retains its sound.

  2. 2 A 1 CYCLES Jun 21st, 2011 at 8:26 am

    looks like they are trying to cool the exhuast port only…and using swedged metal tubes with orings. honda has done this for years, very simple design easy to produce and should drop head temps very well, but what about leg temps???? wow, we dont run the bottom panniers in florida becuase of temp..now you turn them into radiators? my guess would be a tourqe based v rod engine in a bagger chassis..would love to build one for a client.. 155 hp, 115 ft. lbs . with a turbo 50 mpg and water cooled..good combo

  3. 3 Paul Rosebrock Jun 21st, 2011 at 8:57 am

    What is it about a cooler engine that reduces emisions?

  4. 4 deadwood1783 Jun 21st, 2011 at 8:58 am

    Notice the similarities with the XR1200 head cooling. This is the same advanced cooling system it uses, with the exception of the XR uses oil as its cooling medium. This year,,,who knows. But there are some who say the TriGlide will get it this year and serve as the beta testing unit before the whole line gets it. Kind of like the 2006 Dyna beta tested the six speed and hydraulic cam plate before being rolled out to everything in 07. It’s all speculation at this point. We may never see this released, but as Cyril noted, the next three years will be interesting.

  5. 5 J Jun 21st, 2011 at 9:05 am

    Paul, I believe the benefit is that is allows the engine to run leaner mixtures- leaning it out increases temps, which are then offset by the drop in temps by liquid cooling…. I recall tuning on my Porsche 914 years ago, when I cleverly removed the efficient fuel injection system, replaced it with carbs- I monitored it by watching how orange the exhaust pipes turned, lol.

  6. 6 lonny Jun 21st, 2011 at 9:41 am

    Why Not Oil Cool the head like the XR 1200R?

  7. 7 BadMonkeyMW Jun 21st, 2011 at 9:57 am

    The unfortunate fact is that motorcycles account for barely 1% of registered vehicles on the road, therefore the emissions from them is totally insignificent to the overall amount of pollution in the air. Nothing more than another attempt by our government to exert unnecessary control over the citizenry.

  8. 8 Alfy Jun 21st, 2011 at 10:03 am

    Oil is not as efficient as water with regards to “absorbing” heat. College is in the past, but it has to do with the specific heat of each product. The tables are available in thermodynamic books (how primitive) and on the web somewhere.

    With regards to going water cooled, it all about increasing efficiency. WC allows much tighter tolerances, use of thinner lubricants (i.e less viscous, less friction -> 20W50 air cooled, 10W40 water cooled, and even less in cars 0W, 5W and 20 and 30 for the hot range). Also the mixture can run leaner (excess air in the ratio-> more gas in burnt = less emissions). If it is leaner, the engine will run hotter. Again water is not only better at cooling than oil, but it is much, much better than air. In a liquid, molecules, touch each other (not in a gas), so heat transfer is much more efficient.

    I think one of the best cooling agent is sodium. Large exhaust valves in old aviation radial power plants were sometimes filled with sodium (in a cavity in the stem) for evacuating the heat away as fast as possible from the valve seats.

  9. 9 TRexSG Jun 21st, 2011 at 11:22 am

    BadMonkeyMW hit the nail on the head.

    The whole process is a waste of time and money in regards to motorcycles. Not only do motorcycles account for only about 3% of the vehicles on the road they are also driven a fraction of the miles of cars. If we took the time and money wasted on this and put it into repairing rail infastructure we could get the majority of the polluting diesel semi’s off the road. The roads would be less clogged, the air less polluted and we could all travel safer without 80,000 trying to run us over!

  10. 10 TRexSG Jun 21st, 2011 at 11:25 am

    80,000 lb Semi’s that is!

  11. 11 JSDiamond Jun 21st, 2011 at 1:42 pm

    Water cooling and EFI will do two things: Make HD more powerful, run faster with more opportunity to say FU to the EPA.

