CornishMade Posted March 14, 2019 Share Posted March 14, 2019 Totally loving this, I think someone will have to visit and see this is going it's good to know that something that was left that long is still good on the inside, even if the outside is not💗💗 Quote Link to comment Share on other sites More sharing options...
CornishMade Posted March 17, 2019 Share Posted March 17, 2019 Father says sand blast the metal liner so the leather will bond to it better, ours is the same, our one was made new to fit with girls punched out , using various local facilities Quote Link to comment Share on other sites More sharing options...
Old Bill Posted March 30, 2019 Share Posted March 30, 2019 Dad is keeping things moving and has been busy in the paint shop again. This is the pump drive spring with a coat of green. The water manifolds and the starting handle assembly have been to the sand blaster's and they have been painted as well. The starting handle will require some attention so that just has a single coat of primer to slow the rust down. These castings are very fine and I am very glad not to have to make patterns for them! The timing case cover looked a bit scruffy. A good clean soon brought it up and it is in very nice order. There are two sumps with twin, linked, test cocks. These have been dismantled to allow the bodies to be removed. Unfortunately both the tap bodies and various drain plugs were solid so we used the age-old heat treatment to good effect. Before cleaning: And after! Something else to be packed away ready for re-assembly. Steve  3 Quote Link to comment Share on other sites More sharing options...
Old Bill Posted May 6, 2019 Share Posted May 6, 2019 Well, we are still doing odds and ends whilst we try to keep a lot of other balls in the air. Going to drop one sooner or later but in the meantime the lorry is a making a little progress. Dad is still working on the chains. They are a tedious job and best attacked in small doses. I wanted to get the pistons out so I can have a look at making some new ones. Big end is fairly conventional. A bit of contortionism! And off it came. No wobble or wear. A really nice joint. I wish the last owner had taken a bit more care. There is no wear at all, just two broken castings! Actually, the castings are amazingly thin. They are iron and only around 1/16" thick. I don't expect that mine will be quite so light. Lubrication to the big ends is by splash in this engine. See the big holes at the sides of the journal to let the oil in. The magneto bracket has been annoying be. It looks as if it has taken a bash and bent the crank case. I set about taking it off with some coaxing and oil. Off it came. The base plate is broken but replaceable. The best bit was that the crank case casting isn't bent so that is a win. On the other hand, i tried to unscrew a bolt from a boss on the side of the case and it split. I think it was cracked already but it is a real nuisance and will take some sorting. On to the governor on the other side. A lot of it is missing but the basic mechanism is still there. # With the cover off, there is a lever carrying a yoke. The yoke sits on these two pins which push it back and forth, actuated by the bob weights inside. This sping sets the governed speed. It has no adjustment and is set in position by a cross-pin under the washer. Once slid off the shaft, it is again in beautiful condition with no wear. The drive gear spindle has a key along its length which takes the drive for the weights. The gear is in lovely order too. Bob weights removed. The magneto drive gear on the other side is nice too. Dad has picked up the cam followers for a clean and inspection. Again, no wear at all but some corrosion on the rollers. I see these very much as borderline and am deciding whether to replace them. The last three have very corroded tappets. Dad has reached the conclusion that they are a metric fine thread which I find bizarre for an Americn lorry. He has ordered some bolts to try in the holes and will make up some replacements in due course. We want to turn the engine pver and lift the crank next time we get together. Once that is done and the camshafts are out we can get on with creaning and putting it back together. I must get on with the piston pattern. Steve  4 Quote Link to comment Share on other sites More sharing options...
