I like the concept of a bike engine driving the two front wheels of a 3wheel set up. Maybe a narrow canoe style body with passenger sitting behind the driver. There are hill-climb machines built like this... but does anyone know of a road-going model. We live in perilous times. This could be the answer for achieving fuel economy AND a sporty ride. Brian

early morgans had a front Vtwin bike engined FWD 3 wheel layout. ISTR that the BRA CX3 was a kit based on the same formula.

The Lomax 332 and blackkjack avion had the same layout, but with a 2CV engine. Have a look at the new Blackjack Zero. same, but uses a VW beetle engine.

Alfasud / 33 flat four layout would be ideally suited to this.
The later 33 motors have quad cams and 16 valves, and produce good power.



Stu

Hudson kindred spirit

My mate now owns all the jigs and rights etc etc.

Have a look here, possibly the worlds worst website but it gives you an idea.

I know he a had a mega fire at his workshop and the V max spirit was destroyed.

he does own another one which has aIIRC a renault 5 gordini engine in it running nitrous too!

Let me know if you want his number.

http://www.blackjackzero.com/mainindex.htm

sorry to hi jack but what kind of liecence is needed to drive one of these bike or car always wondered and have a nice design in head but want to know if its worth trying to make it?

Cheers

Tri

The Blackjack Zero would be pretty sexy with a BMW motorcycle engine

Hmm. Thanks for the interesting replies... but none of them actually lead to what I was looking for ".. bike engine driving the two front wheels of a 3wheel set up. .."

Anyone know of such an animal existing in roadgoing form?

Brian

quote:

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sorry to hi jack but what kind of liecence is needed to drive one of these bike or car always wondered and have a nice design in head but want to know if its worth trying to make it?

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quote:

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Originally posted by Ratman
Hmm. Thanks for the interesting replies... but none of them actually lead to what I was looking for ".. bike engine driving the two front wheels of a 3wheel set up. .."

Anyone know of such an animal existing in roadgoing form?

Brian

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Here is a site with plenty of info http://www.3wheelers.com

[Edited on 2/1/07 by ZEN]

Thanks Akumabito
You have spotted my dilemma (weight out front)
My throught is to have a regular mc engine/trans out front with chain driven FWD diff as close as possible behind this. But it does put the engine a long way out front with the inherent risk that the car will stand on it's nose under braking. To counter this I was thinking of making the body quite long and thin, with a passenger seat behind the driver and fuel, battery etc rearmost. If the car is low, I can get a safety factor of 2 against tipping up with a coef of friction of 1. This is a very basic built concept.. not trying to mimic anything or pander to style. If any style is involved I was thinking of WW1 aeroplane detailing.

Thanks Zen

I had already found that site (
http://www.3wheelers.com ) and spent some time searching it. Fascinating, but there is just too much stuff there. Do you know of any FWD bike engine examples there?

Here's a question: why do yo want a FWD BEC again? Or let me split that quesiton up into two parts:

1.) Why a FWD car? If you want a sporty vehicle, it seems to me that RWD would be more suitable for your needs? Especially if you're hell-bend on using a bike engine, it would make much more sense to go for RWD.

2.) Why a bike engine? You mentioned fuel efficiency in the opening post. If this is important to you, then surely a car engine would be more suitable. Also: you do not need 180Hp to have a sporty ride in a vehicle that only weighs a couple hundred kilos.

But here's an idea that'll nicely combine CEC and BEC aspects:

Remember how the old VW beetles have the engine in the rear, behind the rear axle? Well, if you'd use such a VW transmission, you could position the engine in the front, right behind the front axle. Using such a transmission will leave you with two possible problems: the first is steering, I don't know how you would get the linkage to work around the transmission, and the second would be shifting. Depending on the body style this nees not be a problem: if it's car-like you can use a car-like shifting pattern, bt if it's more of a bike than a car, you will not have sequential shigting, and changing gears may be cumbersome. Luckily, these VW transaxles also have an automatic version that may solve that..

