Centauro throttle bodies on a sport i ...

[Pierre]

Hey guys, thanks for the help on the engine lightening question. Responded here: http://www.v11lemans.com/forums/index.php?...indpost&p=84610

and added some additional info I received from Mike Rich.

 

Next question - does anyone know if the throttle bodies on the Centauro / Daytona (51s) will slip onto my sport i manifold? I understand I'll have to bore out the manifold - but curious what the interchangeability is? Anyone done this?

 

TIA.

[Mike Stewart]

Pierre,

 

I came across this site that can bore your stock throttle bodies to a larger size.

 

http://www.cycle-rama.com/ShopTour.html

 

Humm, now you got me thinking....

 

Mike

 

 

Hey guys, thanks for the help on the engine lightening question.  Responded here: http://www.v11lemans.com/forums/index.php?...indpost&p=84610   

and added some additional info I received from Mike Rich.

 

Next question - does anyone know if the throttle bodies on the Centauro / Daytona (51s) will slip onto my sport i manifold?  I understand I'll have to bore out the manifold - but curious what the interchangeability is?  Anyone done this?

 

TIA.

84657[/snapback]

[dlaing]

Pierre,

 

I came across this site that can bore your stock throttle bodies to a larger size. 

 

http://www.cycle-rama.com/ShopTour.html

 

Humm, now you got me thinking....

 

Mike

85325[/snapback]

I think you need to modify their 124 cubic inch twin cam kit to fit the Guzzi

But seriously, didn't someone post that our throttle bodies work well on the smaller Guzzi engines like one the 1000 and 850LeMans????

If that is the case, perhaps a larger bore would be an easy way to more power on the 1100s.

I am pretty sure I make maximum power at WOT for every RPM down to 3000RPM, so the higher RPMs could probably benefit from bigger TBs and intakes

[motoguzznix]

Hello Pierre

 

I think it is a good idea to swap to the Centauro throttle bodies at your state of tune.

I would use the complete centauro setup - intake manifold, rubber and throttle body and the connecting parts to the air filter. When all that fits into the cantauro in the same frame, the swap sould be straightforward. Modifying the intake manifolds of the V11 should not be possible as these have too thin walls.

[Skeeve]

Next question - does anyone know if the throttle bodies on the Centauro / Daytona (51s) will slip onto my sport i manifold? I understand I'll have to bore out the manifold - but curious what the interchangeability is? Anyone done this?

But seriously, didn't someone post that our throttle bodies work well on the smaller Guzzi engines like one the 1000 and 850LeMans????

If that is the case, perhaps a larger bore would be an easy way to more power on the 1100s.

I am pretty sure I make maximum power at WOT for every RPM down to 3000RPM, so the higher RPMs could probably benefit from bigger TBs and intakes

85347[/snapback]

 

I'm coming late to this party, so some background, please:

 

Pierre: are you saying the TBs from the 90's bikes are larger than the v11 series motors? If so, I'm kinda surprised [but not entirely, given the 4v vs. 2v differences.][1]

 

Dlaing: (You probably already know this, but just for the record...) The nature of FI negates the need for small intake diameters (somewhat.) Back in the day, if you wanted decent mileage & tractability, you usually had some small dia. carbs on the engine, as the high (local) velocity thru the carb improved atomization & mixing of the fuel. For a race engine, that was basically run WFO all the time, the speed "trick" was to jump the carb size significantly: thus, you had the factory moto-xers running 36 or 38mm carbs on their 125cc single, where the "same motor" for mass-consumption was sold with a 26 or 28mm mixer.

 

There are limits, however. If there is a significant, sharp change to the diameter of the intake tract when Pierre bolts up the Centauro TB to his 2v motor, it's not going to run for cr@p, fuel injection or no: the step will upset the flow. OTOH, if there isn't a sharp change, then he should be able to just bolt on the larger dia. pieces and get some easier breathing at WFO throttle w/o compromising the low rpm tractability too much. And w/ the 2v motors, and decrease in restriction = an increase in power. But as Pete Roper likes to say, WFO is not what the 2v motor is best at...

 

Ride on!

 

[1] Surprised only because over time, bike intakes seem to grow, not shrink. In the 60s, a 125cc 4stroke single would have probably averaged an 18 or 20mm carb throat; in the 70s, 22mm; in the 80s, 26mm; 90s-28mm; post-millenium, 32mm. So, w/o really giving it much thought, I would have guessed that the Daytona/Centauros, w/ an engine designed in the early 90s would have had a FI throttle body of comparitively HUGE (by carb standards of the time) dia of around 44mm, and the later evolved v11 motors to have a similar or slightly larger size, because only being 2-valvers. This is why you really shouldn't make assumptions based upon inadequate information!

[Paul Minnaert]

The 2v guzzi's have 45mm tb and the 4V have 50mm tb. If I'm correct on the first, I'm sure on the second. I know one case where someone bolted the daytona Tb to a 2v egine, that was a racer and it didn't stay on long. That was mainly because it didn't run right.