[Spridgets] SU Carb Help Sought

miniac7 at aol.com miniac7 at aol.com
Mon Jan 16 08:41:02 MST 2012


I recently had an A-series engine built for a street driven Sprite and now
need to select the intake system. I am trying to decide between twin SU
HS2bs or twin HS4bs, and I have the following questions:

a) Which of the above choices would be most appropriate for this engine?

b) Which needles and springs should I start off with?

The engine spec is as follows:

1275 block bored .020 (1293)
surfaced .010 clean up cut
1.625 con rods balanced and reconditioned
.020 Omega 6 cc dish pistons with Swain Tech PC 9 skirt coat
1275 12g 1316 smog head
ported and chambers shaped
new cast valve guides
hard exhaust seats
1.410 intake valves and seats cut to match
1.150 exhaust valves and seats cut to match
Kent MDM 276 camshaft
1.5 alloy roller tip rocker assembly
Isky springs and alloy caps
Approx. compression ratio 10:1
Pertronix Ignitor Ignition
Rebuilt and recurved Lucas 25d distributor
LCB exhaust manifold with tuned exhaust

I am considering using twin pancake K&N air filters, possibly with internal
stub stacks.

If you cannot help answer these questions yourself, I would like to know who
the bgo-to-guyb is for these types of SU carb selection and tuning
questions.

Thank you.

Howard Collins
Virginia Beach, VA.
'60 AH Bugeye Sprite
'68 Austin Mini


More information about the Spridgets mailing list