Hints and Tips - Cozette and Jameson Blowers

From: Stuart
Sent: 30 May 2002
To: David Whittle
cc: british-cars-pre-war
Subject: Fake Cozette info

Dear All, I am about to investigate the innards of my mock Cozette blower (of Stuart Rolt origin) because it has begun to make an interesting clicking noise at about 1200 r.p.m. Suffered some backfires through the induction of my blown Ulster special at moderate (3,500) r.p.m. during a bout of valve trouble lately, now resolved. Rather suspect damage to the blower vanes. I am told these may be made of a variety of Tufnol called carp. Does anyone have experience or knowledge of these blowers? Is carp the material of choice? I have seen a suggestion that it might be better to make the blades of DuPont "Delrin". Any comments or advice gratefully received.

Regards, Stuart

PS Rather agree with Ian Kerr about modern bits on VSCC cars; so why am I using a fake Cozette when I have real ones on the shelf? Because I remember what using a real one is like and I'm not prepared to go through that again! Sorry!
--
Stuart


From: Charles Ping
Sent: 30 May 2002
To: Stuart; british-cars-pre-war
Subject: Re: Fake Cozette info

Stuart

The fake cozettes, from my investigations, are really like a Judson under the skin. I'm not sure that they give any performance advantage but are significantly easier to make/repair. The delrin/tufnol debate has featured in the Judson newsgroup over the months - the archive for this is at: http://www.team.net/archive/judson

I can't remember the details but delrin seemed a good choice and then very quickly became a bad choice - They talk far too much about making "spridgets" go fast so I tend to ignore a lot of it. You could always ask the straight question and see what wisdom comes back.

Charles


From: mark roper
Sent: 30 May 2002
To: Stuart; David Whittle
cc: british-cars-pre-war
Subject: Re: Fake Cozette info

I made some replacement blades for a friends Judson blower from Delrin, so far so good and it needs less oil than the old Tufnol blades

Mark Roper


From: Alan
Sent: 31 May 2002
To: british-cars-pre-war
Subject: Cozette info

While on the topic of Cozette blowers....Originally, there was a valve that opened when the accelerator pedal was depressed. This valve allowed oil to flow to the supercharger from the oil tank. Does anyone know where I might find one of these valves or if they were common to some other use.

A week or two ago, we fired the 1930 Supercharged Ulster up for the first time in over 60 years. It ran very well but the original Cozette carb was a source of problems. I would be interested in suggestions for a different carburettor. Is there not a Solex or Zenith that will fit?

Alan
http://roverworks.com/


From: David Cochrane
Sent: 31 May 2002
To: alan
cc: british-cars-pre-war
Subject: Re: Cozette info Ulster

Hi Alan,

You wrote:
> A week or two ago, we fired the 1930 Supercharged Ulster up for the first
> time in over 60 years. It ran very well but the original Cozette carb was
> a source of problems.

This sounds interesting! More please ....?

Best wishes, David C


From: Chris Nowlan
Sent: 31 May 2002
To: british-cars-pre-war
Subject: Re: Cozette info

Alan,

A similar valve was used on Powerplus equipped J4 & K3 MG's. It was known within MG as a "fluff-fluff" valve. It was linked to the throttle and provided additional lubrication under load. I have no idea where to obtain such a device would be interested to hear other suggestions. Only a handful of Powerplus superchargers seem to have survived.

Does anyone know what an eccentric vane "Jameson" supercharger might have been fitted to? It seems appropriate for approx. 750-1,000CC application. It's similar to a Centric, Powerplus or Cozette with a circular carb flange and rectangular opposing exhaust port. It has a shaft out both ends as though one end was intended to drive ancillary equipment. Any comments would be appreciated.

Chris Nowlan
L2-002,J2-4159


From: David Cochrane
Sent: 31 May 2002
To: Cnowlan
cc: british-cars-pre-war
Subject: Re: Cozette info

Chris,
> Does anyone know what an eccentric vane "Jameson" supercharger
> might have been fitted to? It seems appropriate for approx.
> 750-1,000CC application. It's similar to a Centric, Powerplus or
> Cozette with a circular carb flange and rectangular opposing
> exhaust port. It has a shaft out both ends as though one end was
> intended to drive ancillary equipment.

Murray Jameson worked for Austin in the mid-30s, starting by developing their existing racing Sevens. He was a supercharger expert I believe. He went on to design a completely new 750 single seater racing car, really a state-of-the-art racing car in minature. What you have might have belonged to one of these. What he did after he left Austin and before he was killed spectating at Brooklands I don't know, perhaps he went freelance?

David C.


