Carbs are so confusing... How to tell what's installed? =(
 

http://i97.photobucket.com/albums/l2...i/red_76_6.jpg

I'd like to start my engine clean-up with replacing the huge, plastic air box, replaceable paper filter and and fugly snorkel with a washable K&N type cone filter like this one:

http://www.gbcarparts.com/prodimages/filtercone.jpg

http://www.gbcarparts.com/proddetail...ilterCone1%2E5

According to places like MiniMania, I BELIEVE that the 1992 Mini Sprite (1275cc) was fitted with a single SU HS4 carb (see: http://www.minimania.com/web/Item/FZ.../InvDetail.cfm), however other carbs (HIF6, HIF6/44) are often bandied about...

Is there a simple way for me to ID once and for all what carb I have installed, so I don't end up getting the wrong part?

Also, if I replace the air filter with a unit like this, will I be able to remove the silvery, dryer-vent-looking material currently attached to the underside of the plastic airbox? That venting material is all frayed and disintegrating (maybe from vibration) and needs to be replaced or made obsolete ASAP. It looks like the cone-style filter bolts right to the back of the carb and has no snorkeling or venting at all...

Last, do you have any opinions on the cone filter I linked to? It's less than half the cost of a K&N unit, so I wonder if it's either grossly inferior or does not have all the needed parts. K&N assemblies have the required gasket, for example...

Thanks in advance!

EDIT: Could be a HIF38 as well... I don't suppose there's an ID number stamped on the carb smewhere, or would that just make too much sense? :)

OK - potatoes and rice - they're "high glycemic" or "bad" carbs... as are refined sugars. But a few green beens once in a while are pretty good. But most fruit is really sweet and has lots of bad carbs. But blueberries are good carbs. But bread is the 70's Stornberg of carbs... sudden death... keep away from that... clear?

Just representin' for the late Dr. Atkins. Sorry.

Without looking it's hard to tell, but I think what you are referring to is the heat stove piping. It's to get warm air to the carb for better cold start running. I doubt you'll be doing winter driving with Mini.

IMO I'd buy the K&N. Call the fellow I told you about. He can get the parts you need. He's back in town.

K&Ns are very cheap from AJUSA.com
 

and the previous poster is correct. the stove pipe typically goes to a baflle controlled by a bi-mettalic spring to get warm air in to help with atomization of gas in a cold car. Tear it out as well.

I'd just take the filter assembly off and look at the carb itself. I'm not too familiar with the ones used on Minis, so don't know about identifying marks. Just snap a digital photo and send it off to one who would know.

But that stupid snorkle thing gets air from in front of the motor , where it should be cooler.

Matt

Okay..this is easy....first take off the aircleaner assembly. Look at the carb. If it has a float bowl next to it on the driver's side on your car, it is an HS. If there is no float bowl on the side of the carb, then the float bowl is under the carb, and you have an HIF.

To determine whether a carb is a 2, 4, 6, or 8 measure the diameter of the carb throat/throttle diameter.

1 1/4 = HS2
1 1/2 = HS4 also HIF4
1 3/4 = HS6 also HIF6
1 7/8 = HIF7
2" = HS8
38.0mm (1 1/2in) HIF38
44.0mm (1.73in) HIF44

A cone filter may require re-jetting the carb, at least a re-adjustment as it flows MUCH more air. It is also noisier. I use one.

Also, the pre-heat tube is used in cold climates as SU carbs are prone to carb icing. Most remove the factory stuff and bin it.

Wow - that's impressive - where were guys like you when I had my 77 Triumph? :)

What kind of Triumph were you afflicted with? :wink:

A 77 would have had Stromberg's. Yuck!!!:no:

It's an age thing...
 

when I was driving a Fiat I got pretty good at identifying a whole bunch of Webers.

Matt

:lol: :lol: :lol: FIAT = Fix It Again Tony :grin:

Unless you know the history of the car and carb (unlikely, hence this thread), you need to ID what needle the SU is fitted with. As Minimad said, if you change to a K&N (or a Klone), you'll likely want to invest in a different needle. Depends on what's in there now. At the very least you'll want to know what you already have (make a note of it - it will be useful info once you do a full stage 1 upgrade). Also, if you have a big hole in the firewall behind the carb, plan on plugging it up.

