Could you fit aircooled/2v barrels & heads onto a SBK/4v bottom end? Interested into the theory behind running a 2v lump in a SBK chassis, with the single-sided swinger etc? Rumour has it the head studs are a different spacing?
yep all fits up until you get to the 996 and testastretta motor then the studs were moved but case mounts are still the same air cooled superbike has been done there was a racing class that made it popular feeling better mate? Steve
This is the sort of post that just feeds my sickness.. :smile: Right then, if you use the 4V bottom end could you just ditch all the water pump malarkey and fit a 2V alternator cover, giving you somewhere to plumb the oil returns from the barrels?
In my Monster build I bought an ST2 engine (cam donor), the bottom end is basically the same as my M900 and 916, the ST2 being a 'hybrid' having the 900 crank and the 916 ignition pickup and water pump drive. I sold the ST2 bottom end to a chap who was using it to rebuild a 900 Monster that had cracked the case (chain break), assuming you swap over the flywheel/alternator/ignition pickups etc then it should be fine as the mounting points for the aircooled pickups are still fitted in the watercooled cases. You 'may' need to cut the excess off the end of the shaft that drives the water pump but it looked as though it would clear OK, and it would be harder going the other way as you'd need the longer shaft plus I'm not 100% certain if the air cooled engine has the correct cutout in the gear for i.e. ignition pickup? Sometimes cost-cutting by a cash-strapped manufacturer has it's benefits... :biggrin:
Buy cheap 74*, 9*6 with a broken motor (belt snapped etc), get a cheap 900 motor off the forum/eBay - & a project begins!
All combinations are possible - some require more money and time than others. Take my 900SSie - 1000DS barrels and pistons - had to sleeve the stud holes and rebore (they are different spacing) and external oil feed to the heads. 1100 crank - just fits in. Lightwaight flywheel and balance. Goes quite well if I say so myself. So much so I have a customer who has hired it 3 times this year at Castle Combe - his 'normal' ride is either a BMW 1000 and a GSXR 750 - he loves the low down torque. Dont tell him but I've not put the 14 tooth front sprocket on yet
