Old Bill Posted January 8, 2010 Share Posted January 8, 2010 Adrian, Ben and Phil. Thank you very much for your very kind offers. 1/2" downwards seems to be obtainable if one looks hard enough. It is the very large (by our standards anyway!) sizes which are so difficult. I must admit that I hadn't thought of India but the trouble is, I don't want to buy 1000 of the things! Silencer nuts must be very prone to coming loose because they are in a vibrating environment, go through thermal cycles and can't be done up very tight without crushing the casing! I think we will have to assess ours very carefully when it is finally assembled. I have seen them with lock nuts on both ends which might be a solution. Cross that bridge when we get there! Steve :thumbsup: Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 9, 2010 Author Share Posted January 9, 2010 Tony finished the Coupling Pins yesterday - they now just await the completion of the Bronze Blocks - those have to be "radiused", bored out and have oil passage ways drilled. Quote Link to comment Share on other sites More sharing options...
Bystander Posted January 10, 2010 Share Posted January 10, 2010 Tony finished the Coupling Pins yesterday - they now just await the completion of the Bronze Blocks - those have to be "radiused", bored out and have oil passage ways drilled. Beautiful! Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 10, 2010 Share Posted January 10, 2010 Tony, do you have a tool post grinder attachment to give a good surface finish to pins like these? Will Steve have the pins to make sure that they are a 'good fit' in the blocks or can you rely on dimensional accuracy alone? Barry. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted January 10, 2010 Share Posted January 10, 2010 No, I don't have anything as sophisiticated as that, Barry! The pins are 7/8" Silver Steel and I think that the Silver Steel has already been ground to a fine finish by the manufacturer as it is spot-on 7/8" in diameter and has a very good finished surface. My own thoughts about this were that we final-finish the Bronze Blocks with a 7/8" Reamer when the holes in them for the pins are opened out and that would probably be quite adequate. Steve might want to comment on this as well when he picks it up. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 10, 2010 Share Posted January 10, 2010 When I pick up the blocks for final machining, I will take the pins as well, and bore the blocks to fit. I don't think my lathe could cope with a 7/8" reamer in bronze! I am actually more concerned about the fit in the ends of the prop shaft as we have now placed the order for that as well. I hope that the pins will be a firm push fit with no rattle. We could cope with 0.001" clearance by using Loctite but if there is much rattle, we might have a problem. Fingers are crossed! Steve Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 13, 2010 Author Share Posted January 13, 2010 The Water Pump Cover has now been machined and is virtually completed. The holes around the flange have to be opened up and there are three others to go in. It has been a straight forward exercise and the sequence of photographs tell the tale. The only disappointing factor is that we have come across some porosity in the casting on the inside - it seems quite sound on the outside. Provided that there is no leakage through this, then it can be ignored as it will not harm - there is plenty of metal there. Possibly these small imperfections could be sealed with an Epoxy Resin - or even soft solder - but no final decision has been made on this. Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted January 13, 2010 Share Posted January 13, 2010 That looks more like inclusions, displaced sand or slag, than porosity. Should be no big deal for the duty that casting will be in. We used to use CASTINGITE to pressure impregnate / seal castings like these, but there's no way that will need it. A coat of epoxy internally maybe? Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 13, 2010 Share Posted January 13, 2010 I like the way how Steve has drilled the flange holes. No rotary table was used here, just an old fashioned set of dividers. Barry. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 13, 2010 Share Posted January 13, 2010 I like the way how Steve has drilled the flange holes. No rotary table was used here, just an old fashioned set of dividers. Barry. Not I ! That's Father's work! Steve Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 15, 2010 Author Share Posted January 15, 2010 Whilst Dad has been busy with the pump cover, Steve has been pattern making again to replace the incorrect one found over Christmas. It proved to be quite straightforward and just a variation on a theme really. Hopefully, this one will point at the radiator outlet this time! Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted January 16, 2010 Share Posted January 16, 2010 ... will the moulder be able to use the new pattern without any technical stuff, as with your original effort? Looks to me that the new version should draw straight in a conventional two-part mould? Gordon Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 16, 2010 Share Posted January 16, 2010 Hi Gordon. Yes, hopefully, it will be a straightforward draw. I have made a couple of compromises to allow this though. The 'lump' around the flange bolt hole hidden behind the elbow has extra material running tangential to it and perpendicular to the split line so there is no re-entrant shape which would drag through the sand. I have also added an extra bit to the small flange as well. Hang on a minute, I will take some pics. Worth a thousand words as they say! Steve Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted January 16, 2010 Share Posted January 16, 2010 (edited) Yes, absolutely. I'd think this was the original configuration, able to be made much more easily, and the one you originally copied came later for some special purpose. Gordon Edited January 16, 2010 by Gordon_M Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 16, 2010 Share Posted January 16, 2010 Part of the 'subvention' scheme requirements were that the radiator be mounted entirely above the chassis which is where ours is. However, the pump we copied came from a lorry that was just post war and the radiator would very likely have been mounted much lower with the starting handle through it. Therefore the elbow I originally copied pointed much more downwards. Obvious now! Steve Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 18, 2010 Author Share Posted January 18, 2010 The Water Pump Impeller casting has now been machined. Again, it was a very straight forward exercise and the series of photos speak for themselves and show the process. There were some inclusions in the casting, but they have mainly machined out this time. A keyway has yet to be cut, but Steve has a slotting attachment on his lathe and will do this later. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 18, 2010 Author Share Posted January 18, 2010 The concave side of the Impeller is machined out at an angle of 19 degrees, whilst the convex side is machined at an angle of 60 degrees Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 18, 2010 Author Share Posted January 18, 2010 And finally, the two machined components of the Pump together - two down, four more to go! Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted January 19, 2010 Share Posted January 19, 2010 Tells us about your plans for balancing the impellor and the shaft then. I'd reckon you would put the shaft and impellor together, and then just do a static balance, as I think it is unlikely that a WW1 engine will rev fast enough to need a dynamic balance? Did you leave any spare meat on the impellor to allow truing up when on the shaft or happy just go with the lathe accuracy? Gordon Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 19, 2010 Share Posted January 19, 2010 I must admit that I hadn't thought of balancing at all! It runs at camshaft speed, say 500rpm peaking at 750 so I am not really too concerned. However, I will roll it across the surface plate and see how it looks. If it is drastically out, I shall have to attack it with a file! Steve Quote Link to comment Share on other sites More sharing options...
phil munga Posted January 19, 2010 Share Posted January 19, 2010 I've spoted a problem , once these parts are fitted you will not be able to see them again , great work , balancing would not think at that speed it would be of to much concern unless out quite a bit , if you had a lightwieght lathe that could spin just about a thousand RPM it might give a clue how much out it is , also like you say if you roll it across the surface plate sevral times and put a dab of paint on at BDC it would give a bit of an idea Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 19, 2010 Share Posted January 19, 2010 (edited) Something which has just crossed my mind is the size of this water pump. On the later developments of this engine and indeed on the larger 60HP White and Poppe engine the water pump is so much smaller (See picture below). Can anyone offer any explanation? Barry. Edited January 19, 2010 by Asciidv On reflection the answer to the question may be rather obvious...... Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 19, 2010 Share Posted January 19, 2010 You are quite right Barry. This pump is enormous compared with later pumps. I wonder whether it was just a rough estimate as to how big it should be and they made them smaller as experience showed what they needed. I have seen it written that the subsidy engine didn't need a pump at all and would survive quite happily relying only on a thermo-syphon. Mind you, at what speed does yours run? Is it camshaft speed or crank speed? Doubling the rotational speed would allow you to reduce the diameter by a half and still maintain the tip speed. Steve Quote Link to comment Share on other sites More sharing options...
phil munga Posted January 19, 2010 Share Posted January 19, 2010 . I have seen it written that the subsidy engine didn't need a pump at all and would survive quite happily relying only on a thermo-syphon. Would not have thought there would be many latter vehicles that would use this means of cooling system but the Munga does , Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted January 20, 2010 Share Posted January 20, 2010 The earlier White and Poppe engines also used the smaller pump so perhaps there was something in the subsidy specification. Quote Link to comment Share on other sites More sharing options...
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