I find this incredibly interesting...and clever. A company called Lone Star Light Sport just revealed at Oshkosh a new 1/2 VW that uses Harley Davidson parts. They claim 60hp. The company's website is still being developed, but they have a very active Facebook group. They wrote this in the group:
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Compression will be set up at 8.5 : 1 for test runs. We will be monitoring the temps closely. CHT and EGT are expected to be lower than a 7.5 : 1 half vw thanks to 100% more cooling fin surface area!. This setup will allow for compression in the 9.5 : 1 range in the future. Hoping to achieve 60 hp at 9.5:1With the bore to stroke ratio of this engine I expect torque numbers to exceed the hp numbers in the 32-3400 RPM band.
If it flies, floats or fornicates.... rent it! Flight Leader
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Clever! Not before time either; oddly enough I was looking at alternative barrels and valve gear that would be compatible but being in the UK I hadn't thought of the obvious one!
First I've not heard of the engine, and maybe it will turn into something good, but at 45 HP some folks were having crankshaft problems with 1/2 VW engines, so it doesn't make sense that the cranks would hold up at 60 HP. There's a fair amount of "expecting" and "hoping" in the quoted text, but I wish the developer success.
Lynn
Edit.....I omitted the word "not" in the first sentence when I originally posted and have edited to add that word.
Do you know if any mods are done to the cranks in 1600, 1835 and 2000 cc VW car engines to cope with the extra loading? If so, can those mods be applied to the half VW engines too?
Sorry, Bob, but I don't have any knowledge of the differences in various displacement VW engine crankshafts, so I'm not going to pretend any expertise.
I do have to post a correction to my post #3, and have gone back to do an edit. I originally said, "First I've heard of the engine", but I meant to say "First I've not heard of the engine". Quite a difference, and I apologize for my typo omission.
First I've not heard of the engine, and maybe it will turn into something good, but at 45 HP some folks were having crankshaft problems with 1/2 VW engines, so it doesn't make sense that the cranks would hold up at 60 HP. There's a fair amount of "expecting" and "hoping" in the quoted text, but I wish the developer success.
You could very well be right. I have no stake in this engine. I just think it's an interesting idea. Time will tell.
I believe the issue with VW cranks is not about power exactly but instead a problem of harmonics and torque twist through the crank. I believe I have also read that improved counter weighting does much to reduce the problem?
Interesting to note that even in motorcycle use they are having challenges with dissipating heat in Harley motors as they get larger and more powerful. The classic look dictates air cooling but demand for more power pushes the limits of air cooling. Latest compromise is oil cooling on the newer 4 valve Milwaukee 8 motors.
The Lone Star booth at Oshkosh was right next to David's booth and they had a Max on display. The engine sure looked neat and I am very interested in keeping tabs. Wonder if it will leak oi'l like an HD?
This is not a good idea. Volkswagen make better engines than H-D whose engines shake their iron motorcycles to bits. Even on a boxer crank, it looks like reducing the toughest Max to matchwood once the throttle is opened.
This is not a good idea. Volkswagen make better engines than H-D whose engines shake their iron motorcycles to bits. Even on a boxer crank, it looks like reducing the toughest Max to matchwood once the throttle is opened.
The 1/2 VW conversion is only using the HD cylinders (and possibly the carb), not the rest of the engine. The new engine will have a completely different firing interval than the Harley. It will also be a boxer and not a V configuration. There's simply no way that it will shake like a traditional Harley engine.
Here's the reason why Harley engines sound the way they do (and shake so much)...
A Harley engine has two pistons. The difference in the Harley engine is that the crankshaft has only one pin, and both pistons connect to it. This design, combined with the V arrangement of the cylinders, means that the pistons cannot fire at even intervals. Instead of one piston firing every 360 degrees, a Harley engine goes like this:
-- A piston fires. -- The next piston fires at 315 degrees. -- There is a 405-degree gap. -- A piston fires. -- The next piston fires at 315 degrees. -- There is a 405-degree gap.
And the cycle continues.
At idle, you can hear the pop-pop sound followed by a pause. So its sound is pop-pop...pop-pop...pop-pop. That is the unique sound you hear!
A Harley dealer acquaintance of mine always described the sound as "potato-potato".....really.
BTW, I feel qualified to poke a bit of fun at Harleys since I still own a '73 Sportster that I bought in '74. I have no desire to ride it or sell it. It can leak oil in my son's garage some day
Ive been holding my tongue on this, but I own both a harley (big bore, stroked shovelhead) and a 45hp hummel on a max. Ive thought for a long time that a harley component derived engine would be great but I feel the half volkswagen path is not the right one. There is still the problem of cylinder centerlines being offset that creates a "twisting" mode of vibration in the engine when looked at from above. The hummel uses an external balancer on the prop mount to help offset that (and I believe the crank failure problems are related to engines that do not have that, though dont quote me on it) and by the time you get to the 45 you are running out of room on the case itself. For less than $5000 you can get a turnkey hummel with years of flying validation, nickasil aluminum cylinders, mag ignition, ect so they had better be coming in alot cheaper than that if they want me to be one of their testers, i mean "customers". When hp is the direct equation of hp=(torque×rpm)/5252 and they are "expecting" torque to be higher than hp in the low 3000 rpm range, game over, I have no faith in their "engineering", they may get something together that works and I hope they do, but I wont be buying one until it has thousands of hours in multiple planes as proof that it works. Now if somebody actually did the math on and derived a harley radial.....they already use a master/slave connecting rod setup, drysump oiling, intigrated generator, and do it in a crankcast not much bigger around than a football I would be interested
There is still the problem of cylinder centerlines being offset that creates a "twisting" mode of vibration in the engine when looked at from above. The hummel uses an external balancer on the prop mount to help offset that (and I believe the crank failure problems are related to engines that do not have that, though dont quote me on it) and by the time you get to the 45 you are running out of room on the case itself.
Yeah, they definitely have some engineering "challenges" to sort out. I'm not sure if they are even engineers (probably not).
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I wont be buying one until it has thousands of hours in multiple planes as proof that it works.
I heard that ninety percent of all Harley Davidsons are still on the road. The rest made it home. BMW also make a heavy engine but it has been used in aircraft with some success. If I were adapting a VW motor, I would use parts designed for one, of which there are many available from simple hop ups to full race so why pull an expensive motor apart to do this?
We at Team are installing one on a 1300Z-Max to help prove the Engine design, at 105 lbs. And 55 Hp We are honored Steve from Lone star is sending use one very soon.
We at Team are installing one on a 1300Z-Max to help prove the Engine design, at 105 lbs. And 55 Hp We are honored Steve from Lone star is sending use one very soon.
Could you keep us updated on this? Maybe post some pics of the installation?
I may need one to replace the stolen Zenoah G50 reduction drive that was in my trailer(also had one of my wings stolen too). How much are they going to sell for, and Dave are you considering becoming a distributor for them? Thanks, Scott Luckman 731-935-9601
I may need one to replace the stolen Zenoah G50 reduction drive that was in my trailer(also had one of my wings stolen too). How much are they going to sell for, and Dave are you considering becoming a distributor for them? Thanks, Scott Luckman 731-935-9601
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