Too bad...
 

my name is Matt. If I'd known that I would have kept going to Tony to have him fix it!

Matt

I was afflicted with a fine '77 TR7 with a long and glorious list of ongoing disorders, including the ever-present and never-effective Stromberg carb... But I got good and randomly turning the screws to see what would happen - kinda like attempting to solve a Rubic's Cube with no method or logic, just blind luck... and the approach was strangely, if only temporarily, effective at transforming the Shape of Things to Come into something between inanimate wedge and unreliable transportation. Luckily, I was a bicyclist back then...

Wow Blimey you had just about the worst Brit car ever made. Before or since. I'm glad you're cured & drive a MINI.:nod: :thumbsup:

yeah...
 

but the little V8 in the TR8 seems like it would be fun to stuff into our little four-banger!

Matt

Yeah. At the time I really wished I had a TR8. Or a Yugo. Or a golf cart. Or a dogsled (in eastern North Carolina). Or ANYTHING other than the wedge.

It only took 21 years - but I'm finally over it... Now I can again drive/enjoy British cars AND lettuce wedges (with extra ranch and fried onions - yum).
:)

Matt the funny thing is once they came out with the TR8 they'd made it into a decent car.:nod: What did they do then? Discontinued it after a 1000 or so were made. Go figure.:confused:

The brillance of British car companies
 

is shown once again!

Matt

I assume it's got whatever was standard for that carb - it doesn't look like anything under the bonnet is upgraded except the addition of the electric radiator fan...

How involved is a needle swap? We're talking full carb strip and rebuild, right? Man, it's been a while since I dissassembled a carb, and I've never had one apart in frint of me without a "real" mechanic standing at my elbow for when I decide to leave out parts... :)

If you do it...
 

just remeber pretty much all rebuild kits have extra parts as they cover a range of carbs! The first time I rebuilt a carb I was wigging out over all these extra little parts!

And like most things on cars, I don't think a carb rebuild is too tought, just getting tto the parts is the hardest part. But every carb I've ever rebuilt required a lot of tuning after, as it had been tuned based on all the deposits that had built up! Clean that crap out and it sure shifts the tune a bunch....

With carbs, it's good to have a clean workbench, and good light as some of the parts are so small. I haven't done an SU in ages (jhelped on some in High School), but I don't remember them as being hard to work on, just, uh, somewhat persnicity with unique personalities!

Matt

Needle swap is easy
 

The needle swap is easy ... three screws will loosen the 'pot' over the carb and let's you remove the piston that holds the needle. One screw holds the needle...very easy to change. The hard part is knowing what needle to put in as after a ton of research the only common advice I found was get it on a dyno with a gas analyser and a hand full of needles..... Altho I'm sure that a little time on the phone with MiniMania or Seven will get you off to a good start. I had the luxury of living near a shop that really knew SU's and had a dyno..... Yes, you can find seat of the pants techniques, but nothing beats a pro. When I took my car in they knew where to start adjusting just from the idle sound, and things just kept getting better from there. (Virginia Beach area, PM if u want the name)

You may want to get hold of a copy of "SU Carburetters Tuning Tips and Techniques", Brooklands Books.
http://www.minimania.com/web/Item/BO.../InvDetail.cfm

This page is a good starting point - altho many of the links r dead now....
http://www.teglerizer.com/sucarbs/index.html

Attached (upside down) is something I found either here or at Minimania. Its what I used to change my needle. No guarantees, but it may be a start. (The scribbles reflect my change. Note that my Mini has a "full" Stage 1 (carb, manifolds, exhaust), so I saw a significant improvement from the stock needle. You may not see as dramatic a change, but it looks like you'd see some improvement once the filter is changed out.

The other thing that makes this a little less scary than the old days is digital cameras... easy and cheap to take LOTS of photos as you go...

"Hmmm.... where did this piece go???" :)

Or, even better, the camera, plus videotape running on the tripod the whole time - so you can slowmo those special moments when four pieces all fly off at the same time...

http://www.beavispits.co.uk/winsu/winsu.html

needle selection guide