New engine pics.

[Ian Inverarity]

Hey guys,

Follow the links to the CMB 45 gearbox and Picco 2003 XP 90.

http://perso.wanadoo.fr/xavier.cardinale/first_US.html

Some interesting stuff for those wanting to try 45 gear drive monos and maybe riggers.

The Picco is interesting with a CMB EVO 90 style crank, rod and AAC P&L, dished piston. Note the ports in the piston with no corresponding ports in the liner?? :- I like the case split tho. The taper on the end of the crankshaft rasies some very interesting questions regarding crank end float control.... ???

Nitrocrazed racing: Being an individual like everyone else.

 

[Mike Bontoft]

The Pico engine is set up for multi racing and they have the thrust bearing in the front of the prop shaft. I cannot see what kind of bearing they are using to support the other end of the crank, if its a ball bearing I do not see why that could not act as the thrust bearing, Like on the A-90s and the zenoahs. The bearing would have plenty of lubrication and I am sure the crank is strong enougth to take the load. Just my oppinion, I am sure there will be some that disaggree.

Mike

 

[Ian Inverarity]

Mike,

Good point about the thrust bearing on the prop shaft of Multi's. I think the Picco would be fine with square drive's in an oval racing application too, but I think it would be in trouble with a flex hex! Especially as I presume the bearing adjacent the zimmerman disc will be a needle roller for induction port clearance reasons.

But the Zenoah cranks are absolutely massive for the power that they make. And the A-90's have 4 bearings to keep the crank from bending under axial thrust loads. Even so I only use square drives on mine.

I just wonder why Picco chose to go down that path (tapered crank) instead of a tapered split collet like all their other engines. :- I understand the A-90 design philosophy (4 bearings to keep the crank straight and take the thrust on the second large crank bearing) but I dont understand why Picco would have not used a tapered split collet. ???

Ian.