(To see what prior mods have been done see John's original Rippin' Rosso article here. - Ed. - Todd)
I took the engine out for a new case courtesy of MGNA (bubble/flaking problem) so while out I figured I'd have at it. First thing was a set of Carrillo rods. Lighter, stronger and great looking. Sent the crank, pistons, rods and entire clutch assembly out to get lightened and balanced. The balancer said my engine was the second most lightening he has done to date. (old Hemi 'cuda was fatter) Balanced it to 51%. (as per Dr. John's recommendation) Talked to Mike Rich at length. No timing gear set. Unless racing, he didn't like them for a street engine. Galling of the aluminum gears and exploding steel gears scared me off. His words: "chains are good" Cam: Yup! Megacycle 620X9. Most radical "drop in" cam you can use without valve clearance problems. More mid and upper power. Just what I wanted... With the cam was a set of Mike Rich racing valve springs. Needed with the more radical cam lobe profile. New lifters also. Mike did my heads last year along with new valves and guides. The cam
is the icing on the cake!!
Results? WOW!!!!!
My bike was putting out just over 90 RWHP before, now it feels way more!! Nail it and the front tire comes off the ground and stays there. The engine is super smooth now and winds out so fast you have to be fast on the shifter or you bang the rev limiter at 8600rpm! I will be bringing it to a Power Commander Tuning Link Center next week to have a new custom map done and a final H.P. reading.
Note: I did ALL the work on this engine from taking it out of the bike, disassembly and re-assembling it on the new block. (was easier than I thought) This was all under the watchfull eye of Alex from Branchville motors in CT. (thanks Alex)
I was slow and meticulous in the whole job. Every gasket and O-ring was brand new. Every nut was torqued perfectly and job was a real joy and very satisfying. I will be back with the dyno numbers after the new map is done.
UPDATED:
Well folks, I'm done with the mods on the Rosso and I'm very happy.
Engine mods:
Mike Rich head work, ported and flowed with racing valve springs and hardened valves.
Carrillo rods, engine lightened and balanced.
Megacycle 620X9 cam
Stucchi crossover
Agostini C-F slip ons
Drilled airbox with K&N filter
Power Commander with new custom map
I wanted more power but also wanted a very well behaved engine. In other words, I was looking for the ultimate Guzzi street motor. I think I finally found it. The Megacycle 620X9 cam is a direct drop in Cam with no other modifications needed to the valve train except for stiffer valve springs to help with the more radical cam lobes. As you can see by the graph there is no downside to this cam at all. More hp at all revs and torque is much improved. This engine just pounds out the thrust when you crack the throttle. There are no more flat spots and the engine does not need to be revved to hell to get the power. The cam along with the Carrillo rods and the much needed lightening and balancing make this a very snappy revving Guzzi! I'm sure you could get more peak hp out of a Guzzi two valver, but then the trade offs for the street would be too much for me.
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John Tavolacci
Jtavo<at>optonline.net