H4 ST Twin SU

[rolesyboy]

Does anybody have details of the length of braided hose that sits atop of a pair of ST H4 carbs please? I am about to have some braided and don't know how long they should be or the correct route this pipe should take ie over the inlet, behind the carbs etc?? Any pics and measurements would be appreciated in my time of need.... Cheers. Mark

[Toby]

From the centre of the banjo to the end its 40 cm

[rolesyboy]

Thanks. How is it meant to be routed? What fittings go on the end? Cheers. Mark

[su_mark]

Routing is up to you (and length really, depending on routing..) but is normally something similar to the pic below. Fittings would be double 90 degree banjo on one side for the fuel inlet to that chamber and on to the second chamber, then single banjo on the other side. Held in with standard SU chamber banjo bolts and fibre washers. Just about visible in pic.
You can either use 'push on' type banjos and clip or crimp the hose to them, or, as in this pic, use threaded banjos and have screw on fittings crimped to the hoses...
There is a theory that a nice long connecting hose from one chamber to the other can help with fuel starvation caused by hard cornering if you race....

[mk1]

Welcome to the forum Mark!

I guess you should be elected our new Carb Guru

Incidentally, how much do you know about tuning Amals?

[su_mark]

I guess you should be elected our new Carb Guru

Elected sounds a bit formal! happy to help where I can!

Incidentally, how much do you know about tuning Amals?

Not my personal top subject but as above, try me! Plenty of expertise in the room next door!

[rolesyboy]

Magic, thanks SU Guru.... Any chance you could email me a copy of that picture so I can zoom in on it. I will send you a private message with my address on. Thanks for your help. Mark

[dgear1984]

Hi,

What should the length be of the hose from the chassis hard fuel line to the first carb? Also need to get some hoses made

Thanks Dave

[dgear1984]

Hi,

Do you know why the bmc st parts manual has AUC4045 choke levers and my SU book says a mini cooper needs AUC4823 (AUC4817)

Thanks Dave

[su_mark]

Hi,

What should the length be of the hose from the chassis hard fuel line to the first carb? Also need to get some hoses made

Thanks Dave

I think it is a case of measuring really as it depends on the set up/space in the engine bay. I'm sure there is standard measurement somewhere but even changing the type of carburettor will require a slightly different length. Best thing is to measure using a flexible piece of garden hose or similar so you cAn work out the length including any bends etc. I would always allow an inch or two extra as it's better to be a little on the long side, rather than short!

[dgear1984]

Hi,

What should the length be of the hose from the chassis hard fuel line to the first carb? Also need to get some hoses made

Thanks Dave

I think it is a case of measuring really as it depends on the set up/space in the engine bay. I'm sure there is standard measurement somewhere but even changing the type of carburettor will require a slightly different length. Best thing is to measure using a flexible piece of garden hose or similar so you cAn work out the length including any bends etc. I would always allow an inch or two extra as it's better to be a little on the long side, rather than short!

I'll gets the string out just to be on the safe side. Thanks

[dgear1984]

Hi,

Do you know why the bmc st parts manual has AUC4045 choke levers and my SU book says a mini cooper needs AUC4823 (AUC4817)

Thanks Dave

Can anyone shed any light on this? Was planning on ordering the bits i need to rebuild the h4's on Monday. Will also ask su when I order the bits. I know a lot of people put h4's on minis

Thanks Dave

[66S]

Here is the alternative fuel line route, used in some applications.

The choke arms on mine seem to have the part numbers hand stamped, so possibly made from something else. In my notes, I have written "AUC1019" possibly the number cast on them.

Regards
Al

[dgear1984]

Hi,

Finally got around to building up my H4's today.

Can anyone tell me what the throttle bracket is that I see people using in there photos?

It look similar to the AEG349, although taller and also looks like it has an anchor that can rotate.

Thanks Dave

[66S]

Hi Dave,
The bracket I have was on the car when I bought it so I can't tell you what it is. I'll attach a couple more shots that might help. The works setup shows the cable passing through the abutment plate and there is a socket on it that the cable would spigot into but, if aircleaners are installed, the cable won't fit there so there must have been an alternative cable bracket for use with aircleaners. Maybe the one on my car is the proper part for use with aircleaners ??

Regards
Al

[dgear1984]

Thanks for those pictures, at least I know what to look out for now.

It wouldn't surprise me if it's something out of the mg parts bin.

I'll keep looking

[SteveG]

Nice carb porn Al

[dgear1984]

well I have done a fair amount of google image searching and can't seem to see any brackets like that, only complete used carbs with the same or very similar bracket to yours

Thanks

[dgear1984]

well I have done a fair amount of google image searching and can't seem to see any brackets like that, only complete used carbs with the same or very similar bracket to yours

Thanks

can't believe it, found a bracket in a box of rubbish in dad's garage. Still not sure what it was from......

[66S]

Wow, that looks pretty much the same Dave. How often does that happen? You search everywhere for something and then find one in a box at home !!

Al