Any of you crazy kids ever thought, tried, wondered about a m/c engined bug, heaps being used in all sorts of cars now, wondered if anyone has tried and succeeded or failed???
Thought a Goldwing 1500 flat 6 would fit nice, must be heaps of these in the USA sitting around doing nothing.
Cheers for your thoughts.🤓
It's been hashed over and there are a few interesting attempts out there. The main things to think about are:
1. Motorcycle engines put out lots of power, but are not designed to put out that sort of power continuously. If you're doing it for giggles and you don't mind a 500 mile rebuild time a motorcycle engine may be for you.
2. Most of the successful motorcycle engine transplants are into very light vehicles. A VW is on the high end of the weight range.
3. Gearing is an issue. Do you use the MC gearbox or try to link it to a VW gearbox?
4. Most motorcycle powerbands are very narrow. You may need more gears than you have to keep it on the pipe.
I went to Yamaha HQ last night for trade evening with my work.
The bike motors make pretty impressive hp, we were able to examine a R1 motor 998cc (182 PS at 12,500 rpm, and a torque output of 115.5 Nm at 10,000 rpm with natural aspiration.) pulled completely apart, very impressive but I'm not sure how long one would last powering a comparatively heavy car like a Beetle, a Smart car maybe. The big end journals were only about 25-30 mm and the con rods were just a little too big to put on your key ring
They also make a bike called a V Max, 1679cc V4 engine 147.2 kW (200 bhp at 9000 rpm, and torque output of 166.8 Nm@ 6500 rpm. This bike does 9 second 1/4s from the showroom and a special version was built in Japan with 280 PS, still naturally aspirated.
These look like impressive numbers, but look at the torque figures, the new VW Polo 1.4 makes 130 Nm@4200
The big motorcycle engines are mostly fine pieces of engineering. A few years ago I fitted a Suzuki Hayabusa 1300cc engine to my son's PRB clubman,a very light car. Apart from some big and small hurdles, the result was a very fast little car - 1m 2.3s at Wakefield Park!
One major problem is a lack of reverse gear. This was overcome by fitting a (very expensive) Quaife reverse box in front of the tailshaft. Interestingly, this gave an exiting 6 speeds - backwards!
Cheers, Greg
I'd rather wear a Beetle out by racing it than by polishing it!
I read somewhere that to get a reverse gear with a bike engined car you fit starter motor and ring gear on the sprocket, you just engage the starter when you want to go backwards.
That's not a bad option, if there is enough room down there. Or you could do what they do on the Aussie Legends - fit what looks like a windscreen wiper motor & a big gear wheel near a rear brake rotor!
Cheers, Greg
I'd rather wear a Beetle out by racing it than by polishing it!
GeorgeL wrote:1. Motorcycle engines put out lots of power, but are not designed to put out that sort of power continuously. If you're doing it for giggles and you don't mind a 500 mile rebuild time a motorcycle engine may be for you.
500 mile rebuilds? what are u basing that on? the only engines in bikes that are in need of rebuilds in short periods are the two strokes as they rev twice as fast and hard but any mod 4 either V/inline is very very reliable(unless its worked to an inch of its life).
Take the Gsxr, they are proven for 100 thou plus before major rebuild work, they rev to 18 grand with the power coming on around the 5 grand mark. they love to be floged and do so day in day out with just normal sevicing, Honda fireblade engins are the same. There are many that are good, strong,powerfull and reliable engines out there that would not need rebuilding every 500 miles.
For a bike engine to work in a car the said car would have to be ultra light, weight will be the biggest issue.
GeorgeL wrote:It's been hashed over and there are a few interesting attempts out there. The main things to think about are:
1. Motorcycle engines put out lots of power, but are not designed to put out that sort of power continuously. If you're doing it for giggles and you don't mind a 500 mile rebuild time a motorcycle engine may be for you.
2. Most of the successful motorcycle engine transplants are into very light vehicles. A VW is on the high end of the weight range.
3. Gearing is an issue. Do you use the MC gearbox or try to link it to a VW gearbox?
4. Most motorcycle powerbands are very narrow. You may need more gears than you have to keep it on the pipe.
Point 1 and 4 was true in the 1980's for a high performance two stroke, but is completely untrue today. My bike has 60,000kms and is still like new.
