I've been considering replacing the ZS with an SU HIF6 from the Marina.
It's a direct swap, as I understand it. What sort of
performance/economy gain will I see, if any? I'm also thinking about
putting in a pre-75 cam, along w/higher compression pistons, in an
effort to get a little more gusto from the thing!
(PS- I have a 1979 B)
Cherrs,
Brian Furgalus
Thomas James Pokrefke, III wrote:
>
> Chris Delling wrote:
>
> > I have a RBB, and no experience with S.U.'s. I know that different types
> > were fitted to B's. Which type is preferable, and why?
>
> Chris:
>
> It's a matter of personal prefrence. The SU's fitted to MGB's were the
> HS series and the HIF series. I run with the HS's, any comments
> regarding the HIF's comes directly from the Haynes Carburetor Manual.
>
> With the HS's, the entire device is much simpler. In fact, I have
> totally dismantled my carb, in emergency situations, with the body still
> attached to the intake manifold. There are seperate 'areas' for each
> component, ie - the float bowl is independantly bolted to the body, the
> suction chamber is easily accesible, etc.
>
> The HIF has two unique features that make it more complex and, in some
> instances, more desirable. HIF stands for 'Horizontal Integral Float
> Chamber'. The float chamber is at the bottom of the carb body, sealed
> by a large O-ring. While this arrangement elimantes the sometimes
> troubling jet tubing found on the HS series, it also eliminates the
> possibility of two minute float adjustments and fuel bowl cleaning.
>
> The major advantage, in my opinion, of the HIF is it's temperature
> compensation device. Down here in Mississippi, my HS's run fine in the
> hot, humid summers. During winter, we go from 60 degrees to 30 degrees
> in no time. The HS's, or at least mine, don;t take this well.
>
> The HIF uses a bi-metallic strip of metal to control the height of the
> jet (and consequently how much fuel gets mixed with the incoming air).
> The HS series offers no such provision.
>
> Of course, it's a personal choice. I had a chance to upgrade to HIF's,
> but the HS's are still there. One thing is certain, though. Either SU
> is better than the Z-S.
>
> Thomas James Pokrefke, III
> pokrefke@c-gate.net
> 1970 MGB
> 1995 Nissan Pathfinder
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