    And it will make my shovelhead worth $50k to collectors! ; p

  12. 12 johnny Jun 21st, 2011 at 2:18 pm

    Harley will now be a jap bike and wait till the other company’s produce’s more power
    The tradition has died the harley is dead put up a tom stone and bury it

  13. 13 Jackson Johnson Jun 21st, 2011 at 3:49 pm

    TrexSG, your ignorance in regards to semi tractor trailers is staggering. It is stupid people driving like idiots around semi’s that are the problem. According to a University of Michigan highway accident study in 2009, 90% of semi/auto accidents are caused by the driver of the car, not by the driver of the semi. Also, by using your infinite intellect, tell us how your motorcycles, building materials, house hold goods, food, and everything else gets delivered at a reasonable cost without tractor trailers. I don’t know, maybe your house is next to a set of rail road tracks, and maybe you won’t mind if a 2×4 costs 25 bucks instead of 2.50.

  14. 14 lonny Jun 21st, 2011 at 3:50 pm

    With the radiator in the lower leg fairings ?? That would blow all that hot air on the Riders legs ???

  15. 15 tom Jun 21st, 2011 at 4:33 pm

    harley goes to watercooled engines the end other companys who make motorcycle also make cars harley makes one thing motorcycle EPA and CARB harley needs to fight harley does not need water cooled engines thats not what made harley

  16. 16 deadwood1783 Jun 21st, 2011 at 4:55 pm

    Nope. “During use, the duct 172R redirects air flow away from rider, discharging air into a low pressure, high velocity air flow location. Duct 172R is designed to minimize restriction to air flow, while maintaining clearance for the rider’s leg, foot, and motorcycle controls (e.g., rear brake pedal, shifter lever). The duct 172R is positioned to expel heated air into a relatively low pressure, high velocity flow region of air stream around the vehicle. The duct 172R allows heated air to be carried away from rider by slipstream air flow around bike, with minimal recirculation rearward of the right and left lowers 44L, 44R. The duct also improves air flow performance through the radiator due to a greater pressure differential between the air duct inlet and outlet.”

  17. 17 Philip Jun 21st, 2011 at 7:08 pm

    I take back what I said a few articles ago that Harley would never change anything. Three cheers, the big 110’s are running too hot, this should cool them down nicely. Now how about a big twin Cafe Racer or something kind of wacky? Take a chance, surprise us.

  18. 18 roscoe Jun 21st, 2011 at 7:20 pm

    It will make the engine quieter as well, which will be a good thing. I like to hear the exhaust note, not so much the valves. It is a win/win situtation. Longer life engines, more power, quiet valve train, lower temps for the rider, etc.

    Is it Kawasaki or Yamaha that has been doing this for awhile now.

  19. 19 Keith Stone - Kiki & Angel Jun 21st, 2011 at 10:26 pm

    Damn that’s a big Honda motor……. LOL H-arley…… H-onda…… All the ‘old’ air cool’s are going to be going for big bucks I guess in 13’…. Hold on to your scooters if your looking to sale……

  20. 20 Woody Jun 21st, 2011 at 10:43 pm

    If that’s worthy of patents then I have a great idea for something I’ll call the “the wheel”. I’m currently working on an idea for a room below a house (working title of “basement”) and a way to put a motor on the back of rowboats……………………….. 😉

  21. 21 luSca custom design Jun 22nd, 2011 at 2:00 am

    it is fun to read the reasons that explain why they are forced to go to what they have always mocked… progress! :p

  22. 22 Wiz Jun 22nd, 2011 at 3:58 am

    Yeah, Our scooters do do hardly nuthin’ to damaging our precious little world! How about BP ‘an what they did to the Gulf with damn near no consequences!! Big Bucks Industry pays a little under the table ‘an our Government “Inspectors” look the other way! “God Grant me the serenity to accept the things we cannot change”. Wiz