Now then, starting from this transaxle, let's talk engines: the stock beetle engines are not very powerful, and not tremendously economic either. For a sportier ride, as well as better fuel economy, you'd need something else: if you want to go BEC-but-not-over-the-top, and stick with the VW transmission, I'd recommend the BMW motorcycle engines. BMW has air-cooled, 2 cylinder bike engines that produce around 100Hp, are lightweight and provide very reasonable fuel efficiency.

The VW transmission and the BMW engine sound like a good match to me. I'm pretty sure it has been done before, too, you can probably find adapter plates over at Kennedy Engineering. Although I'm not sure the automatic transmission would be too happy with 100Hp (the manual transmissions can take it, especially considering it's a light vehicle)

quote:

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Originally posted by Ratman
Thanks Zen

Do you know of any FWD bike engine examples there?

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Akumabito.. Thanks for your posting

1) Why a FWD car? I like this formula for a three-wheeler. To get good stability you need to have plenty of weight on the two front wheels, so you might as well have them doing the driving as well. When the single rear wheel is doing the driving there is going to be a lot of wheel spin.

2.) Why a bike engine? I was thinking of no more than 600cc and as you say, a very light car. What I like about the bike engine is that it is powerful for it’s weight. It also comes with a 6 speed close ratio sequential gearbox. The std car gearbox is used in a very light weight car has only about 3 of the 5 gears in it that are useful, so it’s a bit like driving with an old pre-war three speed gearbox. Please don’t start talking Quaife boxes etc to me unless the word “Locost” has suddenly disappeared from the URL at the top of the screen.

The current car I’ve built has a VW engine in it, upped to 2165cc, mid mounted and RWD. So I’ve done that, and I’m interested in something quite different. I had a ride recently in a friends FWD car at a track day and I was really impressed at how early in the corner you can put the power on with a FWD car and how stable and spin-out free the FWD car is.

Zen.
I think I’ve followed up all the links above. I didn’t find any that were specifically bike engine FWD. Which are you referring to please?

What if you use a diff that turns the "wrong" way? That way you could drive the front wheels while the engine would be right behind them, instad of having a large front overhang.. perhapsthe rear diff of a Honda S2000, or the front diff of a 4WD (freelander)?

I just checked the front diff on my Suzuki, and it turns the same way, relatively, as a normal rear diff. Also.. I think the S2000 is the first Honda 4cly engine that turns in the "normal" direction. But this need not be a problem, your idea is a good one. The Suzuki diff would work well as it is quite small and comes with independent suspension and disk brakes. Ratio is a bit low though.

Another idea I had was to place a typical motorcycle engine in normal (for a bike) orientation behind the front axle and drive forward to the diff with a chain alongside the engine. The output sprocket would need to be extended out from the geabox and an additional bearing used to support it. Still not too complex.

If you want to do thzt, it may be easier to look at a 2 cilinder engine instead of a 4 cilinder. A narrower 2 cilinder engine would nearl have the same width as a diff+chain drive..

Yes... I was thinking along those lines. Or possible a v4 like a Honda VRF. Actually, I was also wondering about making everything as minimalist as possible. 3 wheels. one seat. open frame body.... and single cylinder engine. there are off road singles up to 650cc but friends who ride these bikes warn me off this as they are very unpleasant engines to be close to and recommend using a touring bike engine if possible so this does suggest a big twin.

Well, not necessarily, there are lots of Japanese light-tourers / 'choppers' which use 400 to 600CC single-cylinder engines. They're very simple and reliable engines usually.. What sort of power are you looking for? I can ask some biker friends for engine advice, too

I do keep changing my mind on power. I originally liked the idea of 100hp... but I've gone off that now in favour of simplicity and lightness of weight. I'm thinking now more like 40hp - 60hp, but a tough motor that can be held at full power continuously. Friends tell me that you can't expect to do that with a off road bike motor as they will overheat. Then again, I wonder if this might be addressed with more radiator. I like to check out likely motors that I come accross on this site http://www.bikez.com/brands/index.php

Most motocross engines are air cooled. You'd probably be better off with a water cooled engine.

