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Dear Martin, Looks nice! I would expect the batteries to be NATO standard or something like a ubiquitous 653 ordinary lorry battery. Except in very cold weather, the Rolls is quite a good starter so a pair of ordinary lorry batteries will be fine. I would advise you to acquire the following publications: User handbook Servicing schedule (Forum members can advise on civvy equivalent lubricants. Engine should be run with 50 % antifreeze and certainly no less than 33 %. This is to avoid cavitation corrosion of the wet cylinder liners. AESP or EMER (I don't which it has) (Army Equipment Support Publication) or Electrical and Mechanical Engineering Regulations. You want the unit and field repairs version. If you cannot get these pubs for the FH70 gun tractor, try and get them for the Foden recovery vehicle instead because they are very similar. However, you will need the correct wiring diagram. It is a hell of a beast because it has the 305 Rolls but it is not that heavy. At the same time, it has a humungous tractive effort with the transfer box in low ratio and six wheel drive. John

Dear All, As it happens I have been talking today to the Home Office officials responsible for these matters but about another issue. I can assure everybody that they do actually know what they are doing. Andy, has put his finger on the issue with his remarks regarding Q14. John

Dear All, On the DPM combat cap, it was the most horrible piece of kit imaginable. I imagine that they were issued to recruits because no one else would wear them. Just not fashionable! The tin helmet was just not practical and 10FM68 is right about its use (of course it would have been effective for the purposes described). The Kevlar helmet was so much better, so it is used much more. 10FM68 is right about it all being fashion and in particular with berets and there could be many different styles seen even within a company / squadron.. On his point about dating, I would imagine there was only a quite short window when Combat High boots were on general issue along with '58 webbing but my memory may fail me. Finally, how do you a group of officers to dress identically? Tell them to come to the meeting in civvies! John

Dear All, I do not profess to be an expert on the FV 430 range but if you have one, you must expect to have to lift the pack out. It would be well worthwhile to copy a pack lifting frame if you do not ready access to one. The pack is easier to lift with a hoist crane rather than a Hiab type of crane. Alternatively, a Hiab type crane with a chain hoist would be good. Terry is right about rotating the engine a little in case the starter teeth are abutting each other. However, I have made a special tool for John D's FV430's. You would find it easier to use a special tool that is no heavier than necessary. If rotating the engine a bit does not do the trick and you need to smack the starter with a hammer, it is time to lift the pack! John

and it is not worth anything like £3K since spares for the engine are no longer easily available.

VMT! John

Dear All, Does anyone know the full nomenclature of the Foden FH70 gun tractor. It would be something like: Tractor Wheeled, 6 X 6, Foden, FH70. A scan of the cover of an AESP would be really helpful. John

On the SD1 Rover, that was done by Charlie Broomfield and I have spoken to him about it. I think he used an OMEC controller that was professionally installed so it would not be cheap but I did not ask any impertinent questions! For a big truck engine, a Speeduino or a Megasquirt controller will do all that is needed. For the Meteor I did indeed need two injectors per cylinder. It would have delivered nowhere near enough fuel otherwise. I had to make what is called a 'peak and hold' injector current control system using LM1949 chips. The data sheet for the chip explains all. On historic vehicle exemptions. The EU Road Worthiness Directive was predicated on the needs of the accession states that still had numerous old and unsafe vehicles in commercial use on their roads. They wanted as tightly drafted historic exemption as possible. From my own experience I know that our Department for Transport wanted to bring as few vehicles as possible into goods vehicle testing because of the very limited road safety benefit in doing otherwise. If a Scammell Explorer is 'historic' I don't know what is! However, having the right petrol engine in stock is a good insurance policy. Equally, a 680 Leyland is a 'historic' engine itself and it is hard to think of anything better to fit to an Explorer. Once I have finished my current work schedule on Meteors, we could put your Meadows petrol into my run-up rig. You will find that it takes quite a bit of time to make one up! Dave, you have the right number for me. Give a ring anytime soon and we can arrange a visit to the barn. Meteor should be running again at the back end of the week. John

Steve, If you think about it, the extra load on the bearings is no more than that would be caused by using a different off-set of the centre. Also your point about over-engineering is very valid. The key point would be to use a material for the extended stud that is at least as good as the original. There will be an "FV" drawing for it, if you or a contact could access it. Macready's USEN 24T is supplied hardened and tempered to 850 to 1000 newtons per Sq mm, 55 to 65 tons per sq in. The material is readily machinable and can be put into service without further heat treatment according to their catalogue. Full ref of the material is BS 970: 1955: EN 24T. Another ref is BS 970: Part 3: 1991: 817M40 but I don't know what heat treatment condition that reference provides for. As it happens, I use Acton Bright Steel for my bar materials. Out of curiosity, what do they weigh on the weighbridge? John

