Malossi Polini swap?

[wax]

I have a malossi 221 engine at the mo in my 152L2 and I am not too happy with it really. It's low on torque, and 4th gear is a problem. The age old: thrash the nuts off it in 3rd, keep your head down and pray there are no inclines coming on the horizon.
I had it dynoed at Diablo and it makes 18bhp, which is a bit disappointing, but as Alan pointed out, with less than 12 bhp at around 4500 rpm, it's not going to pull the gearing, even with a T5 4th gear. An age old malossi trait.

I had a ride on Alan's Polini 210 and it was much better. Power lower down the rev range, with lots more torque to boot.

I should have listened to Alan in the first place......

Anyway, I have decided to go Polini, but time is tight, and I am not prepared to miss the summer waiting for a scooter shop to swap it for me. So I will do it myself, probably.

What I want to know is, with my current set-up. Harry Barlow put the packer at the top of the barrel. Will this work with the Polini too?

Also will the head I already have work with the Polini too?

Is there much difference in the crank case porting between a malossi and a Polini? Will I need to port the cases again?

Any advice would be much appreciated.

Ps anyone want to buy a Malossi kit?

[H,POOL GADGE]

Wax watch this space! my polini 220's gone on dyno(s/erotica)friday, setup and dyno graph will follow.....

[wax]

Super. I would like to see that..........................

[Spanish Fly]

Hi. Polini piston crown is a different radius than the malossi so to do a proper job you need a different head. A specific SIP head is available for 60mm stroke that eliminates the need for a head packer.
Transfer ports in crankcase will be near enough to make no difference.

What exhaust are you using. Maybe a gruntier pipe will help at the expense of top end. Rotary or Reed?

SF

[santacama]

I have a SIP Road in my Malossi 221 (1 mm base gasket, 0,5 head gasket (aprox 125/185), MMW head, RD reeds, all ported, M Tech, Keihin PWK 35 AS, short 4 gear, etc) and it is plenty of power in all RPM range. Top speed is some were arround 135 k/h (no way of measuring) and it can go 120 k/h every were.

Sip Road plus new set of rings = new engine.

[wax]

Kool. I am using a JL left hander and its rotary induction via a 28mm carb. I went for a blast last night and it seems much better than I remember from last time? Tucking my head down at 60 hot me through and into the power again. It's only done about 70 miles, so maybe it's loosened up a bit? Or is about seize due to an air leak! I did a plug chop though and it was brown? The temp on the sip speedo was about 55 degrees too.

[Muttley McLadd]

Is there something wrong with it? The Germans are getting upper 30s from Malossi 221 top ends.
18 seems remarkably low, considering what it is.

(not taking the pi ss)

[wax]

I don't want nothing that crazy! I have a 34bhp TS1 for that. I Just want a reliable scooter that pulls 4th gear and doesn't need filling up every 20 miles.

Perhaps the new malossi kit will sort out the peaky problems? Has anyone dynoed one yet?

[Train Driver]

Al did my polini 220cc it still uses the standard carb,auto lube and SiP road exhaust.
I haven't got the dyno sheets but Al said 19bhp & loads of torque, also getting 12 MPL
It made a bit more power using the polini induction but did 7/8 MPL

[wax]

Sounds good to me Train Driver