N.O.S. Posted June 7, 2012 Share Posted June 7, 2012 .... the gearbox was stripped down some years ago and rebuilt with all new bearings - though we might want to have a look at that again in the light of all the experience that we have obtained since that early time. .......Tony Got time to quickly elaborate on the reason for this please? I can't find anything in the threads. Thanks. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted June 7, 2012 Share Posted June 7, 2012 (edited) Got time to quickly elaborate on the reason for this please? I can't find anything in the threads. Thanks. Sure! Look back to Page 2 of this thread and the series of pictures commencing with no. 20. At that time, Steve had just bought the Thorny bits and he was eager to get going with it. The most complete thing that he had was the Gearbox, and the first picture in that series, no.2, shows Steve and Tim when they were both in their very early 20's getting into their first ever restoration project. No proper press - just a home made improvisation! I am quite sure that the Gearbox is perfectly alright - but Steve wants to just look inside it again to see what was done all those years ago, just to make sure that everything was done properly then, in the light of his further experience! Tony Edited June 7, 2012 by Minesweeper Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted June 7, 2012 Share Posted June 7, 2012 Quote - "If silver solder is a no go then a dab of devcon on the outside could stop the weepage". Interestingly, the cylinders on our Military Autocar are cracked and have been repaired or just sealed with soft solder! Presumably this was done in France where it spent most of its working life - and these have never shown any signs of leekage! Tony Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted June 7, 2012 Share Posted June 7, 2012 Another job slipped in today was a preliminary clean up of the crankshaft. We have two of these but the Timing Gearwheel on the end of the better one is in poor condition whilst the one on the inferior crank shaft is good. So again we have to do a “Mix and Match”. We had thoughts of taking the Fly Wheel off, just to make the crankshaft easier to handle in the re-setting up process as this crankshaft came out of the other crank case and it will have to be set up from scratch. The Fly Wheel would not budge so rather than waste more time on it, we opted to leave it where it was on the crankshaft and work with it as a whole. The air hose was applied to the oil passage ways and they were found to be all clear. These two pictures show the poor condition of the one Timing Gear Wheel that has to be replaced. The first of these three pictures show the initial progress in cleaning up the Fly Wheel with a wire brush on the hand drill. There are two studs protruding from the flywheel rim to take the clutch springs – both are in poor condition and are bent, but they undid easily and were removed so that they can be used as patterns for the replacements. Quote Link to comment Share on other sites More sharing options...
mattinker Posted June 8, 2012 Share Posted June 8, 2012 Something came to mind when reading this. Many years ago, I had a header tank leak on my '52 Land Rover, the only thing I had on me that was vaguely sealant was some glaziers putty, so I applied it to the leak, it sealed straight away and gradually hardened. The "temporary" repair lasted several years, at least until I'd sold it without hiding the repair! Before writing this I looked up "traditional glaziers putty, I knew it container linseed oil, which is a drying oil, but I wasn't sure what was mixed with it. This turned out to be chalk. If the putty is painted over with oil paint it can take thirty years to harden and remain flexible. It is used for joining materials of different expansion rates Completely reversible (with solvents), it could be a substitute for lead/tin solder! A passing thought! Regards, Matthew Quote - "If silver solder is a no go then a dab of devcon on the outside could stop the weepage". Interestingly, the cylinders on our Military Autocar are cracked and have been repaired or just sealed with soft solder! Presumably this was done in France where it spent most of its working life - and these have never shown any signs of leekage! Tony Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted June 8, 2012 Share Posted June 8, 2012 Something came to mind when reading this. Many years ago, I had a header tank leak on my '52 Land Rover, the only thing I had on me that was vaguely sealant was some glaziers putty, so I applied it to the leak, it sealed straight away and gradually hardened. The "temporary" repair lasted several years, at least until I'd sold it without hiding the repair! Before writing this I looked up "traditional glaziers putty, I knew it container linseed oil, which is a drying oil, but I wasn't sure what was mixed with it. This turned out to be chalk. If the putty is painted over with oil paint it can take thirty years to harden and remain flexible. It is used for joining materials of different expansion rates Completely reversible (with solvents), it could be a substitute for lead/tin solder! A passing thought! Regards, Matthew Thanks Matthew - another way! Tony Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted