Ducati Vyper - Ducati is considering a new 1400cc power cruiser

[Porsche Monkey]

Italians don't make cruisers.

Americans don't make sportbikes.

Brits don't make dirtbikes. 

Germans don't make bikes without heated grips

Japanese don't make . . . uh . . . er . . . uh . . . mmm  . . . uh . . . make the beast with two backs, ran out of wit. 

^^^anything I would like to own?^^^

[sbrguy]

that cruiser design is ugly with the two huge radiators on it.  horrible looking bike.

[Norm]

Regardless, I can't see a cruiser selling with radiators hanging off the front. There are ways of getting more stroke in the current air cooled cases, but even with 102 or 104 pistons, you ain't gonna get 1600.

[junior varsity]

my cruiser-esque italian bike will be a moto guzzi at this point. I don't want an origami cruiser from Ducati, though I would like a good long distance bike from Ducati.

[Duck-Stew]

<snip> There are ways of getting more stroke in the current air cooled cases <snip>

Really?  I'd like to know how you plan on surpassing the 71.5mm crank of the DS1000 engines?  I'm really curious!

[ducatiz]

Really?  I'd like to know how you plan on surpassing the 71.5mm crank of the DS1000 engines?  I'm really curious!

is there no way to clearance the case and shave the crank?

when i did vw engines, we could do up to a 94mm stroke, a full 25mm over stock.  required quite a bit of material inside the case shaved out and reinforcing added to the outside.

[Duck-Stew]

is there no way to clearance the case and shave the crank?

when i did vw engines, we could do up to a 94mm stroke, a full 25mm over stock.  required quite a bit of material inside the case shaved out and reinforcing added to the outside.

The interference point on a Duc V-twin is the centerline distance between the crankshaft and the timing layshaft (also taking into account the material around the big-end of the connecting rod.  As it is on a stock DS engine, the cranks will not freely spin around unless the rods are held at the correct angle without the big-ends hitting the timing layshaft.  It's that close.

If someone wants to turn down the timing layshaft some (don't know how much is safe...), you could net a little more stroke that way but as it is...stroking a Duc twin is just about maxxed out with the 71.5mm DS crank.


That is, unless Norm knows more about this than I do.....   (I'm waiting to see if he knows some secret about this.)

[FatguyRacer]

Italians don't make cruisers.

Technically they do (the current Guzzi California and a in the past Guzzi's from the 70's) but practically, your right, they don't. The California was not what I would call a quality ride.

I'm kinda "meh" on the Vyper. Leave the customs to small builders. 

[ducatiz]

The interference point on a Duc V-twin is the centerline distance between the crankshaft and the timing layshaft (also taking into account the material around the big-end of the connecting rod.  As it is on a stock DS engine, the cranks will not freely spin around unless the rods are held at the correct angle without the big-ends hitting the timing layshaft.  It's that close.

If someone wants to turn down the timing layshaft some (don't know how much is safe...), you could net a little more stroke that way but as it is...stroking a Duc twin is just about maxxed out with the 71.5mm DS crank.


That is, unless Norm knows more about this than I do.....   (I'm waiting to see if he knows some secret about this.)

gotcha, so you'd need more distance to the bottom of the jug hole and the layshaft needs to be further away.. i have a feeling the layshaft clearancing is not feasible due to oil pressure, unless there is no oil galley in the layshaft??

[Duck-Stew]

gotcha, so you'd need more distance to the bottom of the jug hole and the layshaft needs to be further away.. i have a feeling the layshaft clearancing is not feasible due to oil pressure, unless there is no oil galley in the layshaft??

As far as stroke goes:  The lay-shaft has no oil passage, so it could be made slightly thinner (I think it's 12mm OD but would have to measure one) so it could POSSIBLY be turned down to allow greater crank and rod clearance but at what point does it become too much effort?!? Also, the spigot ends of the barrels on a DS engine are already 'notched' for rod clearance.  More stroke would require more notching of the barrels. 

Also, as stroke goes up (and the top of the barrels are a fixed point), you've got less room @ TDC to fit 1/2 the crank stroke, a connecting rod and a piston in that distance.  As it is, the DS piston is kinda tight in it's pin to deck height but could be made slightly shorter.  Either way, you're starting to wreck havoc on your rod to stroke ratio...

As far as the bore goes:  Stud spacing for the barrels can be opened up to feasibly, whatever Ducati wanted to open them up to (maybe 120mm would be MAX).  So a *crazy* overbored Duc motor could be possible, but stroke is kinda capped right now...

If it weren't for the timing lay-shaft (you'd need to drive the cams via a different method), stroke could be opened up another 8-10mm (IIRC) so long as the barrels could be further clearanced for the rods and crank and/or that the barrels could be spaced upwards in a reinforced area to provide barrel support and give clearance at the spigot end for the crank and rods....it could be done but you're rapidly approaching cubic-dollars at that point...

[Speeddog]

Not to mention the clearance between the rod big ends and the transmission gears.
A 1400cc+ motor is certainly possible, if you redesign the whole thing.

The chance of Ducati doing that just to enter a totally new market segment (for them) is vanishingly small IMO.

[Monster Dave]

I saw this thread topic and I immediatly throught:



and said "oh no...."

[Speeddog]

ATGATT 

[ducatiz]

PLEASE FLOUNDERS, CHANGE THE TITLE OF THIS THREAD TO "BULLSHIT STORY ABOUT..ETC ETC" AND LOCK IT.. FOR THE LOVE OF MIKE!

[LA]

It would take a 78 mm stroke along with the current 106 mm bore (1198) to yield 1375cc. or 1358 at 77.  That's probably doable. you could run one at about 8500 rpm and be a couple hundred lfpm less piston speed than my 998's 63.5 mm stroke at 11000.

I'm just not a cruiser kind of guy, but I'd love to swing a leg over a 1400 cc ducati.  Bet you could pull stumps with one (at about 130 mph).

LA