BenHawkins Posted August 30, 2015 Author Share Posted August 30, 2015 After quite a bit of tapping the water jacket tops with a hammer they eventually started to move. I poked around in the water jacket with a welding rod whilst having a vacuum cleaner fitted to the water inlet. I think I have all the lumps of rust out. We then started with paint stripper to get the thick silver paint off. The next stage was to clean them up with a selection of wire brushes to get into every area, acid etch and give a coat of engine enamel. It was nice to find the thick silver paint was not covering up any issues. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted August 30, 2015 Author Share Posted August 30, 2015 When I purchased the chassis it had a single silencer bracket so I tidied it up and had a foundry use it as a pattern. For the lower halves I had to cut the mounting arm off and grind it flush. After drilling the holes I was able to blast and paint them and use them to put the silencer in place. The end plates for the silencer were made from a pattern I borrowed from Steve. I need to source some longer bolts to fit it properly. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted August 30, 2015 Author Share Posted August 30, 2015 I had the transmission brake shoe arrangement on another gearbox so I have removed them to use on this one. It all came apart quite easily so I was able to blast and prime some of the parts. Along with the gearbox covers. And the transmission brake hub. I will need to make a pattern for the drum itself but it is fairly simple and I think it is small enough that I can machine it myself. Quote Link to comment Share on other sites More sharing options...
Asciidv Posted August 31, 2015 Share Posted August 31, 2015 Ben, Did you roll the silencer tube yourself? How is the seam joined? Barry. Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 3, 2015 Share Posted September 3, 2015 Did you roll the silencer tube yourself? How is the seam joined? To answer a question not asked... I have one of these and it is rather useful for this sort of thing. I used it to make the silencer and fuel tank for my Ner-a-Car. http://www.axminster.co.uk/750mm-sheet-metal-worker The bending and rolling capacity is rather more than the cutting capacity. And I think it was a fair bit cheaper when I bought mine. Curiously there are several on eBay at much higher prices than the Axminster one. Quote Link to comment Share on other sites More sharing options...
rog8811 Posted September 3, 2015 Share Posted September 3, 2015 I have one of these When I purchased mine Warco were the cheapest. I have always assumed they all came out of the same Chinese factory but in different colours. Mine needed some fettling to get it to a good standard for use but a very good tool for the price. Nice to see it all coming together, keep the reports coming Quote Link to comment Share on other sites More sharing options...
flandersflyer Posted September 4, 2015 Share Posted September 4, 2015 To answer a question not asked... I have one of these and it is rather useful for this sort of thing. I used it to make the silencer and fuel tank for my Ner-a-Car. http://www.axminster.co.uk/750mm-sheet-metal-worker The bending and rolling capacity is rather more than the cutting capacity. And I think it was a fair bit cheaper when I bought mine. Curiously there are several on eBay at much higher prices than the Axminster one. are these generally stable then when working on capacity? do you get a true 90* all the way across when putting returns on sheet? or do you find yourself going to 90* for the centre of any sheet being worked...then bringing back the ends to 90* with the tressle & copper hammer method? mind you at the place i worked they had all stuff like guillotene`s, iron workers, rollers & brake presses... Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 4, 2015 Share Posted September 4, 2015 do you find yourself going to 90* for the centre of any sheet being worked...then bringing back the ends to 90* It is so long since I did a long bend that I can't remember. And when I did I wasn't all that bothered as the next stage was to hammer the flanges flat onto the polypropylene side armour. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 6, 2015 Author Share Posted September 6, 2015 Ben, Did you roll the silencer tube yourself? How is the seam joined? Barry. The outer tube was actually done quite a few years back. My little brother works for a sheet metal company so he rolled the tube and mig welded the seam. Two completed for just the cost of the material; one left on the shelf for the 1908 project. Rolling is something I need so rarely I cannot justify the space in my small workshop. Perhaps it is something to look into if/when I build the next garage. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 6, 2015 Author Share Posted September 6, 2015 The first job of the week was to split pin the rear hub nuts. I was going to fit the hub caps but still await delivery of some 3/8 Grover washers. I blasted the water jacket tops from the engine. This revealed that one of them has a crack running alongside the old braze repair. I might have a go at another braze repair but it is probably time for a new casting; especially as the geometry is fairly simple (the existing part could even be built up into the new pattern). I warmed up the transmission brake hub to remove the wasted away studs. The remaining one that was already sheared off will need to be drilled out. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 6, 2015 Author Share Posted September 6, 2015 One of the arms for the transmission brake mechanism was quite twisted. I warmed it up until it was glowing with an oxy-acetylene flame and used a 1" bar through the eye to twist it back to as close to the original alignment as I could check by eye. The rest of the week was taken up by a trip collecting more junk, Beaulieu autojumble and yet more painting. Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 8, 2015 Share Posted September 8, 2015 I blasted the water jacket tops from the engine. This revealed that one of them has a crack running alongside the old braze repair. I might have a go at another braze repair but it is probably time for a new casting; It isn't load-bearing and will never be > 100C, so why not bodge it up with epoxy putty / Loctite / Edam? Quote Link to comment Share on other sites More sharing options...