June 8, 2012 Share Posted June 8, 2012 Sure! Look back to Page 2 of this thread and the series of pictures commencing with no. 20. At that time, Steve had just bought the Thorny bits and he was eager to get going with it. The most complete thing that he had was the Gearbox, and the first picture in that series, no.2, shows Steve and Tim when they were both in their very early 20's getting into their first ever restoration project. No proper press - just a home made improvisation! I am quite sure that the Gearbox is perfectly alright - but Steve wants to just look inside it again to see what was done all those years ago, just to make sure that everything was done properly then, in the light of his further experience! Tony They were young!! I can understand why they might want to double-check their work, but I'm sure the chief training officer of their apprenticeship training school remains confident :-D A comment on the back of the cracked block saga - it strikes me that there is a point at which technical solutions may fall just short of the 'art of engineering' as may be practised by your old friend and indeed yourselves at times? Some may say there is no place for 'art' in a scientific craft such as engineering, but I think this tale is beginning to demonstrate otherwise. Quote Link to comment Share on other sites More sharing options...
Tanker Wannabe Posted June 8, 2012 Share Posted June 8, 2012 Looking at the timing gear I was wondering that with the machine work I have seen done on this site if it would not be easier to remove it from the shaft which will have to be done anyway to replace it, wel d up the teeth that are bad and then machine them back to the proper profile. I know you can't just run out and pick up a new one and to me this would be the easiest repair and you would also be using original parts Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted June 8, 2012 Share Posted June 8, 2012 Looking at the timing gear I was wondering that with the machine work I have seen done on this site if it would not be easier to remove it from the shaft which will have to be done anyway to replace it, wel d up the teeth that are bad and then machine them back to the proper profile. I know you can't just run out and pick up a new one and to me this would be the easiest repair and you would also be using original parts Well, it is already off the shaft - and we have a sound spare from the "half" engine so that will take care of that! There are some pictures to follow, but that was all very straight forward. It will be put away somewhere safe - "just in case"! But thank you for the suggestion! Tony Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted June 8, 2012 Share Posted June 8, 2012 They were young!! I can understand why they might want to double-check their work, but I'm sure the chief training officer of their apprenticeship training school remains confident :-D That's very kind - and thank you, but the apprentices are now very much more competent than the Chief Training Officer! Tony Quote Link to comment Share on other sites More sharing options...
Great War truck Posted June 9, 2012 Author Share Posted June 9, 2012 The timing gear on the end of the crank has a couple of severely wasted teeth. Fortunately for us, the one on the spare crank is quite good so we set about removing the bad one. As you can see, it has a taper pin securing it on the shaft and that in turn has a split pin through the end. The split pin gave Steve the clue as to which end to hit and it simply popped out, with some velocity I might add. Notice the black dot on my boiler suit! A three legged puller was applied and the job was done. The challenge remains as to how we will press the other one back on. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted June 9, 2012 Share Posted June 9, 2012 Oops. I meant the engine rebuild as was hoping you had all the bits now and looking forward to a video of it running Hi Mike. We are a long way off that yet. This is the current work list: • Rebore cylinders • Fit cylinder liners • Hone liners • Make piston pattern • Get pistons cast • Obtain new rings • Machine pistons • Finish valve caps • Get new valves made • Clean and repair drain taps • New exhaust manifold studs • New rubber seal for block connections • Make up new governor assembly • Fit timing gear to crankshaft • Clean up flywheel and drill out broken studs • Make new clutch spring studs • Inspect bearing shells and scrape to suit crankshaft • Fit crank • Clean up camshafts, check bearings and refit • Repair/replace tappets • Obtain new valve springs • Make pattern for new pump inlet spigot • Get spigot cast • Fit spigot to pump housing and have welded • Make up new flange for fan bearing carrier • Get flange welded and machine. • New gaskets all round • Inspect and repair con-rods as necessary • Scrape and fit big-end bearings • Make up oil pipes • Make up oil filler • Overhaul pressure regulator • Repair/remake oil level indicator • Make/obtain cylinder priming taps • Overhaul carburettor • Make HT lead tubes In my experience, lists like these tend to get longer before they get shorter! There is a way to go yet but we are making progress. Cheers! Steve Quote Link to comment Share on other sites More sharing options...
