Classic Mini, Supercharged!

dickdavid Aug 30th, 2005 Link

How about some pics???!!

db Aug 30th, 2005 Link

Sweet! I’d rather have that then a VTEC powered Mini, that’s for sure.

I know that Moss sells a supercharger for the old MGB engines. I wonder if there is a fitment for the Mini…

peter Aug 30th, 2005 Link

It’s really worthwhile to reinforce the bottom end of that motor, as the rods and crank take a pounding with forced induction such as a supercharger or turbocharger.
What I mean by reinforcement is to upgrade the rods, such as using real Cooper S rods, or aftermarket rods like Carillos, and maybe even a four-bolt main cap. Remember, those motors were designed for use in generators, not high-performance, and they have three main bearings. Argh…..ask anyone who races one what fun that is!

I have seen numerous minis with similar mods blow up due to rod or crank failure. The old Cooper S block was reinforced, the “1300″ block was OK, but the newer 1300 Metro block is the best (strongest).

Not to be a nay-sayer, horsepower is good, but so is a few ounzes of prevention!

Z4MINI Aug 30th, 2005 Link

Moss also sells a supercharger set-up for Sprites/Midgets which, of course, use the A-series engine just like the classic Mini. However, the Moss setup will NOT work on the Mini. Maybe there are not adequate clearances in the engine bay.

jbfromOZ Aug 30th, 2005 Link

http://www.hi-flow.com/HP3Mini%20Super.htm
is a kit that works, is installlable in a bugeye or a mini, runs to around $5,000 australian, and has been around for a while.
I believe the moss kits are possibly this kit re-badged.

I was originally going to use the supercharger off my mini (pre-jcw update) to supercharge my austin healet bugeye, however the charger is just oo large for the installation.

this kit now remains my first choice for charging the A-series in my austin healey.

jbfromOZ Aug 30th, 2005 Link

with regards to boosting bottom end to handle extra power, supercharging is less strenuous on your motor and your motor will last longer, as you dont run the high revs in order to have power. stronger rods etc are not necessary to still get good results in the torque range and especially when kept below 6,500 revs engine life is actually improved with the supercharger.
Turbos are a different matter as you typically use higher end of the rev range for most of your useage wear on valves, valvegear, pistons rods etc is accelerated when they move up and down much faster all the time. This is where the issue is in a turbo setup.
unless you are running spastic boost and stupid revs, the problems are not the same with a charger, as your peak torque is much lower in the rev range.

Vanwall Aug 30th, 2005 Link

The real key to the ‘A’ block Mini is the crank - the original ‘S’ cranks were forged, nitrided EN40B steel, done by Rolls-Royce suppliers, and were stronger than most production cranks available for many years. If you’re lucky you’ll find one that hastn’t been re-ground and the nitriding removed. They’re like hen’s teeth, so dig around and get a good crank, or it’ll grenade for sure.
Vandervell bearings only.

The ‘A’ series is a long-stroke design, with the piston speeds reaching critical if you rev even moderately high - this was the main limitation the factory accepted to get plenty of low-down torque. Remember, the factory was concentrating on rallying rather than track racing - the only over-square ‘S’ engine was the very limited 970 S, which was for the Saloon Car handicap specs. Good rods are a must, but the other limitation from there on in is the head. The non-crossflow, siamesed ports and relatively shrouded combustion chambers are only amenable to reworking up to a point, then the whole Westlake design hits a brick wall.

The usual lowering of the compression ratio is mandatory - the ‘A’ block just doesn’t handle high ratios very well for long. Remember - the tranny is running the same oil that lubes the motor, so oil change intervals should be speeded up if you boost the HP very much. The weak point on the power transfer is the little bitty needle roller bearing on the outer end of the drop-gear - gotta mod that for sure.

I’ve run across a few old Shorrock or other brand vane-type superchargers on Minis, and their relative inefficiancy compared to Rootes-types is actually a blessing - you just can’t push the ‘A’ series too hard in this respect, IMHO. I do like that Aussie HP blower, tho - looks like best for the ‘A’.

The ‘A’ was never designed as anything but an automobile engine - I don’t know where the generator thing comes from, Peter, that was Coventry Climax motors coming from fire pump use, I’m guessing. They have some seriously modded ‘A’ motors out there, so it can be done, but a street Mini with some good basic mods will yield a better HP per hundred-weight than a lot of modern cars. Hey, 10 inch Cosmics with Yokos look real cool, too.

