vauxhallviva.com

Since this went to print I have an update, first in case you didn't know the SU HIF38 is a 1 1/2" and the HIF44 is a 1 3/4" carb. The HIF38 uses a 90 thou jet and the HIF44 uses a 100 thou, the 38 uses an A-- needle and the 44 uses a B-- needle spring loaded. Complicated. The Stromberg CD150 uses a 100 thou jet which got me thinking.

I have since changed the jet in my HIF38 to a HIF44 100 thou with a BDL needle and it works very well with pulling power up to 60 [ speed limit ], I haven't used it enough for economy but the plugs are a good colour. I have also made a new sandwich throttle bracket.

This seems a very simple and worthwhile conversion. Back in the 70's I fitted a 1 3/4" SU to a friend's 1256 Chevette, at that time I was running s DCD Weber on my 1256 Viva. I reckoned the SU conversion far easier to set up and better in every way to the DCD I was running.

The 1 3/4" will probably only have a very slight edge on the 1 1/2" at high revs, so probably very little advantage on going to 1 3/4" unless you envisage further modifications to head, cam and exhaust.

Also, the HIF series is an 'emissions' carb so you may find that your MOT test is easier to pass for those with post Oct '75 cars where emissions are tested.

1972nail wrote:Also, the HIF series is an 'emissions' carb so you may find that your MOT test is easier to pass for those with post Oct '75 cars where emissions are tested.

August 1975 just to be pedantic
I have purchased an HIF 38 after reading this article, just waiting on the car coming back from the paint shop.