  23. 23 billy jack Jun 22nd, 2011 at 6:46 am

    I know it’s gonna hurt all the harley based preformance companies(zippers, S&S, vtwin mfct,ect.) if they redesign the top end, but this dosen’t look nearley as bad as what I thought. Dosen’t look as efficent as an internally routed system and a waterjacket jug either(european and japanese companies have about 50 years of design on harley in water cooling,hell, porshe designed the one for the nova in the 80’s)… seems like something they trew on to make the epa happy. like the firt fuel injection system. My condolences to anyone who had one of those. Seems to me they are sticking with “hiding” new technology. remember the FXR super glides? everybody hated the triangle under the seat(even though the frame was 3x stiffer and WAY lighter) so now the dynas have a small triange hidden by the oil tank. I’m surpried they didn’t make a horeshoe tank to cover it…You have to give their engineers credit, making updates on bikes the sales teams want to look 60 years old. Harley only makes money on somthing that LOOKS like a harley(fxr and xr compared to flh and softails). We can’t expect them to make a great running bike with power and good emissions. (that’s what buell WAS for, hehehe)

  24. 24 billy jack Jun 22nd, 2011 at 6:48 am

    oh, yea. my shovel still gets 48mpg. how many “fuel efficent” cars get that for under $5k…?

  25. 25 Todd8080 Jun 22nd, 2011 at 7:48 am
  26. 26 live2rideaglide Jun 22nd, 2011 at 8:29 am

    This whole ozone , greenhouse effect being caused specifically by combustion engine emissions is a tempest in a teapot , especially in regards to motorcyles. Cows and other animals create more hydrocarbon emissions than combustion engines. As far as water cooled Harley v twins , as long as it doesnt crap up the look and sound I would be okay with it. Where to put the radiator?

  27. 27 live2rideaglide Jun 22nd, 2011 at 8:41 am

    Cows create more hydrocarbon emissions than cars or motorcycles.

  28. 28 robinn banks Jun 22nd, 2011 at 9:53 am

    when you start shooting crap about emission off a motorcycle, well friends i think the goverment is just trying to pull a fast one on us….regulate the bikes so ya can harass more bikers..come on pollution from a motorbike…look at factories!cars! trucks! and big rigs….we all went to china to produce shit so now no jobs at home and we think that we need to apply more regulations on a motor-bikes….maybe we should double check how the drinking water is holding up!!!m.l.r.

  29. 29 rebel Jun 22nd, 2011 at 10:31 am

    warm air could be directable to the feet and rider area for cold weather and away in warm, might even result in more annual seat time for some.

  30. 30 bigalyts Jun 22nd, 2011 at 10:49 am

    I see it like this more Parts to be sold and a little more to learn for the Mechanics out there. There will be more benefits having the HD’s water cooled than not. I believe A1 Cycles got it right: take that V-Rod motor and PUNCH it out, in a variety of ways. Love the feel of that Engine, because of the “Porsche” like way the Engine winds out, long and strong. It would make a great Bagger and ………..! If the HD Purists think this is the end of Harley Davidson as they were, then buy a half dozen and stash them away for a little while.

  31. 31 BC Jun 22nd, 2011 at 12:42 pm

    Randy Aron at Cycle Visions in San Diego has been doing V Rod based Baggers for a few years now. Very Cool!

  32. 32 paco de villalba Jun 22nd, 2011 at 12:45 pm

    head hystory motorcicles harley-davidson, r.i.p.

  33. 33 Robert-viva las vegas Jun 22nd, 2011 at 1:31 pm

    Anybody got new or old info on the old Drake-Knucklehead water-cooled engines?

  34. 34 David Wesley Jun 22nd, 2011 at 7:31 pm

    Interesting design for the ultra. Bound to be other patents in the works for non bagger radiator design.

  35. 35 MikeM132 Jun 23rd, 2011 at 4:53 am

    You guys complaining about EPA regulating bike emissions…..it’s a lost cause. Bikes are decades behind cars and now even diesel trucks in pollution control Your argument that bikes are a somewhat insignificant pollution factor is true. This is why they were largely left along until recently.
    Do you remember the Clean Air Act of 1990 (G Bush the First)? Remember when it was being debated and they wanted to outlaw GAS LAWN MOWERS?? This is evolution. Harely will adjust and so will all of us. No more VW, Porsche or Corvair air cooled motors for the same reason as air-cooled V Twins are going away at some point—-to make them burn clean they just get too hot. Some day we may evolve to a turbo-charged Harley; who knows? Whatever happens, as others have said, HD will make it look classic as best they can. The one thing I can predict for the future of HD bikes is one will NEVER, EVER look like that Victory touring thing.

