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attleej

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Everything posted by attleej

  1. One more point. There are two ways of hurting a Roller. The first is to pull up at full power up a hill, then pull into a lay-by and stop the engine immediately. The other is to over rev the engine. Max RPM is 2200. I never let a 12 litre Roller or a14 litre Cummins exceed that. I would take all necessary steps (political code for war) to slow the engine down from 2300 RPM. On heavy haulage and tank transporters it is very easy for the load to push the vehicle and over rev the engine. John
  2. Jordi, I love a Roller! However, my Scammell Contractor has a Cummins in it and the price of spares is becoming extortionate. £230 for fan belt idler bearing. Fortunately I was able to rebuild it. On the Roller, if it has not got a turbo charger, it is a 220 (BHP). Data plate is on rear left hand side, just below air intake manifold. Points to watch are: Fuel lift pump but an FIP specialist should be able to fix if you cannot get a new one. If it gives you any sort of trouble, get it fixed because it will let you down big time one day. You might find it starts to struggle to pull fuel up from a nearly empty tank. Fan belts need to be a matched set with all the same numbers and from the same batch. Change the belts NOW but keep the old belts on the vehicle as a back up. A Roller will start easily without revving it up. Wait until oil pressure is up before increasing revs after initial start. RELIABILITY For preserved use a Roller should just keep going. PARTS John 1950 is right parts are not so easy as they are not being used commercially anymore. The engine used in the Scammell and Foden DROPS is a bit later and slightly different to a Mk III Eagle. The good news is that there is not much of an export market for a Roller so a whole engine should not be too dear. Fuel and oil filters should not be a problem. REPAIRABILITY I find the Roller easy to work on. ANTIFREEZE You must run it with at least 25%, or better 33%, antifreeze or you will damage the wet cylinder liners with cavitation corrosion. You can use a corrosion inhibitor in the summer of the tropics. For UK, use antifreeze! John
  3. Dear All, I have some tales of woe regarding the Meteor M120 engine fitted to the Conqueror ARV. I had concluded that the plugs were fouling with oil due to failure of the inlet valve oil seals which I have discussed in an earlier post. A problem has been to hold the inlet valve closed whilst the springs are compressed. Help from the Forum has been invaluable. It was decided to take the engine out of the hull for reasons of improved engineering hygiene. Once the special tool was made, changing the inlet valve oil seals was straight forward although I am not convinced that they were the problem going by their condition and position. The top of the valve stem only had about 4 thou wobble. The first big problem was that the camshaft was very badly pitted on some of its rubbing surfaces on the cams. This had taken out 17 rockers/ followers. The valve clearances had opened up to 35 thou. Not too much of a problem. I bought two new camshafts and the rockers came from a scrap MkIVB engine. Then I touched one of the cylinder head /block studs. It was loose! Worse still the stud was sheared. Apparently this is a common problem with the Merlins and Meteors. Ok so I needed to lift of the cylinder head block assy. To do this I made an engine turning frame and special lifting tool to lift the block dead square and vertical. I have made a special tool to drill out the sheared stud accurately. So some problems but still manageable. Then I felt the big end bearings. Unfortunately there was 10 thou in and down movement in the big ends and the mains have problems as well. Fortunately the crank looks OK. There does not appear to be any white metal on the shells! The pistons and liners are great as well. Another problem was that the sump was full of a horrible gelatinous gulutinous muck. This was despite having changed the oil some time ago. I started with the simple job of valve oils seals but now have the engine completely in bits! However, we could not keep running the engine with these known faults as it would certainly have led toa total failure in due course. I wonder whether when the oil sump got contaminated with E5 petrol, that allowed the white metal bearings on the crank to be attacked by the ethanol. SOME LESSONS & TIPS FOR CONQ / CENT The oil sumps needs to come out and be cleaned in case it is full of sludge. In service I expect that they would fit a new engine without cleaning the sump. This would only be done at base overhaul. If you take charge of a meteor, take off the rocker covers and check the condition of the cam shaft. It is the first component to start rusting and the consequences are serious. Check that the corner studs are not sheared. Just check the nuts are secure. Unfortunately the Conq is not fitted with an oil pressure gauge. If it had one, surely it would have revealed that all was not well with the bottom end. The good news is that I am confident that I can get the engine back into good condition. It will just be a little bit more involved than I thought! John
