biggest bore on a lambretta

[cezeta]

ive been working down at southampton uni where there is a building dedicated to an ex (rip) lambretta racer. whenever i go there we speek engines as the new guys are all rd and rgv boys.

we got talking about bore sizes of lambretta being ltd to 72mm max and they suggested having my mugello 225 steel linered much bigger ignoring the studs then having new stud holes machined to suit the new bore size and sleaving them with alli tube and weding them in.

then open up the spiggot to suit and plug the old stud holes then drill new ones, welding if needed.

now they did say "obviously we would need to see the barrel and casings" but they were convinced it had been done before.

my first thoughts were to wonder if the new ford cortina piston that i proposed would infact be running inside the transfers and if this could or had been done?

my motives? well big cc low tuned two strokes are actualy really good. old maicos, mz, cz and air cooled scramblers with long strokes and big bores are great to ride.......sorry charlie edmonds

high revving scooters are great on a track im sure but the track rules just dont apply to the road.

i have a mugello 225 engine spare, im wondering if a 62mm crank with a stepped pin can get as long stroke as is possible then max the ccs too. 76 bore and 66 stroke would make a 300cc

now please tell me how stupid and ill thought out this is

[J1MS]

If I was attempting to make a one off barrel for bigger cubes, then I wouldnt run the studs the length of the barrel, I would fit short studs that bolt the barrel with a flange to a modified case, allowing the space that the long barrel studs would take up to be used by additional transfers or more space for cooling fins or a water jacket.
Best of luck with the Cortina piston

[shocky]

anything is possible limiting factors are money and time for most people, i simpler way would be to remove the all the studded area right back as far as poss then weld a 20/25 mm plate about 110m square on there then you could machine the neck to your desired size and have the stud holes were you want them the mag side might be a problem as the spigot might touch , with the above methos you could just bolt a m/c barrel on there .. the dac boys seem to have the right idea and with the basic kit costin about £1500 inc crank i think they have it spot on if you have the time and money and see it as a long term project just to show what can be done then i wish you all the best it will be fun and you can learn alot ....... for me a straight CR250 ENGINE WOULD BE SIMPLER but as iv had 30 yrs of fabrication and welding in a job im gettin lazy

[shocky]

jims beat me to it

[cezeta]

oh i get ya. not a good example but like this:

[shocky]

yes in the same way as some small frame kits ar fitted

[shocky]

another thing to think of is that lammy run the bore horizontally unlike most others

[carlos fandango]

Biggest bore on a lambretta.....



My wife says its me

[cezeta]

Biggest bore on a lambretta.....



My wife says its me

very good

[red ghost]

Biggest bore on a lambretta.....

A Lambretta is a bore... or a very large hole... that I keep putting money into...but I luv'em!