  36. 36 deadwood1783 Jun 23rd, 2011 at 10:00 am

    Anyone take a look at the patent for the advanced cooling system and the list of credits. One Nick Glaja is listed. He worked for HD at the time and had previousley I believe worked for Polaris, he moved from HD to Indian. Now that Indian is owned by Polaris,,,and everybody is under the same emissions rules,,,an experienced engineer is handy guy to have around. Although watercooling is not here yet,,,,I just can’t seem to find the downside to it.

  37. 37 just my opinion Jun 27th, 2011 at 11:44 am

    The real problem is the EPA. And all these other laws that the so called do good-ers [ green living idiots ] are forcing down our throats. When are we as American going to wake up. Do any of you really believe that if we Americans stop poluting the earth that the rest of the world will follow? The only thing that is being accomplished by all this living green bullshit is we have gone from the most industrious nation to one of the broke nations on the edge of bankruptcy. Sure we could ship every thing made or sold in our country by railway and save the earth but it will cost thousands of more jobs. Truckers will lose their jobs first then all the warehouse workers that load those trucks, but it won’t stop there because all those guys buy houses that need built and yards that need landscaping and driveways that need concrete and they buy cars and motorcycles that need service. And while we are saving the planet from bad chemicals that the earth can and will exsorb anyway because those bad chemicals came from the earth in the first place. China is becoming the new industialized nation with all the wealth and power. Do any of you green living people out there really believe that once China is controlling the earth that any of your living green efforts will mean anything? China is only interested in becoming the new super powered nation, they don’t give a damn about living green and GOD help us if they ever get to be the next super powered nation. I say to Hell with all the green living bullshit lets reverse all those bullshit laws that have killed so many American jobs and get back to work.

    As for Harley going to a liquid cooled bike who gives a shit it is about time.

  38. 38 Tony C. Aug 10th, 2011 at 4:08 am

    Retain it’s sound? Again with this? I’ve heard that nonsense before. Water cooling will not, I must repeat, NOT change how it sounds at all. This drawing will wrap the heads in water and has nothing to do with the timing and/or 45 degree jugs – where the “potato, potato” comes from, it will not effect the exhaust, valves or any other part of the “sound”. Who comes up with this anyway?

  39. 39 Darkshovel1979 Aug 11th, 2011 at 4:55 pm

    Speaking as a master HD technician and dyno tuner. I can say that it is about time. Harleys run fairly well with cruise AFR’S of 15.5- 16 in closed loop at cruising speeds. Making for decent fuel efficientancy and low emmissons. But as stated before, this will result in hotter engine temps which is one of the more common complaints from customers (a proper dyno tune can help greatly with this). So a water cooled vtwin will be much welcomed in my field. As for a VRod powered bagger, I don,t see that happening without major design changes. It’s just a very heavy powerplant. A touring based VROD model is more likely. I absolutely love the VRod engine, any technician with an eye for design and engineering would tell you the same thing.

    On a more personal note, any comments regarding how crappy the EPA is or China is taking over the world, would those people please swallow a knife! Greenhouse gasses are bad for the environment and humans in general. And yes China is becoming the world next reigning superpower because our country is filled with retarded like you.

    Ride safe everybody.

  40. 40 John W. Walke jr Oct 27th, 2011 at 5:20 pm

    I love my 03 FLHRCI. She is black on black with white walls. Aftermarket fairing and jamming stereo. She has been to Sturgis and Daytona several times. Cruises smooth as glass. When I get in the traffic at Main street, she is hot as hell. Have always wanted water cooling with the same style. Having 30K in a bike that over heats next to a Goldwing is not fun.

  41. 41 redfish Dec 16th, 2011 at 9:24 pm

    .. if an empty tourpack sans lites and rails is $800, what will a set of lowers painted to match, plumbed for a radiator, and wired for 2 fans cost..? the baggers with lowers are already $22k..

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