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H4 Carbs on a mk1 1275 s

Posted: Sat Feb 08, 2014 4:40 pm
by dgear1984
Hi,

I have picked up a set of H4 T2 carbs cheaply and I intend fitting them to my 1275 s at some point

They have 20deg bowls, I realise you need 30 deg for a mini, but have heard you can bend them so will try that. Any advice on doing this, I have an oxi bottle to warm them up with.

When the works cars fitted these they used a fork system. Does anyone have any pictures of the c.aht brackets, done a google search nothing really came up.

If someone has some good photos of the setup for real, that also could be nice to go along with the sketch I have below.

Thanks Dave

Image

Re: H4 Carbs on a mk1 1275 s

Posted: Sat Feb 08, 2014 5:13 pm
by 5portsrock
Hi ,
When i bent mine i mounted the bowl in the vice length wise. In this position i measured the angle of the banjo fitting ( using a protractor and bubble from a combination set ) to establish what angle i had once in the vice.
Then rub the leg between the bowl and banjo hole with soap ( once black its ok to attempt the bend ) and heated slowly, I done mine using a small propane torch.

Then placed adjustables across the banjo fitting and moved it slowly till the desired angle was achieved.

As for the fork and peg conversion, all parts are avalable from Burlen, worth a phone call as the bits arent listed on their website.

send me a pm with your email ,ill send some pics of the setup .

Re: H4 Carbs on a mk1 1275 s

Posted: Sat Feb 08, 2014 6:10 pm
by scott6058
PM sent
Thank you Scott

Re: H4 Carbs on a mk1 1275 s

Posted: Sun Feb 09, 2014 3:01 pm
by Toby
Here is a pic of an the conversion kit that special tuning was selling for the fitment of H4 carbs. The bracket you are referring to is the gold coloured one in the middle:

Image

Similar brackets were used on H1 carbs :

Image

I would have a spare one of the black ones

Re: H4 Carbs on a mk1 1275 s

Posted: Thu Feb 13, 2014 11:23 pm
by dgear1984
Thanks for the replys.

I am keen to see some pictures if anyone has some.

I assume the silver parts below the gold bracket are the caht2? Does anyone have any dimensions of these, so I can make some :-0

Thanks Dave

Re: H4 Carbs on a mk1 1275 s

Posted: Fri Feb 14, 2014 12:32 am
by scott6058
masnarda wrote:Here is a pic of an the conversion kit that special tuning was selling for the fitment of H4 carbs. The bracket you are referring to is the gold coloured one in the middle:

Image

Similar brackets were used on H1 carbs :

Image

I would have a spare one of the black ones
Damn Toby what may you not have in your DOUBLE DOUBLE secret stash. You always pulling something special out of you hat.
The kit for the H4's is awesome :o
By the way I almost had the NOS 1071 crank as he called me first for a valuation but at least I'm happy you got it.
My Engine and gearbox build is nearing completion but its held up by me with choosing a cam.
What cam would you suggest for a fast road mini?

Whatever your doing don't stop. ;)
My 1071 resurrection will commence this spring as I now have the time, space and plan.
Cheers Scott

Re: H4 Carbs on a mk1 1275 s

Posted: Fri Feb 14, 2014 12:40 am
by jay weinstein
the silver spring anchors are 4 3/16 " long. the 2 holes are 3 5/8" center to center.
there's a picture of a set of carbs using the st carb kit on the mk1 site at re: goy,the original mini sprint. page 3

Re: H4 Carbs on a mk1 1275 s

Posted: Fri Feb 14, 2014 9:13 am
by mk1
I may still have a few C-AHT2's. I used to get them laser cut by the bucket full at one time.

But since I lost the tooling for the C-AHT1's I haven't bothered getting any more done.

That H4 fitting kit is very nice indeed!

M

Re: H4 Carbs on a mk1 1275 s

Posted: Fri Feb 14, 2014 9:45 am
by Pete
Sorry to swerve slightly OT but I have a beautiful set of H4's surplus to requirements that'd go nicely with a kit if anyone's interested.

Re: H4 Carbs on a mk1 1275 s

Posted: Sat Feb 15, 2014 3:46 pm
by scott6058
PM Sent Pete

Re: H4 Carbs on a mk1 1275 s

Posted: Tue Feb 18, 2014 6:41 am
by Toby
scott6058 wrote:My Engine and gearbox build is nearing completion but its held up by me with choosing a cam. What cam would you suggest for a fast road mini?
If I were you I would go for a 544, it is the best option for a fast road mini with a 1071. Would have to check but I do think I have one in my lock up.

Re: H4 Carbs on a mk1 1275 s

Posted: Sat Feb 22, 2014 11:24 pm
by scott6058
masnarda wrote:
scott6058 wrote:My Engine and gearbox build is nearing completion but its held up by me with choosing a cam. What cam would you suggest for a fast road mini?
If I were you I would go for a 544, it is the best option for a fast road mini with a 1071. Would have to check but I do think I have one in my lock up.

T PM sent

Re: H4 Carbs on a mk1 1275 s

Posted: Fri Feb 28, 2014 2:52 pm
by CooperTune
Strange place to find a cam shaft chat. I have used my share of 643/544 NOS cams over the years. Mostly in serious 1275s. 12.3 to 1 CR, ported head with 45 DCOE, SC/CR 4.35 CWP. Flat foot it at 1800 RPM and it would smoke slicks on 6X10. Add 1.5 rockers and you'd loose 500/600 RPM on the bottom.

I still but NOS ST cams when I can find them. I have been finding all cams I remove from engines have serious cam and lifter damage more than just wear. I removed a APT VP3 SP that had been in place 2 years. He was 1/8 mile drag racing but to have all but one lobe with deep pitting? I swore off regrinds about the time I installed this one. The new cams ground on new blanks with rifle drilling and oiled lobes work for me. I have not revisited one of these yet but holding my breath. Proper spring pressure, lubes and break in oil and procedure. Steve (CTR)

Re: H4 Carbs on a mk1 1275 s

Posted: Fri Feb 28, 2014 9:21 pm
by dklawson
Are you guys really installing H4 carbs or HS4 carbs?

Re: H4 Carbs on a mk1 1275 s

Posted: Sun Mar 02, 2014 7:59 pm
by dgear1984
dklawson wrote:Are you guys really installing H4 carbs or HS4 carbs?
h4 on mine

Re: H4 Carbs on a mk1 1275 s

Posted: Mon Mar 03, 2014 8:37 pm
by dgear1984
masnarda wrote:Here is a pic of an the conversion kit that special tuning was selling for the fitment of H4 carbs. The bracket you are referring to is the gold coloured one in the middle:

Image

Similar brackets were used on H1 carbs :

Image

I would have a spare one of the black ones
What bracket will I need to use to hold the outer part of the throttle cable? Or is it the same bracket as used with the hs2's, aeg349?


Thanks Dave

Re: H4 Carbs on a mk1 1275 s

Posted: Mon Mar 03, 2014 9:27 pm
by Toby
The 349 will do the trick

Re: H4 Carbs on a mk1 1275 s

Posted: Sun Nov 20, 2022 12:23 pm
by 970s
Talking about H4, I would recommend the Swiftune H4 fitting kit that use O ring and spacer to prevent vibration, and a nice set of stud with nuts, worn H4 with OE rebuild kit needs some experience and skills during rebuilt, but interesting.

Al :P

Re: H4 Carbs on a mk1 1275 s

Posted: Sun Nov 20, 2022 1:33 pm
by Rolandino
I have a genuine, barely used 643 cam. Pm me if youre interested. R