carbs

[Morrison]

he guys can u up grade the carbs on the 1098 engine to webbers or somthing like that
?

[minor_hickup]

I believe the a series can be run on:
Various SU's
Downdraught webers (28/36 DCD, 32/34 DMTL, 46/48 IDA Downdraught)
Fish Carbs (Minnow engineering + Leanord Reece + co)
Side draught Webers (40/45 DCOE)
Side draught Dellorto (similar to webers)

[bmcecosse]

Of course you can ! But it's not the first mod to do because the main restriction on power comes from the cylinder head with it's small valves, and the poor exhaust system along with the one-piece inlet manifold which which pours heat into the ingoing air/fuel mix and reduces the barometric efficiency of the engine. So - if you want more power - start with a better head and decent manifolds - then add a bigger carb - and really the 44 (or even the 38) HIF SU is plenty big enough for a 1098 engine. If the engine is in bits anyway - take the chance to fit a better camshaft, but it's not a high priority because the 1098 breaks if you rev it much over 6000! However a crankshaft damper helps with this - so try to get hold of one from a Mini - it bolts straight on.

[jonathon]

I have a super pair of 11/4" SU carbs on an Armstrong branch manifold.Includes all linkages, but may suit a 948 rather than a 1098.

[Morrison]

so what type of head would you all reccomend

[bmcecosse]

The 'standard' answer is the 12g295 head from the MG 1100 (also 998 Mini Cooper) - which has bigger inlet valves and much better porting and combustion chambers! However it needs some skimming to get the compression ratio right - about 80 thou - BUT if you find one it needs to be checked to make sure it hasn't been skimmed already. More adventurous is to use the 12g940 head from the 1275 engines - this needs a bit more work - PM me if you think you want to do this!