Scooterotica

In a recent post I asked about the stroke length on a Vespa Mazzachelli race crank. (It was a 57mm stroke) The barrel tuner needed this info so he could see where to tweak the ports. Anyway barrel and piston back now. However, a few years back, i bought a malossi barrel and piston, but didn't take much notice of it, but have now compared it with the barrel that i have just had tweaked. Now I'm not asking any questions here, but would be grateful for any comments, especially on the top end that I bought a few years back. The tweaking that I requested was for a bit more power but to keep a smoother power curve rather than one massive peak over a small rev range.

The first two photos show the piston. the one on the left hand side is the one that goes with the kit I bought a few years back and shows that the transfer has been elongated. The one on the right is the one just back from the tuners who has smoothed the transfers.




And this is the other side of the pistons



Th barrel on the RH side is the one that I have just got back. The change to this barrel is to smooth the ports and adjust the exhaust port. So for this new tweak, the top of the exuast port is 32mm from the top of the cylinder and 56.5 to the bottom and is 46mm wide. As for the older barrel, the measurements are 32,55 and 41mm wide. In addition, the older barrel has the initials TWS




As for the other barrel ports, they all look similar in size, but with the exception of the old barrel. Here they have crudely drilled out a blanked transfer port.



Your thoughts would be appreciated, as I have a Rally 200 engine that may like the older barrel and piston, provided that the extent of tuning has not been bodged.

look here m8, it looks similar to what worb5 do with their Mallossi-210 tune`s

http://www.worb5.com/vespa_lambretta_sc ... mahle.html

heres a couple more pics i found m8

the first one looks like my old Chislespeed 221 top end (60 crank) with the piston milled out and boost port drilled. went really well and pulled a standard P200E 4th gear no problem. ran it with a 30mm dellorto(non reed) and JL righthand pipe. it pulled us great 2"s up, redheed (the wife)wasn't pleased when I sold it. I should have kept it and and put my EFL gearbox in and disc brake on, would have been a cracking scoot. at the time we were always 2"s up, so we went for a standard 200 for the bulletproofness...(invented new word....... ) try both... see what you like.....

this drilled hole in the boost port m8.
what size is it ?

Just got chance to get back on the forum and thank Norrie and Goldeneye. At this stage, I will put on the top end that I have just had tweaked. This is for a Rally 200 re-build that if I can find time will show the build on this Forum, in the appropriate place.

As for the older kit, I will have a go with it on another Rally200 engine that I have in a GS160. Finally, to answer Norries question, the bridge in the transfer port has been drilled out to 4.5mm diameter.

Did the same tweak on a 210 barrel some times ago.

f@@k me FF is there any beef left in that barrel ? lol
bet that shifts some m8

paulnobodyimportant wrote: Finally, to answer Norries question, the bridge in the transfer port has been drilled out to 4.5mm diameter.

cheers m8

yep M8 drill and up and down and flex in between.