jagnut66 Posted May 2, 2021 Report Share Posted May 2, 2021 Hi, What is the best Carb to get the most out of a Herald 1200 engine performance wise? Personally I prefer SU to Solex or Stromberg but what about a Weber? Best wishes, Mike. Link to comment Share on other sites More sharing options...
Clive Posted May 2, 2021 Report Share Posted May 2, 2021 The lemans spitfires had 1200 engines, and used a pair of webers. But they did have 8 port heads.... There is a lot more to gaining performance than just the carburettors. Within the herald 1200 engine family the power ranged from 39-50bhp, and the mk2 spit was 67bhp. Of course, better, cam, head, compression and a 4 branch manifold all helped, as well as a pair of SU's. Link to comment Share on other sites More sharing options...
AndyTV8 Posted May 2, 2021 Report Share Posted May 2, 2021 The factory upgrade was to switch to a pair of HS2’s on an 1147 Spitfire inlet and exhaust manifold - that is the path I’d go if I wanted a little more oomph from an 1147 Herald. ...... Andy Link to comment Share on other sites More sharing options...
jagnut66 Posted May 2, 2021 Author Report Share Posted May 2, 2021 Thanks for the replies. On the 'A' series in Morris Minors I have always found that a single larger SU works better than a smaller twin carbs set up, though this may be down to the design of the 'A' series itself. However it makes me wonder if a single larger carb may work better on the standard Triumph 1200 than a HS2 twin set up? Of course I am ready to stand corrected on this. Best wishes, Mike. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 2, 2021 Report Share Posted May 2, 2021 probably why 13/60 went to a single stromberg CD150 ?? Pete Link to comment Share on other sites More sharing options...
jagnut66 Posted May 2, 2021 Author Report Share Posted May 2, 2021 As an aside, I have watched the 'Car SOS' episode, when they restored a Herald and updated it to fuel injection. Whilst I like the idea I dread to think how much it cost out here in the real world..... 49 minutes ago, Pete Lewis said: probably why 13/60 went to a single stromberg CD150 Any idea what the equivalent SU would be? HS4? Best wishes, Mike. Link to comment Share on other sites More sharing options...
Clive Posted May 2, 2021 Report Share Posted May 2, 2021 1 minute ago, jagnut66 said: As an aside, I have watched the 'Car SOS' episode, when they restored a Herald and updated it to fuel injection. Whilst I like the idea I dread to think how much it cost out here in the real world..... Any idea what the equivalent SU would be? HS4? Best wishes, Mike. Yes, HS4 is a 1 1/2" carb. The car sos idea failed really, think it got taken off as it just didn't work, it woukld have needed a bespoke ECU/map. If you want more power, use the head (or have yours skimmed) to match a mk2 spitfire CR, and use that cam (or mk3 spitfire profile) Fit the best manifolds you can find, or a 12/50 version at least. And there are adapters to fit a stromberg to replace the solex. That will give about 60bhp quite easily I expect...that is maybe 50% more than what you started with if an early 1200. Link to comment Share on other sites More sharing options...
PeteH Posted May 2, 2021 Report Share Posted May 2, 2021 Patient work, gas flowing the inlets will help, a decent (4-2-1?) manifold will usually produce results. Pete. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 2, 2021 Report Share Posted May 2, 2021 6 hours ago, jagnut66 said: However it makes me wonder if a single larger carb may work better on the standard Triumph 1200 than a HS2 twin set up? I ran my 1200 on a single Stromberg using a carb adaptor; it actually went quite well on the original 6J needle. All I had to do was adapt the throttle linkage. I have one of these for the SU carb and am planning a bit of experimentation later on with the carb from a Morris Minor (or is it the Ford Anglia?) which has the float chamber at the correct angle for this style of adaptor. I have the carb, just can't remember what it came from... I have a drawerful of manifolds - Weber (two variations, plus carb), Twin SU, Alexander Twin Stromberg 125, but most of them will only really work with an uprated cam and other tweaks. For the Weber I have an original blank, never tapped, to fit a carb straight to the original cast manifold which with a bit of surgery you can adapt to use with a tubular exhaust manifold, plus I have the side-fitting version for the 1147 engine. Might get round to trying it someday... Link to comment Share on other sites More sharing options...
jagnut66 Posted May 9, 2021 Author Report Share Posted May 9, 2021 On 02/05/2021 at 21:16, Colin Lindsay said: I ran my 1200 on a single Stromberg using a carb adaptor Hi Colin, Where can I get one of these carb adapters from? Many thanks, Mike. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 9, 2021 Report Share Posted May 9, 2021 They come up for sale online from time to time although nowhere nearly as frequently as they used to. I've amassed quite a collection of different versions for use with different carbs but the Stromberg CD150 was the only one I've actually used in anger so far. If I find one for sale I'll link to it. Link to comment Share on other sites More sharing options...