Here's some 1990's Honda 2-cylinder bikes that shouldn't be too expensive..
Honda CB450 has 44 Hp
Honda NT650 has 58 Hp
Honda VFR 750 F has 100 Hp (V4 engine)
Honda VT 600 C has 41 Hp
Honda VT 1100 C has 67 Hp

Thanks. I'll keep that list handy when I'm checking the local version of ebay listings.

Well, there are probably a lot more suitable donors. It's probably advisable to stick with Honda engines though. The 2-cylinder engines are pretty much bulletproof. I know some people from the Dutch ratbike club that drive late 70's Hondas with well over 150,000km on the clock.

Just checked the NZ ebay listings. There's a good number of 2-cylinder bikes out for reasonable prices. Also a surprisingly large number of old Goldwings. I wish they were that cheap over here!

A mate of mine builds fwd three wheelers with bike engines. He's retired and does it as a hobby basically, and manages one a year. The last one, and the latest nearing completion uses a Moto-Guzzi engine mated to a Citroen 2CV gearbox. He aims for a weight of around 420kg to gain motorbike SVA classification, and only reqs a bike license to drive them.

Sound like just the ticket. Are they like the old Morgan, or more inovative in general layout? Any pix? I was sort of hoping to be able to use the bike gearbox to get that tasty 6 speed sequential shift that bikes all seem to have these days.

Hi Ratman,

I'll sort a few pics & post them asap.

Swizz...

Well, there's more 2CV based kitcars around...

2CV-based kitcar club website

From their site:
Le Patron, Cygnus, Dauville, Manx, Pembleton, Lomax, Charon, Voglietta & Burton.

The Pebleton is my favorite, especially the 4-wheel version, the Pembleton Brooklands. With the BMW flat-twin conversion that car looks and drives great!

Pembleton website

Here it is:



This was built with 2cv engine & box - the guzzi engine being added after, which is why it looks a bit 'added on', as he had to chop the bodywork about a bit with the v-twin.

His latest, which is nearing completion also uses a guzzi engine/citroen box & has the bodywork built to suit so looks really good.

They are both single seaters, weigh very little due to a new chassis & coil/shock suspension & really fly

Thanks Jago
I'm interested in any others similar you know of.
Cheers, Brian

Interesting topic. I just went out to the garage and pulled out a five speed Porsche 914 gearbox (901) that I've had sitting around. I pulled this box out of my 914 when I converted to a Chevy V8 with a Porsche 930 turbo gearbox.

I think that this box would work well with a Harley Davidson motor doing a little front drive Morganesque type thing. Vintage looking with a twist...what do you think?

Here's my favorite, rwd, but cool none the less
Rescued attachment sub2.jpeg

Hello Brian,

I take it you have seen these FWD Trikes? (images hopefully attached)

The only other bike engined FWD trikes I know of are:

1. Lomax - Supa Vee and Guzzi variants
2. Pembleton
3. A mid-80's US one-off which had a Yamaha Virage v-twin motor arrange a la Morgan. Beacuse that bike has shaft drive, it was then a chain drive to the diff. From memory the builder used the gearbox/diff from a FWD car

I think most of these have already been mentioned by others

My 'in head' fanatsy FWD design has always featured a v-twin like a TL1000 or Aprilla. The other key feature being inboard front brakes. So that means either the motor out front like a Morgan, with a connection from the output shaft to something like a Citroen GSA or an Alfasud diff/gearbox, or else out front (crank parallel to axle line) with chain drive to a diff with inboard brakes.

The weight out front is not an issue in my opinion, given you as the driver weigh more than the engine...but the aesthetics could be. To lower the bonnet height you could always move the motor behind the front axle line, but then you start to take weight off the front wheels, which is not so good. And there will be sprockets and support bearings and chains all over the place.