The spread of power depends on what bike the engine comes from. A 1000cc inline 4 super sports bike is a very high revving engine and will seem quite peaky, as it is essentially a road registered race bike. On the other hand a 1000cc V-twin bike is way more torquey, but down on peak power.
In a VW you would use the bike's gearbox and chain drive to a diff spool of sorts. At least that is my plan, I have been watching wrecked motorcycle auctions for a while now.
Reverse would be electric like Steve says. I think the high end drag cars use electric reverse gears.
A motorcycle engine will move a VW no worries, the VW would be lighter after the transplant too.
The power and torque issue is not a problem. Torque is a bit of a silly figure because it gets multiplied by gearing. Horsepower does not. A motorcycle engine revs twice as high as a car engine so can be geared twice as low and still do the same speeds in each gear. This results in the motorcycle engine effectively having twice as much torque. I'll post some graphs later to explain the concept.
There are heaps of motorcycle engined cars out there. There's a european group that have a motorcycle engine powered Ford Escort. There are a few motorcycle engined smart cars too.
I really don't know why someone hasn't done it over here. There are hundreds of lotus7 replicas with bike engines in the UK. These cars are the same weight as a SWB buggy. Fireblade and busa engines seem to be the faves in the UK. There's also a busa powered KE20 corolla rally car in NZ. It's an absolute weapon. If I don't build a rally car for the kids, I'll build some sort of khanaspecial and it may well have a bike motor. These engine/trans setups make for an easy midmount conversion. A buggy with one would handle a lot better than with an aircooled motor too.
This is a graph comparing an older Hayabusa motor (the newer ones are about 50cc bigger and make more power) with a stock type 4 VW motor. You need to compare rear wheel power like I have. I have also shown a curve for a Hayabusa that is geared down twice as much, so it will be revving twice as high as the rpm on the chart, but you can still see that for a given gear it will be able to reach a higher speed than the VW motor (even with the lower gearing). The bikes are geared to do over 300kph, you would only need to gear the car to do 200kph.
As for the original post, I would go with the gold wing motor. The shaft drive set-up will make life more difficult for the conversion and won't be as efficient when done. The Gold wing motor also isn't very performance oriented.
GeorgeL wrote:1. Motorcycle engines put out lots of power, but are not designed to put out that sort of power continuously. If you're doing it for giggles and you don't mind a 500 mile rebuild time a motorcycle engine may be for you.
500 mile rebuilds? what are u basing that on? the only engines in bikes that are in need of rebuilds in short periods are the two strokes as they rev twice as fast and hard but any mod 4 either V/inline is very very reliable(unless its worked to an inch of its life).
I should have said "500 mile rebuilds in your automobile conversion" I am well aware that motorcycle engines have reasonable service lives in their original use.
Motorcycle engines are capable of tremendous power, but how long can you use that 200HP continuously when the engine is mounted in the motorcycle? 10 seconds at that power would put you at 150MPH on the flat. You couldn't continuously use that power climbing any conceivable hill either. Even a Hayabusa spends 90+ percent of its life making only 10% of its maximum output.
Put the same engine in a car and the situation changes. You will be drawing more power from the engine for longer periods of time and the engine just isn't designed for that sort of service. It's like making a sprinter run a marathon.
Motorcycle engines have been very successfully transplanted into cars, but I've not seen very many where the vehicle was intended for long-term service. You might get decent life in a 450kg Caterham, but not in anything much heavier.
The Gold Wing engine might do better for auto service seeing as how it already pushes around 400kg with a modest 104hp from 1800cc.
Hmmm, those numbers sound close to a type IV engine!
On the street you can't use full throttle in the car for very longer either. The motorcycle engine won't be working that much harder in the car if your cruising around. The VW beetle originally had a 25HP engine, so the 150HP+ bike engines won't be working that hard to move them around.
There are plenty of bikes that get flogged at full throttle at track days regularly and it doesn't seriously effect their life.
I had a play with some numbers. A stock Suzuki Hayabusa will do the following speeds in each gear;
1 - 136
2 - 184
3 - 234
4 - 278
5 - 314
6 - 342kph
Obviously that is very tall gearing. In a car I'd gear it down so the top speed is only 230kph instead of 342kph. This would give the following speeds in each gear.