  4. Dear All, Even the E5 bio petrol caused serious problems with the REME museum's Conqueror ARV. I made up a fuel manifold to supply each of the 24 electronic fuel injectors. I used 15mm copper pipe and soft soldered on a compression fitting to supply each injector. In terms of fuel leaks it worked fine for some time. Then suddenly it was spewing petrol everywhere! The bio fuel had attacked the soft soldered joints. Even though the joints had plenty of cross sectional area of solder, they still failed. The new system that I have made has no soft soldered joints. This suggests that many vehicles will need a completely new fuel system with no soft soldered joints anywhere. I will shortly be posting tales of woe about Meteor tank engines and petrol contamination of the sump and the possible effect on the white metal of the crankshaft bearings. I suspect that the reason why Government has not moved faster to E10 is more to do with issues concerning the economics of supply and possible adverse effects there rather than the effect on old vehicles. I think that E10 will be ubiquitous in due course whatever problems it causes to older vehicles. The problems for our vehicles are manageable provided one is not too worries about originality. The real problems will be for those with later vehicles (especially cars) with sophisticated fuel systems which are not tolerant of E10. I expect that the response from classic car enthusiasts will reflect this. John
  5. My guess, and it is only a guess, is that it would have been supplied in Deep Bronze Green gloss. In the UK based TA we stayed DBG gloss and then at some time changed to IRR (Infra Red Reflecting) with non IRR black disruption camo. I don't know what rules BAOR adhered to. At some point, and I can't remember when, in UK we stopped using the lovely 'Div Signs' and went for something much more discrete. For 240 Sqn in Barnet it was "Lond 225". When I started at Barnet in about 1975 we had two div signs. One was the yellow and blue RCT sign with "240 Tk Tptr Sqn" on the top. The other was the London District sign which was a dagger and a castle. I don't know whether they did the same in BAOR. If they did, it would have had a REME div sign with something like "38 Engr Wksp" on the top. The other sign would indicate which formation, ie division the unit belonged to. The round yellow bridge classification plate would probably be 21, I am sure that other will be able to help and correct any errors on my part. John
  6. Dear All, I think that the military B series starter motor has a thermal cut out inside it.. If it cuts out prematurely it may give the symptoms described. It gave me a lot of problems with my Leyland Martian recovery in the TA. Fortunately it was dead easy to start on the handle which I had to do frequently. It was only later that I learnt about the thermal cut out. In my opinion, a thermal cut out on a military vehicle is criminal. Firstly, because it could fail or cut out prematurely when the engine would in fact start straight away if the starter would only work. Secondly, in emergency it may be desirable to move the vehicle just a few feet using the starter even at the risk, and only a risk, of burning out the starter. Andy is right. there is nothing special about these starters. A competent, old school, vehicle electrician / engineer should easily be able to fix any problems. It should be still be possible to pick up a s/h but serviceable 24 civvy starter for spare parts. I would definitely ask for the thermal cut out to be disabled. John
  7. Dear All, Since the engine is fed by an oil bath air filter it may still be quite good. It would use quite a lot of petrol to wear it out! Does it still turn over easily? Has it got six even compressions? I would only give up on it if it has been run for a while and still does not have even compressions My comment is that large petrol engines can benefit hugely from retro fitting electronic fuel injection (EFI) and there are several 'DIY' systems available now. I am working on a system for the REME museum's Conqueror ARV. The reduction in fuel consumption is noticeable between the Conqueror and the Centurion. I hope to be able to report to the forum results from the latest iteration. The carburettor system on a big engine is very crude. However, the designer will have been very careful to ensure that the engine always runs a little bit rich in order to eliminate the risk of burning out the pistons. EFI can ensure that the mixture is always correct and optimal. EFI normally has Cranking Enrichment, After Start Enrichment, and Cold Start enrichment so starting and cold running is much better. The Meteor in the Conqueror always starts directly after about three revolutions if it is going to start at all. It is also possible to retrofit EFI quite discretely. Once I have perfected the system for the Conqueror I will share all that I have learned on this and other forums. I will be very happy to share what I have found out and provide advice on a pro bono basis. John