How about having longer wheel studs made out of EN24T and then insert a 1" spacer ring to give the nec clearance. I think that you would only need 40 studs. It would be easy for someone with a capstan lathe, even with an ordinary lathe it would not be that difficult or time consuming, especially if a Coventry die head was available. Those big tyres do look great! John

Dave, For the RPM and crank positioning I fitted the trigger wheel inside the Meteor's magneto. The "Scintilla" magneto is quite small diameter and might create problems fitting a trigger wheel inside it. You could dispense with the magneto and just use the mounting for the trigger wheel. A hall effect switch is pretty robust and reliable. The only requirement would be to shield it from accidental mechanical damage. The ignition and advance would come from the Speeduino. For certain set ups, you can use the flywheel teeth. However, you might need to have a 'missing tooth'. The size of the engine does not matter. The spec for the injector says how much fuel it will pass at normal fuel pressure and its rough horse power. I had Rover V8 injectors available but the Meteor needed 24 of them to get about 670 BHP which I thought would be enough and it was when I tested it on the heath at Bordon. This the data for the injectors that I am using: ROVER PT No ERC 3620 Bosch Pt No 0 280 150 105 Flow rate 18.1 Lbs per Hr @43 PSI 187 cc per min HP per injector 27.8 Impedance 2.2 Ohms AVAILABLE POWER Is 24 X 27.8 667.2 These injectors have a rubber hose coming off them rather than an O ring fitting. A firm called Turbo Technix used to have a huge stock and would sell them cheaply. New injectors are about £40 to £50 each so it might be better to ID which one is required and get them from a scrap yard. You are correct in your thoughts about the inlet tracts and the plenum. A problem could be the clearance from the side of the engine to the bulkhead. The inlet tract and plenum does not want to be heated as does an inlet manifold with a carb. The plenum would want to be quite big to ensure even air distribution. Say 4" in diameter. You would also need a lambda sensor in the exhaust and as high up as poss. Finally, the throttle position sensor. You could use one off a car or use an ordinary potentiometer. I tried the latter but found the former gave the ECU values that it expected. If you were to swing round to me I can show you the Meteor's modified magneto which I call a discombobulator. Alternatively, you could come up to the barn at Basingstoke and see the complete engine. I thought that your Explorer had a 680 Leyland in it? John

Dear All, Dave (Longen) touched on the fitting EFI to a Meadows petrol engine. In my opinion this would be quite easy and economic to do using a Speeduino as I have done with the Meteor. A key question is "does the inlet manifold have a separate port for each cylinder?" If so, it would be easy to fabricate a new inlet manifold to mount the injectors and provide an inlet tract for the fuel to 'rest' in before being sucked into the engine. When I used an Explorer in the TA in the early 80's, I did not experience any problems with the carbs. However, the system would have been designed to ensure that the engine ran rich in order to avoid any possibility of the pistons burning when working hard. With an EFI system the mixture can be kept optimal all the time. There is provision for cranking enrichment, after start enrichment, acceleration enrichment and cold running enrichment. There is also provision for electronic ignition. On the Meadows there is no vacuum advance for the magneto so the timing cannot be optimal. With Speeduino EFI the ignition timing can be altered to suit both PRM and manifold depression. The bare Speeduino PCB is less than £10. The Arduino MEGA is about £30 and is widely available. The necessary software is open source although I do not understand it. Thus it would be easy and sensible to have a fully programmed spare ECU on the vehicle. With the Meteor engines, I noticed that the Conqueror ARV with EFI used significantly less fuel than the Cent which does not have it. I would expect a petrol explorer with EFI to be significantly more economic. John

Dear All, On Dave's point about how much effort it took, it was about the most difficult and involved job that I have done. The engine is extremely complicated and I had to work out how to do several tasks and these are covered in other threads (esp dealing with the broken 'corner' cylinder studs. On a "long way to go...on reliability and fuel economy", no that is the easy bit. It now only requires a bit of tuning to get all the cylinders firing perfectly. All the cylinders have 150 PSI compression with little variation. The engineering was the difficult and time consuming bit. I will start a separate thread about EFI on a Meadows petrol engine. John

