Scooterotica

I am presently building up an engine for my cousin, I am using the new 177 Parmakit cylinder. (work of art compared to my Polini) Its more for an extra bit of power than a full on race tuned monster so I am not going to go too mad. No replacement for displacement as they say. The engine casings have been ported to match the cylinder, I will use a copy of an SIP road type exhaust that I have had made locally and I will fit a P200 24mm carb. Everything else will be standard PX.

I run a 177 Polini set up myself, and before I replaced the crank with a Series Pro item I cut the standard crank by 19mm as recommended by Polini themselves - My million dollar questions - do I need to cut the crank on this engine ??? if so how much ??? And can anyone recommend the copper gasket set up for the base of the cylinder vs. the head ?? Parma kit supply 5 of each ?!?!?!

I have read online 4 base gaskets and 1 head gasket was the recommendation but the guy complained about a lack of low end power and has since been advised to use 4 head gaskets and 1 base gasket - which to my mind seems too many. Will a cut crank do away with this need to play around with gaskets as the port timing will be longer due to the cut in the crank web ???

Wanted to start building up the engine this week and wanted some firm feedback before I started as I don't want to have to pull the crank out and cut it after I've closed the casings (if indeed its necessary) I have searched the web and cant find any information on this issue at all and the instructions for the kit are written in very poor English.

Please advise
Thanks.

It's fairly safe to assume the Parma will need more inlet timing than a standard machine, I'd try your previous cut crank in there and see how it goes. May need more yet but it's a better starting point unless you can turn up the ideal timings on GSF.

Also noticed that Polini are now doing 2 Evo versions in alloy these days for the smallblock cases.

The gaskets (spacers) are there to allow adjustments to your port timing. With a 57mm stroke you may not need most of them, with a 60mm stroke you will need at least some of them. I'd put it together with no packers and measure the squish... then add packers to get the required squish. I have no idea what Parmakit suggest but it's probably in the range of 1.3 - 1.8mm.
If you place your packers at the base you will get longer port timing, and at the head shorter port timing. Shorter tends towards more torque and longer towards more revs broadly speaking... however on a 57mm stroke you may not even notice the difference.

Cutting the crank does not affect your port timing... it judt holds the inlet open for longer. Once the charge is in the crankcase and the crank closes the inlet the piston opens and closes the ports - that bit is your port timing.

Thanks very much for the quick feedback, I really appreciate it. I will take your advice Juan and use the old cut crank as it cant do any harm to get a bit of extra juice into the casing.

I will do exactly as you suggest Ginch on the squish - start with just one or 2 and measure it and go from there - Parmakit in their semi illiterate description recommend a squish of 1.6 -1.7. They also recommend using 1 base gasket and 5 head gaskets and suggest adding and reducing accordingly until happy with the revs/torque. which sill seems excessive to me if not a pain in the arse trying to get right. Still thanks again for your value input.