Diesel motorcycles. Me want, me shall have.

[Christ]

I'm seriously considering [when I get to it] using a VW 1.5 with some light boost. It fits perfectly between the upper frame spars of a Katana. I'll take a pic someday while I'm moving things around.

However - a 50HP bike that weighs nearly 800lbs [trans n all] would be a slug, at best. Still faster than my Festiva, though.

[Varn]

Still the Vw puts out torque at the mid range The Jetta 1600 puts out something in the range of 68 hp and 115 foot pounds. How does that compare to a v twin? I don't think you would find it a slug. No sport bike but not slow. Certainly better than a 400 NA single.

I would like to see it set in your Katana frame.

Originally Posted by Christ

I'm seriously considering [when I get to it] using a VW 1.5 with some light boost. It fits perfectly between the upper frame spars of a Katana. I'll take a pic someday while I'm moving things around.

However - a 50HP bike that weighs nearly 800lbs [trans n all] would be a slug, at best. Still faster than my Festiva, though.

[Christ]

Originally Posted by Varn

Still the Vw puts out torque at the mid range The Jetta 1600 puts out something in the range of 68 hp and 115 foot pounds. How does that compare to a v twin? I don't think you would find it a slug. No sport bike but not slow. Certainly better than a 400 NA single.

I would like to see it set in your Katana frame.

The 1.5's are considerably less potent, but they also drove a 2500lb car to 60+ via the 4 speed, so they're not at all 'terrible' on the list of engines out there.

I've got a spare Kat frame I need to cut a section out of for a street fighter build, so I'll set it clumsily overtop a 1.5 [as it's taken out of the car] so you can get an idea of how it fits.

Keep in mind, the Kat uses a 'detachable cradle' to mount the engine and then mounts the rear of the engine between the frame spars where the swingarm mounts. I'll get a representative shot of that and edit it to reflect the engine's original mount arrangement as well. I don't believe I have a spare cradle, but they're only a few 50 bucks or so.

FYI, the Street Fighter project I mentioned above may actually BECOME the diesel Katana... I'm just not as interested in putting the 750 motor and trans back into the bike as I was when I started on it in December last year, and would rather have something more 'evil' and 'dirty' and 'mechanical' looking. Mad Max style, if you will.

Also worth noting that I may not even /need/ the cradle considering the mass of the 1.5... it might very well make a good candidate for a partially stressed engine block being iron and all, with simple mount plates to connect the old cradle attachment points to the engine for a 'full stiffness' effect similar to the original bike.

[renault_megane_dci]

Car engines tuned to enter a bike chassis can be made a bit lighter starting with the exhaust header (usually iron, various brackets and maybe the inlet too as it might be a packaging restriction if kept standard.

I like these kind of project.

Do you have the diesel engine already ?

A 50 hp bike is not really sluggish in my book ...

Bike engine usually put out 10 mkg out of a 1000 and at stratospheric high rpm (say 5000 for the bigger engines) if your diesel puts out 12 mKg (usually around 2,5 K) it should be a match for a 1200 cc bike if geared adequately.

What is the gearbox scenario ?

[Christ]

The current header on the bike, provided i can use it [configuration issues] is tubular mild steel and fairly light compared to the shorter iron manifold.

The intake will be replaced with filtered stacks to save space and a little weight, although it's cast alloy already and fairly light. I hope to be able to replace the oil pan and pickup with either a dry-sump setup or a smaller pan, as it's kinda large and hangs a bit, but that's not in the cards any time soon [more research and parts cost].

It's not so much that a 50hp bike is underpowered - it's certainly not - but more that it's a huge addition of weight, especially if I use a 4 speed gearbox setup with it [another 60-100lbs] and may be considered a bit of a 'pig' in terms of bikes. 700lbs of engine and trans is HEAVY when there's another 200-300lbs of frame, suspension, parts, 170lbs of rider, etc. Still not 'slow' by any means, but piggish comparatively.

Depending on which way I need to mount the engine [crank direction], I can probably cut and flip the header so it points in the correct direction, despite that it doesn't /actually/ fit the engine's port design [yet], it still works fine and never seemed to limit power, also took away most of the smoke I was getting, indicative of increased airflow over the original cast hunkapoop manifold.

[mechman600]

http://www.youtube.com/watch?v=yBEgDn2lYNs

Direct drive, no transmission.

[Christ]

All I can say to that video is 'ahahahahahahahahahahahaahiloveit'.

If that's a bosch rotary pump, he could advance it to get rid of the cold start smoke.

[mechman600]

I think that's the least of his worries!

[Christ]

I saw it was longitudinally mounted.. that's a LOT of inertia pushing on one side of that bike LOL. Not to mention the vibration that was quite apparent from the engine and the bike as a whole.

Fortunately, I'll be mounting mine transverse [across the frame] so the inertia won't be such a problem besides trying to flip the bike over the front forks LOL. Maybe I can mount the engine so it rotates backward and it'll help me do a whoooooolie!

[renault_megane_dci]

Originally Posted by Christ

The current header on the bike, provided i can use it [configuration issues] is tubular mild steel and fairly light compared to the shorter iron manifold.

The intake will be replaced with filtered stacks to save space and a little weight, although it's cast alloy already and fairly light.

For the sake of performance, I would try at any cost to keep the intake tract lenght.

Originally Posted by Christ

I hope to be able to replace the oil pan and pickup with either a dry-sump setup or a smaller pan, as it's kinda large and hangs a bit, but that's not in the cards any time soon [more research and parts cost].

Car engine oil pans are not designed for leaning angle, at least an oil pump swirl pot would be mandatory I think.

Originally Posted by Christ

It's not so much that a 50hp bike is underpowered - it's certainly not - but more that it's a huge addition of weight, especially if I use a 4 speed gearbox setup with it [another 60-100lbs] and may be considered a bit of a 'pig' in terms of bikes. 700lbs of engine and trans is HEAVY when there's another 200-300lbs of frame, suspension, parts, 170lbs of rider, etc. Still not 'slow' by any means, but piggish comparatively.

You are very right, the weight is number one issue because of what is gonna require of extra strenght in the handling departement.

I believe a VW 1500 or 1600 diesel is a very poor candidate in this department because it ended life in 1,9 TDi engines up to 150 hp so it means it was a little on the over-engineered side.

I would try and find a 1,5 Isuzu as found in Opels or a Peugeot unit again in 1,5.
There also is a very nice Fiat 1,4 turbo diesel.

How sourcable is it for you, I have no idea (you're in the US, aren't you ?) ?