HS4 vs. HIF4

[tdskip]

Hi guys,

Any thoughts experience on which SU is the better carb for regular road use?

 

[tony barnhill]

I personally like HIF-4's...am in the middle of rebuilding a set of HS-4's right now but its my only car that I've not converted over to HIF's

 

[tdskip]

Tony, in your experience are they as easy to tune as HS-4's ?

 

[DrEntropy]

<*RASPBERRIES*>! /bcforum/images/%%GRAEMLIN_URL%%/jester.gif

 

[tony barnhill]

I'm not a real good carb guy but I like them because of the integrated fuel bowl..the guy who can answer that question is Doc

Right now I've got a set of HS-4's completely apart & there seems to be more possibilities of problems with them (centering jet, etc.)

 

[DrEntropy]

Again, duelling posts! /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif

 

[DrEntropy]

Where's that <squelch> button?!?!

 

[tony barnhill]

Whadda ya think, Doc - personal preference only difference in them?

 

[DrEntropy]

Kinda-sorta. I like the hard mounted needles and the bowl lids for convenience, the HIF's not so much. The floats & needles/seats in the HIF's are more hassle to service. Needles in the HIF's are intermittantly rubbing the jet at changes in RPM. It takes a long time for that to be detrimental (hogs out the jet orifice to an oval) but it kinda seems 'funny' to me. It also makes an odd kind of liquid/vapour column appear at the inboard side of the needle, a laminar flow issue. Not quite as efficient as the older, hard centered piston/needle combo. The "package" of the HIF's is neater looking, the flow characteristics are nearly identical, so really it's down to what you want/like, yup. If it were a car for a track career it'd be the older ones, if a street machine, it would be less an issue.

 

[tony barnhill]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]If it were a car for a track career it'd be the older ones[/QUOTE]

HS-6's for track car - with insulated fuel bowls.

 

[tdskip]

Thanks guys - I appreciate the info.

 

[BOXoROCKS]

I'm sure no expert,but boy I got an opinion on these, I dont like HIF carbs. A pain to adjust the float,and more prone to flooding.They are just a more complicated, expensive carb,and every set I have ever had caused way to much trouble.

Just noticed,is that 66 alfa an "alfa romeo giulia sprint GT veloce" gotta love the Italians.

 

[DrEntropy]

Pick yer "drivers"!

LBC's are my first choice, the eye-tie coupes are a close second. Very close. They're spectacular as trustworthy steeds.

 

[Guest]

The problem of the HIF float adjustment is overrated. Do it right once and you're done. I find the HS far harder to adjust and far more prone to fuel leakage from the jet tube when the tube developes a crack

 

[tony barnhill]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]far more prone to fuel leakage from the jet tube when the tube developes a crack [/QUOTE]

which they will from the constant up & down movement - they'll leak right at the fuel bowl.

 

[Hap Waldrop]

I build a buttload of SU carbs, they are both good carbs and fairly trouble free when serviced and rebuilt with the right parts and by someone who understand these very simple carbs. The HIF4 is easier to rebuild, the HS4s are easier to live with once on the car, for that reason alone, if I'm starting from scratch, I lean towards the HS4s.