Tharper Posted April 2, 2022 Share Posted April 2, 2022 (edited) On 7/11/2021 at 4:51 PM, andypugh said: I think it might take a thermocouple to figure out which way to go. Possibly richer would run cooler? Hello Andy, curiously its actually the opposite. When an engine is running rich the mixture is fuel rich and air poor so combustion is much slower. That long burn allows more cylinder wall to be exposed to the combustion heat during the power stroke and thus more heat is transferred to the block and coolant. If its really rich the burn can carry into the exhaust stroke thus heating the manifold above what it normally would be. If you have primer cups its fairly easy to see what the mixture is doing. With the motor running and up to temp open one of the primer cups and observe the color of the flame. If its red and sooty than the mixture is too rich. If its pale yellow than its too lean. A nice blue flame is what you are looking for. It's a quick and easy method to see whats going on. Here is a demo using the Museum's 1928 Lombard dump truck, https://www.youtube.com/watch?v=ylRn2qy3T7U Also of course the timing can make it run hot as well. All good fun right? Best regards, Terry Edited April 2, 2022 by Tharper 1 Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 13, 2023 Share Posted January 13, 2023 Just posting a few more pics but I am very pleased to read Terry's comments again. I didn't get around to trying the flame test last year but have continued to ponder the mixture. I have a selection of jets that I have turned up so must have a go next time we go for a play! In the mean time, I have been pattern making again. On the front of the engine, there is a casting which carries the outer fan bearing. We call it the 'onion casting' for some reason and, as you can see below, it was pretty poorly. A friend tried a TiG welder on it but the results were awful and we determined to make a new casting instead. I started on the pattern but then we were fortunate to find a good casting at the Banfield sale and that is what is fitted to the lorry. In the mean time, I passed the half-made bits onto Tomo to finish. Just the other day, our pal in New Zealand, who so kindly gave us the differential, asked if he could have a casting as the one for his lorry is rotten as well so I thought I had better finish the pattern off. Tomo had not got around to doing it and kindly agreed that I could have the bits back so I am on with the job again! This is a most cussing awkward shape and has been a real puzzle over how to do it. I eventually reached the conclusion that I need a full-diameter plug with a core to drop in which has part of its surface higher by the thickness of casting to generate the hole in the side. First step, therefore, was to turn up the plug using, as is my wont, a laminated MDF block. Getting the shape I wanted was a nightmare and in the end, I cut a template from platicard with some key dimensions marked on it. MDF dust is pretty horrible at the best of times and turning the stuff in a confined space was nightmarish. I couldn't see for most of the time for the dust on my specs! I brought out my dust extractor and used my respirator to make it liveable. The centre one here is the main plug. The question next was how to produce a core box with this complicated shape whilst maintaining a constant wall thickness. My boring skills are not up to the job but my pal, Adrian, suggested that I make a solid wooden core and then pour resin around it to make a mould. The piece on the right is that core which is 1/4" smaller than the plug all round to give a material thickness. The piece on the left is the same profile as the main plug so I can use it to generate the hole in the side. All three were turned using plasticard templates to control the profiles and have worked out OK. Whilst with Tomo, the bits have received the most fabulous paint job in Bondaprime. It was a pity to cut them! First job was to make the piece for the cavity so I cut a slice off of one side of the block. I then marked it out by eye and cut it to a curve until it fitted the casting. Lots of use of the belt sander here. Hardest thing is trying to hold it as there are no flat surfaces to grip! I was pleased with the result. Then it was time to cut a matching groove in the core itself. it was just a case of nibbling away at it until it fitted. The Bridgeport is a wonderful machine! Then, drop it in and glue it down. The tube is my dust extractor again. Horrible stuff. Then, heart-in-mouth time again as I sawed it in half. The plan is to cast the two halves of the core and make two boxes. The cores can then be glued together before dropping into the main hole. Main plug cut in half. I made up the saw thickness with plywood and then drilled holes for the locating dowels. The hole in the side needs to be opposite the boss which carries the greaser so thereneeds to be a location between the plug and the core. The boss on the plug is easy. However, that on the core is more difficult due to the direction in which I cut it in half. This is where we are today. The parts are painted and complete. I am just making up the core boxes over which the wooden cores will be suspended when the resin is poured in. I haven't tried this process before and am looking forward to seeing the results. Will keep you posted! Steve 🙂 11 Quote Link to comment Share on other sites More sharing options...
john1950 Posted January 13, 2023 Share Posted January 13, 2023 WOW. Hand eye coordination, and skill. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 14, 2023 Share Posted January 14, 2023 A bit more progress today. I have knocked up a couple of boxes from some scrap timber that was lying about. I then fitted some alignment strips to the core block to hold it in position and filled a lot of the cavity around it with offcuts of timber to save on resin. And then there were two! Next move is to pour the resin, possibly later this week. Back to the Peerless now! Steve 🙂 11 Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 20, 2023 Share Posted January 20, 2023 My good friend Adrian has very kindly sorted out the resin part of the job for me. The objective was to use my wooden replica of the core I want to produce to create a mould from which sand versions can be made. First job was to paint the wooden bits with a releasing agent. Then level up the core box on the bench top. And mix up the resin and hardener by weight on the scales. Pour into the gap all round and let it harden off. Once hardened off, the battens were removed. Excess resin was sanded off until the face was flat. Then a holewas drilled through the resin until the core could be reached. The hole allowed the core to be drifted out. And there we have it. A resin lined core box. I will have to repair the areas around the holes but that is nothing. A couple of removable pieces to add and then we will be ready to pour. Thanks, Adrian! Steve🙂 8 Quote Link to comment Share on other sites More sharing options...