Great War truck Posted June 16, 2012 Author Share Posted June 16, 2012 Steve thought he would have a look at the coupling between the two cylinder blocks. Father managed to separate the two halves a little while ago but of the rubber seal there was little sign and the sealing surfaces were very poor. Steve put both parts in the four-jaw chuck and gave them a light skim to bring the surfaces back. Once that was done, he made up a seal using O-ring cord. This is simply a strip of 1/4” diameter rubber which is cut to length and joined using ‘super-glue’. The tricky bit is to cut the ends flat and square so Steve made up a simple guide in the form of a collar to push over the cord. . This worked well but he then found that there cord was simply too big in diameter to allow reassembly of the castings! A rummage in the ‘Old O-ring Bag’ found a perfect fit so that is one more job ticked off. One can try to be too clever some times it seems! Quote Link to comment Share on other sites More sharing options...
Asciidv Posted June 17, 2012 Share Posted June 17, 2012 Whilst a picture of a four jaw chuck is fresh on the page, I just wondered if any of you have any 'trick' for centre'ring up an irregular shaped part. I have always just done it by eye, followed by taking a trial very light cut to see if all is running true. Returning to the 'O' ring I have never really been happy with the homemade glued together type. The junction is always a lot harder than the rest of the ring and never quite seems to seal properly. I an looking foward to seeing the development of the piston pattern set! Is it coming soon? Barry. Quote Link to comment Share on other sites More sharing options...
Thumpercross85 Posted June 17, 2012 Share Posted June 17, 2012 Glad you did not use the fabricated item, superglue is not really suitable for hot water, and yes, the hard spot created is sometimes an issue. Much better to use a proper fully moulded seal, though EPDM or Silicone would be better in the water system than Nitrile which is really for oil contact.... Quote Link to comment Share on other sites More sharing options...
Old Bill Posted June 18, 2012 Share Posted June 18, 2012 When I sent the notes to Tim to publish, I forgot the one which shows the made-up ring in the groove. It proved to be just too big to be installed and, as rubber is incompressible, I was on a hiding to nothing trying to fit it! The smaller ring I eventually used, had been rescued from a hydraulic system and has already seen some service. It is a pretty tight fit though so I expect it will be OK. We shall see! Regarding setting up in the four-jaw chuck, it is very much trial and error for me. I use a clock gauge where I can and keep adjusting the jaws until it is there. In this case, I simply brought the tool up close and rotated the chuck by hand adjusting the jaws until the tool kissed more or less all round. Good enough for this particular exercise anyway, if a bit time consuming. I haven't started on the piston patterns yet. I have a railway engine to build before I really start dedicating time to this project! Steve Quote Link to comment Share on other sites More sharing options...
