SU HIF38 Plumbing/Pipes Diagram

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svenedin
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SU HIF38 Plumbing/Pipes Diagram

Post by svenedin »

A diagram of the various pipe connections to the SU HIF38 carburettor courtesy of Declan Burns. This diagram is referenced but lost from many old threads on this forum.

As I understand it, there are left and right versions of HIF38s with the version with most connections opposite the exhaust downpipe being more desirable in a Minor.

Stephen


HIF38 Vacuum advance.jpg.jpeg
HIF38 Vacuum advance.jpg.jpeg (356.19 KiB) Viewed 2351 times
HIF38_plumbing_GB.jpg.jpeg
HIF38_plumbing_GB.jpg.jpeg (105.57 KiB) Viewed 2351 times
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
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Re: SU HIF38 Plumbing/Pipes Diagram

Post by Sleeper »

Would help knowing what open/extended, A , B are?

John ;-)
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svenedin
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Re: SU HIF38 Plumbing/Pipes Diagram

Post by svenedin »

The tube labelled open/extended is an overflow from the float chamber so it can be left open as a breather or extended with a drain pipe.

A and B are some kind of economy system that weakens the fuel mixture at constant motorway speeds.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
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Re: SU HIF38 Plumbing/Pipes Diagram

Post by Sleeper »

I think B (A in red ) is the distributer vacuum advance

John ;-)
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Re: SU HIF38 Plumbing/Pipes Diagram

Post by panky »

The inlet elbow can be kept as the Mini air box will fit with a simple modification. The vac advance port is shown in the first picture :wink:
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svenedin
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Re: SU HIF38 Plumbing/Pipes Diagram

Post by svenedin »

Sleeper wrote: Sat Oct 25, 2025 11:12 am I think B (A in red ) is the distributer vacuum advance

John ;-)
That's on the first picture on the top.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
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Re: SU HIF38 Plumbing/Pipes Diagram

Post by Sleeper »

Yes.

John ;-)
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