Herald 1200 Twin SU H1 Carbs

[Jon J 1250]

Hi,

Does anyone have any close-up photos of the Herald 1200 (or even 948TC) twin carb arrangement.

I have a used kit to refurb and eventually fit to my 12/50, but the choke cable stirrup connection to the two choke levers is missing and I suspect a bit of the throttle cable linkage is not quite complete either.

Would be useful for comparison, so I can source/make whatever is missing.

Kind Regards

Jon

[Jon J 1250]

Here's a photo

[Colin Lindsay]

https://www.worthpoint.com/worthopedia/triumph-spitfire-mk-ii-herald-1200-168460000

Very small photos on this link, but it's a start. In fact it's NOT Herald 1200, so I'll keep looking...

[Pete Lewis]

burlen show a sectioned views  may help

sucarb.co.uk/technical-h-type-carburetter-diagram

Pete

[Colin Lindsay]

The choke system works on the two levers at the bottom; each has a pivot pin (30) as in the one you still have on the left and they're joined by that small twist of wire stirrup still attached (29). The choke cable comes down through the hole in the middle of the stirrup and is secured with a cable stop. The WSM doesn't really show much other than the assemblies, and yours looks mostly complete. The only part I've found still available is the spring, 108320.

[Jon J 1250]

Many Thanks Colin and Pete, really appreciate you replies, I had a bit of luck whilst searching too and found the instructions for the Triumph kit, so all big help.
Not found any good close up photos yet, but I think I have enough to work with to make it worthwhile rebuilding these carbs, and giving them a try in the 12/50 with a Spit mk2 tubular exhaust manifold.

Do any of the Heralds at the club HQ have twin carbs?

For reference the official Twin Carb Conversion Kit instructions are here:
https://app.box.com/s/o3hq8rip7n2eo6wh6kgb54w145s6h5s6

Colin, out of interest, which workshop manual is you diagram from?

Best Regards

Jon

[Pete Lewis]

its a screen copy from canley classics 

Daves website uses triumph parts list pictures 

www.canleyclassics.com/?catalogue=triumph-herald-948&diagram=catalogues

and carb conversion to twins is also covered 

www.canleyclassics.com/?archive=triumph-herald-1200-twin-carburettor-conversion-kit

 

club shop sells  1200/12/50 triumph  parls list manual 

https://shop.tssc.org.uk/product/parts-catalogue-herald-1200-1250

Pete

[Jon J 1250]

Thanks Pete, i'd never dug in to the archives section of Canley's website, some good stuff there.

Also, I knew the Mk1 Austin Healey 'Frogeye' Sprite also have twin H1's, but on closer inspection it uses the same or very similar choke linkage, and even better, the parts are available!

https://www.scparts.co.uk/sc_en/british-cars/mg/austin-healey-sprite-1958-1971-and-mg-midget-1961-1979/carburettor-and-inlet-manifold/su-h1-carburettors-sprite-i-1958-61.html

[Pete Lewis]

yes it pays to do quite extensive homework on who has what and prices  thereare so many suppliers its a hard job keeping abreast of all 

but of the era most manufacturers used very common and available components 

as fueling electrical and instruments cooling heating all came from a small selection of manufacturers

Pete

[Colin Lindsay]

2 hours ago, Pete Lewis said:

its a screen copy from canley classics 

Yes, the red dots give it away. It saved me taking a page from my own binder and scanning it - am getting lazy!

I've noticed that when searching for elusive Triumph parts, US Suppliers seem to have far more of them available than UK suppliers.

[RogerM]

Hi,  I have just joined the TSSC (again), and have now signed into the forum. I have a Herald 1200 Coupe from 1964, which has twin SU carburettors, so I can try and take a photo and post it.  

I have owned the car since 1980, but its been off the road in storage for most of that time , and is in a bit of a sorry state, and Im planning a ground up restoration, so I'll probably be starting a forum thread on the restoration. 

