mk1-forum.net

970 engine spec:
Standard bore
AE 17271 pistons (9.5:1 Compression ratio)
AEG163 head ported and polished
HIF44 carb with sprung BDL needle and red spring
C1504 Cone Airfilter(MiniSpares).
C-AHT770 MiniSpares intake manifold
C-STR 816 MiniSpares exhaust manifold
RC-40 MiniSpares Twinbox exhaust
C-27H7770 123 distributor no vacuum distributor with #B curve
731 camshaft




I am trying to find someone who has had this setup on a rolling road and has measured mixture strength versus carb piston height versus loaded rpm, so as to determine the correct needle and spring for the carb. I will do it myself if needed, but who wants to re-invent the wheel?I am running a BDL needle and red spring as per 1275 Metro, but I think it is a bit rich. I have set the idle mixture, but seems rich in the cruise range(I haven't had a Fuel Gas Analyzer on it yet).I have only had the fully rebuilt engine in the car 2 weeks.
I found a website that shows how to measure carb piston position while on the rolling road, but if someone has already done this, all the better.

Look forward to your input.

the BDL is the needle off the leaded 12HD24 MG Engine. It was a bit something low and a bit something else high. I think rich:lean. To sort this out, you use a BDK.

A 970 engine deserves to have the most made of it. If you're going to put a metro carb on it, you may as well put the metro engine in it.

I think you will struggle to find someone who has used an HIF44 on a 970S motor.

99% of people who run 970 motors use twin SUs or a webber.

James

Thanks to FNQ for getting an AFR meter on my car. Bit more advance wound in, now goes like a rocket!

In the shed wrote:the BDL is the needle off the leaded 12HD24 MG Engine. It was a bit something low and a bit something else high. I think rich:lean. To sort this out, you use a BDK.

A 970 engine deserves to have the most made of it. If you're going to put a metro carb on it, you may as well put the metro engine in it.

So if I use a Weber carb, should i use an Italian engine?

You could probably get a Maxi carb, or something off an early Montego to make it even more naff.

Remember the comparison in mini magazine from about 96 comparing a 970s to a 998? It pretty much said the 998 was a better engine for your granny to drive around, but the 970 was the base of a pretty serious piece of pedigree racing machinery.

You are either having a laugh rather like saying "I have an original Cooper S and I want to put a clubman front on it", or you are serious, which leads you into 2 further options....an original 970s as-it-left-the-factory restoration, or you're going to race it up and put it in a racing car. What you are suggesting by putting a metro carb on it is rather like putting a set of metro wheels on an e-type.

Put a BDK needle on it and it will "roughly" sort out the problems of your BDL needle. This will get you by until you've got a set of 1.5" SUs, or a Weber.

I removed a Hs6 for a pair of Hs2s on my 1071+ it drives and runs sooooo much better with the twins...

[quote="In the shed"]You could probably get a Maxi carb, or something off an early Montego to make it even more naff.

Remember the comparison in mini magazine from about 96 comparing a 970s to a 998? It pretty much said the 998 was a better engine for your granny to drive around, but the 970 was the base of a pretty serious piece of pedigree racing machinery.

You are either having a laugh rather like saying "I have an original Cooper S and I want to put a clubman front on it", or you are serious, which leads you into 2 further options....an original 970s as-it-left-the-factory restoration, or you're going to race it up and put it in a racing car. What you are suggesting by putting a metro carb on it is rather like putting a set of metro wheels on an e-type.

Put a BDK needle on it and it will "roughly" sort out the problems of your BDL needle. This will get you by until you've got a set of 1.5" SUs, or a Weber.

HIF44 will flow as well as a Weber, and we are talking about air/fuel quantity, so does it matter how this is achieved?

leonrjohnson wrote:Look forward to your input.

Have you seen this?

http://mk1-performance-conversions.co.u ... l_carb.htm

I have sent a brand new version of this to Mark today, version 017,
which is 423K. Hopefully he will upload it to the site.

I don't know why people are "dissing" the choice of carb here: Leyland
eventually worked out that 1x1.75" carb worked very well compared to
the 1.25" twins.

Tuners had already worked this out years ago and the "big SU" was used
by many in place of the much more expensive Weber. Even as far back
as the "Formula Junior" days people were junking the twins.

I found this interesting setup:

"Formula 111 Cooper BMC, 997cc, 1964/1968, HS6, UVP needle, Red spring"
Notice the use of a 125thou needle?

If you are interested to see how UVP stacks up against BDL, the spreadsheet
will tell you as it can make a valid comparison between 100 thou and 125 thou
jets.

Good luck with your project.