Citroman Posted May 7, 2019 Share Posted May 7, 2019 (edited) You say the tappets are metric, they might have been have replaced in france during the war? Edited May 7, 2019 by Citroman Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted May 7, 2019 Share Posted May 7, 2019 Could the thread be Unified National Extra Fine? Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted May 7, 2019 Share Posted May 7, 2019 Apologies in advance for the pickiness, but they would just be National Extra Fine as the "Unified" didn't get added till nearly 1950. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted May 7, 2019 Share Posted May 7, 2019 All very interesting and I am pleased to be helped and advised! The outside diameter - of the surviving clean threads is .3032" or 7.78 mm. No joy with an Imperial Thread Gauge on it and the nearest I can get to this is with a metric Thread Gauge - 1mm - and the bolt thread sits very comfortably on that so I assumed that it must be a 8mm fine thread............ I have no threading tackle of that size but I await some 8mm 1 Nuts and bolts and it will be interesting to see if they fit. Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted May 7, 2019 Share Posted May 7, 2019 4 hours ago, Gordon_M said: Apologies in advance for the pickiness, but they would just be National Extra Fine as the "Unified" didn't get added till nearly 1950. No need to apologise, I've learnt something new today. Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted May 7, 2019 Share Posted May 7, 2019 13 minutes ago, MatchFuzee said: No need to apologise, I've learnt something new today. Ta.  It does explain why there were so many threads used on our WW2 trucks that are non-standard today too.  I can't find anything US with a .3032" thread OD though. Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted May 7, 2019 Share Posted May 7, 2019 17 minutes ago, Gordon_M said: I can't find anything US with a .3032" thread OD though. Not here either but you may be interest in this handbook:- https://archive.org/details/screwthreadstand2811unit Quote Link to comment Share on other sites More sharing options...
andypugh Posted May 7, 2019 Share Posted May 7, 2019 7 hours ago, Minesweeper said: The outside diameter - of the surviving clean threads is .3032" or 7.78 mm. No joy with an Imperial Thread Gauge on it and the nearest I can get to this is with a metric Thread Gauge - 1mm - and the bolt thread sits very comfortably on that so I assumed that it must be a 8mm fine thread............ 5/16 UNF is 0.3035 OD at 24tpi once you take in to account thread truncation. (5/16 UNEF is rather larger) https://docs.google.com/spreadsheets/d/1m5zkO9-SbQaYWbTPlQXJ2VA73Ys8WgWDrPk_rEukHc0/ It would be 0.3038" @ 25 TPI, which would fit the stated thread gauge better. As others have said, the engine predates the standards that we have tables for, and there is no need for those parts to be _any_ standard as they are not intended to be interchangeable fasteners. So the degree of crest truncation (or even rounding) might make up the difference. You might be able to figure something out by the shape of the roots and crests (flats or rounded) but that would take a lot of work with a shadowgraph for dubious benefit. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted May 8, 2019 Share Posted May 8, 2019 On ‎5‎/‎7‎/‎2019 at 7:01 PM, andypugh said: 5/16 UNF is 0.3035 OD at 24tpi once you take in to account thread truncation. (5/16 UNEF is rather larger) https://docs.google.com/spreadsheets/d/1m5zkO9-SbQaYWbTPlQXJ2VA73Ys8WgWDrPk_rEukHc0/ It would be 0.3038" @ 25 TPI, which would fit the stated thread gauge better. As others have said, the engine predates the standards that we have tables for, and there is no need for those parts to be _any_ standard as they are not intended to be interchangeable fasteners. So the degree of crest truncation (or even rounding) might make up the difference. You might be able to figure something out by the shape of the roots and crests (flats or rounded) but that would take a lot of work with a shadowgraph for dubious benefit. I tried a 5/16" UNF Nut and Bolt on them today to test the threads, just to make sure - and they do not go. Starts off but binds up. Quote Link to comment Share on other sites More sharing options...
andypugh Posted May 8, 2019 Share Posted May 8, 2019 It could be something completely special. Or an SI thread even, so ISO metric wont fit either. Metric isn’t impossible. About this time Morris were using metric threads with Whitworth head sizes in their engines. Quote Link to comment Share on other sites More sharing options...
dgrev Posted May 8, 2019 Share Posted May 8, 2019 Andy What ever inspired them to do that? The desire to confuse everyone? Regards Doug Quote Link to comment Share on other sites More sharing options...
