Tweak the Polini 177cc kit

Hello !

Ok ! so little want more…
Is it possible to tweak the Polini 177cc cylinder kit to deliver more power [:look:]


Machuzzelli racecrank
28mm Dellorto
177cc Polini kit
welded and milled engine halfes
Polini exhaust


Hi Pallla!
I agree 100% with Curare!(and JuanK) He know´s his stuff.
The Polini exhaust you use now is not much better than original exhaust. But as Curare says, by swaping the exhaust you can get the engine to work it those power ranges that you prefer.
If the rotaryvalve isn´t leaking I would keep it.
I use rotaryvalve on a similar setup and it works perfect!
If you are going to get the cylinder tweak then look at this!

Best Regards

Here´s one for you Curare!

I would just go for a better exhaust.
With the 177 the reed modification give you same benefits but not that mutch since the 177 is a kit that doesn’t rev that high as a Malossi.
If you are after max top speed the Taff, as adviced by Juank, is a good choice. If you want more low, mid power range and torque get an RZ.

The best place to start is porting the barrel assuming this hasn’t already been done.If you’re confident with a dremmel it’s possible you could do this yourself with info on where to resize and reshape them.

Or use a tuning shop.

The next step could be to fit a reed-valve induction presuming that you’re still running the rotary system.Again,this could be done yourself or by a shop.

After that(or before if you want) get a decent expansion chamber.My preferance is for Taffspeed but there’s are others you might want to consider.