fv1609

The parts catalogue is Army Code No.61456

The 12v coil would have about twice the resistance of the 6v coil. So when fed with a 6v supply it would nowhere near saturate the coil core with magnetism to give the full HT output. You need to establish whether the coil is for a negative or positive earth & that it matches the polarity of your vehicle. To ensure not only that you are getting a negative spark but you are not having to fudge it with a wrong polarity coil wired in reverse to give a negative spark. If it is the latter case you will lose 600v of HT compared to the correct coil. Not a vast voltage but may make all the difference up hill.

I'm afraid I know nothing about the electrics in a Dodge, whether it is an insulated or earth return system, if it is earthed whether that is positive or negative, or whether it has been changed & whether the LT connections have been swapped or whether a proper coil has been fitted wound for the appropriate earth polarity. The practical point is to establish the polarity of the spark in the present set up. I use an old analogue Avo, using the highest voltage range (1kV or 2.5kV) hook up a wire from the negative prod to the junction of a sparking plug & its connector. Take the positive lead to chassis assuming it is an earth return system. Briefly crank the engine. An upward rise of the needle indicates a negative spark. Downward a positive spark, so swap the LT terminals on the coil. There is something to be gained (600v) using a coil of the correct earth polarity rather than the quick trick of swapping the LT connections. This is from an article I posted on here about screened ignition but the spark polarity issue is the same. I have edited to suit. It is important to verify you are using the correct type coil. It is also important to confirm that it has been connected up correctly. The wrong polarity of coil or the correct one incorrectly connected will have three consequences. 1. The polarity of the HT spark will be reversed. The ignition coil doesn’t mind the change of polarity but the sparking plugs do not function so well. Engines are designed so that the polarity of the sparking plug terminal is negative. If the polarity of the spark is wrong, it would need a greater voltage for proper functioning. This is because a spark finds it easier to jump from a hot central electrode than from the cooler side contact that is in thermal contact with the engine casting. If the polarity is wrong up to 40% more HT may be required to create a spark at the plug. 2. Sparking plug life will be shortened as metal will be lost from the side contact making gap adjustment short lived. The central electrode is much longer and is designed for this erosion. 3. Similarly there will be increased erosion of the rotor arm. This will be explained in the distributor section later. I know of one Rover that left Army service with the connections to the coil reversed. The engine ran poorly and needed a lot of choke, the rotor arm and the adjacent lead terminals were markedly carbonised. Correcting the polarity of the LT terminals on the coil gave easier starting, smoother running and more power. Modern unscreened coils have terminals marked – and + so that in a negative earth vehicle the – terminal supplies the contact breaker, which on older systems was marked CB. Older coils used in a positive earth vehicle should have the + terminal supplying the contact breaker. In either case the other coil terminal is fed with the energising supply originating from the ignition switch that used to be marked SW.

Yes of course Chris being a bit dim tonight (esp)

A while ago I was out metal detecting on a beach not too far from here. Talking to someone else doing the same thing, he told me of a medal he had found there earlier in the year that had a good result. http://www.southwales-eveningpost.co.uk/family-reunited-lost-world-war-medal/story-29298542-detail/story.html

Chris so it got through the second layer of armour, where did the projectile end up? In the other side of the Pig or did it whizz around inside?

Yes there was indeed Richard I have a picture somewhere I'll post up when I find it.

Something to check is that you are running with a negative spark rather than a positive spark which will be less effective at high load & high revs. Are the coil LT connections the right way round? Are you certain that the coil is of the correct earth polarity for the set up in your vehicle? If the polarity of the earth has been changed sometimes people simply reverse the LT connections on the coil so as to give a negative spark. But that way you lose appx 600v of HT compared using a coil designed for the specific earth polarity of your vehicle.

Has this always done this during your ownership or has it always worked fine & then started playing up?

A couple of these became Flying Pigs, 07 BK 39 & 12 BK 30. Thank you once again Chris.

The trouble is Terry, people might not realise the significance of all that mess & assume you have just been using it to play paint-ball?

Catalogue of Ordnance Stores & Ammunition Section H1(a) Paints, dopes & varnishes 1978. Any other editions (or of Vocabulary of Army Ordnance Stores - VAOS) 1950s-70s would be welcome & indeed most VAOS/COSA of any other Sections are of interest either to buy or pay for copies/scans. I have the 1980 edition above, but I am after the preceding edition 1978 & earlier.

The first Pig has new front wings these have no lockers & of a thicker steel supported by two parallel wide top-hat sections underneath. So they didn't normally sag like the earlier ones which would often reveal the pattern of the cruciform reinforcing strips underneath. The view of the rear doors open is interesting & suggests this is after March 1975. On the right hand door to the left of the red handle for the use of the crew, I can just make out a small horizontal bar. This was so that the driver could lock the rear doors once the crew had debussed to protect himself & the empty Pig. This bolt was formed by a small rectangular piece of bar with an end piece bent up at the end for the driver to operate. It is a shame that the man with the red paint brush didn't highlight the end of this bar, unlike most of the other red paint, this might have been useful for the driver scrambling into the back in the dim light trying to secure the vehicle to see this small end of the bolt. This modification was not in an EMER, rather than the time delay in getting MVEE approval, it was locally designed & implemented as: N IRELAND LOCAL E AND M ENGINEERING INSTRUCTION WHEELED VEHICLES N 257/2 (N IRELAND) MOD INSTR NO.1 The last Pig looks as if was a part-time Flying Pig. You can see a wing supporting strut above the rear wheel arch where the lockers once were. At first I thought it was 11 BK 68 but that was struck off (& not recovered) in 1967, I think it is 11 BK 56 which was indeed a Flying Pig.

The graphs now have translations.

Richard I don't know, 223 gets mentioned a number of times in the original German papers. This report is from the Combined Intelligence Objectives Sub-Committee Item No.19 File No. XXIX-54. I'll try & post up some more extracts but upload speeds are very slow this morning.

Chris well done, the ignition was the result of an injection but of what I know not, other than it was "Ignition Oil".

Richard that is a good link to a most impressive bit of engineering. But it doesn't cover the aspects of this particular research I have in front of me, this engine was running off 87 octane petrol. The issue investigated was the novel method of ignition & in the earlier MO it was overcome with a low voltage spark sliding on the porcelain of a special plug.

A lot depends on when in August, as there is lot going on in July & August (not round here mind you) When you know a date & if, as your website suggests, you want multi-period then it might be worth posting on here: http://www.livinghistory.co.uk/index.php

Neither are mentioned Richard.

Wally I don't know if ethanol is part of it but there is no mention of ethanol. The focus of this investigation was on the ignition method (as outlined in MO No.190 high voltages were a problem at high altitudes).

Nope not water Wally.

Yes it has a bearing Nope

Sorry missed you there Pekka, not multifuel as we know it but there is something in what you say.

No not that Tony

Not a turbocharger Richard, does this help?