Alternatively - how about AWD? Have the motor behind the front axle line, but driving all 3 wheels? Allows for skinnier tyres, lower bonnet line. But adds complexity, and the need to make the chassis stiffer to keep that driven rear wheel in place



Regards
Glenn
Rescued attachment hc_trike1.jpg

Just to let you know you are not alone...

http://www.clevislauzon.qc.ca/Professeurs/Mecanique/ethierp/3-wheels/index.htm

Glen, buddy, thank God, there are others out there. Huge relieve.

How about using the early 1600/1800cc subaru 4WD mechanicals, but putting a motorcycle shaft drive rear wheel onto the end of the rear drive shaft. Find the right sized wheels to suit the resulting gearing. This early scooby engine has good power for it's light weight and the later ones are single OHC and turbo to boot. 125hp or so I believe. These don't have inboard brakes... but the hand brake works on the front wheels, which is handy for a 3wheeler as there is not much weight on the rear wheel. the only major challenge is to change the front suspension from strut to something else.

Brian

Hi,
Having grown up with minis, I know how much fun it can be with all the weight on the front wheels driving, and the rear end tagging along, so this idea has always interested me. I've been drawing up ideas for some time now, as we have a huge choice of lightweight fwd setups avail in NZ, I was looking at a transverse set like a swift GTi or mazda mx6 v6, for the main reason that the tail of the gearbox wouldn't intrude into the cockpit area as a subaru would, and with the height of the crank in the subaru there wouldn't be too much difference in the cog. I'm looking at a making a backbone chassis from 1" rhs and round tube for diagonals, with outriggers to at the rear to hold a cockpit tub that would be glassed marine ply, the outriggers would give me fixings for belts etc and the ply tub would stiffen up the whole thing and add some protection. I think the great thing about this setup is that as there is no diagonal weight transfer across the chassis as such, it will not twist like a 4 wheeler, and the weight transfer either piviots across the front axle lie, or side to side at the front, so effctivly a very rigid chassis without being all that heavy. For the main body I'd use segments of flassed foam for the lightweight aspect, and try and use the donor front struts to make it easily serviceable, hopefuly the height of them can be absobed by the topers lining up the where the a-pillar would be at the bulkhead. I plan on doing an open top, canam style. The rear end will be from 3mm RHS, and using the rear stub of a fwd corolla (they bolt on with a flat 4 bolt flange) complete with the brake, utilising the handbrake aswell, I was thinking of using a rear brake regulator off a van, the ones that restrict the pressure dependant on load, and lever this off the rear trailing arm to avoid lockups and still pass as having a rear brake, similar to a mini, but in a warrent station on the brake roller, there will be no weight transfer to the front, the rear will still be low, and so the regulator will be open for a strong brake, while on the road with slight tail lift the pressure will be throttled back.

Perhaps its just wishful thinking, but would it be possible with some thought to convert the back end of the MK Sprint R to a single wheel, perhaps chop off part of the back end a reshape the chassis ???

The Berkely probably was/is the definitive example of parallel twin cylinder bike-engined front-drive installation, was produced in four- and three wheeled forms.
Today, though, hooking up a BMW or Guzzi twin to an Alfasud/Subaru/Audi/Renault fwd transaxle might be a better proposition.
Front-drive has several advantages for three-wheeler. Two wheels up front is inherently the more stable layout; concentrating the mechanical mass at that end furthers the stability aspect; and front-drive (with an open diff) confers an element of roll-over inhibition because if the machine lightens, let alone lifts, the inside wheel, the outer wheel is robbed of torque to the detraction of cornering force.
But bear in mind that the vagaries of front-drive may require more sorting (then with a rear-drive car, for example) to avoid torque steer and other nonsense. Anyway, an interesting adventure.
Pls keep us posted about developments.
Cheers
Clubmanic

Thanks CGILL for sharing your thoughts and plans. I'm not sure that the requirement for torsional stiffness in such a vehicle is that much lesser than for a 4 wheel car. In a 4w car, low torsional stiffness can mean that the car flexes and the suspension will not work properly unless it is much softer than the chassis. In a 3w car, poor chassis torsional stiffness might not be so critical to suspension, but because the moment caused in cornering by the C of G being a certain height above the ground can only be resisted at one end of the car, the car can actualy twist and the single rear wheel lean over if there is not enough torsional stiffness. Only 1 or 2 degrees of twist is very noticable and looks awful. This picture demonstrates this problem..



