Wintonian
Member Since: 14 Apr 2006
Location: Winchester
Posts: 10
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Gurvan wrote:Just a ignorant question... Reading on your website, it seems that there is no pressure valve to prevent over-inflating. Why is that ? Too difficult to build ??
It is possible to build an over-pressure valve into the bag itself, but I have not done so. This is because it would be exposed to damage and therefore possible failure, just when you need the jack most.
Instead, we rely on the fact that the rubber cone would be so difficult to hold on to the exhaust pipe at pressures over 10 psig that you would not, in practice, do that. If someone did decide to force the issue, the non-reinforced rubber exhaust delivery tube would inflate to a large diameter before bursting with an extremel load bang. The bag would remain inflated, of course, thanks to the non-return valve in the connector.
Gurvan wrote:Also, just as ignorant, why don't you do a twin inflatable system so that, instead of blocking one exhaust and using the other one, we could use both of those ?
I can see no benefit at all in this. The hose connections would be bulky and expensive to make and assemble. The bag would still inflate at the same speed because there would be no change in the gas flow rate. MUCH easier just to block off the other pipe.
Even better would be for Land Rover to stop doing unnecessary engineering at the rear of their cars. I can see the point of giant twin exhausts like those on the Porsche thingy. The purpose there is to frighten little old ladies and small children. And impress some other people.
But the Land Rover tailpipes are invisible! One would therefore suffice. And probably be cheaper to make!
David
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 15th Apr 2006 4:32 pm |
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Wintonian
Member Since: 14 Apr 2006
Location: Winchester
Posts: 10
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dickgriff wrote:Thanks Wintonian - You'll appreciate no doubt that this was purely freindly advice 
No problem dickgriff. I understood you perfectly, and was not in any way offended. This is one of the most friendly forums I have seen, with far more intelligent posts than many others.
I hope that Martin will let me know if I stray beyond acceptable bounds.
David
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| 15th Apr 2006 4:36 pm |
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chippypip
Member Since: 13 Dec 2005
Location: The Lake District
Posts: 127
 
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I am very impressed by the pictures submitted showing the jacks operation and the fact that there would appear to miminal damage caused to the vehicle by using one.
I've used the supplied jack once....never again!
These would look good with 'DISCO3.CO.UK' on too!
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| 15th Apr 2006 5:47 pm |
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Gurvan
Member Since: 02 Jan 2005
Location: Germany... Not far from both the US and Hard German rock...
Posts: 1089
 
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Thanks for the pictures Slimer... That'll do the trick to show SWMBO... 
Thanks for the answer Wintonian... The first one made sense according to the KISS principle...
As for the second one, even though I understand what you are saying, I was thinking of something simple like a giant Y with one side to the ballon and the two others for the exhausts pipes with 2 non return valve in the pipes instead of one... But, again, that is only for the sake of the discussion as your system seems to work pretty good as it is !
Thanks for taking time with us Wintonian... And I agree that the bag with the Disco3.co.uk would look good...
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| 15th Apr 2006 6:26 pm |
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lefred45
Member Since: 11 Aug 2005
Location: Saint Gondon
Posts: 125
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Hi,
In front of the tests and the photographs seen on the site. I have just bought an air jack of 4 tons. It was to be useful to me for my 109 and disco 3. But there, I think that it will be useful to me only for the 109. 
Impossible to raise the vehicle in spite of the account-turn to 2500-3000 turns and this for one long period trops for me  (the ventilator started several times). Thus I need a further information.
Thank you by advance and to excuse my very bad English, but I am French...
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| 18th Apr 2006 6:43 pm |
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Slimer
Site Moderator
Member Since: 06 Jan 2005
Location: Last Exit to Nowhere
Posts: 16295
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What make air-jack did you buy?
If it's one of the cheap ones it won't lift anything near what it claims to do.
I'm not just saying this because I have one of the expensive ones now, I've also got and have tried one of the cheap ones and know from experience they won't lift anything heavier than a small saloon car.
The decent type as sold buy Wintonian will lift the D3 on tickover, the 2 tonne version managed it but was getting towards the limits of it's abilities so the 4 tonne version is a better option The End
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| 18th Apr 2006 7:10 pm |
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lefred45
Member Since: 11 Aug 2005
Location: Saint Gondon
Posts: 125
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I bought what one finds in France, that is to say a version 4 Tons
with 179 euros.