            BCNU,
          Rob in Dago

Z4MINI Aug 31st, 2005 Link

“http://www.hi-flow.com/HP3Mini%20Super.htm is a kit that works,… I believe the moss kits are possibly this kit re-badged.”

Actually, the Moss kit is completely different. I believe it uses an eaton supercharger. In any case, it will not work on the Mini.

rdb Sep 5th, 2005 Link

The moss spridget kit is not a rebadged kit! It is home grown and will make your midget/sprite(even bugeye’s) scoot. The supercharger is a modern roots-type blower. This is a nice kit. It is not likely that it will fit underneath the hood of a mini. Although, a little modification may fix that.

rdb

miniman Sep 15th, 2005 Link

I got a new MINI supercharger and bolted it onto my min van engine in front of the cylinder head, It runs 10 psi as standard and is so much smoother than a Turbo on power delivery, the only problem is fitting the radiator and oil cooler in front of the engine so I lengthened the front a little!

It is cheap power if you can get hold of a blower for reasonable money off ebay!

miniman

minigrl Sep 20th, 2005 Link

That sounds super hot!!!
I have the mags, tailpiece, bullet- head mirrors, wheel arches, a supercharger is on my list!!!

Andrew Sep 22nd, 2005 Link

Hi,
Does anyone know whats happened to the Vmax Scart website? I’ve seeen it in the past, but its not there now? Any idea if the kits are still available and where?
Cheers

lancey45 Sep 29th, 2005 Link

just finnished building a blown a series for competition use.. used orig 19320 s pistons a 76mm 40b forged crank with arrow rods. compression is down to 7to1.x drilled centre strapped etc etc. thought ya may like to know after about six hours on the rolling road its putting out a real 180 at the wheels about fifty horse up on my 1398 8 port.. the motor has lotts more bottom end than the normally aspirated lump and the torque rather than the power was the most supprising about 170lb ft, thats not far from a golf vr6.. building the unit for the road would not be a great deal of hassle just running the pulley slightly larger maybee only 1.4 to 1.5 to 1..will mail again after the first test day…..

buggychap Oct 4th, 2005 Link

I’ve been looking into this supercharging for a while, to “bolt” onto my mini based beach buggy, i have a fair bit of space to play with (and can make more with a little hacksaw…) but have only seen a kit advertised in the back of miniworld a
while ago (might be VMAX?).
Can miniman publish a bit more on how he acheived his install?

minman Oct 6th, 2005 Link

Of course!

You first need to get hold of a Supercharger, I used the BMW MINI supercharger (very cheap on ebay) and made a bracket up that allowed me to mount it in front of the spark plugs, I then got hold of a multi v belt pulley and got that lathed down to fit onto the mini crankshaft, that left an alternator to fit and then lining all the pulleys up so the belt doesn’t jump.
I have retained the water pump that BMW use on the end of the supercharger and just made a bracket up that let me connect into the old water pump plate.

If you are still using carbs then you need to bolt one onto the supercharger and sort out the pipework to the manifold. I have bosch k-jetronic fuel injection so I just made up some connections to the manifold and had to fit a recirculating dump valve to stop the throttle butterflies bending under boost with the throttle closed (idle and decelleration)

I have fitted water injection which helps with detonation but still need to fit an intercooler to get the best out of it!

If you want to retain the standard pistons then you will have to get a Spacer plate machined up to put between your head and block with a head gasket either side, this will help bring the compression down to a reasonable level, although the most reliable option is to fit low compression pistons and maybe grind out the cylinder head to bring the compression ratio down even more.

I will email you a few photos buggychap so you have an idea what I have done!

miniman

WestfieldMan Oct 11th, 2005 Link

Hi there, I am putting an A series from a Midget into a Westfield 11 but happen to have an Eaton M45 from a Bini lying round on my garage floor. Post the SVA I am planning to fit the blower to avoid any registration issues.

I was wondering if Miniman could let me know where he got the multi v belt pulley, my single v belt one needs replacing anyway so fitting a blower ready item would be a good idea.

Thanks

gaz Oct 31st, 2005 Link

just a quick question for anybody in the know!ive just ordered a new mini cooper s with the jcw kit on it,does anybody know if a dump valve can be fitted,if so would be an easyish job to do 2)is it mini specific(if not what would i be looking for ie fitment for which car) 3)where would you recommend one from?any help with this would be gratefully received.cheers

miniman Nov 4th, 2005 Link

Dumpvalve on a Cooper S?

