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Triumph Spitfire - Twin SU 11/4 on a late 1980 Spit

Hello,

I saw on e-bay a pair of SU carbs with an intake manifold. It was said that it will fit 1296 and 1500 spit or Midget. Is it true. And will it be benificial to the spit if compare to a sole Stromberg set-up.
I like the Spit but it is anemic for performance. Is there a way to give some guts to that car without transforming it like a comp. one.

Thanks,

JGC
Jean G. Catford

What you want are H-4 "1 1/2" carbs.
Then you will have to redo your linkage.
This is the way they sold in Europa.

bernie
Bernie

Hi Bernie,

I already have plenty of HS4 at home but does the 1296 intake manifold will fit a 1500 and what will be the improvement.

Thanks,

JGC
Jean G. Catford

Hi,

Not a very popular thread as few people are here to participate. My second question is: does a one weber set-up will be better or should I try a twin SU on a 1500 engine.

Thanks,

JGC
Jean G. Catford

Well, it depends. Which "one weber set-up" are we talking about? If you are talking about the single downdraft DGV (could be DGAV, DGEV depending upon choke type) carb, they work pretty well out of the box. Bear in mind that this is not really a performance carb, it is a nice no fuss, no muss street carb and as long as you don't want to set the world on fire it will do a good job for you. If you are talking about the single 40DCOE or 45DCOE set up, it gets more complicated.

The DCOEs are a performance carb and can be set up to work well, but generally are not set up correctly for your application out of the box. You will have to play with jets and venturis. The great thing about the DCOE is that it is infinitely adjustable, the frustrating thing about the DCOE is that is infinitely adjustable. If you are thinking about going the DCOE route, get your hands on the John Passini book(s) (at one time it was two books, went out of print, came back into print as a single book, don't know the print status of it now). There is another good one out of the UK you should get, Des Hamills "How to Build and Power Tune Weber & Dellorto Carburettors." The Pat Braden book is another good one, but not as good as the first two mentions in my mind. The Haynes manual is Ok from a repair standpoint, but does not really go into the operational theory of the DCOE carbs like the others.

On to the SUs, they can do anything. From an easy going street carb to a rip roaring race carb. If I a remembering correctly, the manifolds from the 1300 will fit the 1500, but the HS2 carbs would be stretched at the upper ranges. You really need to go with HS4 or HIF4 carbs on the 1500. Manifolds can be found, you may want to contact Ted Schumacher at TSI imports, that is where the one for my wife's Spitfire came from. Sometimes Ted even gets the factory air filter assemblies.

Try these the Totally Triumph Network and Paul Tegler's "Teglerizer" as they have more Spitfire information:

http://www.totallytriumph.net/cgi-bin/dcforum/dcboard.cgi

http://www.teglerizer.com/triumphstuff/index.html
SteveP

Hi Jean: I have a '74 Spitfire. I am currently running a twin HS2 setup on it as we speak. My setup was off of a '69 Spitfire, that would make mine SU HS2 AUD285F and AUD285R, with AN needles. My intake manifold is for a 1296. It fits and runs super, these are a big improvement over the single stromberg. I also have a set of HS4s that I removed to rebuild this winter. I do notice a slight decrease in overall preformance with the HS2s, however I was running a stock airbox with the HS4s and K&N filters with the HS2s. I don't have a weber setup on mine but I have driven ones with the downdraft carb on. They are fine but not worth paying $400 to $600. Remember that carbs are only as good as the rest of your cars systems, they won't cure a bad engine, but can make a good one better. You should be careful about buying anything on ebay, ask lots of questions about what the seller is selling, arm yourslef with knowledge!
Alan S.

Thanks All,

I think I will go with SU set-up as being more affordable and having a lot of knowledge with them. The Spit engine is in good shape but I have in mind it is only a 1500.

Cheers,

JGC
Jean G. Catford

This thread was discussed between 08/02/2005 and 12/03/2005

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