I have a question about the twin SU's: I have heard somewhere that these came as a factory-fitted option on a new car, but I also understand that they might have been an owner modification.  Is there any records anywhere, or other related forum topics, that might confirm the case in general or with this car in particular?

 

[Pete Lewis]

a heritage certificate will give some build details but don think they show any dealer/  options over and above the base car spec.

https://www.britishmotormuseum.co.uk/archive/heritage-certificates

my lynsay porter and peter williams  resto manual shows 1200 coupe as 5.319 built  61 to 64  

com numbers  ga609cp  to ga162103cp   np mention of engine spec   WSM has no clues  just states single solex downdraft 

but the pre 1961 says twincarbs as saloon   (guess thats aimed at a 948cc) )

sorry not a lot of help 

the nearest is a 1147  Spitfire spec  but theres a a good few small changes there  like cam shaft and valve collets 

Pete

[Colin Lindsay]

10 minutes ago, Pete Lewis said:

a heritage certificate will give some build details but don think they show any dealer/  options over and above the base car spec.

If it's a factory twin-carb saloon - (the 948 coupe was but the 1200 coupe wasn't?) it may show on the BMIHT Certificate as a TC, or else the carbs may be listed on the 'equipment' section along with the heater etc.

[Jon J 1250]

1 hour ago, RogerM said:

Hi,  I have just joined the TSSC (again), and have now signed into the forum. I have a Herald 1200 Coupe from 1964, which has twin SU carburettors, so I can try and take a photo and post it.  

I have owned the car since 1980, but its been off the road in storage for most of that time , and is in a bit of a sorry state, and Im planning a ground up restoration, so I'll probably be starting a forum thread on the restoration. 

I have a question about the twin SU's: I have heard somewhere that these came as a factory-fitted option on a new car, but I also understand that they might have been an owner modification.  Is there any records anywhere, or other related forum topics, that might confirm the case in general or with this car in particular?

 

Many thanks,

It would be really helpful to see some detailed photos. Yours being a 64 model may have the later kit with HS2 SU's rather than H1's, but still, will be interesting to see.

Regards
Jon

[Jon J 1250]

1 hour ago, Pete Lewis said:

a heritage certificate will give some build details but don think they show any dealer/  options over and above the base car spec.

https://www.britishmotormuseum.co.uk/archive/heritage-certificates

my lynsay porter and peter williams  resto manual shows 1200 coupe as 5.319 built  61 to 64  

com numbers  ga609cp  to ga162103cp   np mention of engine spec   WSM has no clues  just states single solex downdraft 

but the pre 1961 says twincarbs as saloon   (guess thats aimed at a 948cc) )

sorry not a lot of help 

the nearest is a 1147  Spitfire spec  but theres a a good few small changes there  like cam shaft and valve collets 

Pete

I think any 948 Saloon or Coupe could be factory ordered with twin carbs, where they also got the small instruments inc temp gauge.
When the 1200 launched the twin carbs became a dealer fit option, including things like double valve springs with collets, better camshaft, and new main bearings (to protect against wty claims presumably) and importantly an instruction to skim the cyl head to bring the compression ratio up from 8:1 to 8.5:1.

At some point (probably when the mk2 chassis was launched) the dealer fit kit changed from twin H1 carbs to HS2 as per the Spitfire, but the Herald presumably did not make as much power as the Spitfire as it is missing the tubular welded exhaust manifold.

My plan is to fit the Herald SU H1 kit, as that is what I have, but a Mk2 Spit tubular manifold and will eventually get the head skimmed, when the head eventually needs some work. My 12/50 already has the necessary camshaft.

Any guesses how much power this would make, assuming an otherwise healthy engine....?  I am hopeful for something just north of 60bhp.

Regards

Jon

[Colin Lindsay]

The twin carb saloons were an individual model, distinct from the single carb saloon and the twin-carb coupe and had their own commission numbers GY1 - GY11392. I thought they used the H2 carb and the Spitfire got the HS2, but haven't confirmed that.