jagnut66 Posted May 9, 2021 Author Report Share Posted May 9, 2021 Hi Colin, It looks like you have the type I'm after for the SU, so if you spot one for sale I'd be grateful. I shall heep an eye out too, what brand are they (generally speaking)? Many thanks, Mike. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 9, 2021 Report Share Posted May 9, 2021 bear in mind some adaptor angles do not take into account the jet height and float level angles it can be a must have that turns into a headache do some good homework of what will work Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 9, 2021 Report Share Posted May 9, 2021 4 hours ago, jagnut66 said: Hi Colin, It looks like you have the type I'm after for the SU, so if you spot one for sale I'd be grateful. I shall heep an eye out too, what brand are they (generally speaking)? Many thanks, Mike. Speedograph used to be the main type that came up for sale. As Pete says buy the correct SU carb with the float chamber at an angle - mine is from either an Anglia or a Morris Minor but possibly one of the slant-four Triumphs would supply an equivalent. The pic is just a mockup ( actually back to front) but it shows how the manifold fitting and the base of the float chamber are in the same plane. Link to comment Share on other sites More sharing options...
PeteH Posted May 9, 2021 Report Share Posted May 9, 2021 Way back. I grafted a Donated Stromberg, onto the Mini. Only required an adapter plate and two extra gaskets. I think it is still sculling about somewhere.? In my view it was not a successfull graft and soon reverted back to the O/E. Pete Link to comment Share on other sites More sharing options...
Andy M Posted May 11, 2021 Report Share Posted May 11, 2021 Wouldn’t part of the question be what is “best”? In very general terms (carb designs and manifolds etc. will of course have a significant impact too) a single carb is likely to have higher gas velocity and thus better fuel atomisation at lower revs so will generate it's torque at lower revs - good for a heavier saloon. Twin carbs or twin choke Weber might flow better at higher revs so be good for a revvy light car, like a Spit, but actually generate less torque at lower revs. All depends what you want. Torque at lower revs is nice for a street car...Power is good bragging rights but if it all happens north of 4000rpm it’ll be a horrible drive on the road... I cut my teeth on a 1300 Dolomite (single Larger SU) and then moved to a 1296cc Spitty with Twin HS2s. Spitty liked to rev but needed it to shift. Dolly was happy to chug along. More or less the same engine. In the end, the best 1200 carb might just want to have more cubes on the engine end of it, as the Americans sort of say 😚 Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 11, 2021 Report Share Posted May 11, 2021 Interesting that my 948 coupe was twin SU but I was looking at a 1200 coupe recently that is single Solex carb. With the uprated cam and manifold they must reckon the Solex has the extra oomph necessary. Link to comment Share on other sites More sharing options...
jagnut66 Posted May 22, 2021 Author Report Share Posted May 22, 2021 A single 1 3/4" SU would be my preference, if I can ever find an adapter to swap from downdraft to sidedraft. Never been a fan of Strombergs. Best wishes, Mike. Link to comment Share on other sites More sharing options...
Badwolf Posted May 23, 2021 Report Share Posted May 23, 2021 Mike - Don't tell that to Pete L, he'll cry!! 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 23, 2021 Report Share Posted May 23, 2021 cry, if it messes it up it wont be my fault!!! have to say 1 .75" on a 1147 sounds a complete oversize stromberg rules the day , all day Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 23, 2021 Report Share Posted May 23, 2021 36 minutes ago, Pete Lewis said: have to say 1 .75" on a 1147 sounds a complete oversize stromberg rules the day , all day Pete That is big. I ran a 13/60-sourced 150 on the 1200 for a time, never really messed with needles but always wondered if a 125 might not have been enough. The Alexander manifold used twin CD125s but really needed a hotter cam for best performance. Link to comment Share on other sites More sharing options...
jagnut66 Posted May 23, 2021 Author Report Share Posted May 23, 2021 Sorry, error on my part, I meant 1 1/2". Best wishes, Mike. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 23, 2021 Report Share Posted May 23, 2021 1/4" size matters Ha Pete Link to comment Share on other sites More sharing options...
Prince Brainier of Meccano Posted June 14, 2021 Report Share Posted June 14, 2021 Many years ago I was offered a 28/36 DCD from a 1500 cortina as the corner of the top casting had snapped off. I araldited it back on and had no problems with it at all. Then, how to make it fit the standard herald 1200 manifold. Just 4 sheets of 3/16 aluminium later it was on! All sheets cut to the size of the weber base and corner drilled for fixing. inch and a bit hole in the bottom one and fixing holes for manifold. Cut to size hole for the twin chokes in the top one. Bottom one bolted to manifold, next one cut to fit round the bolts. 3rd one sort of average of 2 and 3. Then removed and roughly "flowed" into best fit from top to bottom with a round file. Re assembled with gasket goo and worked like a charm. Dramatic difference. I reckon it was as fast as 1600 vitesse. BIG MISTAKE. put the float at the back of the carb so it flooded under hard braking. Other than that I think more economic on the small choke and very rewarding when floored. 1 Link to comment Share on other sites More sharing options...
jagnut66 Posted June 14, 2021 Author Report Share Posted June 14, 2021 Hi, I spotted this kit for a Land Rover SU conversion but would the base be too big? Best wishes, Mike. Link to comment Share on other sites More sharing options...
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