  8. Dear All, I have now got the engine out and at my workshop. I am now considering the using the compressed air trick to change the inlet valve oil seals (now in stock). The worry about the comp air trick is dropping the valve down the cylinder. With the engine out it is easy to see how I could lock the engine at TDC for the cylinder in question. In that position, I don't think that the valve could actually fall right out of the valve guide. I could also engineer a high reliability air supply. Does anyone know for sure if the valve would not be able to fall out if the piston was at TDC? John
  9. Dear All, Thank you for your input it is much appreciated. The problem with the J60 24 volt starter is that it is an ordinary 4.2 litre XK engine and not a J60. I don't think that it is straight forward to fit the J60 starter. "Clive" is Field Marshall Clive Elliot our Chief Electrical Engineer. I am not too worried about the starter throw in solenoid as it will only be overcurrent for a moment until the starter starts turning the engine. In other words, it will not have time to overheat. The external starter sol / relay is already 24 Volts. The positive temp co-efficient of a steel resistor could be beneficial as if the resistance was selected by experimentation the current through the starter would be reduced if the steel resistor got hot. However, what I have done is to order (quite cheaply) 2 metres of 2 mm Manganin resistor wire. I need a resistance of between 0.12 and 0.04 ohms. By chance the resistance of 2 mm, 12 AWG Manganin wire is 0.04 ohms per foot. With a bit of experimentation I should be able stop 24 volts from sending the starter into orbit. I will let you know how I get on with it. John
  10. Dear All, The so called Jaguar J60 engine fitted to the Conqueror is really a 4.2 litre car engine with automatic gear-box. It has J60 ignition and inlet manifolds. I did not think it would be easy to fit the FV 24 volt starter (it is not) so I left it on 12 Volt starting and used the 12 Volt system for the main engine EFI system. I found the usual dual voltage problems! Therefore the tank will now be all 24 volt. I would like to keep the 12Volt starter, use 24 Volts but keep the current down by means of a very heavy duty resistor. I could either use some proper heavy gauge resistance wire or use steel by cutting out a 'tortuous path' in a sheet of 1.5 mm steel. Alternatively I could try just using another starter motor field wing in circuit. Probably one for Clive to advise on! Does anyone have a figure for the current going through a starter on an Jag engine? If so I could calculate the required length of 1.5 x 10 mm steel strip (equivalent of) to give the desired resistance. John
  11. Dear Terry and Diana, Thank you for your help. All I have for an air filter is an after market gauze cone for a car. Thus probably not enough suction from the air filter. Since the engine runs for only short periods it is not worth fitting an oil bath. I could plumb it into one of the main engine air filters (and might do so) but that would not solve the suction problem. Does Diana know what material I should look for on Flea bay? It would be quite good to have some available for doing fuel pump diaphragms as well. John
  12. Dear All, The J60 fitted to the REME museum's Conqueror ARV is poor at starting from cold but is fine in other respects. The position of the cold start lever on the carb has no effect. I have only managed to start it in the past by pumping the accelerator. When I strip the carb is there anything to watch for in respect of this fault? I will obviously give it a good blow out and check any available jets. Are there any diaphragms etc that I could change? John
  13. Dear All, This is such a fabulous forum no matter what level of experience or expertise one is at.. This thread is but one example and I am so grateful for the help. I was aware of the Indian Rope Trick. However, with a V12 it would be quite slow. I had not thought of the compressed air trick and I already have a suitable adaptor for another purpose. I however, I cannot take any risk of the valve dropping into the combustion chamber / cylinder bore. There would be almost no chance of getting it back in the guide without lifting the block off the crank case, pistons etc. What I will do is to make a copy of the tool shown in Lauren Child's photo. As the engine has twin spark plugs I can insert a camera through the other spark plug hole and ensure that the tool is in the right position to reliably hold the valve in position.. Many thanks for the help. John
  14. Dear All, I need to change the inlet valve oil seals (Pt No 3 RR EM5114) on the REME Museum's Conqueror ARV. The EMER Power S544/1 Pt 1 lists the valve holding tool LV3/ RR Z2997. Unfortunately I do not have one! There is a photo of it in use (it fits into spark plug hole) but no indication as to how it works. I can easily make one if I could see how it works and I would rather not have to re-invent the wheel! Does anyone have one of these tools or knows anyone who has one. Even a photo of the business end would be useful. Ideal would be a sketch with dimensions. If I can change the oil seals I am hoping that the plugs will not come out wet with oil. John