I've found a couple of photos of the 948 TC setup on the Herald-tips-&-tricks site.

 

You can also tell by the manifold; Herald version is much lighter than the Spitfire version.

 

 

[Jon J 1250]

7 minutes ago, Colin Lindsay said:

The twin carb saloons were an individual model, distinct from the single carb saloon and the twin-carb coupe and had their own commission numbers GY1 - GY11392. I thought they used the H2 carb and the Spitfire got the HS2, but haven't confirmed that.

I've found a couple of photos of the 948 TC setup on the Herald-tips-&-tricks site.

 

You can also tell by the manifold; Herald version is much lighter than the Spitfire version.

 

 

Thanks, yes those pictures show H1 carbs as per my kit, but I think the US version of the kit for a side draught air filter, rather than the UK top draught + pancake filter, and the manifold on the left is the same H1 1 1/8 manifold and the one on the right I think is a mk1 spit manifold for HS2 1 1/4 carbs.

[Colin Lindsay]

19 minutes ago, Jon J 1250 said:

 I think the US version of the kit for a side draught air filter, rather than the UK top draught + pancake filter,

It's US, the pedals are a dead giveaway but on any of the UK models I found, everything was hidden under the huge filter, as in my 948 Coupe here...

[RogerM]

This is the TC set on my 1200 Coupe...it has the shiny pancake air filter canisters. 

[Jon J 1250]

39 minutes ago, RogerM said:

This is the TC set on my 1200 Coupe...it has the shiny pancake air filter canisters. 

Fantastic, that's a great shot of the throttle link, i was a bit sketchy about that as Colin says you can't see much under the regular air filter, so most pics I have seen haven't been too helpful.

I really appreciate your help, thankyou.

Best Regards
Jon

[Jon J 1250]

18 hours ago, Colin Lindsay said:

It's US, the pedals are a dead giveaway but on any of the UK models I found, everything was hidden under the huge filter, as in my 948 Coupe here...

Thanks, good point there about the air filter obscuring things.

Do you notice an appreciable difference in power on the twin carb version as opposed to the single Solex? (assuming you have experience of both)

Regards
Jon

[Colin Lindsay]

Well it was a 948 but uprated cam and twin carbs so yes in its' own way, it flew! Of course my other cars were all 1200, the latest is 1300, so it would just about hold its' own against those in standard form. I'd like to try a fully breathed-on 1200, twin carbs, hotter cam and flowed head, just to compare - but it would need to be standard in all other ways, not a rally-prepared vehicle. Just the engine. Oh, and maybe the brakes too... that 948 was front drums and could be scary.

[Jon J 1250]

Visited the excellent NEC Classic car show on Saturday and the club had brought along their lovely Lichfield green convertible which has twin H1 SU's and even better the bonnet was up.
Thanks to this I have finally seen the whole assembly first hand and have taken plenty of reference photos too.

What I can see is that there is no way the Spitfire Mk2, 4 branch exhaust manifold will fit behind these carbs, the inlet manifold is far to short, however may still go ahead anyway, but guess I will need to find a twin carb cast manifold, or cut the inlet part off of a 12/50 (preferably) manifold.

[Colin Lindsay]

Easy to do; just be careful but there's plenty of room for manoeuvre. I've used both parts of the 1200 manifold in my time, top part for a tubular manifold and lower part for twin carbs.

  

 

 

[Jon J 1250]

22 hours ago, Colin Lindsay said:

Easy to do; just be careful but there's plenty of room for manoeuvre. I've used both parts of the 1200 manifold in my time, top part for a tubular manifold and lower part for twin carbs.

  

 

 

Great to see the results of someone who has alreaddy been there and done it, looks like they separate quite cleanly, still a bit reluctant to do this to my original 12/50 manifold, but how long will it take me to find a second one, not found one yet.

Many Thanks