1 - 92
2 - 124
3 - 157
4 - 187
5 - 211
6 - 230kph
If you put it in a stripped out VW you could easily get the weight of the car, fuel and driver to 800kg or less. This would give the following performance figures;
0-100kph = 4.5s
1/4mile ET = 12.5s
1/4 speed = 175kph
So from those performance figures you can see that it won't be working very hard to drive the car around at a normal pace.
Baja Wes wrote:The motorcycle engine won't be working that much harder in the car. On the street you can't use full throttle for very longer either.
There are plenty of bikes that get flogged at full throttle at track days regularly and it doesn't seriously effect their life.
You can use considerably more power continuously in a car application. Climbing hills is one example.
Bikes do get flogged at track days, but this is a fraction of their lives and, again, they don't see high power demands for very long.
This is all academic until the time comes to pay the bills. I'm not saying "don't do it", just be aware of the possible pitfalls. There's a reason why automobile engine designs are different from motorcycle engine designs. Sometimes, as in the case of Goldwing, the designs converge a bit.
Oh, another thing to check is engine rotation. There's a good chance that the Goldwing, like quite a few other Hondas, rotates the opposite direction of a VW.
Baja Wes wrote:I edited my post above with some more info to show what I mean. Moving the car isn't that much hard work.
Tell you what, get a Hayabusa and a stripped out bug. Push each 100 meters over a flat surface as fast as you are able and see if the car requires more work to push. Then think about the poor aerodynamics of a bug compared to the Hayabusa. It's apparent that a Hayabusa engine will be working quite a bit harder to move the bug than it does to move a bike.
It's not all about RPM. It's also about the power being demanded of the engine and the engine structure (bearings, etc) that is supporting that power production. You can push on smaller parts turning faster to make the same power, but that is also a way to wear things out quickly.
A Hayabusa doing 200+kph on the autobarn (they sit on even higher speeds than that happily) will be working harder than it would pushing a bug at 100kph. Bikes cruising at high speed wear the rear tyre out quite quickly, the engine really doesn't care that much.
Bikes are made to cruise at higher rpm, it doesn't cause them any issues. Mine cruises at 5,000rpm at 100kph.
Why does anyone want to fit another type of engine in a VW ? Is it to get HP or reliability ? In my book the ideal would be a big HP VW engine that was RELIABLE!!!! They are light, and fit neatly in the space provided. There are plenty of big HP VW engines about, and plenty of reliable ones, however to get a combination of the two needs a good engine builder (fairly hard to find), and money (even harder to find)!
Motorcycle engines, particularly big ones, are great..............in motorcycles!!!!!!!
Cheers, Greg
I'd rather wear a Beetle out by racing it than by polishing it!
Baja Wes wrote:A Hayabusa doing 200+kph on the autobarn (they sit on even higher speeds than that happily) will be working harder than it would pushing a bug at 100kph. Bikes cruising at high speed wear the rear tyre out quite quickly, the engine really doesn't care that much.
Bikes are made to cruise at higher rpm, it doesn't cause them any issues. Mine cruises at 5,000rpm at 100kph.
As I said, there is more to it than RPM. You're also putting higher stresses on all the parts of the engine. higher stress leads to quicker fatigue leads to quicker failure.
And honestly, what percentage of a Hayabusa's life will be spent in autobahn-type conditions?
Trust me, the bike engines are plenty tough. There are a lot of turbo kits for Hayabusa's. Getting 280HP is relatively easy. There was a guy in NSW that had a Suzuki Hayabusa turbo that kicked out 500-600HP on the dyno. He's ride it to the drag strip, do 8 second quarter mile runs (fighting traction and wheelstands most of the way) and then ride it home again. They are very tough motors, moving a VW around isn't that difficult for a 1300cc motor.
What would better than a Hayabusa?....... 2 Hayabusas. There is someone - in Sth. Africa I think - who is building V8 engines using 2 Hayabusa engines! Big capacity, big HP! WOW.
Cheers, Greg
I'd rather wear a Beetle out by racing it than by polishing it!
We have a customer who has one, bloody MASSIVE thing!! as far as he knows its the only one in Qld at the moment. The biggest problem with it is when u give it a crack of the throttle the engine wants to rock and twist making the bike go with it!! He said it can be a bit scary oh and add into that the weight its a bit of a monster.
Personaly not quite sure why anyone would want one, apart from the "look at me factor" i see no gain of having a 6.2l V8 in a bike. lots of downfalls tho. Then there is the price! just a toy i supose ....
