996 Cylinder compatibility with 748?

Anyone know if the 996 cylinders are compatible with the 748 motor (besides the need to mill out the crankcases for the larger cylinder spigots). I'm wondering about stud placement & diameter, head compatibility, etc.

Anyone know?

Thx.

the stud spacing is different, so the holes won't line up. if you machine your cases out big enough to take the spigots there'll be not very much left to hold the studs in. vee two do a 98mm conversion for small stud spacing big blocks that involves cnc machining to leave material in the cases around the studs but not between them.

the 996 cases, cylinders and heads are unique due to the stud spacing. the heads are different in the exhaust cam section too (lower). everything else for a given year model should be a straight swap.

Thx Brad.

I figured that if anyone knew the answer, it would be you!

Good info - saved me from bidding on a set of used 996 cylinders, to find they don't fit....

I have a set of 996 cases if you really want to tackle the project, but by the time you by a 996 crank, rods, pistons, cylinders, etc., you'd be far better off just buying a 996 motor and slotting it into your 748 chassis.

748 crank in 2mm over 100m bore 996 cylinders (pistons from bcm) with some custom length carillos will be 966cc.

all you need is cases, cylinders, bare heads, valves, exhaust rocker covers, pistons and the carillos. how hard could that be?

LOL! Harder than a non-machinist can undertake!

I do wonder, however if boring the 748 crankcase to take 98MM bore thin steel sleeves (similar to the Fox 96MM kit but with a small 2MM widening of the crankcase spigot and using milled 996 98MM pistons on custom Carillo rods.....

Let's see....an 11500RPM 927cc 748 running a set of 36MM /31MM valves through a good port job under a set of 996 SPS or Veetwo cams, through 54MM throttle bodies under an oversize airbox, and pushing through a 45/54 Silmoto system should be quite a screamer - dispalcement WITH lots of revs! I'd guess around 140-150 SAE BHP should be attainable?

Oh well....nice to dream, but I think it'd be tough to find a tuning shop who would be willing to take on such a build - for a reasonable price, eh!

and you think my way is complicated!

call fox and see if he's interested in 98mm kits. not a bad idea. you'd get 102 from a 996.