Anyone got a spare supercharger lying around?

Location: Sunny Surrey

Hang on Mike I'll just have a look under me bench!

Oh, if there is more than one, I'd also be interested

Location: Staines

Mike
No, I don't have a spare. I have 2 and a bit and am always looking for more!
However you need to be more specific. Cozette 4,Centric 125,Rootes (various)?

Charles

Any complete one of any suitable type will do, then I'll work out a way to make it fit.

Location: Sunny Surrey

Hello Mike,
I found a nice modern one suitable for a 7 on ebay recently for 320 € with p&p.
We discussed it here http://pub25.bravenet.com/forum/static/show.php?usernum=2099944454&frmid=5&msgid=897803&cmd=show

Location: Brittany, France

You could try

http://www.classiccarama.com/classic-car-parts/advert/supercharger-repair-and-manufacture-by-derek-chinn/

Location: New Forest Hampshire

yes I have one but I suppose its tolate by now

Hans,

Never too late for a supercharger, going by the response on the forum but I think more details would help.

Tony.

Location: Melbourne, Australia

Thanks for the replies. I have one now, a 300cc Roots type, it has totally transformed the car, stunning torque and acceleration running at 12psi boost.

Location: Leafy Surrey

Impressive stuff Mike, well done!

Mike, is it an Aisin AMR300? If it is, could I possibly see a photograph of the installation?

Alan

Location: Brittany

Mike, Did you change the camshaft?

Is that it!

The blower is an Aisin AMR 300 driven at under 2x crank speed. The camshaft was changed, it is a full race cam with max lift, long duration and long overlap. Very lary.
In spite of that the car is very drivable with great torque and stunning acceleration, often making up four or more places between the start and the first corner. With a lighter jockey I believe that it would be unbeatable.

Location: Leafy Surrey

Removing all the silverware might make it a bit lighter too!

I'd also be keen to see how it is installed and driven actually. It sounds very interesting.

Simon

Location: Auckland, New Zealand

All is shown here:

Here

Location: Guildford

Blower in situ:

Location: Leafy Surrey

Congratulations for that splendid work Mike.
And thanks for the photos.
Renaud

Location: Brittany

Well done!! Very neat installation and plainly effective.

Any tricks with the ignition or oil in with the fuel? Anything special for cooling or to hold it all together? The Myall AMR500 seems to be the other way up (or inside out). Any logic to which way up these things go? Is that bit of aeroquip an oil feed or to a boost gauge?

...and what tricks have you up your sleeve over winter?

David

Location: Lewisham

Nothing special regarding ignition but I use NGK Iridium plugs, no oil required in fuel as the AMR gear set is sealed in its own oil bath. The 300 produces its boost out of the outer port, which makes for a neater installation, the 500 is the other way round. The 300 is considerably lighter and requires less power to drive, also revving slightly faster and lower volume per revolution reduces pulsation at lower revs making pick up smoother and faster.

The Aeroquip take off is for the boost gauge. The engine is all steel and lightened and balanced as much as you can with an Austin 7 engine.

Cooling is looked after by a large alloy radiator with electric water pump and thermostatic fan. An oil cooler and external filter keep the slimy stuff clean and cool. All lubricants are modern fully synthetic provided by Opie Oils.

Next year....who knows?

Location: Leafy Surrey

Mike, what a wonderful bit of engineering! I bet it goes like the clappers!

I know your car is not not for VSCC events, but I can see why they resist the march of modern components so firmly.

It doesnt matter what sort of racing you do, if development is allowed, developemnt will take place. I have mentioned before that when I raced in Saloon cars, by the ultimate development, the only unmodified component on the car was the drivers side door lock (the passenger one was removed)! Your A7 appears to be much the same!

All the best

Stuart.

Location: Devon

Hi Stuart, the car indeed does go like the clappers.
The only "modern components" are the electric water pump and fan. However it does not have any modifications that were not done in period, in fact it has far fewer modifications than most of the Works cars. Your comment that the car appears to be modified like your racing saloon car could not be more incorrect.

The blower is a Roots type which were developed in the late 1800s as air blowers for furnaces and were the type used on many of the Works cars in the 1930s.
My car uses original Austin front and rear axles, Austin clutch, Austin gearbox, Austin springs, Austin dampers, Austin steering column, Austin steering box and Austin steering wheel. The brakes are Austin tho' hydraulically operated, the engine has an Austin starter, the wheels are Austin as is the radiator cowl. The chassis is pre-war Austin.

The Works cars used aluminium cylinder heads with 25 studs, they has special thick walled crankcases and blocks. The Jamieson "Rubber Ducks" had special magnesium crankcases and dry sumped oil systems, fully counterbalanced 1 and 11/16" big end steel cranks with very exotic rods and pistons. The blocks were massively reinforced, the tappets were pressure lubricated, the alloy cylinder heads had 2 plugs per cylinder, boost of up to 24psi, and the later cars ran on specially blended fuels running at up to 8500rpm.

