696 Engine modifications

[Raux]

looks like Ducati beat me to the punch and made the new HM 796 with 66mm stroke we've been talking about. wonder what they did with the pistons and what compression ratio they are runnning? the upgrade gave only 1hp but 5.1 lb ft more torque.

hmm i still think with the stroke and cleaning up the exhaust intake, dp ecu or PC V (or both) and maybe even bigger valves... you can get some great power out of this little motor.

[dbran1949]

I thought I read the displacement was still going to be the same as the 696, the new number is going to mean something about performance. Kind of like the new BMW 328i and 335 both having the same 3.0 liter motor.

Which BTW I think is a bad idea if true

[Raux]

I thought I read the displacement was still going to be the same as the 696, the new number is going to mean something about performance. Kind of like the new BMW 328i and 335 both having the same 3.0 liter motor.

Which BTW I think is a bad idea if true

it's on the ducati website. 66mm stroke for certain.

[Raux]

and while i'm thinking about engine stuff.
throttle bodies. seems all the air cooled monsters run 45mm throttle bodies. but the 4v's are running 50mm. wonder if the 4v throttle bodies will fit on the 2v engines? anyone tried this or knows how to get larger throttle bodies?

[dbran1949]

it's on the ducati website. 66mm stroke for certain.

I didn't even check there, going off what I read in an earlier post that linked to hell bent for leather.
This is good news, I really didn't want to see Ducati playing with displacement numbers. (I don't mean a few ccs of course if they wanted to call the 796 an 800 that would be fine)

[Duck-Stew]

The 4V throttle bodies are mounted differently and would require some custom machining to get them to fit.  Someone was doing 748 throttle bodies on DS1000 motors a while back but with serious re-welding/re-configuring of the ports and the frame too IIRC.

They chose (IMO) the engine designation of 796 to differentiate it from the older 800 motor as it's really very little the same motor anymore.  And, BTW, both motors displace 803cc's.

[dbran1949]

the marketing folks probably thought seven-nine-six sounds better than eight hundred. I read something years ago about auto manufacturers like to label product with things like stx or vx etc. Things that end in x like six are supposed to trick our brains into thinking "sex"

[cokey]

Can you bore out the 696 throttle bodies?  We do it for cars all the time. 

[caperix]

I am surprised at how little of a gain the extra 100cc of displacement gave in power.  Though some of that may just be how the motor is tuned.  I did not see a dyno graph on Ducati's website to see when those numbers happen.  The numbers are very close to what the 1000 ds makes.  At 45mm per throttle body I wouldn't think they a very big restriction, 5mm increase is not much and the 4 valve heads do flow alot more at higher rpm.  The 696 uses cams similar to the 1X00 ds, if they swap that may be worth looking into. 

[Duck-Stew]

My thoughts on extra displacement and the new bikes not making much more power:

Emissions standards are getting awfully strict lately.  Lower amounts of fuel in = lower emissions but has the side effect of lower power too.  Me thinks a DP ecu & exhaust kit fitted to the new HM796 would see large gains over the stock power curve.

[Raux]

I am surprised at how little of a gain the extra 100cc of displacement gave in power.  Though some of that may just be how the motor is tuned.  I did not see a dyno graph on Ducati's website to see when those numbers happen.  The numbers are very close to what the 1000 ds makes.  At 45mm per throttle body I wouldn't think they a very big restriction, 5mm increase is not much and the 4 valve heads do flow alot more at higher rpm.  The 696 uses cams similar to the 1X00 ds, if they swap that may be worth looking into. 

so you thinking a 1x00DS cam swap would provide more air to the motor than a 50mm TBs?

[brad black]

it's possibly just a 696 motor with a 66mm crank, so it may not have any reason to make much more power.  especially if the 696 is overvalved or just overrated to make it look better on paper.  it certainly looks like your normal 1000ds based head design.

[caperix]

so you thinking a 1x00DS cam swap would provide more air to the motor than a 50mm TBs?

I just don't think the airflow of the 45mm TB's are being maxed out.  They are used on all 2 valve bikes from the 620's to the 1100's.  I'm not sure if the cams would be an improvement or not, the 696 uses more agressive cams than the old 800.  I still wonder if the 796 was tuned for a broad flat torque curve compaired to the 696.

[Raux]

well the 66mm crank got here today. sending it to a shop to get lightened 

also maybe moving from 44/38 valves to 45/40 with ported and polished heads

have a friend i'm gonna ask to do a CF airbox or i'll use lightweight aluminum to build one. there's a HUGE filter taking up room inside where the crankcase breather tube goes. gonna go to a K&N for the breather anyway, so gonna try and expand the airbox size inside. may think about working tubes from the new front fairing to get some ram air action. with the BMC filter i got and larger velocity stacks i think i should be getting as much air into the motor as i can

Also gonna work on getting the flywheel lightened.

looking at 848 clutches as well maybe an ergal slipper to lighten the load.

i think that's about it for the motor. besides the PC V to run all the changes. which still isn't available for the 696

[cokey]

Sounds good.. deff want to see what it does for you.. so when I can get mines ill have more options..