From: Stuart
Sent: 01 June 2002
To: Chris Nowlan
cc: british-cars-pre-war
Subject: Cozette info and Jameson

Chris, Suspect you have a Jameson - Gillett blower of mid 30s, marketed by Gillett, Stephen and Co ltd, Atlas works, Little Bookham, Surrey. Will send jpeg to you direct to see if it's the right one. Jameson Engine Co. also built two fascinating twin blown two stroke racing engines built into rather pretty Jameson Specials 19333/4. Wonder what became of them?
Regards, Stuart


From: Stuart
Sent: 01 June 2002
To: A1 STORAGE
cc: Charles Ping; british-cars-pre-war
Subject: Re: Fake Cozette info

I see that Derek Chinn advertises in the VSCC newsletter and may be able to supply a period blower, if that's really what you want. In my experience most old blowers need rebuilding and then you need to overcome lubrication problems (see Alan's recent post). Might be best to bite the bullet and pay for a new replica Cozette, not that I am feeling particularly in favour of them just at the moment! At least you will evade the oiling nonsense! Blown cars are wonderful to drive and I think are well worth the odd hiccup. Good luck.
Regards, Stuart


From: Stuart
Sent: 01 June 2002
To: Charles Ping
cc: british-cars-pre-war
Subject: Re: Fake Cozette info

Thanks to all who replied to this. I will report on progress.
Regards, Stuart


From: Stuart
Sent: 01 June 2002
To: Alan
cc: british-cars-pre-war
Subject: Re: Cozette info

Have used an F type horizontal Solex with success on blown Ulster engine many years ago. Believe this carb may have been fitted to Riley 9s. Do Gallay radiators, who supplied the Cozette, still exist? They might have details of the scroll valve. I know they used to retain a great deal of information on file. The Cozette handbook helpfully refers to this as a "special cock" and tells you no more. I've never seen one, but have seen simple valves like a radiator tap with a long lever used for the same purpose. I would presume the relative lengths of the operating levers are critical.
Second David's request for more info!
Regards, Stuart


From: Alan
Sent: 01 June 2002
To: british-cars-pre-war
Subject: Re: Cozette info and Riley Sprite

Hello all.
The 1930 Super Charged Ulster that is in my shop belongs to a gentleman in Vancouver B.C. I have asked him to do a write up of the car for the list. It was exciting reawakening the engine after such a long slumber! The car is "correct" with all the major bits intact (crank case, chassis, blower, rear end, front axle etc.). However, we are missing some small original parts such as the accelerator linkage and scroll valve for oiling the blower. Any original parts, even if for pattern only, would be of interest. The car is very original and we would like to maintain it accordingly.

On another note. I have received to my shop a Riley Sprite which I am doing an estimate for repair. This car is original but has had a very rough (but interesting) life. If anyone has chassis detail pictures or chassis measurements from an original I would be grateful. I am particularity concerned with the area where the chassis is boxed at the spot where the pedal assembly meets the chassis.

There are some pictures on my web page of the Austin engine laying in the car when we were "mocking it up" a few months ago. Click the Images button.

Alan Simpson
http://roverworks.com/


From: The Austin Seven Fanatic!
Sent: 01 June 2002
To: Alan
cc: british-cars-pre-war
Subject: Re: Cozette info

End pumps - my understanding is that these fell off and caused the blower to seize!! Certainly, the oiling must have been somewhat suspect with all the levers and adjustment needed, plus the chassis flexing too.

I use 40:1 petroil mix and with the end bearings fitted to mine, which are not the original, large ball-race type, this gives adequate lubrication. It was always necessary to put oil in the petrol anyway, to lubricate the vanes and of course remember to turn on the oil supply every time the car was used. Oh fun! Shaking the car before use is a good idea too when its been left for a while....

Apparently, supercharged engines, although highly stressed generally, suffer far less bore wear at start-up due to residual oil in the 'blower. We are of course talking here about gear-driven supercharging, rather than the other sort, commonly called turbocharging. However, a worn 'turbo probably "oils" the bores as well!

My Ulster has a repro blower, of unknown origin, but it is heavily modified I'm told, whilst it was in Oz. Apparently - I've never had it apart - yet, it has either solid Delrin or PTFE-tipped vanes and a mod to the ports too; it does have a large dose of Araldite certainly. Also, it is an inch or so longer than normal and is geared up, so not only moves more air but blows at relatively high pressure compared to "standard" - up to 14psi. From what I remember of Alan's blower (I think I remember a picture he sent me), it is nearly as long as the crankcase.

As far as carbs go, I use an SU "H" type, which is not only period enough, but works reliably too and unlike SU's normally fitted to A7s, almost certainly opens fully. From what far more knowledgeable people than I say, is that period Cozettes and Solexes (and probably Zeniths) are ok for looks only. On a run (to Beaulieu), I got 42 mpg, yet my Ulster will do 50+ in first and over 70 in second and we're talking mph not Phillistine here. 20 mpg is about the best for a Cozette-equipped, road-going Ulster I'm told (by Reg Nice) and hardly into double figures under racing conditions, although under these latter conditons even an SU will only manage about 15.

If you want some pictures of the SU-equipped car, I can oblige.

Barry Lovelock
http://www.theaustinseven.com

Alan wrote:
> While on the topic of Cozette blowers....Originally, there was a valve that
> opened when the accelerator pedal was depressed. This valve allowed oil to
> flow to the supercharger from the oil tank. Does anyone know where I might
> find one of these valves or if they were common to some other use.
>
> A week or two ago, we fired the 1930 Supercharged Ulster up for the first
> time in over 60 years. It ran very well but the original Cozette carb was a
> source of problems. I would be interested in suggestions for a different
> carburetor. Is there not a Solex or Zenith that will fit?
>
> Alan
> http://roverworks.com


From: The Austin Seven Fanatic!
Sent: 01 June 2002
To: Alan; british-cars-pre-war
Subject: Re: Cozette info

I just looked at Alan's car and I must have been talking about another blower - sorry.


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