Morris Minor Owners Club

As the title suggests, how much power can be safely put through a MM back axle? I'm not wanting to run a 2ltr Zetec or anything through it, just upgrade to something more modern to improve usability.
Thanks

"More modern" can mean many things.

My Mog was fitted with an MM axle, though it's a '59 '1000', by some bodger, and it runs perfectly fine. Bit slow, and the speedometer is off, but otherwise fine. So I know a slightly-souped-up 948cc will work!

I would guess no more than sixty horses, but I'm not at all sure, and I don't know that there's a way to be sure without testing it...

Do you actually mean MM as in a Series MM? Or MM as in 'Morris Minor'? I'm not sure of the exact figure, but i have a feeling 85/90bhp would be alright. Standard halfshafts can be broken by standard minors if you've got a very brutal clutch foot. You can get hardened half shafts that are supposed to be unbreakable, but that doesn't stop the diff itself breaking.

I think it depends on your driving style, they can be broken with the standard engine if you try and take off in first while the car is rolling backwards.
I never had a problem running a 1275 engine, but they were always in the back of my mind so I never tried for any wheel spin, just feed the power in once it was moving.

I don't know if the special hardened half-shafts are available for the MM axle ? I think it's pretty weak old thing!!!!!!!!
For the Minor axle - the special shafts are available, and a limited slip diff can be fitted. Should all be fine up to 100 bhp - but as ever - take care on starts, especially on a turn!

apologies, my lack of technical minor knowledge was obviously confusing!! I mean a morris minor, is there a way of identifying axles? I'm certainly not planning on 'drifting' anywhere, actually been looking at 1.25 and 1.4 Zetec SE engines which are 74 and 89hp respectively, so the latter could be on the limit for reliability?
thanks
Oliver

Fine if you get the better shafts and possibly the Limited slip diff. I would have thought these days folks would be looking for small diesel engines to put in the Minor !

Whats the advantage of a limited slip diff ?

limited slips diff send power to the wheel with the most grip. a normal diff by virtue of its design (not particularly intentionally) sends power to the wheel with the least grip. normally you'll find that if you accelerate from standstill whilst turning you will spin all your power away on that inside wheel. a limited slip diff would send all the power to the wheel that isn't spinning so you get better acceleration. this feature is also good for snowy weather, normally if you found yourself with one wheel on a patch of ice, no matter how much grip the other wheel had, you'd be spinning the wheel on the ice. an LSD would only become unstuck if both wheels were on icy patches!

trouble is they're a good £600 for a diff from Quaife

The advantage is that it shares the power between the two half shafts, instead of putting it all through one - thus reducing the chances of failure. They also allow much better control of the rear of the car, especially on loose/slippery surfaces, and of course - they are tougher and can safely handle more power. Sadly - as above -they are not inexpensive !

can't help but feel that if you outlay for uprated shafts and an LSD you'd be pretty much at re-conditionned escort axle prices??! I was hoping you'd tell me lots of people were safely running 90-100bhp through standard axles!!

as for small diesel engine, yes it would be great, but I wont do massive miles, and the little petrol engines are much simpler with loads of kit-car/escort RWD bits that can be bought/adapted without too much fuss. As much as I love the theory of old technology, I just want to know it will work if I've not touched it for a month and then decide I want to go out for the day!! (also had all of the spare engines/gearboxes/axles stolen last year - see 'stolen' section - so that kind of encourages me down the 'newer' engine route)

thanks again.

Indeed a Ford axle is stronger/cheaper etc - but your query was about the MM axle - although turned out to be the Minor axle after a while....... My view - if you want to run Ford engine/gearbox/axle/brakes and wheels - buy a Ford !! The A series engine etc is simple - and mine never fails to start/run well even when neglected for months on end........

I apologise, I certainly didn't want to offend with my 'non-purist' approach...

I already own an old ford, and have had several mini's and minors, This is for the restoration of a convertible we have owned for about 30 years and I would like to keep it very 'morris minor looking', but there is no denying that the technology is very, very old, and I'd like to employ some modern techniques to improve on what is intrinsically an extrememly interesting and attractive vehicle. I thought this was the place to ask morris minor related questions and opinions of people who have had many years of experience with them?!

If it's reliability even when neglected you're after, then the A-Series has it in spades! If you're fed up with the points and condenser ignition system then you could always fit a fully electronic distributor. If you're only looking for 70-80bhp then a 1275cc A-Series would give you that with some very mild tuning. As it's not economy or massive power you're looking for then a 1275 must surely be the best route. You could even fit an injection system from a late Mini if you fancied some extra modern-ness!

dollie007 wrote:I thought this was the place to ask morris minor related questions and opinions of people who have had many years of experience with them?!

it is! and don't be mislead into thinking BMC is a purist!

the consensus seems to be that the answer to your initial question is about 90bhp. Anything over that and to keep the standard look and standardish mechanicals, and i'd be looking at uprated half shafts!

I totally agree and like what your trying to do here. I'm about to start a very simiar conversion on my everydsay minor, and was too haoping to keep the standard minor axle. I have purchased a 1.4 fuel injected engine with ecu and rwd conversions already. - also have a 2.0 zetec to go into the project car which will have all ford axles, discs and gearbox, wheels, so I have to totally disagree about the buying a ford.. I love the minor and thesr are all just realistic upgrades and not specifically just coz there ford parts. Best of luck with it. JLH is going to been soon doing this conversion so onfo and parts or ready built cars could soon be available, and proves the good engine choice.

Oh yes - it's your car and you do whatever you wish with it. I'm certainly no 'purist' - my Mini had Fiesta brakes etc It's just my view that it would be better to run say a MkI Cortina/ Escort /Capri and have all the Ford bits supplied with the car! Rather than struggle to fit all these parts into a very different car. If you change all the mechanicals to Ford parts - then a Ford forum will serve you better for questions on these parts - but we will still be here to advise on body/chassis problems. beware too your car may fall foul of the DVLA rules, and have to undergo a full Vehicle Inspection (not cheap) and be issued with a Q plate - and have to pay VED each year..........

I'm no purist either but the answer to

How much power safely through standard MM axle?

is "little more than the original engine"

The thing is no fords had all these parts as standard, their all from different models from different years, and can be as hard to retro fit to any ford.. With regards to my previous comment on here, have a look at this thread, towards the bottom if interetsed http://morrisminorowners.co.uk/about2989.html

yes very interesting indeed!! thanks a lot, I will follow with interest... I didn't realise JLH were going to start doing that conversion with the 1.25/1.4, and with regard to the previous answers, the zetec se (or sigma as it's correctly known) is a joint Yamaha/Mazda developed engine, all alloy, and very different to the larger 'zetec' 1.6/1.8/2.0, the main disadvantage of it being that no ford bits bolt straight to it!! there are conversion parts available via the kitcar market though as they like the 1.6/1.7 variants.
I will admit to being slightly biased, I already have a mk2 escort, and the interchangeability of parts/upgrades is fantastic, but I also love the minor convertible and want to be able to enjoy it, previous to this I had a beauifully restored original spec minor convertible and it let me down several times with silly little things, and always felt 'vague' on the road.

thanks for all the input/opinions though, all are very much valued.