6 replies to this topic

[The-Womble]

Model: Sprite 1275 Carb
Year: 1993
Description of problem (please be as in depth as possible):
I currently have a stock 1275 engine in my Sprite. I've bought a new Stage 2 Maniflow LCB and centre exit, and will be fitting it along with a water-heated inlet.

I'd like to change my air filter too on my HS4, from stock to a K&N Cone filter or Pancake filter, although I don't really know what the difference is in terms of efficiency/performance etc.

Which would be more suitable?

Thanks

Any non-standard parts that might be involved with the problem?
Maniflow exhaust system
Water-heated inlet manifold

[Stevee]

cone filer more area for air to flow into the engine

pan cake filer restricks the flow of air.

[Barman]

Cone filter with Stub Stack?

[Cooperman]

You need not bother with the water-heated manifold. It is usually better to keep the inlet charge as cool as possible. As for filters, the K & N cone with a stub-stack is the best. Another good 'tweek' is to put a small chamfer on the carb piston at its leading edge. A 30 degree x 3/16" chamfer, smoothed off with emory, does give slightly better throttle response and it's easy to do.

[Cerberus]

Cone filter with Stub Stack?

+1,

vizard recommends stub stabs highly.

This is what I shall be replacing my old pipercross filter with.

[The-Womble]

Ah yes, forgot to mention that. Got a stub stack to go on too. Looks like I'll try and get myself a cone filter then.

[bmcecosse]

You can instead simply file a nice smooth entry radius on the mouth of the carb - as large as possible. This will eliminate the vena contraca just as effectively as the 'stub' - and still keeps the inlet a good distance away from the front face of the filter. If the 'stub' has any length - it ends up far too close to the filter end cap. Pancake filter is useless - don't do it! The radius on the piston leading edge is also well worth doing - as are the various other mods á la Vizard!

Edited by bmcecosse, 31 October 2010 - 06:08 PM.