24 replies to this topic

[minimender]

Heard a lot of different needles suggested for a stage one kit.

How does one decide which needle for 998 stage one or again which is best for 1275 stage one ?

I've seen AAA needles suggested for 998s but this needle was original equiptment for a two inch carb with the same size jet as a hiff 38 so how would that work ?
Is the profile so different or is it just thinner all the way up ?

BDL is another one that has been suggested but that is from a hiff 44 with a bigger jet. Not all hiff 44s have a bigger jet so, again, how can one needle be best for both size jets. ?

You can have two identical carbs both with different jets requiring different needles so it's not that easy to state which is best.

AAU is as fitted to an early 1500cc MGB and BDK is as fitted to early Volvo engines with hiff44 and jetted at 0.100" so a lot of fuel passing by that needle or very little if put into a hiff38 or HS4.

I've swapped and tried hundreds of needles in the past and hardly ever looked at the code on them, I usually run the needle between my thumb and forefinger to get an idea of the profile before adjusting with some fine wet and dry. Some needles are thick all the way down and some tapered to a fine point, thick is best for experimenting with if doctoring it.

There are hundreds of different codes for needle profiles but only three jet sizes, Hiff 38 and HS4 are usually 0.09" and hiff44 are in the main 0.09" or 0.100" but it depends on what the carb came off originally.

So how to decide on a code for your car? anyone know ?

[lrostoke]

I would say a lot of it is down to experience and listening to what the engine tells you

I recently fitted a stage one and fitted the AAU needle which comes standard with most 998 stage one kits, really big flat spot when changing up through the gears, but then woosh off it went, bit like turbo lag..
I'd noticed with choke it was fine, so this suggested a richer profile was needed lower down the revs..

a bit of internet searching and I found this

http://www.mgb-stuff...k/fueltext2.htm

and

http://www.mintylamb.co.uk/suneedle/

I was undecided between AAM and AAA, but by recomendation went for AAA

[Sutty01]

im very interested in this thread we should try to put together some kind of table for all carbs for minis and what corisponding needle/+carb fits best on differant engines?

[Big_Adam]

Get a weak needled then go and get it profiled to suit you're engine.

Simple, noi?

[v8mini]

my clubby estate is 998 stage 1 and was running really bad, was rolling roaded a couple of weeks ago, and now has a AAA needle fitted, now runns great through the whole rev range and has loads if go. resulted in 46.2 BHP at wheels after a tune up using LCB, Manflow exhaust, 1 1/2 su with K&N filter, rest of engine is standard that i know of.

Edited by v8mini, 08 February 2008 - 01:01 PM.

[Sutty01]

Quote :Get a weak needled then go and get it profiled to suit you're engine.

Simple, noi?

Well yes this would be, unless you want a personal touch/opinion or to do the work yourself?

Not flaming , just think thats what he was going for....if not just me

Edited by Sutty01, 08 February 2008 - 01:07 PM.

[lrostoke]

im very interested in this thread we should try to put together some kind of table for all carbs for minis and what corisponding needle/+carb fits best on differant engines?

I don't think its really that simple, you can get ballpark ideas, but not all needles will suit all engines

Mine is

1984 , 998 City leaded head using additive
Aldon ignitor electronic ignition using original dizzy
Maniflow stage 1 center exit
K&N replacement element in original box (drilled)
Lucas sport coil (non ballast)
HS4 1.5" carb with AAA needle CO 2% at idle, timed to 8 degrees @ 1000 rpm

Sisters

1989 998 unleaded
points on original dizzy
maniflow headers, mini spares inlet
RC40 big bore center exit
K&N replacement element, standard air box
ballast standard coil
HS4 1.5" carb AAU needle CO 3% at idle , timed to 5 degrees @ 1000 rpm

[minimender]

im very interested in this thread we should try to put together some kind of table for all carbs for minis and what corisponding needle/+carb fits best on differant engines?

We can safely say that ADE ADZ and ADP are standard needles for 998 HS4 + hif 38. ( all jets 0.090" )

BDL was for MG Metro with hif 44 but with bigger jet ( 0.100" )

BDD was for Metro Turbo hif 44 again with 0.100" jet. (also used on RR Silver Shadow)

BBW was used with Hif 6 not sure of jet size.