These cars were intensively developed in period and I do not think that the VSCC would exclude them from today's racing on the basis that they were "over developed".

My car was not designed to satisfy the foibles of the VSCC, it was specifically designed to be a very fast Austin Seven racer, using original Austin Seven components where available and employing a few of the tricks used by the Works cars in period.

Location: Leafy Surrey

Thank goodness you didn't put an adjustable brake cable on it Mike!

Hi Mike

I hope you didnt get the impression that I disapprove? I whole heartedly approve of A7 racing development continuing with modern materials and technologies, such as multi V belts, aluminium radiator cores, silicon hoses etc.

regards

Stuart.

Location: Devon

Hi Mike, that's very cool and I like your approach of keeping it all 'standard' as much as possible. I am keeping the same idea in mind with mine.

What size carb are you using there and how did you work out the correct needle for it?

Simon

Location: Auckland, New Zealand

It's a 1.5" SU, and the needle was arrived at after a fair bit of dyno time. I suspect that the engine could easily cope with a 1.75 or even 2" carb without any loss of low end torque. The power is only limited by the amount of fuel mixture that you can get into it, and with a blower forcing the mixture in, the bigger carb the better. A smaller blower will gives better torque and a broad power curve, a larger blower will give peak power at higher revs and a poorer torque curve, or so I am informed by my American drag racing chums. (not drag as in ladies clothing).

Now reliability is something else.........

Having said that, so far I have had absolutely no engine related reliability problems at all......touch wood.

Location: Leafy Surrey

Awesome to see a neat installation that provides reliable but chunky torque. SIgns of a well thought out concept.

Location: Sunshine Coast

Thank you Duncan, I am very pleased with the result. I am doing a bit of tidying over the winter, so hopefully it will be even neater next time out.

Location: The well known Arctic village of Freezin'mebollocksov

Any progress on the setup?

The question I'm pondering at the moment is quite how the pulley attaches to the crank. Any tricks in there?

David

Location: Lewisham

Pulley made by Pigsty, attached to crank gear by six bolts threaded into the crank gear and sits in a modern lip oil seal in a redesigned front cover. It works very well.

My latest supercharger installation

Location: Chilly Surrey

This one gives a view of the pulley arrangement.

Location: Chilly Surrey

I have a non-supercharger-related question. You appear to have short radius arms attached to the chassis side members, and a beam axle. If that isn't the arrangement My question is irrelevant, but if it is so, why isn't the axle a strong anti-roll bar?
Or maybe it is!

P.S. - I like your installation, nice workmanship!

Location: Richmond, Texas

They are not radius arms, they are the dampers, but to some extent the axle does act as an anti-roll bar, there is very little suspension movement with this setup, very similar to the original "Rubber Duck" type, but it produced results, so it seems to work. There are standard radius arms in the conventional sports position. The axle is above the spring to get everything nice and low. The whole car has neutral to slight oversteer handling, so great in the dry, not so easy in the wet.
This is the latest front view of the installation



Credit also to Pigsty.

Location: Chilly Surrey

Thank you - I wasn't confusing radius arms with dampers, I just didn't make out correctly where the after ends were fastened. Got it now!

Location: Richmond, Texas

Mike, what is done exactly when the engine is dry decked. What paths does the water take around the cooling system. I'm intrigued !.
Regards Ian.

Location: Worksop Notts.

So just to be sure the radius arms end in a ball joint below the gearbox and what must be some way above the chassis. The engine mounts on pillars?

What struck me most is the size of the catch tank. Is it larger than the sump????

David

Location: Lewisham, London

Water goes in at the front of the block, circulates around the cylinders, exits block at rear and enters rear of cylinder head, circulates around head and exits to radiator at top front of head. Solid copper head gasket and sealed block to head holes ensure that no water can get to cylinders reducing possibility of blowing gasket.

Simples...

Location: Chilly Surrey

As you correctly observe, the radius arms meet in the centre of car in a ball type joint above the chassis rails and below gearbox, the engine is located engine on pillars to achieve an approximately horizontal drive line, the catch tank is wedge shaped to fit below the carburettor alongside the chassis rail and is MSA regulation size of 2 litres (Q.19.9.2).

Simples...

Location: Chilly Surrey

Mike, is the side water branch blocked off?
How are the holes in the block and head sealed?
My Mother always said I ask too many questions!

Regards Ian.

Location: Worksop Notts.

If I told you I would have to kill you......

Location: Chilly Surrey

Location: Near Bicester

I think the valves may have a problem opening if that was the case!

Anyway I suspect it would have been dry decked with screw in plugs and then machined flat.

Location: Guildford

would be better job to have a new one cast off Tony Betts (?) pattern and delete the holes for the water.

If its anything like my pattern you need some of the holes to support the water jacket core in the casting,in mine 6 .

Location: back in the garage