imola porting help !!!

[rocho68]

hi lads , im an engineer in the west midlands , just getting back into the scene after 20 years away , i used to do my own tuning ie kwak 240s , suz 190 etc back in the day , ive now just brought myself an imola to start off with but am looking for help on the porting aspect ie how wide do i go with the ports and how high do i raise them ? ive already welded the casings and matched the transfers and have also pre welded a piece where hopefully i can get a boost port in but need my mind refreshing !!!! any help more than welcome !!!

[sean brady scooters]

is this for the road or track....?

your kit is already in a high state of tune....porting wise,so what do you hope for in further mods...
the exhaust port is already approx 68/70 % of bore wide as std.
and duration must be in the region of 185 ....

welding up your casings and enlarging the transfers is good as is putting the extra feed port from crankcase to reed block.....
the holes in the piston could be enlarged a bit ,and intake side of skirt shaped better perhaps.
but you really do not need to do to much else...
and bear in mind,that if you do alter exhaust port more ,you may need to replate the barrel.
perhaps just fit a JL4 and match the exhaust manifold to the barrel.

[rocho68]

hi sean , thanks for that , infact id already measured the exhaust port and come to that conclusion today after looking at your tips on ts1 tuning , ive already purchasd a jl4 also so i look to be on the right track , weres the best place to take it to get the boost port done or wouldnt you bother for the amount of cost to the gains involved ?
cheers lee

[sean brady scooters]

to do the boost port you may still have to factor in a replate if needed....as you would need to cut a hole into the spiggot to feed it....
Although it is often possible to do it without a replate ...its just that it depends on the quality of plate ....sometimes they just chip away....no matter how skillfull and careful you may be....

but theres another option here maybe so long as you have put extra weld on top of your crankcase far enough back.....
and that is to not have a hole in spiggot at all ....just extend right back into crank circle area...if you know what i mean...
its still more expence for ever diminishing gains though....maybe far better to spend your hard earned on other things
a good gearbox/clutch etc....and hopefully a lightened flywheel...