BDK was used with Hiff 44 and 0.100" jet on Volvo motors.

AAU was used on twin HS4 or H4s for MGBs with 0.100" jet

AAA was used on old 2" carbs with a small 0.090" jet

Looking at that info we can see that the AAA is a rich needle but AAU is leaner in a Mini carb as it was used originally with a bigger jet.

HIF 44s have various jet sizes depending what car they are off.

HIF 38s also can have different jet sizes

HS4s are all 0.090" jets

So one needle does not suit all carbs for stage one.

We can say that needle XXX goes very well in my Mini but would it go better if another needle was tried or do we leave it there?
I have a micrometer for measuring needles but no longer have a stock of needles to compare. A couple of years ago I could have measured my performance needles to compare with say an AAA.
The best needles that I had tapered quite a bit towards the end I remember.

If your car is flat at say 2500 then the needle is too fat half way down so fix it !
It could be that your dizzy is worn though and not advancing smoothly.

It is quite easy to profile your own needle, just takes a little patience.

Edited by minimender, 08 February 2008 - 10:00 PM.

[Dan]

im very interested in this thread we should try to put together some kind of table for all carbs for minis and what corisponding needle/+carb fits best on differant engines?

No we shouldn't, the whole point is that every engine build and every driver's needs will be different and so require a slightly different needle. As Adam says above a profiled needle will suit your engine and your requirements far better than a standard one will, what Adam suggested is the personal approach while choosing a standard needle certainly isn't. There is no point us putting together a list, there are software packages (WinSU for example) that can calculate a rough needle choice for you to work from. There are thousands of needles and hundreds of possible engine configurations, if you want a list of needles ask BFS for one. They publish the list as a book and it's also in the SU workshop manuals.

Edited by Dan, 09 February 2008 - 12:17 AM.

[yorkshirechris]

I have a 1275 with a stage 1 kit but just a inch and half carb with a K&N, not sure which needle I should have?

[Dan]

If you have a Stage 1 Kit then you use the needle that came with it. If you have swapped the exhaust and added a new inlet manifold and filter all of your own choosing you don't have a Stage 1 kit. Most places that sell kits sell them properly developed (or rather Mini Spares does) with a needle that suits the components supplied. That's why it's called a kit.

[yorkshirechris]

I didn't fit the kit nor did I own the mini when it was fitted, the local Mini specialist guy said he isn;t sure whether it's the right one but just said see how it runs. Just thought I'd ask to see if anyone knew the standard needle type/size/spec what should be in the stage 1 kit.

[lrostoke]

We can safely say that ADE ADZ and ADP are standard needles for 998 HS4 + hif 38. ( all jets 0.090" )

There was an AAC fitted to my 998 HS4 ?? , as far as I'm aware it was standard, air box, pea shooter exhaust

[Dan]

It depends on all kinds of things, who's Stage 1 kit it is, what year engine the kit was designed for etc. It could even be that the kit (if it was a kit) was originally desinged for a different engine spec and was moved accross from another car. You don't say what carb it is beyond being 1 1/2", as Mini Mender points out there are different needles needed for different carbs. What make is the inlet manifold? What layout and make is the exhaust and manifold? All these things make a difference. If you say what you've got then maybe someone can have a guess or you could use WinSU to choose a good needle to start from.

by the way I didn't mean anything by what I wrote above other than what it actually says, it may have come accross a little abrupt. Sorry about that.

[lrostoke]

I agree profiling needles to suit your engine is the ideal, but on the other hand there are probably people like me who have a stage one mainly for the asthetics and also a better sound plus the added bonus of extra humph but aren't really to concerned if its performing to its maximum as long as it feels OK to drive.. accelerating in all gears, no flat spots and 95mph and still a bit left seems ok to me . the car shake gets a bit much anyway
which in my case the AAU needle supplied with the kit didn't work out of the box, and yes profiling would have worked, but now I've looked at the profile of the AAA on the minty lamb site, you can see the AAA gives the extra fueling where it seemed to be missing on mine, so for the cost of £8 it was a quick swap and did all I wanted it to do.