Twin 1 1/2 inch carbs on A series

[gavin]

Considering this wee upgrade alongside getting my new exhaust system built. Are there any differences between different carbs of the same size ie 1 1/2 SU, 1 1/2 s4 etc? Any recs for what to drop in to an A series from a Marina?

Cheers,

G

[gavin]

Re: Twin 1 1/2 inch carbs on A series

Duh!

Found it all out.

For numpties / newbies like me here is the gen...

The SU refers to the manufacturer, Skinners Union. The number refers to the size, in 8ths of an inch plus one inch, so an HS4 is made by Skinners Union, and is 4/8th of an inch pluis 1 inch ie 1 and 1/2 inch in size.

Phew! From the info I\'ve found the 1275cc A series will take HS4 or HS6 size twin carbs.

Prolly not news to anyone here but theres bound to be someone (ie another total newb ) who finds it useful.

G.

[ggrum]

Re: Twin 1 1/2 inch carbs on A series

Gavin,
You could consider fitting a single 1 3/4" SU carb (HS6 I think) instead of the twins. Much easier to set up (no balancing) and much the same performance. Most of the Mini tuning outlets supply a water heated inlet manifold that takes this carb. I did this when I had a highly tuned A series engine in my car and was very pleased with the results. Although I took this engine out several years ago I might still have the details of the needle and jet I used if you are interested.

[dogoncrazy]

Re: Twin 1 1/2 inch carbs on A series

Try WinSu on your PC for carb needles and the like. If you can beg ,steal or borrow a copy of David Vizard'sbook on tuning the 'A' series that will also help,though you may be persuaded to consider a single carb set up on a decent intake manifold [a single 1 3/4 inch HIF type from MG Metro and it's manifold] This will have the advantage of having a needle that will be virtually correct for your engine.

[amalgamated users from prior forum]

Re: Twin 1 1/2 inch carbs on A series

Message originally posted by: Alan Hogg
Carb and manifold on e bay. Item no. 300042542139

[b_caswell]

Re: Twin 1 1/2 inch carbs on A series

I have looked through my ref books and all the A series 1300 engines use HS2 in pairs or just one HS4 only the older H4 carb is listed as a converion in pairs. I think twin HS4 and definately the HS6 will be over carbing the engine which will cause iceing up. But askBurlen Fuel Systems Ltd. they produce all the SU spares etc. www.burlen.co.uk

[amalgamated users from prior forum]

Re: Twin 1 1/2 inch carbs on A series

Message originally posted by: Peter Nutter
Gavin, You might try a phone call to an old friend of mine call Stuart at Minisport Padiham (I used to work there)01282 778731 He will ask loads of questions, Cylinder head std/modified, carbs, air filter, camshaft std or what spec. But he should be able to get you close on needles. If you fit the twins then balancing them is an art, you need someone who knows the SU's or if you wish to be spot on then rolling road is only way

[mary-anne.caswell]

Re: Twin 1 1/2 inch carbs on A series

su's are great but not an exact science if you are looking for out and out power on a tuned engine a single side draught webber has got to be better surely failing that you could always put it on throttle bodies !!!!!!!!!