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| 19th Apr 2006 7:59 am |
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lefred45
Member Since: 11 Aug 2005
Location: Saint Gondon
Posts: 125
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It had started to inflate.
What I reproach, it would be rather the obligation to put the disco 3 in surrégime to be able to inflate the pipe and the air Jack
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| 19th Apr 2006 8:04 am |
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IanD
Member Since: 11 Mar 2006
Location: (Too) close to Paris
Posts: 516
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lefred45 wrote:I bought what one finds in France, that is to say a version 4 Tons
with 179 euros.
Looks like that might be the problem! Since living here, I have found it difficult to find any kind of decent quality tools on the market in France. The 4 ton Easylift is around 515 €, so you would expect it to work better. It shouldn't cost very much to have one sent here.
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| 19th Apr 2006 10:13 am |
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lefred45
Member Since: 11 Aug 2005
Location: Saint Gondon
Posts: 125
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Yes, but the problem is that this air jack functions well on a HDJ 80
equipped raid...
It is necessary that I stop the second exit of
exhaust.
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| 19th Apr 2006 11:55 am |
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Wintonian
Member Since: 14 Apr 2006
Location: Winchester
Posts: 10
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| French Air Jack (Cric Air) |
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Cher lefred45
Pouvez vous svp me dire qui fournit le cric d'air de 4 tonnes dont vous avez parlé. Je voudrais obtenir des détails du produit, tels que ses dimensions.
[Can you please tell me who supplies the 4 tonne air jack that you talked about. I would like to obtain details of the product, such as its dimensions.]
David
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| 19th Apr 2006 12:08 pm |
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lefred45
Member Since: 11 Aug 2005
Location: Saint Gondon
Posts: 125
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Cher Wintonian,
C'est un Air Jack DS,
4.3 Ton
Diamètre environ 55 cm (je peut prendre les dimensions exactes ce soir)
De toute façon si avec un nouvel essai en bouchant une sortie d'échappement, cela ne fonctionne pas avec le moteur au ralentie, la société qui me l'a vendu me le reprend.
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| 19th Apr 2006 12:28 pm |
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Wintonian
Member Since: 14 Apr 2006
Location: Winchester
Posts: 10
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I hope this doesn't bore everyone, but the following table illustrates the relationship of air bag diameter to lifting capacity at a given pressure. Higher pressure will give greater lift capacity, but we work to a maximum of 0.7 Bar (10 psig) so that the product is safe and easy to use. In addition it does not subject the exhaust system to undue stress. Please remember that a petrol engine creates over 120 psig inside the bores when running.
..............................................ELH02.......ELH04
Air Bag Diameter (cm)...................60............86
Air Bag surface area (sq cm)......2,827.......5,809
Exhaust Pressure (Bar)....................0.7..........0.7
Total Lift Capacity (Kg)..............1,979.......4,066
Total Lift Capacity (Tonnes).............1.98.........4.07
This is all a matter of 'O' Level physics and so it applies to all lifting bags. So if a bag has a diameter of 60 cm or less, then the maximum it will lift is going to be less than 2 tonnes. And it will require the full 10 psig to do it.
It is quite normal to use a lifting device rated well above the required lifting capacity. But not one that is rated below.
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| 19th Apr 2006 2:20 pm |
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lefred45
Member Since: 11 Aug 2005
Location: Saint Gondon
Posts: 125
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Dear Wintonian,
For my air jack 4.3 Ton
diameter: 60 cm
heigh: 65 cm
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| 19th Apr 2006 7:04 pm |
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Wintonian
Member Since: 14 Apr 2006
Location: Winchester
Posts: 10
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Cher lefred45
Les dimensions de votre cric sont presque exactement identiques à notre cric de 2 tonnes. Il n'est pas assez bon de soulever une Discovery 3 parce que le véhicule est trop lourd. Afin de soulever 4,3 tonnes, vous devriez employer la pression d'environ 1,5 barres.
[The dimensions of your jack are almost exactly the same as our 2 tonne jack. It is not good enough to lift a Discovery 3 because the vehicle is too heavy. In order to lift 4.3 tonnes, you would need to use about 1.5 Bar pressure.]
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| 20th Apr 2006 9:26 am |
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