I think what In the shed is getting at is that you have a very desirable period engine and it would look better keeping it in period with a set of twins!
Putting a 44 on it will just make it look like any old A series from the 80s.
Why not sell the 970 and get a 1275 with a 44 all set up and still have money in the bank

AustinSuperSeven wrote:I think what In the shed is getting at is that you have a very desirable period engine and it would look better keeping it in period with a set of twins!
Putting a 44 on it will just make it look like any old A series from the 80s.
Why not sell the 970 and get a 1275 with a 44 all set up and still have money in the bank

I dont care what it looks like, it is still a 970 that revs like stink compared with a 1275(dime a dozen). I dont want to sell it: I've always wanted a 970, and now I have it running GREAT!!!!!!!!!!!!!!!!!!

AustinSuperSeven wrote:...a very desirable period engine and it would look better keeping it in period with a set of twins!
Putting a 44 on it will just make it look like any old A series from the 80s.

Good point.... Could be a "Street Sleeper" though, a decent 970 should out-perform
your average 1275cc Metro engine anyway.

I ran a 998cc years ago,
12G295 Head 1.312" Inlets, 1.0625" Exhaust, 10.5:1
Offset bush welded-up pressed steel rockers
MG Metro Cam
MG1100 Exhaust
Janspeed Inlet
Modified single 1.5" HS SU, No7 Needle, Blue spring
K&N with a proper shaped "stack"
N7YCC Plugs
etc etc...

When I stuck that lump in, the people I worked with didn't "get" the fact that my 998
would be better than the standard 1098 that came out. In fact, it would obliterate
a 1275GT...

It went to 8000rpm regularly and would out-accelerate a Turbo Metro quite easily 0-60mph.

... until I blew it up one day! The 970 should be fairly bomb-proof!

Flow is such a crude measure. You have a number of sub factors concerning fluid flow, the way the gas deals with velocity changes in the carb, the way resonance alters it, how this responds in a siamese into 1 system, etc, etc.

People used pretty big SUs on short stroke screamers. Sometimes up to 2" pairs. Albeit with silly camshafts. Webers tended to be popular on longer stroke engines.

Either do the thing justice, or sell i to someone who will. It's like me handpainting my cooper with Hammerite just to say "fuck you all".

I'm sorry to sound like an idiot, but HIF44 on a 970S. How about you put a 2.7 final drive on it so it also has a nice cruising speed on the dual carriageway?

Sorry, but I didn't see anywhere he is trying to build a period car, and personally I wouldn't be bothered fiddling with 2 carbs if one would be better. Probably better torque low down anyway.

leonrjohnson wrote:

AustinSuperSeven wrote:I think what In the shed is getting at is that you have a very desirable period engine and it would look better keeping it in period with a set of twins!
Putting a 44 on it will just make it look like any old A series from the 80s.
Why not sell the 970 and get a 1275 with a 44 all set up and still have money in the bank

I dont care what it looks like, it is still a 970 that revs like stink compared with a 1275(dime a dozen). I dont want to sell it: I've always wanted a 970, and now I have it running GREAT!!!!!!!!!!!!!!!!!!

you might as well chuck a rod change gearbox on it to give you a smoother gear change!
Only joking big boy! It's your engine and you do as you please with it. It's just us old boys getting nostalgic over a wonderful period motor!
But please dont tell us it's fitted in a Mayfair!

I have fitted a rod change to it, and it is fitted to a 1977 Mini Clubman!

wantafaster1 wrote:Sorry, but I didn't see anywhere he is trying to build a period car, and personally I wouldn't be bothered fiddling with 2 carbs if one would be better. Probably better torque low down anyway.

No, I am not building a period car, and yes,1 carb easier to fiddle with than 2! :)Can't comment about low end torque as I haven't had twins on it to compare.

In the shed wrote:Flow is such a crude measure. You have a number of sub factors concerning fluid flow, the way the gas deals with velocity changes in the carb, the way resonance alters it, how this responds in a siamese into 1 system, etc, etc.

People used pretty big SUs on short stroke screamers. Sometimes up to 2" pairs. Albeit with silly camshafts. Webers tended to be popular on longer stroke engines.

Either do the thing justice, or sell i to someone who will. It's like me handpainting my cooper with Hammerite just to say "fuck you all".

I'm sorry to sound like an idiot, but HIF44 on a 970S. How about you put a 2.7 final drive on it so it also has a nice cruising speed on the dual carriageway?

I think I am doing it justice: I got it going like stink now! I suppose you disapprove of BMW twin Cam heads too. What about Honda VTEC or Hayabusa transplants ?

....tick, tick, tick.......

leonrjohnson wrote:I have fitted a rod change to it, and it is fitted to a 1977 Mini Clubman!