Great War truck Posted June 19, 2012 Author Share Posted June 19, 2012 The cylinders are now back from being re-bored – 60 thous have been taken out so that the diameter of all four cylinders is 4 1/2” plus 60 thous. The pitting is so deep in the one cylinder so that it is still very much apparent after re-boring. It is not safe to bore the cylinder any larger and let us hope that the sleeves will take care of this. This sequence of 3 pictures show the first block. This is the other cylinder block – there is still some rusting apparent at the top of one cylinder but this not deep and again, we hope that the sleeving will take care of that Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted June 19, 2012 Share Posted June 19, 2012 The cylinders are now back from being re-bored – 60 thous have been taken out so that the diameter of all four cylinders is 4 1/2” plus 60 thous.The pitting is so deep in the one cylinder so that it is still very much apparent after re-boring. It is not safe to bore the cylinder any larger and let us hope that the sleeves will take care of this. Possibly too late now, but would it be possible to build up the pitted portion by either electroplating or metal spraying and then honing the result to get a smooth and true bore before sleeving it? I'm not sure if you can spray metal inside a cylinder though - the gun may be too large to fit inside. What you probably need is a spark eroder in reverse! Chris Quote Link to comment Share on other sites More sharing options...
mtskull Posted June 20, 2012 Share Posted June 20, 2012 Possibly too late now, but would it be possible to build up the pitted portion by either electroplating or metal spraying and then honing the result to get a smooth and true bore before sleeving it? I'm not sure if you can spray metal inside a cylinder though - the gun may be too large to fit inside. What you probably need is a spark eroder in reverse!Chris A spark eroder in reverse is called an arc welder! Quote Link to comment Share on other sites More sharing options...
Chris Suslowicz Posted June 20, 2012 Share Posted June 20, 2012 A spark eroder in reverse is called an arc welder! Well, yes, but metal spraying is apparently done at a much lower temperature than welding so would be less likely to cause more problems than it solved. Electroplating would probably be the best bet - wax or otherwise protect the good parts of the bore and see if you can convert the rust beck into iron and then continue building it up until it can be machined flush with the existing surface. Just a thought. Chris. (Neither a mechanic nor a metallurgist!) Quote Link to comment Share on other sites More sharing options...
Old Bill Posted July 3, 2012 Share Posted July 3, 2012 I have just had a very nice chat with a gentleman at Westwood Liners and he suggests that we have finish machined liners a close sliding fit in the bore and secured with Loctite. He says that for a low performance engine (this is less than 6hp per litre!) we won't have any problems at all and it offers the least risk to the block. He can make 'wavy liners' which have 1/32" of intermittent clearance to give space for a special adhesive whose name he couldn't remember but which they use on early Rolls Royce motor cars with very fragile blocks. However, Loctite will be fine for us. He suggested that we only Loctite the lower part to give us time to get it into the block before it goes off so we will do that. I am going down to Devon this weekend so I will measure it all up and produce some liner drawings. All I need now is a source of Loctite 620! Steve Quote Link to comment Share on other sites More sharing options...
alixcompo Posted July 3, 2012 Share Posted July 3, 2012 Hi, I expect that you noticed this on Ebay (item no. 300723171766) Possibly a bit modern for you at 1937..? Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted July 4, 2012 Share Posted July 4, 2012 Hi, I expect that you noticed this on Ebay (item no. 300723171766) Possibly a bit modern for you at 1937..? Yes, we had noticed that one - no good to us - but thank you! Tony Quote Link to comment Share on other sites More sharing options...
alixcompo Posted July 4, 2012 Share Posted July 4, 2012 And just for info in my 'Historic Commercial News' mag this month there is a pic of a very collapsed 1929 model PB Thornycroft which needs rescuing. It is in a very poor state Again probably too young but the rad looks very similar to yours. If you are interested at all I could scan the pic and post it on here Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted July 4, 2012 Share Posted July 4, 2012 And just for info in my 'Historic Commercial News' mag this month there is a pic of a very collapsed 1929 model PB Thornycroft which needs rescuing. It is in a very poor state Again probably too young but the rad looks very similar to yours. If you are interested at all I could scan the pic and post it on here Probably of no interest to us - but please publish the Picture as it coud well be of interest to somebody else! Tony Quote Link to comment Share on other sites More sharing options...
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