h4 questions

[almondgreen]

Yesterday I got a twin H4 carb set.

I have some questions about them.

The linkage under the carbs (choke?) is missing.

Is it possible to run them without it ?

The setup is for left-handed cars, the fuel bowls are both on one side to give clearance to the brake master cylinder.

Is it possible to fit the choke linkage, when the fuel bowl is between both carbs ?

[LarryLebel]

If they are H4s I would be inclined to consign them to a museum or do you mean HS4s. You won't be able to start your motor without chokes. FYI twin carb LHD cars, at least Cooper and S, had handed carbs with float bowls on the outside. What you probably have is single carbs cobbed to fit on a twin carb setup. There are twin carb setups that use 2 single carbs, the 1800 S comes to mind. To get around the problem of operating both chokes a twin choke cable was used instead of a linkage. I once looked for a twin choke cable for one of my Landcrabs but they are thin on the ground. I think some Triumphs used them as well. You might be able to get away using a choke on only 1 carb.

[almondgreen]

Ok, I will throw them away....

[rich@minispares.com]

andreas

you can buy a kit from burlen that allows you to remove one (or both) chokes from the bottom of h4's

my 1071 road car has run with a set of single choked h4's for years with no issues, the cable just pulls on the one choke lever

[mk1]

If they are H4s I would be inclined to consign them to a museum,

So all the folks running FIA pre 66 Historics who are paying £1000 for a new set from Burlen are wasting their money are they?

There are a number of advantages that H4s have over HS4s one is the stud pattern, that matches the HS2 stud pattern, another is the fact that the body is longer which tends to improve low end torque. I would never use a set of HS4s over a set of H4s.

There is no reason why you shouldn't be able to run them without a choke as long as they are a little rich at the bottom end. but as Rich suggests the best thing to do is have one carb choked and the other not, I have done this mod on lots of sets. That way you should be able to get a choke in OK. I haven;t built a LHD set so cant suggest part no's etc.

[swindrum]

Twin choke cables were available on Sunbeam Alpines, I think I might even have one.

[dhenry]

H4 carbs are superb. They will perform admirably if built and setup properly. I look after race cars that have no chokes and they start just fine. Even on cold days. You can get all the parts you need from Burlen and there is no reason the two choke arms cannot be linked to pull from one cable. Using the choke on just the one carburettor would work ok too. One of the pair should have a fast idle which will be linked to the choke arm. Use that one for a single choke setup.

[mini63]

andreas

you can buy a kit from burlen that allows you to remove one (or both) chokes from the bottom of h4's

my 1071 road car has run with a set of single choked h4's for years with no issues, the cable just pulls on the one choke lever

yep, single choke twin H4s work fine.

[mk1]

Quick pic of my rubbishy old 1300's engine c/w it's only fit for the scrap bin H4s.

[smithyrc30]

I've got some rubbishy H4's as well. Plus a bunch of choke levers.

All the holes in the levers are much bigger than the pins which makes me think I am some bushings short because when they are assembled without them the flop about all over the place.

Am I missing some bits?

Cheers

[dhenry]

No the levers are just worn out. You could try to bush them or buy new ones from Burlen.

[mk1]

Some types of lever did have a large hole for the choke actuator it was to allow some built in "slop" so you could get some fast idling before the auto enrichment kicked in.

[smithyrc30]

I just went to look at the Burlen site and pretty much most of the levers have 'large' holes where mine do.

Which lever part numbers would be used for the Mini set up please?

I have 3 sets of carbs two on Mini manifolds and they all have different levers.....

[mk1]

There are various levers that can be used.

The ones I use are AUC 4045 which are having just checked the ones that Comps Dept used too.

M

[smithyrc30]

Hmm, ok they look like a set that I have and the holes look to be the same size.

However there seems to be a big discrepancy between the pin and hole.

I'll take some measurements over the weekend.

['S'-type]

While this is a hot topic , I don't suppose anyone has got 4814 and 4815 (30 degree) floatbowls for sale (just the bare bowls). Trying to convert some horizontal H4's for mini use. Wrong section I know.

[mini63]

Here's my shite H4s....problem I have is i cant get them to run anything other than perfectly....

[mini63]

While this is a hot topic , I don't suppose anyone has got 4814 and 4815 (30 degree) floatbowls for sale (just the bare bowls). Trying to convert some horizontal H4's for mini use. Wrong section I know.

4815 is standard OHV morris minor....
4814...yes, a little less common.
Burlens £72...

[mk1]

However there seems to be a big discrepancy between the pin and hole.

See my comments above. The big hole & small pin is to allow for some free movement. If everything is tight you have to be Hercules to pull the choke knob.

[velopackrat]

If this works, attached is a pic of my H4 setup with only one carb choked, which works perfectly fine to get the engine going. LHD car. When I had both carbs choked, the cable tension was quite a lot and not easy to operate.