Originally Posted by
keavze
other than gaining more topend, any 'ill-effects'?
sucks more nitro, hotter, etc...?
other than a slighter higher consumption, I have not seen any side effects.
I'd recommend the 2617 pipe after you shimmed it.
if i add 0.2mm under sleeve, i got to remove 0.2mm from the button head right? to have the same head clearance...
Yep, that's correct
Btw, I am using head shims of a .26 GO engine. These shims have an inner diameter of 17.2 mm. Our engine (Picco & Nova based) sleeves have an outer diameter of 17 mm. The won't fit on Sirio, there sleeve OD is 17.5mm.
I cut the outer rim of the shims with lexan scissors.
There is also a RB 323/523 engine which has head shims with 17 mm ID, but it's a bit of a tight fit.