swapping carbs on 1200

[Ali Ramjet]

WE have a 1200 estate and are thinking of ways to up the performance a little. can we swap the solex carb for twin su carbs from a 13/60 and if we do would we have to also swap the exhaust manifold?

[Mark Hammond]

Exhaust manifold, 6 port inlet manifold all from Spitfire MKl or ll but you'll need a hotter cam and the Spitfire dizzy plus a head skim to see any benefit.

Mark

[Clive]

Different cylinder heads as mark points out. You need the bits from a spit 1 or better spit 2 (which has a proper 4 branch manifold)
Fit a full spit 2 engine and you should get about 70 bhp.

However, there are a couple of flavours of herald 1200 engine, from a little under 40bhp up to about 50. Worth checking which engine you have. (pretty sure the main differences are cam and CR)

Of course, there is alwasy the engine swap option......

[Ali Ramjet]

We don't want to go down the engine swap option as here in NZ you have to get this certified and give lots of money to someone just so they can say it's safe. WE had a 2000 engine that would fit but decided to stick with the 4 pot. From what I can tell it's the 48hp engine that came out just before the 12/50. It's registered as a 1968 1200 estate so one of the last 1200's made. Had been stripped down to the chassis before we got it and we have since fitted disc brakes to the front and vitesse seats. also mgf wheels and are giving it the woody look. My sons project(his first car)

[Ali Ramjet]

I've done a bit of research and we have a gd engine which should have the "Hot" cam from the 12/50 engine. I also have a 2 inch exhaust pipe that could fit and there is a 2 inch 4/2/1 manifold available. Could I bolt all this on and improve the power.

[nang]

If you could find a Spitfire engine our vehicle inspectors wouldn't know the difference. It's still a Triumph and still a 4 cylinder.  >:(
They don't in Wairoa and I'm sure they wouldn't in Dannevirke either.
Tony.

[logicaluk]

If you can sort out a decent manifold the 1147 on is appalling,  im planning to build my own, I temporarily used a 1300 exhaust but it never sealed properly. Then go for it The solex is pretty crap, every time ive looked for twin su's they were pricey so I used a pair of acclaim carbs, sleaved on to the 1147 inlet manifold stumps.

I think there's a spit 1500 cam giving almost 0.100" of extra lift, (same timing) in it but ive not checked yet. I do have a lucas dm2 40755 dizzy whith 16 deg mec and 12.5deg of vac advance. All this and a lot less body work makes for a fun drive in the special.