Malossi Vespa Mods Thread (V4 head stuff mainly)

[Micah / AF1 Racing]

I had recently the opportunity to do another full Malossi kit, this time for a 300 Super "Race Vespa" and was thinking we could all probably benefit from compiling the majority of technical photos and data into a single common thread. The Malossi V4 head is the same part number whether it is used on a 200cc, 250cc or 300cc Piaggio motor so other than cam specs this is a good place to collect data for all three models. Here is a series of pics covering that conversion from literally out of the box stock from Malossi to ready to bolt onto the racing Vespa out of the NY area. If this was your motor please post up and let me know how it is going, you said you found me via the forum so if you see this please humor us and let us know how it worked out, especially compared to other Vespa "racers" on track with you.

So this is literally fresh out of the box, I see much room for improvement but as delivered it is LIGHT YEARS ahead of the stock head!

http://www.apriliaforum.com/forums/attachment.php?attachmentid=190217&d=1335967469

This is the view from the bottom of the head looking from the intake side of the combustion chamber. Rough at best, no always a bad thing but look at the exhaust ports, much to be gained in the floor transition at the very least!

http://www.apriliaforum.com/forums/attachment.php?attachmentid=190209&d=1335967432

The fact that the stock valves and seats were not even finish ground bothered me...no they did not leak...but I am rather anal about this sort of thing. If nothing else was altered I would still have done the valve seat grinding. This was done with 600 grit Clover compound so I could clearly see the areas not to fuckin' nick with a tool while porting the head.

http://www.apriliaforum.com/forums/attachment.php?attachmentid=190212&d=1335967444

This is the dead stock intake port at the transition from casting to steel valve seats...oh yes, this can be improved easily enough.

http://www.apriliaforum.com/forums/attachment.php?attachmentid=190210&d=1335967435


This is the stock Malossi Piston for use with the Malossi Cam or the 300 Super camshaft which seems slightly more aggressive than the 200-250cc cams from Piaggio. Piaggio had to make the stock cams on the race-y side to cope with the fact that the motor is severely intake and exhaust port/valve size limited in terms of how much power it can potentially produce. I like neither sharp edges nor rough surfaces on my pistons...so they had to be modified as well.

http://www.apriliaforum.com/forums/attachment.php?attachmentid=190215&d=1335967460

As you can see in this pic the stock Malossi casting shrouds the low lift valves pretty severely, easy enough to fix now that a quick valve seating has determined the safe and unsafe areas for cutting....

http://www.apriliaforum.com/forums/attachment.php?attachmentid=190206&d=1335967004

[Micah / AF1 Racing]

This is the finished product, ready to be boxed up and shipped back to it's owner in NY. The total gains for this motor in the upper end of the rev range should be in the 30-40% range over stock if used with the correct injector/fuel pressure and smart pipe and intake mods. Basically it will be night and day different compared to the stock bike, and hopefully just as reliable as the stock motor too. A genuine 20-22bhp at the tire is possible, nothing to sneeze at in terms of scooter power, this is enough to loft the front wheel coming out of corners or leaving the line, or almost enough to call it the "right amount" of power.

Here are three shots of the finished combustion chamber and valve seats and a little of the ports:


http://www.apriliaforum.com/forums/attachment.php?attachmentid=190201&d=1335966983



http://www.apriliaforum.com/forums/attachment.php?attachmentid=190202&d=1335966987



http://www.apriliaforum.com/forums/attachment.php?attachmentid=190203&d=1335966991

And one more with the valves back in place.


http://www.apriliaforum.com/forums/attachment.php?attachmentid=190204&d=1335966996

Piston ring end gaps needed to be filed, I went .4mm on top ring, .55mm on second ring and .5mm on both oil rings. The piston's sharp edges got all worked down to something that was not razor like!


http://www.apriliaforum.com/forums/attachment.php?attachmentid=190214&d=1335967454


Here is the valve set and a close up of only one of the valves to show seating.


http://www.apriliaforum.com/forums/attachment.php?attachmentid=190218&d=1335967603

Valves just do not look right to me until you know they are properly seated...


http://www.apriliaforum.com/forums/attachment.php?attachmentid=190219&d=1335967607

Not the best pic of the intake port but fairly realistic for how it finished out. Upping the size of the port is not a real option since the manifold and throttle plate are not getting any bigger.


http://www.apriliaforum.com/forums/attachment.php?attachmentid=190213&d=1335967449


The exhaust port ended up pretty nice, and no bigger than the gasket....because that makes no sense to do!


http://www.apriliaforum.com/forums/attachment.php?attachmentid=190216&d=1335967465

That's all for today's Malossi installment. If anyone wants their Vespa "Prebuilt" to these specs just order it and plan on spending $1500-$2000 or so and waiting an extra 2-3 weeks or so for delivery or pickup.

[bunnybash]

I am a bit slow, but I think you are saying we can order the head from you?

[Micah / AF1 Racing]

Nope, we no longer deal with Malossi direct so I would send you to Rich at High Gain Tuning for the parts order. I need to order a head from him very soon myself. I think I am going to keep my stock cylinder and bore size and just machine deeper valve pockets which are obviously wider as well into the stock dished piston since it will end up under pressure on the intake side. Stock looks perfectly suited to boost as far as the piston is concerned. Without the Malossi head there is no point in even trying to boost the motor on my bike, the valves are way too small on both sides to flow decently once back pressure and manifold pressure are added to the equation.

Depending on where you are located there are a few remaining Malossi dealers iin the USA. Rosell Imports in NY, MRP in FL, Rich at HGT in CO. If you can think of others feel free to add them in a post in this thread. We got tired of dealing with Malossi, it just got too complicated and expensive with the exchange rate going horribly out of our favor iin the past, better now though!

[bunnybash]

Nope, we no longer deal with Malossi direct so I would send you to Rich at High Gain Tuning for the parts order. I need to order a head from him very soon myself. I think I am going to keep my stock cylinder and bore size and just machine deeper valve pockets which are obviously wider as well into the stock dished piston since it will end up under pressure on the intake side. Stock looks perfectly suited to boost as far as the piston is concerned. Without the Malossi head there is no point in even trying to boost the motor on my bike, the valves are way too small on both sides to flow decently once back pressure and manifold pressure are added to the equation.

Depending on where you are located there are a few remaining Malossi dealers iin the USA. Rosell Imports in NY, MRP in FL, Rich at HGT in CO. If you can think of others feel free to add them in a post in this thread. We got tired of dealing with Malossi, it just got too complicated and expensive with the exchange rate going horribly out of our favor iin the past, better now though!

I guess there is no way that I can order any of these things from Australia is there?? sigh...

[Micah / AF1 Racing]

Rich can send you the parts to Oz no problem. High Gain Tuning in Colorado. Find em' on the web and email and order to him. Trusted forum member, great guy, genius tuner...no worries mate.

[jrflanne]

My Vespa just passed 14k miles. As I dimly recall, I think the motor was done at around 9.5k, but I am not sure. Anyway, the thing is running flawlessly.

[Micah / AF1 Racing]

Glad to hear it, maybe a valve inspection after the 1102cc Tuono is finished just to be safe with the Malossi head.