I think you will find that there is already one fitted!
Although it will not be one of those boy racer noisy things as the S has a supercharger it needs to use a recirculating dumpvalve(bypass) which basically returns the boosted air back into the inlet side of the Blower when the car is at idle and decellerating.

So in short no!
Although the MINI isn’t really that short is it to be fair!

I hope that helps!

miniman

dmxmini Nov 24th, 2005 Link

im wondering if miniman could contact me & give me some tips of how i can pimp up my mini’s engine.

I have a classic austin mini-1000cc engine & the only thing i have done so far is install a hi-power air filter.i tried your link but it did not work.

waiting for your response!

sprite-mkii Nov 27th, 2005 Link

If it’s not already so, install a 12G295 or 12G206 cylinder head. You can see the casting numbers in the top of the head, under the rocker shaft, if you pull of the rocker cover. These are the choice head for the small bore A-series, unless u want to relieve the top of the block and use a 12G940 big bore head.
Also, the larger combustion chamber will drop the compression ratio, which is good if you want to supercharge.
An LCB(long centre branch) exhaust with just a glasspak silencer will ensure that people hear you coming, and turn to see…. what makes such a sound…….?

miniman Nov 28th, 2005 Link

mmm…….

If you really have to keep the engine then I suppose the best places to start are the places which cause the most restriction to power output.

Without hurting your wallet too much I think you would be safe with a stage one kit comprising of a good inlet manifold, lcb exhaust manifold, rc40 exhaust system and a needle for the carb, as you have the filter I think you should be ok, although I have always found that a K&N filter in the mg metro filter housing is superb!

Anything more than that will start to cost money and involve engine rebuilds, although a high lift rocker set works pretty well and can just be bolted on if your valve springs will take it at full lift without binding.

Next on my list would be cylinder head and cam!

I would seriously consider putting in an MG metro engine as these things standard will produce far better torque and power than you could hope to sensibly achieve with a 1000cc and you could always go 1380cc later if you fancied it.

And before anyone asks, yes it is a very easy engine swap to do and all the parts interchange pretty well!

If you want to read a book on engine tuning for the A-series then I can thoroughly recommend Tuning the A-series by David Vizard, it is very informative and will help you to build an excellent machine!

Hope that points you in the right direction!

miniman

miniking Feb 9th, 2006 Link

I have been keeping an eye on this tread for a while now, inthrawled with the idea of supercharging a mini but not really knowing which to go about it.

After recently having to take my daily driver off the road and reverting back to the trusted mini for a good few years i am looking at going the supercharged route now, i was wondering if the charger could be mounted at the rear of the engine like the shorrocks were. can anybody shed some light on this, i think the front bulk head cross memeber might foul the install making it impossible without redesigning the cross memeber completly, something i don’t fancy doing myself.

thanks in advance

Miniking

miniman Feb 10th, 2006 Link

Hi miniking!

The vmaxscart kit sits on an inlet manifold at the rear of the engine, so it is really a bolt on goody!

do a google on it and you should find some good photos!

Miniman

miniking Feb 10th, 2006 Link

cool i did a search and yeah loads of good pictures….. could it be fitted to a 1098, only they list it for 1275 upwards

miniman Feb 11th, 2006 Link

By all means you can fit it to a 1098 but the crank,clutch,conrods,gearbox etc aren’t really up to the extra torque that it would produce!
If you bought the kit then your best bet is to rebuild a mg metro turbo lump at the minimum and use that as a basis for a good setup.

My friend has the vmax blower and his mini produces 160bhp!
poor old gearbox!

I have almost sorted my traction problems now! I have stopped it from wheelspinning in third by only taking the mini out in the dry!…………..

check out my website and have a laugh at my long minivan!

miniman

miniking Feb 12th, 2006 Link

Hi Miniman

taken a look at your site, very impresive i must say, i hadn’t thought about the gearbox as such, i had planned to fit a SW5 cam or Kent 286 cam with a stage 3 head and flat top pistons, i had planned on running this through a possible 3.1FD am also planning on lightening and balancing the flywheel.

I wasn’t planning on buying the kit but rather build it, i think i can do i can buy the parts cheaper seperatly over time, and the engine modifications would set me along the way whilst getting the parts together.

of course i could do the proposed mods only without the supercharger and build myself up a nice charged 1380, i would be able to sell the 1098 in it’s tuned form quite easily as i belive it would pull around the 54bhp with over a 50% torque increase

miniman Feb 15th, 2006 Link

Hi miniking,

I think 286 is probably a little too much overlap for blower on the road, not sure about the swiftune though, stage 3 head sounds good but you need to ensure that you have the largest possible combustion chambers which means don’t skim it more than is required to clean it up.
Flat top pistons are probably a big no no as you need a deep dish piston to lower the compression ratio to around 7.0:1

I have a 3.1FD and find that with the extra torque it wheelspins in first second and a bit in third on 12″ wheels with yokohama a539 tyres.
When I get the chance I might change it up to 2.9FD as it screams along at 4000rpm @80mph at the moment!

