Scooterotica

If you have enough power in your engine to acheive 80mph then it doesn't matter what kit you are using, you will need a seriously good crank, clutch, chain and guides, new bearings throughout the motor, very good tyres, a well set up carb, a good quality expansion chamber, a disc brake etc etc etc. And thats before you buy the cylinder. £1500 quid kerching!
ignoring any of the above you are just p1551ing in the wind.

Get your standard jet cylinder tuned properly, get a 30 phbh carb and a good pipe, have your timing checked and set properly. Jet your carb right. You should come in just around your budget if you are careful. 65mph probable, 80? eat lots of beans and find a big hill. But your bike will feel like it does 80!! :baddevil:

servetakid wrote:So the speeds I hope for aren't the preserve of the the rb and ts1 crew?

No,its just with ya TS's and RB's,they will do it most days,the iron SIL will do it on a good day on the right road.

Ignore my desired speeds, just go with "a bit faster than a T5".

Just been talking to the lad who was going to tune my barrel and the port timings are very low. 143 degrees on the exhaust port and 93 degrees on the transfers. Apparently, to get the desired port timings, the barrel would need machining from the top...

servetakid wrote:Ignore my desired speeds, just go with "a bit faster than a T5".

Or,



All of these will go slightly faster than a T5. And none of them involve messing with the rest of your Lambretta

I'll just try and shoehorn one of those engines under my pannels

e type wrote:At least with cast you can rebore it no expensive nicasil Replates when it go's boom lol

Which it will.....

servetakid wrote:Ignore my desired speeds, just go with "a bit faster than a T5".

Just been talking to the lad who was going to tune my barrel and the port timings are very low. 143 degrees on the exhaust port and 93 degrees on the transfers. Apparently, to get the desired port timings, the barrel would need machining from the top...

Good timings for touring would be 148 inlet, 123/4 transfers, 172 exhaust. With a good expansion and a 30mm PHBH running through a breathesweet filter you should acheive mid/high 70's mph, hold at 60/62 cruise. A T5 won't get over low 60's mph in reality, and the above state of tune on a 225 lambretta would have about 17/18 bhp which is well above the 14/16 bhp that a Mallossi 172 T5 will put out without serious modification. You need a tuner who's able to actually port the transfers to get the timings required rather than adjust them by using spacers (although a combination may be the best solution)

To those who think that the inlet timing I suggested is a bit tame . . . . I really, really don't like fuel spitting back out of carbs and this timing is enough unless you are after balls out revvy power (nothing wrong with that if it's what you prefer just not my cup of tea these days)

servetakid wrote:So the speeds I hope for aren't the preserve of the the rb and ts1 crew?

yep.....

Special X wrote:

servetakid wrote:Ignore my desired speeds, just go with "a bit faster than a T5".

Just been talking to the lad who was going to tune my barrel and the port timings are very low. 143 degrees on the exhaust port and 93 degrees on the transfers. Apparently, to get the desired port timings, the barrel would need machining from the top...

Good timings for touring would be 148 inlet, 123/4 transfers, 172 exhaust. With a good expansion and a 30mm PHBH running through a breathesweet filter you should acheive mid/high 70's mph, hold at 60/62 cruise. A T5 won't get over low 60's mph in reality, and the above state of tune on a 225 lambretta would have about 17/18 bhp which is well above the 14/16 bhp that a Mallossi 172 T5 will put out without serious modification. You need a tuner who's able to actually port the transfers to get the timings required rather than adjust them by using spacers (although a combination may be the best solution)

To those who think that the inlet timing I suggested is a bit tame . . . . I really, really don't like fuel spitting back out of carbs and this timing is enough unless you are after balls out revvy power (nothing wrong with that if it's what you prefer just not my cup of tea these days)

I think the idea with skimming the barrel, was that the port timings are so low this would be the easiest way of raising them. (Tho not ideal).

Definitely not ideal as although it will advance exhaust and transfer timing the inlet will be decreased. Also the ports need to be enlarged and reshaped to deliver optimum performance. It may be that a combination of raising the barrel and porting is the ideal. Sometimes you may get away with using a 1mm spacer and a thin or no head gasket without skimming the barrel.