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Carb type
Posted: Tue Jan 03, 2012 8:00 pm
by 54woody
I'm trying to determine the tyoe of carburetor that's on my car. I'm thinking it's an H2, but would appreciate if someone could verify that for me. The car is a 1954 but it doesn't have the original 803cc engine. Instead, it has a 948cc, but I don't know what year as there is no ID tag on the engine, nor is there an SU ID tag on the carb float bowl.[frame]

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Re: Carb type
Posted: Tue Jan 03, 2012 8:01 pm
by 54woody
Here's a look from the underneath...[frame]

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Re: Carb type
Posted: Tue Jan 03, 2012 8:02 pm
by 54woody
...and from the other side...[frame]

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Re: Carb type
Posted: Tue Jan 03, 2012 8:13 pm
by bmcecosse
Yes! It's an H2. I'm intrigued by the 'band' round the piston bell. Is it a heater element for cold weather??? Is that another heater in the black isolating spacer between manifold and carb ??? And - that air cleaner will be losing you some power - it's far too close to the mouth of the carb ie - it's too shallow..... I like the 'joined up' throttle cable.....

Re: Carb type
Posted: Tue Jan 03, 2012 8:33 pm
by mike.perry
If it came off the 803 engine it would have been an H1 semi downdraft. It has obviously been got at with the modified cables and linkage as well as whatever that is around the carb. The piston cap would normally be brass, not plastic and it would not have the small allen key bolt heads.
The original carb on the 948 was an H2, later changed to an HS2
Re: Carb type
Posted: Tue Jan 03, 2012 10:44 pm
by bmcecosse
H1 has different fixing flange - that IS an H2. Yes - it has a later damper piston fitted.
Re: Carb type
Posted: Wed Jan 04, 2012 1:20 am
by mike.perry
The H1 and H2 have the same position fixing flange, the difference being the distance between the carb mounting bolts. The plastic cap piston damper will fit both the H1 and H2 carbs. The only difference I can see is the relative positions of the tickover and fast idle screws. I will have to check my H2s in the morning.
Re: Carb type
Posted: Wed Jan 04, 2012 7:01 am
by Alec
Hello BMCE,
yes you are right, the band on the bell housing is an anti icing heater.
Alec
Re: Carb type
Posted: Wed Jan 04, 2012 1:56 pm
by 54woody
I think Alec is right about the band around the dashpot. It has a screw terminal on it with a wire connected which runs back to a terminal on the funny looking black carb spacer. There is another electrical wire also connected to that spacer, but I haven't traced it yet to see where it comes from. You can't see it very well in the photo, but the on the band it says "SU AUC 1279". A google search didn't turn up any relavant hits. The car came to me from Colorado, so a de-icing heater might make sense given the high altitude and coooler climate.
The spliced throttle cable, the multi-part fuel hose, the too thin air filter canister...just a few of the "interesting" bits that need to be sorted out on this car. I think the PO's real hobby must've been fabricating improvised car parts. There are just so many "interesting" bits and pieces on this car!
Thanks for the help in ID'ing this carb. The choke doesn't seem to be working so I want to add a service/rebuild kit for it to my next parts order. Who knows what "interesting" things I may discover on disassembling the carb.

Re: Carb type
Posted: Wed Jan 04, 2012 3:45 pm
by bmcecosse
The flange shape tells me it is an H2. I don't see a cable attached to the choke mech of the carb - is there one ? I wouldn't rush into any 'overhaul' of that carb - it won't achieve anything worthwhile - and you may end up with a very leaky carb. Leave well alone I say!! Get a decent air cleaner -new accelerator cable - connect the choke and it should be fine.
Re: Carb type
Posted: Wed Jan 04, 2012 4:26 pm
by mike.perry
How do you distinguish the flange on the H2 from the H1?
I checked mine this morning and the only difference was the spacing of the mounting holes
Re: Carb type
Posted: Wed Jan 04, 2012 4:30 pm
by 54woody
Yes, the choke cable is attached. Just not shown in the photos I posted.
Re: Carb type
Posted: Wed Jan 04, 2012 5:58 pm
by bmcecosse
Mike - the H1 flange is kind of 'shaped' more - and the studs closer together.
On the choke - so if you pull the choke control. inside the car - does the bottom lever pull up and so then (via the pivot) pull the jet assembly in the base of the carb down ?
Re: Carb type
Posted: Thu Jan 05, 2012 4:25 pm
by mike.perry
I still think it could be an H1[frame]

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H2 Carb
Any ideas what this manifold comes off?[frame]

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The choke control pulls the bottom lever up which pulls the jet down. A spring on the other side of the jet returns the lever to the closed position.
There are various designs of lever, depending on the application[frame]

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Re: Carb type
Posted: Thu Jan 05, 2012 6:49 pm
by bmcecosse
Are these really H1s? They look like H2s...... and a very after market manifold. Any marks on it to suggest the supplier?
Re: Carb type
Posted: Thu Jan 05, 2012 7:01 pm
by mike.perry
The single carb is an H1, the twins are H2s, no identification on the manifold. The carbs were fitted with long trumpets.
Re: Carb type
Posted: Sun Jan 08, 2012 10:02 pm
by 54woody
Took the silly excuse for an air cleaner off and measured accross the throat. 1 1/4", so it is an H2.
The choke cable was attached, but no movement of the jet when the cable was pulled. I removed the cable and operated the lever by hand. Jet does not move up/down (see photos).[frame]

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Re: Carb type
Posted: Sun Jan 08, 2012 10:03 pm
by 54woody
Lever up...jet remains in same position.[frame]

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Re: Carb type
Posted: Sun Jan 08, 2012 10:24 pm
by bmcecosse
Is the lever broken at the pivot?
Re: Carb type
Posted: Mon Jan 09, 2012 2:54 am
by 54woody
bmcecosse wrote:Is the lever broken at the pivot?
No idea. I'm not familiar (yet) with how this lever is supposed to operate or even if it standard faire for a Minor. I was hoping someone recognize the lever and advise whether or not it's moving as intended. From the photo, it does appear as though it's either broken or is actually two levers.