alsfarms Posted January 20, 2023 Share Posted January 20, 2023 Very nice work you crafty rascals! Al Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 20, 2023 Share Posted January 20, 2023 Steve, why didn’t you just put screws into the wooden core and try and pull it out as if it was a conventional core in a sand filled core box? Or was it Adrian’s experience that told him the only way to get it out was to use a hammer from the opposite side? I suppose a hundred years ago if they were doing this plaster of paris would have been used rather than resin? Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 21, 2023 Share Posted January 21, 2023 Hi Barry. I bow to Adrian's judgement on this one. It certainly took some shifting to get it moving! The first few hefty wallops had no effect and I suspect that screws would have pulled out of the MDF. I haven't tried plaster of paris for pattern making but suspect that it might have broken up if given this treatment. That is something else to keep up my sleeve. Steve 🙂 Quote Link to comment Share on other sites More sharing options...
flandersflyer Posted January 23, 2023 Share Posted January 23, 2023 Bit of compressed air rather than a drift would've seen that out...? Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 25, 2023 Share Posted January 25, 2023 We have had a chat about this one and suspect you may be right as the air would get beneath the whole area and unstick it in a much more gentle fashion. One to try for next time! Thanks! Steve🙂 Quote Link to comment Share on other sites More sharing options...
Old Bill Posted February 3, 2023 Share Posted February 3, 2023 (edited) I have now completed the last bits. Inside the casting are two bosses which could not be added to my wooden core as they would have prevented us from lifting it out or, indeed, the sand core when the time comes. At the bearing end, there is a grease hole to the bearing. This is drilled down the middle of an internal boss. At the other end is a boss through which screws a long bolt to prevent the gland nut from turning. The only way these can be done is with some loose pieces which are lifted out before the main core is removed. The top of the mould needs to be left flat so that the sand can be strickled off so the loose piece must sit in a rebate. Good old Bridgeport! The resin cut quite nicely. Then a piece of wood cut to fit. The end was curved to form half of the boss and a pin was fitted to secure it in place. I took the same approach at the other end. This time, the lift-out piece was bigger so I glued some extra on the end before pinning it into position and then dressing it to shape with the Dremel and glass paper. The two loose pieces from the boxes held back to back to demonstrate the shape of the boss. All done! They are now on their way to the foundry for the moment of truth! Steve 🙂 Edited February 3, 2023 by Old Bill 11 Quote Link to comment Share on other sites More sharing options...
Zuffen Posted February 4, 2023 Share Posted February 4, 2023 You have to wonder what devious mind thought up such a complex casting back in the day. Great effort. Quote Link to comment Share on other sites More sharing options...
dgrev Posted February 4, 2023 Share Posted February 4, 2023 An engineer with a vendetta against mold makers/foundaries? Quote Link to comment Share on other sites More sharing options...
Old Bill Posted February 4, 2023 Share Posted February 4, 2023 Yes, this one has certainly been a challenge and I wouldn't have got this far without Adrian. There are two things which would have resulted in such an awkward shape, I think. One is that 100 years ago, making things out of wood was very common and there were a lot of highly skilled people about. Casting was the standard process for making shaped parts and there was a foundry on every corner. They would also have had some really nice timber of exotic species available to them which would make things easier. The second thing is that, in my experience, not a lot of thought is given by the draughtsman for the pattern maker and moulder. One of my colleagues was drawing up a casting at work and whilst looking over his shoulder, I suggested that if he taper it the other way it would make it far simpler to get out of the sand to which his reponse was 'I expect they'll sort it out'. He had no interest or consideration for their problems. I have seen this in the radiator castings too. The Peerless bottom tank is a simple draw using one pattern and one core box, all nicely thought through. The Dennis tank has a plug and six core boxes, two of which are to simply provide an aesthetic feature. I bet the pattern maker cursed when he saw that drawing. I certainly did when I realised what I was going to have to do! There is one more pattern on the horizon for the Peerless fan bracket but that should be a simple one, fortunately! Steve 🙂 4 Quote Link to comment Share on other sites More sharing options...
Old Bill Posted February 22, 2023 Share Posted February 22, 2023 Well, now is the moment of truth! these are the cores produced from the core boxes. They really are nice. And here is the casting! The core was made by gluing the two halves together before putting it into the mould. Even the removable piece came out OK. And the one the other end! I am very pleased with the result as this was quite a difficult one for me. Many thanks to Adrian for all of his help! Back to the Peerless now. Steve 🙂 13 3 Quote Link to comment Share on other sites More sharing options...
alsfarms Posted February 22, 2023 Share Posted February 22, 2023 Hello, you are probably sleeping well after the successful completion of this casting project. It is simply a big labor of love and a true piece of art. I hope you cast up a spare to help out the next poor chap that is in dire need of one of these.....it always happens! What material was used for this casting? Al Quote Link to comment Share on other sites More sharing options...
Old Bill Posted February 23, 2023 Share Posted February 23, 2023 Hi Al. Thanks for your comments. This is the first casting and a tester. Now that the pattern is proven, I am getting some more for several friends who want them. The silly thing is that I don't actually need one myself! Oh well. The pattern can go in the box with the others ready for the next time. I have made, or friends have made for me, 35 patterns for this lorry so it is quite a resource for anyone doing another. The next pattern is for the Peerless and is a lot simpler! Cheers! Steve 7 Quote Link to comment Share on other sites More sharing options...
Longen Posted February 24, 2023 Share Posted February 24, 2023 Steve, Bravo.👏 you and the team are an inspiration to us all. Dave. Quote Link to comment Share on other sites More sharing options...
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