Morris Minor Owners Club

Hi All,

have been perusing previous threads to glean information on the above, but I've not found anything definitive, so I would like some help from the SU boffins out there if poss., please!

I have a K&N-alike cone filter which will go on the carb; this then goes on an oselli torquemaster inlet manifold, onto either a 12G295 or a 12G940 (the latter if it fits; if not I'll use the 295 until I can do the machine work on the 940). The exhaust is a iron Mini one which has had the conjoined inlet manifold sawed off. This goes into a standard bore moggy s/s exhaust.

My current needle is bent which has lead me to think about changing it prior to bolting the above on and just trying it.

I would have gone AAU as you can just buy them off ebay easily. Your thoughts will be appreciated.

Cheers,

Russ

You don't say what size engine you have. I assume it is a 1275.
The Marina 1275 used an AAQ or an ADG. The AAU needle is considerably richer than the other two. When you are using a non standard set up it is really trial and error or a rolling road. What is the bent needle and what was the carb previously used on?

Hi Mike, thanks for your response. Sorry, forgot that important detail re the engine!!

The engine is a 1098. I dont know what needle is in the carb; the vendor said it came off a 1977 Mini 1000 automatic. I didnt check the marking as I thought it'd be scrap anyhow, with it having a bend (albeit a slight one).

Cheers,

Russ

If it was on a 998 Mini Auto then it was probably an ABX. I can't really give any recomendations as it is about 35 years since I had an HS4 on a 1098 Minor and I'm afraid that I can't remember what needle it had. It went quite well with a 3 branch exhaust system though. I seem to remember transfering it to a 1098 engined Mini and that went like snot off a stick!

I dont think anybody can give you a definite answer as to what needle to use, if they say they can I would not believe them.

You need to analyse the mixture under different engine loads and modify or choose a needle to suit. The easiest way I have found to do this is a rolling road tune up by an operator who knows what he is doing. I used to use GRV at Littleborough but I dont think they have their road any more. Dave Bogg at Malton can also sort SU`s.

AAA is the needle to start off with ! But it really will be 'try it and see'. HIF 38 carb is much better than the HS4 if you can get one - no fuel surge being the main benefit!

Hi all,

Thanks for your comments.

My main problem is that the needle in my HS4 is bent, and thus will need replacing - is this a fair assumption?

If not - no probs, I'll just bolt the carb on and see what happens.

If so, could anyone suggest a needle that will get me closest to "right", or at the least will run OK with no flat spots (based on my engine spec above)?

I thought AAU as I figured my spec is probably not far away from a stage 1 998 mini set up, but I thought you guys might be able to confirm/deny/hazard a better guess.

Cheers,

Russ

PS - I know that the rolling road is the "right" way to do this - but I dont have the money to spend on one just at the mo - so feel free to suggest something, with a technical rationale if poss (or could someone WINSU it?). Many thanks

PPS - an answer tonight would be ideal as I will need to order one tomorrow ideally.

Russ, hang on for a few mins and I'll pop out to the garage and see what I have in mine. It will give you a baseline but, as I think has been said, it may not be perfect for yours.....

Right then, carb is in bits on the bench and I have an "ADO" needle fitted. This is the car with the 295 unleaded head, 3 branch manifold and K&N filter.... I'm happy with the way mine runs, if this helps you in any way?
Rich

Isnt there also a programme called winsu that someone on here had a copy of.

Rich,
ADO is not listed in my charts. Do you mean ADQ?
The markings are a real magnifying glass job.

I have already suggested AAA - go with it - it works !

It could have been ADQ Mike. It was late and I certainly wouldn't be 100%

Hey Guys!

thanks for helping with your comments - PSL, you deserve a special mention for going and stripping your car down to facilitate the discussion!! That really is going the extra mile!

BMC, I appreciate your advice, I think my hesitation is due to the fact that I just dont know what the letters mean - for instance, AAA vs AAU - what's the difference? If I knew that I could make an educated guess as to which was the best for my personal set up. I've visited a few websites but they only seem to give 3 digit numbers (dimensions I guess) but...so what? ABQ etc. - now we are really in the depths of the black magic eh!

I dont know where I would buy an AAA anyhow, but there are AAUs on ebay & thus are accessible to me.

I want economy of course, but power is important too as I will be putting my 3.7 diff in soon, and may need to rev the engine in lower gears to get it up some of the hills round here, and I dont want to run out of steam.

Will track down an AAA if that is the best failsafe but AAU - accessible, common power upgrade choice - seems to fit the bill.

Anyhow, will cogitate this pm and probably order tonight. Thanks once more to you all for taking the time to help me out. Much appreciated.

Cheers,

Russ

PS - once i've slung it all together I will post the performance characteristics on the forum. Might be next week.

IIRC the free version of WinSU has a feature where you can select a needle code and it will show you a graph of its profile. It will even show several needles on the same graph so you can compare them. You can buy needles from SU.

Aquiring a needle chart would seem to be a high priority so that at least you know what the needle codes refer to. For all your carb. needs including needle charts, reference catalogues and workshop manuals phone Burlen Fuel Systems 01722 412500.
That is probably advertising again.

Quite a few needle charts on the internet - although they don't all show all the needles. AAA is a very 'standard use' needle for modified Minis with this carb - and it's working well in my slightly modified 1098 in my Traveller. I see the AAU is very much weaker especially in the mid-range - and they are probably on ebay because they are no use - and have been taken out of carbs to be replaced with AAA needles !

AAA 890 850 814 785 755 720 674 630 600 580 560 540 520 500 480 460
AAU 890 850 828 806 780 745 710 675 647 620 590 560 530 500 470 440

ADQ 900 868 838 813 788 760 735 713 692 670 650 630 610 593 575 560
ADE 890 855 832 807 787 765 725 715 708 691 674 657 640 623 606 589
The ADQ as you can see is incredidbly weak, although because it (very unusually) is 900 at the start - it will need to be set with the jet slightly further down to get a good idle, which will richen the mixture all the way. I wouldn't think that will be good for performance - or piston life! My AAA needle gives me nice light tan spark plugs - I wouldn't want to go any weaker.

You cynic!

Well - that's why stuff gets on ebay - it's no use to the owner any more - so he flogs it!

I guess you are right BMC, although I did think these needles were from storeholders....but perhaps just those who mop up all the unwanted AAUs and sell them on at a profit!!

Anyhow, I am going to go AAA, will be on the blower to Burlen this morning. Thanks for all the help everyone.

PS - I'm giddy - I'm fitting my wolseley brakes today!! (Wife singing in background "I'm an anorak and I'm OK, I sleep all night and I work all day....")