As discussed above.. using a car transmission , e.g. Renault, has conveniences, but I really like motocycle gearboxes for their lots of gears and close ratios.

One problem is that if you have light weight construction and an engine (and transmission?) ahead of the front wheels, you have to have all the weight very close to the ground to avoid the risk of standing the car on it's nose in hard braking. I was thinking of making the car extra long and with a back seat, in part, so that this problem can be addressed. I have been using 1G as a design value for braking resistance in these calculations.. is this reasonable?

Some models of Fiat car have that same sort of rear brake pressure limiting valve that is mentioned above.

.. Brian

[Edited on 29/4/07 by Ratman]

Hi Brian,

One unit that I looked at for a driveline, was the engine and box from a subaru ace van, it's transverse, and in the van, the engine is in the back - behind the rear axle, it is also mounted on a canter to give a lower deck height. I was thinking in a 3 wheeler setup that the engine being behind the front axle and low would prevent bringing back memories of front wheel stands on BMXs from front braking... haven't layed out boxes and seats to see what the legroom would be like though.

It's a little 3 cylinder 1000cc, but I'm sure with a small turbo it could be made scarey enough.

Perhaps a bike engine could be used and drive a chain driven quad bike diff, or a sierra like drive coupled to the bike output through a CV to take up movement (was thinking of the CV in the middle of driveshafts as used in commodores, SD1's etc.

Was looking at a backbone similar to this www.spydercars.co.uk/practical_classics_pg1.htm

I believe the doran is similar, but looks like its made from huge sections of rhs fron the few images I've seen.

Seeya
Chris

I was looking at one of those vans... a pick-up version actually... just last month thinking about it's posibilities. Hadn't thought of it as a FWD donor, but you're right. That would work well. I have some reservations about gear ratios. It's nice to have lots of gears but if you take a power unit from an "underpowered" vehicle it is bound to have wide spaced ratios, and this means one or two low gears that you never need to use in a lightweight car.

Seductive as they look, I'm not a fan of backbone chassis. It seems a bit redundent. You still have to build a structure to protect the driver... so why not make it the main chassis as well. The only downside of this thinking is if you want an open car with doors. Then a backbone is a handy solution.

I was wondering about side mounting motorcycle V twin just behind the front axle and offsetting the driving position a bit to one side to balance the weight. drive could be by chain either to front or rear. This gets all the mass close to the front axle.. ??

Cheers, Brian

How about mounting the center of a subaru viscous diff between sealed bearings, fitting the toothed gear to where the crownwheel gear bolts... although I'm not a fan of LSD on fwd, it is a sealed unit.. and a vtwin behind this centrally between footwells so the chain drives forward to the diff?

Yes.. I like that option. Cooling might be a problem. Maybe use a watercooled v4 like a Honda VRF*** .chain drive could add to the width of the power unit a bit, but you could just add more front wheel base for that, or use up some passenger side footwell area.

A leaf blow fan attached to the crank? lol....
Was thinking that as the foot wells will be lower than the scuttle, there would be a gap between the bonnet line and the top of the foot wells of about 6-8 inches, the vtwin between them, an undertray that ducted air from the front under the motor, up, and out the sides of the bonnet, would probably need an electric fan for when not moving, but still a bit of a worry for the bottom of the rear cylinder. I wonder how much flow you could get through a trans tunnel .

Also thought worth a mention, the subaru rear diff splines are the same as the front, so the struts can be cut down, and top hatted to provide uprights and axles that will plug in nicely, subaru rack is infront of the hubs, and with the rack with power assistance removed would give a neat pseudo quick-rack .

That is very usefull information. Thanks for that.