Hooking up a HIF carb

[alex_holden]

I've now got a HIF38 carb to fit to Fenchurch (actually, I've got two - I bought a second as a spare). I also have an alloy inlet manifold, a spacer block, a choke/throttle bracket, and a few questions.

1. Can anyone post a picture of how the choke and throttle cables attach to the bracket? I think there must be a couple of bits missing from mine:

I don't mind making replacement fittings but it would be handy to know what they're supposed to look like first.
2. What's the stud on the top of the bracket for?
3. Is there supposed to be a separate throttle return spring between the end of the cable and the exhaust clamp like with the HS2 carb, or are the two springs on the butterfly valve shaft sufficient?
4. Does the bracket normally go between the manifold and the spacer, or between the spacer and the carb?
5. Is the connection I've circled in this photo supposed to be piped to the rocker cover breather? If so, is there supposed to be some kind of inline filter in that pipe?

6. Is it normal the angle of the flange on the manifold causes the carb to be tilted towards the engine slightly?
7. Both the carbs are quite dirty and were sold as "unknown condition," but they don't look badly worn. Do you think it's worth fitting full service kits (which cost more than I paid for the carbs), or are they likely to work OK if I just give them a good clean inside and out and oil the linkages?
8. I've bought a K&N cone air filter for it (pricey ). It draws air in from all around the cone rather than sucking it from around the exhaust manifold area via a tube - is that likely to cause a problem with carb icing or long warmups in winter?
9. Does anyone have a registered copy of WinSU and would be willing to run my details through it and tell me what needle it recommends?

[Welung666]

Hope this is of some help.....

1. Red = Choke, Yellow = Throttle


Choke cable is held by a small spring clip that fits in the slot on the plate.

2. Air filter mounting thread.

3. In a word no Not that I've ever seen anyway.

4. Between the carb and spacer (Always use a new gasket though).

5. IIRC the breather that was on there went into the original plastic air filter.

6. Yea they normally sit at a slight angle.

7. I'd personally pick the cleanest and clean it again. if it doesn't work as it should then maybe get a recon kit.

8. It won't help winter warming and could potentially cause some icing in really cold weather.

9. Can't help with the WinSU but try here. Easy enough and shows you a rough comparison between 5 needles.

[Packedup]

1. Can anyone post a picture of how the choke and throttle cables attach to the bracket? I think there must be a couple of bits missing from mine:
I don't mind making replacement fittings but it would be handy to know what they're supposed to look like first.

I can't post a pic, but you need a spring clip for the choke. You see the slot in the bracket? One end of the clip goes in there, the other end clips over the edge of the bracket, clamping the cable in a raised section. I'm pretty sure the clips are available for around a quid from Minisport and the like.

The throttle cable slides into the hole from the side, and has two large plastic flanges to stop it moving back and forth. I might even have a NOS Mini/ Metro one here, but I'm not sure it'd be long enough for a Minor.

2. What's the stud on the top of the bracket for?

Air filter housing - I'm guessing it's a Metro carb, so there'd be a wing bolt screws through the housing onto the stud normally.

3. Is there supposed to be a separate throttle return spring between the end of the cable and the exhaust clamp like with the HS2 carb, or are the two springs on the butterfly valve shaft sufficient?

There's no extra return spring, the ones on the carb are enough. And they also act rotationally rather than linearly on the spindle, another reason why the HIF is a better carb

4. Does the bracket normally go between the manifold and the spacer, or between the spacer and the carb?

I can't remember for sure, but I'm pretty sure it's manifold, spacer, bracket carb. It's obvious when you fit the cables though as the wrong way makes them look just wrong, IIRC.

5. Is the connection I've circled in this photo supposed to be piped to the rocker cover breather? If so, is there supposed to be some kind of inline filter in that pipe

Yes, and no. Well, normally it hooks up to the crank (and on 1275s transfer housing) breather system, which have oil/ air seperator cannisters. But it's not a problem to plump the line straight in without seperators, filters etc. I know there's been a lot of debate (OK, arguments) over this, but I'd vent the rocker to atmosphere (running a pipe so the fumes didn't enter the cabin) and blank off the breather inlet on the carb altogether. But unless your engine is breathing very heavily you're not going to be getting critical amounts of oil vapour back into the inlet side of things anyway (the reason this is bad is the warm oil/ air mix ignites too easily, causing knocking and general lack of peak power).

