Stroker Cranks 44 mm

Velo

Velo

Well-Known Member
Hey there. I have been told that the Crank fabrick that makes Polini and Stage 6 cranks allso makes a Scooter cranks with a stroke of 44 mm. Mosly identical with the Polini Racing but with a 44 stroke and 12 mm pistonbolt.

At the Moment I have a Fabrizi 44 mm (Maxi kit) stroker but I would like one more and the Fabrizis is kind of expensive.

So if anybody knows where to get them and what name thay are sold under. I wouldn't mind knowing.

Stay Tuned
Velo
 
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Originally posted by aerox-evo70
the new malossi prototype (testcilinder) also uses a 44mm crank.
don't know wether they make those themselves or they order them somewhere else...
Click to expand...

'Sounds like some heavy duty power.
Hmm I'll cross my fingers and hope Malossi are out with a stroker shaft. The Fabrizi is ok. But the impression isn't top class. (And having visited the Fabric in Rome) that isn't a big thing ither.
 
I just talked to the Malossi Tech Center. They said that they do not have a prototype cylinder or crankshaft. They also said that they are NOT in the process of re-designing a new MHR Race Team Cylinder KIT (31.9128) . They said that they have had great success with their MHR Race Tram Cylinder Kits.

They only have the "New" Titanium Crankshaft (53.9703). The difference is that they use a 85mm con rod, were most companies use a 80mm con rod. Malossi Crankshaft (53.9212) also uses a 85mm con rod. The difference is the price. You need deep pockets for the Titanium crankshaft. Only the con rod is Titanium.

Fabrizi also make a crankshaft (7013) like the Malossi, but the bottom end lobes are 72,5 dia., you have to modify the crankcase casings to fit it like the (7015).

If you use the Malossi crankshaft with a Fabrizi Maxi Kit, the piston will not come right to the top. You will have to shave the bottom of your cylinder. If you use a Fabrizi Stroker crankshaft (7015) with a Malossi MHR Cylinder (31.9185) you will need to use a spacer to raise the barrell.

The only other companies I know that sell stroker crankshafts are:

1. Athens (was Eurocylindro)
2. Simonini Racing
3. Nuova Mazzucchelli Srl (they make Fabrizi Crankshafts and cranks for most other companies)

Note: Good Luck

Added Speed
 
there's indeed no prototype malossi cylinder with 44mm crank. That is just the 2Fast project but got nothing to do with 'Malossi' itself

But about your question about the carnk fabrick that makes polini & Stage 6 cranks.. they made so many different types.. and even on specification on-off cranks. I'll ask for you...
They got no email so far as I know.. I only got an address and they don't speak any other language as Italian :D
 
Originally posted by Razma

They got no email so far as I know.. I only got an address and they don't speak any other language as Italian :D
Click to expand...

Sound like when I wisited Fabrizi.
It is just a old Villa with a workshop in the basement. Serious stuff.
 
Originally posted by Speed
[Lots of good info.]
Added Speed
Click to expand...

Uhh thanx many times.
I have a Fabrizi Maxi kit 2001 but I have had a piston failure. And they use a special size piston (Hight from the pin is 4 mm higher than Normal Asso piston for f.eks. EVO) And I am not that happy with the design a quality of the kit. So I don't want to spend BIG € on a spare piston through Belgium.

The Malossi kit sounds Nice though. Do you have any other info on it.
Pictures would be great.
Prices even better. (Both = you are god)

Conserning space in the engine. The Fabrizi kit I have is just like the MHR kits where you need to dremel/CNC to make the cylinder/crank fit.
 
This is my suggestion, for I have this set up on one on my Championship Zips.

Invest in a Malossi MHR Race Team Cylonder Kit for this project. Being Malossi uses a 85mm con rod & the bottom of the barrel is thick. Yes, the casings needs to be modified to fit the cylinder. You should already have had this done in order to fit the Fabrizi Barrel. (I would mill the casings to keep it even and neat).

With the Malossi cylinder you will need a spacer of about 1.3mm. You can you the gaskets of different thicknesses to adjust you squish & compression. Just lower your exhaust port to match the piston at BDC. DO NOT lower you transfer ports. You HP should be much greater than the Fabrizi if the rest of your set up is working in hormony with the motor.

If you use most other cylinders you will need a spacer of about 5-7mm. The barre will sit too high and the bottom of the cylinder skirt will brake off or the bottom of your piston will.

Note: I use a Polini Evolution #7 Exhaust System with this set up. It produced the most HP.

Added Speed
 
The Engine is BTW a minarelli engine.
(I guess that you malossi numbers are Piaggio since you talk about EVO #7)

I have ordered a Malossi Cross Piston for my Pro Race kit wich I intend to use together with the stroker crank.

I hope for a good outcome.

Thanks for the info.
 
as far as I can remember the MK Pro Race's standard Piston is the same as the Malossi Cross Piston...

Dunno about the Fabrizi Piston, could very wel be the same too...
 
Originally posted by $aint
as far as I can remember the MK Pro Race's standard Piston is the same as the Malossi Cross Piston...

Dunno about the Fabrizi Piston, could very wel be the same too...
Click to expand...

All three of them I have is different.
 
I have already used a Metrakit Pro Race Cylinder with a Fabrizi Stroker Crankshaft. Sooner or later something will break inside your engine. The cylinder barrel sits too high. It does not make a difference if it is Minarelli or Piaggio engine.

Yes, all three are different. The Metrakit cylinder uses a special "Gold" piston ring supplied with its Pro Race Cylinders. I have seen the stress test that they perform when I visited their factory. I also raced there Piaggio Zip in one of the Races in Spain.

Added Speed
 
Originally posted by Speed
Sooner or later something will break inside your engine.
Click to expand...

As long as it is fun while it lasts. That is ok with me. (I guess, lets see what I come up with during winter)
 
Originally posted by Speed
I guess you are right. My bike was a rocket until it broke. Good luck my friend.

Added Speed
Click to expand...

Isn't it all about having fun?

BTW:
Those Malossi partnumbers you postet higher up. Was that for Minarelli or Piaggio.
When I search on them Zip is the only thing comming up.
 

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