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Ray White
Joined: 02 Dec 2014 Posts: 6313 Location: Derby
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Posted: Sat Feb 13, 2021 8:45 pm Post subject: double trouble or twice as reliable? |
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Perhaps someone could explain what is going on here and how it is wired?
This XPAG engine is being supplied with two petrol pumps and two coils. Seemingly two condensers are needed as well?
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DM
Joined: 21 Dec 2008 Posts: 212 Location: North Cornwall
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Posted: Sat Feb 13, 2021 8:59 pm Post subject: |
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The second coil is not wired, it is in place as a spare allowing the wires to be quickly swapped over.
Can’t see the wires and pipes on the second pump but expect it is a spare as well. |
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Ray White
Joined: 02 Dec 2014 Posts: 6313 Location: Derby
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Posted: Sat Feb 13, 2021 9:09 pm Post subject: |
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DM wrote: | The second coil is not wired, it is in place as a spare allowing the wires to be quickly swapped over.
Can’t see the wires and pipes on the second pump but expect it is a spare as well. |
Sent you a PM. |
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Ray White
Joined: 02 Dec 2014 Posts: 6313 Location: Derby
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Posted: Sat Feb 13, 2021 9:14 pm Post subject: |
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It looks like the low tension of the two coils are connected (via two condensers) somehow.
The two pumps are also in tandem.
Worth doing? or overkill? |
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Rick Site Admin
Joined: 27 Apr 2005 Posts: 22446 Location: UK
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Ray White
Joined: 02 Dec 2014 Posts: 6313 Location: Derby
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Posted: Sat Feb 13, 2021 9:40 pm Post subject: |
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Rick wrote: | Maybe used for long-distance rallies?
RJ |
The car is a TA and has (wiseley, in my opinion) been fitted with an XPAG engine. It has definitely been used for some long distance runs. Hence the velcro!
Here it is. Nice one I think.
https://www.carandclassic.co.uk/car/C1162820 |
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Peter_L
Joined: 10 Apr 2008 Posts: 2680 Location: New Brunswick. Canada.
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Posted: Sat Feb 13, 2021 11:31 pm Post subject: |
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Personally, I don't see anything more than installed redundancy with a very simple changeover system. The unused coil has no electrical connection. |
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alastairq
Joined: 14 Oct 2016 Posts: 1954 Location: East Yorkshire
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Posted: Sun Feb 14, 2021 12:18 am Post subject: |
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It seems typical of a vehicle used on events focussed on 'reliability' [such as , classic reliability trials?] where the first objective is to 'finish'...regardless of one's performances during the event.
Motor sporting events such as the one I mentioned above do not permit backup support, such as a convoy of vans and posh gazebos to service, maintain & repair competing vehicles.
In fact, aside from the friendly co-competitors help, one is very much on one's own.
Hence, to enhance the ability to finish, all weak points which prevent onward motion are duplicated...preferably sited to avoid spending too much time conked out.
In the above mentioned type of events, competitors often carry a spare differential or two in the back...possibly the odd replacement alternator [engines can be bump started].....and duplicated ignition & fuel components..
Throttle cables duplicated, etc etc....
Nowt worse than knowing one can fix it and get going again...if only one had that simple, easy to carry component.
[Often a fellow competitor can help one out, but don't bank on it.]
I believe these posh classic rallies operate on a similar principle, but cost one heck of a lot more. _________________ Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
----------------------------------------------
Ford Pop chassis, Ashley 1172 bodyshell, in pieces. |
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Ray White
Joined: 02 Dec 2014 Posts: 6313 Location: Derby
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Posted: Sun Feb 14, 2021 12:21 am Post subject: |
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What I see is a wire connected to the lower post of the top coil that joins the lower post of the bottom coil. It seems to be connected to two condensers.
The petrol pumps are plumbed together but I can't confirm their electrical connection. |
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Peter_L
Joined: 10 Apr 2008 Posts: 2680 Location: New Brunswick. Canada.
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Posted: Sun Feb 14, 2021 1:19 am Post subject: |
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To utilise Coil 2, move the LT cable and HT Cable. Ignore the capacitor, only one is in circuit.
SU Pumps. The male spade connector on the one nearest the camera has no cable, part of the spade is visible.
It is all what it is, there is nothing other than redundancy and easy change over.
I had a Mini with which we did considerable long distance trips across West and East Europe then a much modified Cortina Estate that did similar and North Africa. Multiple redundancy and spares were order of the day. Example: The Mini also had three petrol pumps. Two connected to the two isolated fuel tanks, installed as per the Mini Cooper and a none connected spare. |
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ukdave2002
Joined: 23 Nov 2007 Posts: 4104 Location: South Cheshire
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Posted: Sun Feb 14, 2021 1:13 pm Post subject: |
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In this set up there won't be a reliability improvement ; if either the coil or pump fail, it still involves stopping, opening the bonnet and swapping a wire.
To change a coil or fuel pump (with the spare unit in the boot) is a 5-10 min job, so the only benefit in having them fitted this way is where speed is important, as Alastair comments its probably originally from a competitive set up where 5 mins time saved could be critical.
For authenticity they could loose the modern blue B&Q plastic crimp on the fuel pump!!
Dave |
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Ray White
Joined: 02 Dec 2014 Posts: 6313 Location: Derby
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Posted: Sun Feb 14, 2021 1:27 pm Post subject: |
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ukdave2002 wrote: |
For authenticity they could loose the modern blue B&Q plastic crimp on the fuel pump!!
Dave |
I think if authenticity was important it would have an MPJG (rather than XPAG) engine. |
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lowdrag
Joined: 10 Apr 2009 Posts: 1585 Location: Le Mans
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Posted: Sun Feb 14, 2021 3:58 pm Post subject: |
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C-types always had two coils, ready for a swap if one failed:-
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peter scott
Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh
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Posted: Sun Feb 14, 2021 6:50 pm Post subject: |
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Ray White wrote: |
The two pumps are also in tandem.
Worth doing? or overkill? |
Paralleling the pumps will permit greater flow rate but I doubt that tht would be required with the XPAG. The 3½ litre SS Jaguar used this arrangement but I don't think it was even necessary there. Fitting the double contacts is well worthwhile though for reliability.
Peter _________________ http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon |
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Ray White
Joined: 02 Dec 2014 Posts: 6313 Location: Derby
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Posted: Sun Feb 14, 2021 8:14 pm Post subject: |
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peter scott wrote: | Ray White wrote: |
The two pumps are also in tandem.
Worth doing? or overkill? |
Paralleling the pumps will permit greater flow rate but I doubt that tht would be required with the XPAG. The 3½ litre SS Jaguar used this arrangement but I don't think it was even necessary there. Fitting the double contacts is well worthwhile though for reliability.
Peter |
I have seen two pumps fitted to other cars where a supercharger is used but I don't know if this was done from experience or as a precaution. Mine has the larger 1 3/4" SU (as opposed to the 1 1/2") and having been advised that the engine runs better with being a bit richer I wonder if I will need two pumps?
I suppose the proof of the pudding is in the eating.
Let's see how it goes first. |
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