Power

[Oldnwiser]

I just listened to a podcast with Darin Morgan and I am convinced that a two valve intake system with the valves making a straight shot to the chamber would have velocity to maintain fuel atoimization to the prime position for fuel to maintain its pressure and velocity to feed the plug without any lean spots right in the middle of the chamber without plug wetting. They can be at the angle open to feed the chamber without more than one turn. The manifold can be widened to alleviate any disruption of the flow and then tapered to a round port on the manifold big enough to feed each cylinder 2 manifolds and two carbs big enough to feed the tract on each side. 27 ci per cylinder and the manifold can be longer than stock . I really wish I could still do this!

 

[Hudriwudri]

I just listened to a podcast with Darin Morgan and I am convinced that a two valve intake system with the valves making a straight shot to the chamber would have velocity to maintain fuel atoimization to the prime position for fuel to maintain its pressure and velocity to feed the plug without any lean spots right in the middle of the chamber without plug wetting.

That's in slightly different words exactly my point.
Btw, You won't need 2carbs per port as a good modern flat slide carb is more that that engine will be able to handle.

Kind regards christian

 

[Oldnwiser]

I’m sorry, I meant 1 carb per cylinder. The port would be like the 3V engines with a divider running down to the split into two valves. We were talking about the same thing. The smaller valves and port division are easier to keep the fuel in suspension, and the exhaust valve and port blowdown are great for the velocity of the two valves and the split port. Would that be neat or what? The intakes could be widened and a pair of Del Orto carbs an onlooker would have to look to know it has two intakes valves per cylinder. I haven’t seen Kip Martin in a long time, but he is Darren’s Dad. I am running one of Kips oil pans on my FE. I ran the idea by him and he said that the improved mixture homogeneously divided would increase efficiency by a good amount to split that pumper carb and the smaller port at the chamber would act like a taller cam on a bigger core by the % of relation. All it would take is to widen the port with the manifold round and as long as possible and the divider would make a straight shot into the two valves of each intake sides pair and the single exhaust is sufficient I can see it in my mind. Thanks Christian!

Bill

 

[Hudriwudri]

@Oldnwiser
Of course it would be very neat and one could use less radical cam profiles on the intake (some tuners tried years ago something quite similar with Norton twins don't remember the name right now)
As mentioned I'm happy with the engine the way it is and should get eventually when I'm done with it, and i simply love pumped up 2v engines.
(Or else I wouldn't own 2 moto Guzzi's)
If you're so intrigued by the 3V lay out you might want to have a look at some of the honda engines (guess Honda hawk, Africa twin and some CX engines afaik) or at the Ford modular engine as i think some came with 3V lay out.

All the best and kind regards

Christian

 

[Oldnwiser]

Naa, I still stop and listen when I hear a 360 or 270!twin. I fell in love with the XS2 42 years ago, and ironically today is my anniversary, my wife and I were married 42 years ago. I left her the 69 Galaxie, and I rode the XS2 to work. Man those are years to look back on fondly. I wish I had the vision to ride and drive. The sound of an XS2 at 700 ccs and with a shaved head is invigorating. It kicked hard. But man it had a tone! I had the short glass packs that were blown out and it sounded good. It had to be making more than 53 hp and 44 ft lbs. I could run off and leave my father in laws XS2. If I could just go back 42 years I would wouldn’t charge a thing. I am the most fortunate man in the world.