  15. Dear All, IMHO all the Stolly needed was a means to declutch the fore most and rearmost wheel stations when not needed. Then there would be no wind up loads on the transmission. John
  16. Does anyone know which ZF automatic gear box is fitted to the Unipower BR 90 TBT? John
  17. I believe that David and Andy are right. You can have the same NSN for two or more different FV numbers. This is because the FV number refers to a drawing or at least a parts list of other FV numbers. My understanding is that you can have the same NSN for two different parts provided that they have the same form, fit, and function. If a part has to be made a different way eg forged rather than fabricated it would be allocated a new FV number because the engineering drawing has changed. When a manufacturer is designing a piece of equipment for FVRDE / MOS / PE ie the Ministry, they would surely be allocated a batch of FV numbers to use for each drawing they produce. This would account for why some numbers are similar. Clearly most components are designed and drawn by industry and not the Ministry. John
  18. Robin, All I know is that the "FV number" is the drawing number. As you well know there is also the NSN. Out of interest, most drawings should still be available. For instance I have got several for the Conqueror a few years ago. I would be very surprised if two identical parts had different FV numbers. In the case of the FV oil bath air filter, the basic filter assembly might have one FV number, but if there is the slightest difference, say elbows or mountings etc it would have a its own FV number and drawing. That drawing would refer to the basic assembly FV number and then the additional parts. This is only my view and is not authoritive. John
  19. Andrew, I expect that I would have a few in stock. However, I think that the best way would be to have that quantity machined from hex bar on a capstan or CNC lathe. They could be made on an ordinary centre lathe. I would imagine that the economics are quite similar for any of the three ways. You would have to think about the material. EN1A free machining would be the easiest to use but might not be strong enough. Hex bar of the right size across flats would be available but I doubt that there would be much choice about grade of steel. If hex bar of the right grade cannot be obtained then the correct size could be milled down from the next hex size down from a suitable and available material. I hope that this is helpful. John
  20. Paul, the pressures will not be particularly high since the Chieftain is a very old design (1960s). I would use a modern quick release coupling with roughly the right bore size. It is only the starter so it is very intermittent. If you need some adaptors turned up, there is not much that I cannot make. John
  21. Dear All, This makes a great headline but it describes a situation 23 years ahead! We have no idea what technology will offer at that point. However, it is very unlikely that we actually drive our day to day means of personal transport. Everything new will be driverless. As for liquid fuels it is merely a chemical that is heavily taxed. There will always be something available for classic equipment and vehicles. I once ran out of petrol in my aunty Rover but had 5 litres of thinners. It went fine! Of course, another system of taxing road transport will have to be devised. I would not worry about it. It was just a headline stating the blindingly obvious. John
  22. Rick, I have found that for people at our level the mags are pretty straight forward especially if you have an EMER that covers them. The EMER for the Antar and the Meteorite gives full details but I don't know what is covered in the 4B EMER. Apart from the rotor arm are there many parts which are handed? Even the testing of them is not particularly difficult. It is basically to ensure that regular sparking occurs at a certain number of revs and continues at higher revs. The HT has to be able to jump a prescribed gap. I would have thought that if you had an old inlet mag and a rebuilt Exhaust mag you could make a good inlet one. The Antar EMER describes overhauling the plug lead harness. It is pretty straight forward apart from the need to pull the new HT cable through the harness. You would need to get some small dia HT cable. John
  23. Dear All, The Rolls Royce part number I have used in the past is ST 81712 but unfortunately whilst it is recognised by Perkins it is no longer supplied and there is no alternative. Has anyone worked out what to ask for from a transmission specialist, ie cross section and length? Note that the manual states that it is very important that the belts come from the same batch of manufacture. John
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