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Thread: Malossi Vespa Mods Thread (V4 head stuff mainly)

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    Honest always, feared often Micah / AF1 Racing's Avatar
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    Malossi Vespa Mods Thread (V4 head stuff mainly)

    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!



    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!



    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.



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




    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.



    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....

    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  2. #2
    Honest always, feared often Micah / AF1 Racing's Avatar
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    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:












    And one more with the valves back in place.




    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!





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




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




    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.





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




    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.
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  3. #3
    apriliaforum Member
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    I am a bit slow, but I think you are saying we can order the head from you?

  4. #4
    Honest always, feared often Micah / AF1 Racing's Avatar
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    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!
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  5. #5
    apriliaforum Member
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    Quote Originally Posted by Micah / AF1 Racing View Post
    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...

  6. #6
    Honest always, feared often Micah / AF1 Racing's Avatar
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    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.
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  7. #7
    apriliaforum expert jrflanne's Avatar
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    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.
    Bikes:
    2007.5 Tuono-Black, with 1102cc's of micah's badness!
    2012 Griso-Silver and black, Agostini pipe, some carbon bits.
    2006 Vespa GT200-bitubo suspension all around, Malossi big-bore, head and cam, Akrapovic pipe, all put together by Micah.

    gone 2002 Caponord-Oyster gray (as faithful as a hound dog)
    gone Futura-Red (on the AF1 showroom floor. Get some.)

    The more I learn about people, the more I appreciate rocks.

  8. #8
    Honest always, feared often Micah / AF1 Racing's Avatar
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    Glad to hear it, maybe a valve inspection after the 1102cc Tuono is finished just to be safe with the Malossi head.
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  9. #9
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    So is the $1500 on top of the parts for the porting, ring filing labor? It looks like there is some more material to grind out on that exhaust to match the exhaust gasket by the picture you sent? Dont you typically want to match port size to the gasket/exhaust opening?

    Quote Originally Posted by Micah / AF1 Racing View Post
    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:












    And one more with the valves back in place.




    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!





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




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




    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.





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




    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.

  10. #10
    Honest always, feared often Micah / AF1 Racing's Avatar
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    There is honestly no need to have an exact match on the exhaust gasket surface between head and pipe. On two strokes you can see real gains, on four strokes of modern design there is often a LOT of port left between the gasket and the pipe. D shaped ports work very well, but D shaped headers are far less common outside of GP applications.

    BTW, we have added back some Malossi parts to the store, more coming as time goes on. Here isa link to the most complete kit offered.


    http://www.af1racing.com/store/Scrip...dproduct=74402

    If you want rings pre sized and ground, head ported, polished and such that part alone adds about $300-400 in labor depending on how far you want it done. I would personally recommend just light cleanup type porting. Piston shipped pre-installed into cylinder so with care you can slide in wristpin without removing piston from cylinder. Getting the rings right can be done at home easily enough, as can valve seat grinding, YouTube is your friend there. I have seen little gain if any from mirror polishing parts, just take off sharp edges and for porting the real gains only seem to accur in the valve seat to head casting transition area, make sure that stuff is smooth and the valves seal properly, and you are good. ALWAYS set valve clearances to spec before ever installing motor, check again in a few thousand miles, most wear/break in occurs in this time frame.
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  11. #11
    apriliaforum newb
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    I found something interesting when combining the Malossi V4 head with PM Tuning's exhaust (I have the PM80, but it should be the same as PM68): The exhaust pipe flange tapers down at the head to match the stock head's port diameter. The outside diameter remains constant on the header pipe, while the inside diameter is roughly 3/16" smaller in diameter in the last 1/2" of pipe.

    I used a dremel tool to make the diameter match the copper gasket... hopefully will see some power gains.


    Also for anyone that has a PM tuning exhaust, I think the OEM exhaust nuts are too large and cause the exhaust studs to be spread apart when tightened. Mine eventually broke an exhaust stud... (which was then an excuse to upgrade the head... and cylinder...)

  12. #12
    Honest always, feared often Micah / AF1 Racing's Avatar
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    Those pipes are a pain in the ass to fit but in principal the design is pretty good as you have seen, the header length issue and the way they resolve it to get a reasonable length is pretty eloquent. Keep us posted. Have you ever cut apart a stock pipe and seen how Piaggio gets header length closer to right with stock pipe, more going on inside your stock pipe than you might expect really!
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  13. #13
    apriliaforum newb
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    Quote Originally Posted by Micah / AF1 Racing View Post
    Those pipes are a pain in the ass to fit
    Agreed... I found that it is easiest to leave the header attached to the motor when removing & reinstalling, rather than deal with getting the header nuts threaded. The only M7 nuts I could find locally had an 11mm head, which were impossible to get a socket on.

    I ended up using some stainless steel ARP 12-point nuts (Part# 400-8356). They aren't cheap, but they do have a 9mm head that allows a 1/4" drive socket to fit. (BTW: 9mm 12 point 1/4" drive sockets are also hard to find)

    For those who haven't seen the PM80 & PM68 header pipe:
    Click image for larger version. 

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  14. #14
    apriliaforum newb
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    Micah,

    First off, thanks for posting such detailed photos and descriptions. It's been really helpful!

    I know this is a really old thread but hopefully I can get some feedback from you. I'm about to put a head & cylinder kit on a 250 and I'm scratching my head when it comes to the ring gap. I've been having a hard time figuring out what it should be. I've been getting wildly conflicting information.

    I will primarily be commuting on this scooter but it will see prolonged periods of WOT.

    Most of the documentation recommends a setting from .004" to .005". The guy I bought the kit from insists that I will blow up the engine if I touch the rings because they're 'Malossi Special'. I saw that you went with I went .4mm on top ring, .55mm on second ring and .5mm on both oil rings which is slightly greater than this range. What was the reason for this choice? Do you have any feedback on how it's held up over time?

    For reference, the conversion spreadsheet I'm using based on tables I've found from various sources. ** is the closest to yours.

    Bore (mm) 74mm
    2nd Ring add 0.002"
    Oil Ring 0.0075"

    Gap Factor (in/in) 1st Ring (mm) 2nd Ring Oil (mm) Rings (mm)
    0.0030 0.22 0.37 0.56
    0.0035
    0.26 0.41 0.56
    0.0040
    0.30 0.45 0.56
    0.0045
    0.33 0.48 0.56
    0.0050
    0.37 0.52 0.56
    0.0055
    0.41 0.56 0.56 **
    0.0060
    0.45 0.59 0.56

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