Hi guys,
I've been spending a little time with the above matter and I have some problems. On my earlier post, several people kindly answered and informed me that the way to tell was to measure down to the rubber base from the top of the steel ledge on the displacer. Standard Mini's were about an inch and Cooper S and Clubman GT's were around 5/8 or a lot less.

I've just returned from measuring two different lots of S bags ( 21A 1804 and 21A 1872) and I find that thay are around the same dimension as 21A1477 (the standard Mini bag). I also notice that all the bags carry the 21A 1477 number on the rubber, the 1804 and 1872 numbers were stamped into the body.

My question is, why am I finding the dimension the same as a standard displacer? Am I measuring in the wrong place? Could the displacers used in Australia be Australian made or is the information kindy supplied simply wrong? Can anybody shed any light on my problem please?

I have located a set of bags with a AYG4113 part number and these are of a Clubman GT, is this a suitable number for a Cooper S?

Best regards
Al

How's this. . .

Two displacers - the one on the left is from a Deluxe and the one on the right is from as S:



Deluxe:



S:

Hi Pete,
Thank you for the brilliant photo, it confirms I have been measuring in the correct place. However, even though I've measured bags with Cooper S displacer numbers stamped into them, the dimension is no different than the regular one yopu have shown. Have you been able to find a number on your displacers? The numbers on the ones I've measured are stamped into the outer wall, just below the waist.

Thanks again
Al

I have Cooper S displacers with the same part numbers that are as different as the two in the photo.

Cooper S displacers, or displacers from a Cooper S?

Anyhow, the number on the S bags that I have (made in 1969 if that makes any difference) is quite clearly printed as: 314 21A2 14D 69 (with gaps as indicated)

So that doesn't really help at all, does it?

FWIW the Deluxe bag is stamped 247 21A2008 67

Both. Cooper S displacers from my Cooper S.

I have 3 different types of displacers, I have just been out in the shed and given them a quick wire brush and on the first one I discovered some slight markings, so I gave it a squirt with WD40 and I fount it was silver paint with a part number 21A2014 (with 21A1477 on the top of the rubber spring)
The next one I cleaned was orange with 21A1811 (with 21A1477 on the top of the rubber spring)
The next one was silver again.
The last one I could not find a number but I guess it is a Deluxe or GT displacer as it has Made in Australia on the rubber spring, it looks like the two silver displacers.

Here are some photos of my displacers.


Notice the rubber springs are different, just like the two that PetenSoafposted in his pic...








The Made in Australia one is on the left...

According to the Vizard book the Orange 21A1811 one that I have is the "Two orange band" Stiff displacer.
It was a competition car so it kind of makes sense.

I just found this on the net.. Mini DIY Guide: Cooper S hydro bags.
So that makes my rear displacers "standard Cooper S late rear displacers"

Thanks for all your help guys. Am I correct in my observations that the displacers 1100 has photographed have the same previously described measurement (1") down to the rubber? They look like they are. If so, it would seem there are two typed, so not all will have the smaller 5/8" dimension. Maybe the ones with the 5/8" dimension are Aussie made, what do you think??

Thanks also for the great information on that link, I've printed it off for future reference.

Regards
Al

The ones in my photos have two different depths.
The "made in Australia" and the two silver 21A2014 ones have the shorter 5/8th" depth.
The "Twin Orange Band 21A1811 Special tuning" one has the 1" depth.

Just to add another type.
Here are the blue Cooper S displacers from a 1966 Australian S.

My 1968 S had silver displacers with (from memory) twin silver bands on the displacers as well as the hoses. The rears had single silver banding.

Hi guys
Thanks Wild willy and 1100 for your replies and photos. Wild willy, are yours 5/8"? They look like they might be.

It is starting to look like British ones might be 1" across the range, it's only the Aussie made Cooper S ones are 5/8". Does everybody agree with my assumption?

Thanks again
Al

No. Only one of mine is Australian made. The other three are UK made. So I have both Aussie and UK that are 5/8"

The part numbers are a clue to the place of manufacture. Australian made parts will have a "Y" in the part number.
From the 1969 BMC parts book I have the following numbers...

Rear displacers.
AYA4090 (Australian part number)
21A2010 Double Orange band.
21A2014 Double Blue Band

Front Displacers.
21A1477 Deluxe.
AYA4090 Deluxe, 1 Orange Band. (Australian part number)
21A2010 Cooper S, 1 Blue Band. (YKG2S2-1918 to 3716)
AYG4113 Cooper S (From YKG2S2-3717) (Australian part number)

Now about the stamping on the displacers...






It is very hard to see these numbers at all. I didn't think that the camera would pick them up as I have trouble seeing them myself.

Hey all there is a displacer for sale on EBAY http://cgi.ebay.com.au/ws/eBayISAPI.dll ... escription
and this was in the Q&A

Q: Do you know what colour the indentification band on it was before it was painted black? 21-Jul-08
A: Hi, It appeared to be a dark green,I know your looking for grey and it would be easy to say that,but for the record the only different to Cooper S and Non Cooper S was the length of the hollow output sharft from the displacer as it was 1/4" longer to give more pressure and a stiffer ride handling yes they had a different part number or paint code on some to account for this. I did remove these from a MK1 S many years ago but who knows as they too may have been changed at sometime. There is a set of these but one has some rust where the rubber dust boot covers the displacer wont affect the unit but doesnt look pretty,I have another unit for sale on OZtion.

I have not heard of this before. I would have thought an extra 1/4" would only raise the ride height at a given pressure, so to get the ride height right, you would have to lower the pressure thus softening the ride

I just thought I might resurrect this thread again,

I've been going through my box of displacers, and noticing that half have 21A***** numbers, and the other half do not. The half without the 21a****** number instead have two digit numbers stamped on the case, 05 or 32 or 41 or C61 (with a 31 below it) all are on the displacers marked 211063. Can anyone tell me what these are out of? No paint markings remain unfortunately...

_________________
SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.