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About attleej

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  1. attleej

    Thornycroft Big Ben

    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
  2. attleej


    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
  3. attleej

    JAGUAR STARTER, 12 / 24 V, One for Clive?

    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
  4. 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
  5. attleej

    JAGUAR J60 CARB, cold start

    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
  6. 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
  7. attleej


    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
  8. 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
  9. attleej

    Army's Mechanised Infantry Vehicle

    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
  10. Dear All, Thanks for the info. Very helpful. John
  11. Does anyone know which ZF automatic gear box is fitted to the Unipower BR 90 TBT? John
  12. attleej

    FV part numbers rationale

    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
  13. attleej

    FV part numbers rationale

    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
  14. attleej

    1/2" BSF nuts

    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
  15. attleej

    CHieftain GUE hydraulic hoses

    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