52 replies to this topic

[jamiestevenbell]

hi guys just a quick question in general how much power can be ran on a set of twin hif38s, i mean as in whats the limit of them? im rrunning a hif 44 at the moment but im thinking it may be restricting me a little, and im running 93bhp at the fly. Any advice is much appreciated i just dont want to be cutting the bulk head for a webber at the moment.
cheers

[jaydee]

If you can find a set twin HIF38s..although its possible to get twin HIF44s i'm afraid theres no handed HIF38 so you have to fabricate your set yourself.
Someone on here has done it though, so worth have a look around.

Much easier to get hold of a set of twin HS4 carbs which will be perfect for your engine.

[jaydee]

Burlen seem to sell a RH (rear hand) HIF38 body, if you want to build your own set:
http://www.sucarb.co...earch=&Id=27619

[jamiestevenbell]

ah ok thanks ill have a look around but that link would be useful if anyone knows where it is and id prefer twin hif38s over twin hs4s in an ideal world lol. wont hif44s be too big?

[jaydee]

Yes, 44s are too big, 38s would be ideal.

[jamiestevenbell]

or are twin hif4s what i need

[jaydee]

Why are you so exotic..
They're mg carbs so you can find a set of twins already build, but i have no idea of them in a mini. They should be the same of HIF38s, but dont quote me on that.

[jamiestevenbell]

ye i have just seen a set on ebay from what i can see the difference is the flanges on the carb where it would mount onto the inlet manifold. if any one else could tell me the difference it would be much appreciated

[freshairmini]

I think the general thing thats used are twin HS4's as I dont think you can get an intake with twin HIF flanges, only the HS flange ones, or at least that will fit a mini.

[jamiestevenbell]

ok thanks guys ill have a look into it.

[Cooperman]

With a high compression big-valve gas-flowed head, a really good exhaust system and a 'hot' cam you would be advised to use twin HS4's on a good inlet manifold.

[jaydee]

Maniflow sells the inlets (pricey stuff) alternatively you can just drill two holes to the twin HS4s inlet.

[jamiestevenbell]

ah ok and cooper man it sounds like just what i need im running a 286 cam, big valve head, maniflow stage 2 manifold and maniflow single box exhaust system. thanks guys

[Cooperman]

I run twin H4's on my rally 'S' with 286 etc, and it does go very well. They came off of an MGA and I got them in the USA, then re-built them for a Mini with certain mods to improve their flow capability.

[Petes.one]

From time to time on eBay manifolds are available with square carb mounting flanges which can be drilled for a four bolt HIF type carb, or if you can locate a good fabricating engineer have a similar manifold to the Maniflow one made up. HIF4 carbs work well and are 'sided', but need a bit of modification to work best. The anti-run-on butterfly valves are best changed to the plain ones (don't want that bulky valve sitting in the air flow), and most HIF4's had no vacuum take-off (was on the manifold). HIF4, like the HS4 and H4 is imperial, one inch and four eighths, ie 1 1/2".
HIF38 is the metric version. HIF38's can be used as twins easily enough although the chokes can't be directly linked unless you can get hold of an RH body. Alternatively it's not too difficult to make up a split choke cable to connect to both. The HIF38 and HIF44 carbs have a bearing that the dashpot piston rides in, making its action smoother than the earlier HS type cabs.

Twins will look the part but probably not perform much better than your HIF44! Remember only one inlet valve is open at a time, so each cylinder will be exposed to a 38mm/1 1/2" or a 44mm carburettor at a time. You would need a well designed manifold to get the best from twins, and the typical log type manifold with that gaping big balance tube disrupting flow is not the best option.