The main problem with supercharging is that you need to lower the compression a lot to stop the engine knocking, I have managed to get mine to a reasonable level but have still had to fit an intercooler and water injection to get it to run reasonable amounts of timing advance to run off boost nicely.

I was wondering why build a tuned 1098 at 54bhp when a standard 1275 can easily give 56bhp, is there a shortage of available parts in your area? If I wanted a good engine to start with then I would use an MG metro turbo lump and rebuild that but it would have to stay to standard bore sizes as the 73.5mm(1380) doesn’t leave enough meat between the bores to take the boost pressures reliably. The other good thing with the turbo engines is they have sodium filled exhaust valves and slightly better sizing on some gearbox parts.

It is always fun making things that are different so keep at it and have a look over at alt.autos.mini newsgroup if you have any problems as there is always someone who can answer a question, however silly it might seem to you!

miniman

miniking Feb 16th, 2006 Link

hi miniman

the reason behind the 1098, was because i have this available to me today as it were, as soon as i take it out of my estate thats being scrapped that is, i could just not use it and wait and put it in my pickup in just standard form after a through checking over of course.

I have been broading my thoughts past the 1380 idea for the same reason as you mentioned, i found that the 1275 head bored out would not be strong enough to take the pressure i would be looking at running so have been trying to find other engines to satisfy my needs, i know that the austin minx 1750 e series was a favorite transplant many years ago and these engines can also be found in the alegro, they produce the same power as the metro turbo in standard de-tuned form, alternativly i had thought of the rover 216 (around G reg) i owned one of these cars years ago and it has to be the best engine i have ever owned, being made by honda it is a all alloy block thus light weight, comes with a 5 speed box (always handy for motorways) and is fuel injected, the cars are also pretty cheap to buy aswell, i picked mine up for around £200 i think, 1 problem though is that i don’t know if it would fit, not having owned it for at least 6yrs i can not recall if it was a big engine or not, or the layout of the engine/gearbox

your thoughts??? i’m not sure i’d be able to fit a charger but i’d certainly look into it depending on power outputs (which i can’t find out at this time either)

would it be possible to contact you directly, you know your stuff and i would hate to gum up the board on a non supercharged tangent

miniking

miniman Feb 17th, 2006 Link

You will find my email address here for a while until I have rejigged my website properly!

http://homepages.nildram.co.uk/~deffee/page3/contact.html

miniman

barry Apr 10th, 2007 Link

I am fitting a 1300 MG in a 1974 mini clubman need all the help i can get with rad and all tips you can give

buggychap May 20th, 2007 Link

You’ll find the 1300 MG complete unit will go straight in. Just swap the right hand engine mounts from your mini onto the new gearbox before you start. The only messy bits are swapping the thermostat housing (dependent on year) so it mates with your rad housing, and I recommend fitting a 3 core or better rad to cope with the increased output, too. Oh, and the later engines had a verto clutch with a shorter arm and different clutch slave cylinder and hydraulic pipe etc. These bits are costly if you dont have them, so use the old (long arm)parts from your existing engine. It all works fine, the verto was just a smoother (less flex in the arm) development.
Easy job overall - if you’ve had an engine out before, there’s little to worry about, just replace all the consumable parts and oil seals you can get too to keep it all nice and clean.

Stephen Sep 8th, 2007 Link

Hi
I am goung to fit a BMW mini supercharger to my 1275 clasic mini. Can you tell me what the diameter is on the BMW crankshft pully, The compresson ratio that i shoud run if its going to be used on the road and the su needle jet i should run.

Ben Stimpson Oct 6th, 2007 Link

Have you had any information or replies to your request. Iam seeking the same answers to your questions. Iam fitting a M45 charger to my healy sprite. Repowered with Nissan/Datsun A 15 1500 cc engine and 5 speed box. This is a jap copy of the BMC A series engine. Has 8 port alloy head and 5 bearing crank. Iam from New Zealand. Thanks for your help Regatds Ben Stimpson

Stephen Oct 23rd, 2007 Link

Ben
No i havent. I also live in NZ