David Herbert Posted May 8, 2019 Share Posted May 8, 2019 1 hour ago, andypugh said:  About this time Morris were using metric threads with Whitworth head sizes in their engines. In the 20s and 30s the Germans were building steam locomotives with Whitworth threads but metric head sizes. David 1 Quote Link to comment Share on other sites More sharing options...
dgrev Posted May 9, 2019 Share Posted May 9, 2019 (edited) I can just picture the corporate mind set "this will capture them, they won't be able to them or find anything else that will fit and have to come back to us for parts". Edited May 9, 2019 by dgrev Quote Link to comment Share on other sites More sharing options...
andypugh Posted May 9, 2019 Share Posted May 9, 2019 6 hours ago, dgrev said: What ever inspired them to do that? The engine was designed in metric, but they were aware that UK mechanics only had imperial spanners. Quote Link to comment Share on other sites More sharing options...
dgrev Posted May 9, 2019 Share Posted May 9, 2019 Ah, so, was logical after all. Quote Link to comment Share on other sites More sharing options...
IAN_B Posted May 9, 2019 Share Posted May 9, 2019 8 hours ago, David Herbert said: In the 20s and 30s the Germans were building steam locomotives with Whitworth threads but metric head sizes. David My 1938 Lanz Bulldog has imperial threads with metric heads. Ian Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted May 9, 2019 Share Posted May 9, 2019 I now have M8 x 1.0 pitch Nuts and Bolts - but remain puzzled! The nuts screw on the original Tappet thread comfortably and I would be perfectly content to use them as the locking nuts for future use. The bolts screw in finger tight to a depth of about 3/8" only but then they start to tighten which makes me think that this cannot be right - they should screw down to almost 1 3/8" length to be similar to the originals if this is the right size. Further thoughts, please! Tony Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted May 9, 2019 Share Posted May 9, 2019 Well I'm out of immediate ideas for this. You have looked at American threads, but you can match neither the pitch nor the diameter. You have looked at Metric threads, and can match the diameter and approximate the pitch ( binding after 3/8" ) I can only suspect the hidden hands of Peerless Trading here, like the water pump. Â Is it some antique British thread, like a BA variation or something for Wheeltappers & Shunters? Â ( gives age away ) Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted May 9, 2019 Share Posted May 9, 2019 13 minutes ago, Gordon_M said:  Is it some antique British thread, like a BA variation or something for Wheeltappers & Shunters?  ( gives age away ) British Standard Cycle Thread? Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted May 9, 2019 Share Posted May 9, 2019 14 minutes ago, Gordon_M said: Well I'm out of immediate ideas for this. You have looked at American threads, but you can match neither the pitch nor the diameter. You have looked at Metric threads, and can match the diameter and approximate the pitch ( binding after 3/8" ) I can only suspect the hidden hands of Peerless Trading here, like the water pump. Â Is it some antique British thread, like a BA variation or something for Wheeltappers & Shunters? Â ( gives age away ) Made me smile! Tony Quote Link to comment Share on other sites More sharing options...
dgrev Posted May 9, 2019 Share Posted May 9, 2019 I am so glad that all but one of my vehicles uses UNF threads (British and American vehicles!), the other one uses metric. British Obscure threads sound like a nightmare. On that note, when I did my trade as an electrician they told us at tech that the screws that are used on Australian power points and fittings are unique. Apparently when the Oz electrical industry was being born, there was difficulty in obtaining the required machinery and tooling. Somebody found out that a Scottish factory (nobody seems to know what they made) had gone bust and their equipment was up for sale. It was one of those places that had their own proprietary thread form. We still use it - not that you can buy taps or dies to suit. BA is not even close. Regards Doug Quote Link to comment Share on other sites More sharing options...
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