Dear All, I think that you will find that the correct description is "Deep Bronze Green, colour code 224 to BS381C". Unfortunately it is a colour that does seem to come out differently every time. When I did the Antar the above was what I ordered but each batch of paint was very slightly different. However, they were always the right sort of green which I think is important. John

Bob, The amount of fuel that the engine requires varies according to engine RPM and manifold depression and is not a straight line graph. In addition, you want the medium power 'cruise' condition to be relative lean for fuel economy whereas full power and high RPM conditions require a richer mixture to avoid any possibility of burning out the pistons. The "map" is a table of volumetric efficiency of Manifold Air Pressure versus RPM. At the moment the table is roughly correct at idle only. 'mapping' is the process of building up the table so that all the values in it are correct, or at least not too weak for safety. The system also has a feedback loop to correct the mixture. The mixture is measure by the O2 or lambda sensor. John

Dear All, I am pleased to announce that the Meteor M120 petrol engine that belongs to the REME Museum’s Conqueror ARV is now running with stability. By that I mean that it will idle and rev up but still a bit rough because the fuel has not yet been properly mapped. However, all the basics are there. The fuel injection is being controlled by a Speeduino using an Arduino MEGA microcontroller. As would be expected there are a few minor leaks to be cured. Unfortunately, I will have to change the generator drive oil seal but it is not too difficult. Once I have mapped the fuel as well as I can on the run-up rig, I will be fitting it back to the tank where it belongs. I hope to be fitting it in Mid January 2021. Thank you to everyone who has helped me do this with parts, advice or help and in some cases, all three! Next on the slab will be a ‘take out’ Mk IVB which has the same problem with at least two snapped corner studs. It will be interesting to see how long they take to do now that I have developed the technique to do the job. John

I don't have any manuals but I, and many others on the forum, do have a lot of experience with this vehicle. Do not hesitate to post any queries and we will try to help you. John

Ian, The way in which it is wrapped up with that greased or paraffin waxed textile is consistent with it being defence store item. Some of the experts might be able to make sense of any numbers on the box. John

Dear All, Here it is: https://www.legislation.gov.uk/uksi/2020/1178/regulation/2/made John

I will try to provide a link. John

Dear All, I am very keen on acquiring information as to what people are doing to comply with the new regulation. Does anyone have a quote for new 1500 or 1600 R 20 of either Michelin or Far East manufacture. All those with AEC militants, Foden EKA Compacts or DROPS will need new front tyres. I fear that private operators of HGVs will be the only ones to be adversely affected. On a commercially operated HGV, the tyres don't stay in service for 10 years. One operator said to me "If only we could get a tyre to last 10 years!". Reputable coach operators don't own their tyres. They have a contract with a tyre company. Only operators at the bottom of the market own their own tyres (as did the operator of the coach that crashed on the A3). Private HGV operators cover very low mileages and so our insurance costs are very low. The cost of the tyres will be far more than the cost of the insurance which, amongst other things, covers all the costs of accidents. There will be two very bad road safety effects of this new regulation. In my opinion and experience, a Michelin tyre will last indefinitely and will always be better than a Far Eastern tyre. However, because of this regulation, I am sure that many will have no choice but to remove the perfectly good Michelin tyres from the front axle and replace them with a Far Eastern one. When I rebuilt my Scammell Contractor, I fitted new tyres all round. Two of them will now have to be replaced after about 5000 miles at the most. If someone was doing the same project again, they might not fit new tyres because of the possibility, left open by the Government, that ALL the tyres might have to be less than ten years old. On the issue of remoulds, I know that this was carefully considered but I cannot remember what the arguments were! John

I don't think that the relevant Statutory Instrument has been laid yet but I am watching out for it. When I rebuilt my Scammell Contractor I put ten new tyres on it. I now have to buy two new ones but as the size is 1200 R 24 I have no use for the old ones. Remember when you buy new one, make sure that you know the date of manufacture. You don't want ones with only eight years life left! It would be very useful for my day job to know of any problems being experienced with getting tyres with sufficient 'life' left in them. John

From my memory, which my fail me, the LAD would be on a different UIN (Unit Identification Number) so a transfer to or from the LAD would matter. John

On the working of the forum I found that an out of date web browser (whatever that is) was causing me all sorts of problems with various site. Up to date browser solved all the problems. John

Judging by the thickness of the windings, my guess is that it is some sort of current relay or cut out. I expect Clive will tell us exactly what it is! John