6. Is it normal the angle of the flange on the manifold causes the carb to be tilted towards the engine slightly?

Yes - These carbs are angled slightly on Metros, perfectly normal.

7. Both the carbs are quite dirty and were sold as "unknown condition," but they don't look badly worn. Do you think it's worth fitting full service kits (which cost more than I paid for the carbs), or are they likely to work OK if I just give them a good clean inside and out and oil the linkages?

If the jet looks ovalled then replace, otherwise see how it goes. You'll have the wrong needle anyway, so worry about smooth clean running later

8. I've bought a K&N cone air filter for it (pricey ). It draws air in from all around the cone rather than sucking it from around the exhaust manifold area via a tube - is that likely to cause a problem with carb icing or long warmups in winter?

I hate the cone filters because of the hot air issue. As in they will breath some of the hot air from the exhaust area, as well as the generally warm unbonnet air. Less so than the standard Minor setup I suppose, but still more than is needed. Personally I'd use the Metro filter casing (with a K&N element if I could afford one) and run a cold air feed from the grille to it. So in other words, you shouldn't have a problem at all with icing.

Can't help with WinSU or needle choice, nut I'd throw it together and see how it drove. If you can afford a rolling road session or can get hold of WinSU then all teh better (rolling road being the best), but you can roughly work out the right needle by finding the flat spots and cross referencing on the cspec charts/ lists

[chrisd87]

Alex, I think you might have an HIF38S carb, same as I have in my garage. This is because it has the (snipped off) pipe joining the flage on the manifold side. From memory, it should join the outlet you have circled in pink. This is an additional weakening device that leans out the mixture slightly at part-throttle cruising for better economy. If you have a copy of the Vizard book then it should be explained in there (on p. 127/8 in my 3rd edition copy).

[alex_holden]

Thanks, that's a big help.

I'll probably turn up an adapter widget for the end of the throttle cable, and drill out the spigot on the carb body so I can attach the choke cable in the same way as on the HS2 carb.

I wonder how hard it would be to get hold of a new oil separator canister for the breather pipe.

I think I may have spotted a way to deduce the recommended needle from the information the unregistered WinSU provides. I'm a bit of a cheapskate so the full rolling road treatment isn't really on the cards. ;)

[alex_holden]

Alex, I think you might have an HIF38S carb, same as I have in my garage. This is because it has the (snipped off) pipe joining the flage on the manifold side. From memory, it should join the outlet you have circled in pink. This is an additional weakening device that leans out the mixture slightly at part-throttle cruising for better economy. If you have a copy of the Vizard book then it should be explained in there (on p. 127/8 in my 3rd edition copy).

Very interesting. I thought that was something to do with the float chamber breather. Both the carbs have it, and the rubber pipe has perished and broken on both of them. I don't think it connects to the pink-circled connection though, the pipe goes to the connection next to the petrol inlet on both carbs.

I still haven't got around to buying the Vizard book...

[Kevin]

2. What's the stud on the top of the bracket for?

As mentioned its for holding a mini or metro style filter housing in place by (as also mentioned) with wing bolts the other stud would have been in the elbow outlet on the other side of the carb, I intend changing mine for an MG metro filter housing as the current K & N cone one that is fitted is just too noisy for me, so just beware that they do give off a lot more induction noise.

[alex_holden]

I've poked around a bit with the unregistered WinSU, and I think it's recommending the AEH and AEJ needles, which are almost exactly the same as each other.

I can also tell from the profiles in its technical library that the two needles I have (AEG and ADS) are virtually identical, and they're similar to AEH/AEJ at the low-mid range but a fair bit too lean at the top end.

[alex_holden]

As mentioned its for holding a mini or metro style filter housing in place by (as also mentioned) with wing bolts the other stud would have been in the elbow outlet on the other side of the carb, I intend changing mine for an MG metro filter housing as the current K & N cone one that is fitted is just too noisy for me, so just beware that they do give off a lot more induction noise.

I had one on my Land Rover (combined with a Weber carb) and I rather liked the gurgling idle and the "whoosh" it made when you revved up

[Packedup]

Found the clip

http://www.minispares.com/Product.aspx?pid=37553



It looks suspiciously like the ventilation control cable clip on my Triumph too...