Asciidv Posted September 8, 2015 Share Posted September 8, 2015 It isn't load-bearing and will never be > 100C, so why not bodge it up with epoxy putty / Loctite / Edam? If you are seeking genuine grover washers I don't think 'bodging' is on the menu, be it edam or not. New casting please. We like to see it done right! Barry. Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 8, 2015 Share Posted September 8, 2015 If you are seeking genuine grover washers I don't think 'bodging' is on the menu, be it edam or not. New casting please. Joking aside, there are two ways to argue this, and it depends how much you value actual original parts over good replacements. Ben seems to be buying Dennis chassis in bulk, and I suspect that this is just an original Grover washer harvesting excercise. Quote Link to comment Share on other sites More sharing options...
flandersflyer Posted September 9, 2015 Share Posted September 9, 2015 One of the arms for the transmission brake mechanism was quite twisted.[ATTACH=CONFIG]107610[/ATTACH] I warmed it up until it was glowing with an oxy-acetylene flame and used a 1" bar through the eye to twist it back to as close to the original alignment as I could check by eye. [ATTACH=CONFIG]107611[/ATTACH] The rest of the week was taken up by a trip collecting more junk, Beaulieu autojumble and yet more painting. is that a forged item? If so then have you altered the grain structure by heating? did you allow it to cool slowly? Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 13, 2015 Author Share Posted September 13, 2015 is that a forged item? If so then have you altered the grain structure by heating? did you allow it to cool slowly? You are quite right to be concerned about this. I believe it probably is a hot forging but I do not know how the original was allowed to cool so by heating it up and allowing it to cool I have certainly annealed it to some extent in that area. It has quite a large cross section so I hope not to have massively effected the parts performance. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 13, 2015 Author Share Posted September 13, 2015 I put the transmission brake hub on the milling machine, lined up with the centre of the stud and drilled out to the tapping size of 1/2" BSF. I could then extract the spring of thread left behind and use a tap to clean up the threaded hole. The level tap for the gearbox had a broken off handle and was seized up. After freeing it up I drilled out the stub of the handle, worked out it was 0BA and then turned up a new one. Another part ready to use. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 13, 2015 Author Share Posted September 13, 2015 I collected together all my spare Grover washers, blasted and primed them. My very expensive new Grover washers have arrived. I am still working on buying some from India but progress on this front is slow. When I blasted and painted the gearbox covers I did not do the output cover as I could not extract the speedometer drive. I finally freed it off so that is now blasted and primed. I left the drive gear and boss in oil for a few days before pressing the gear out. This points upward and was full of water when I collected the gearbox (and probably for the previous 50 years!). This has taken its toll on the end where the speedo connects which probably had a female square drive originally but has completed corroded away to nothing. I am just amazed the water never got past this and into the gearbox. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 13, 2015 Author Share Posted September 13, 2015 As mentioned previously I am making the gear and brake lever set up from a later pattern set. The brake lever forging is essentially identical but would have pivoted on a 1" shaft rather than fitting to a 1.25" shaft with a pinch bolt and Woodruff key. As part of converting it I took a bar end of phosphor bronze I purchased at scrap value, turned the OD and bored it out to size. I didn't really have enough length to part it off so used a hacksaw before turning it around to face and chamfer the end. And then just put it in the lever. Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted September 13, 2015 Author Share Posted September 13, 2015 The rest of the week seems to have been spent on engine related jobs. Although I like to use as many original parts as possible I would also like to be able to tighten the water jacket tops enough that they will not leak so have decided to build up the cracked water jacket top to use as a pattern. I started by grinding back the braze, blasting and priming. On the inside I have built up the corroded areas with filler but still need to glue on some wood where the casting will need machining. I will probably also glue a strip of 1.5mm ply around the outside of the flange to account for shrinkage. I spent quite a while grinding in the valves. The exhaust valves are a little loose in the guides but I don't think I will go for new valves just yet. Many hours were spent freeing off the stuck piston rings. This was done with penetrating oil and gently wiggling the rings. I didn't break any so took the top ring off No.1 piston and tried it in the bore. The engine bore is 75mm and this piston ring end gap is 0.022". From the limited information I have managed to find it would seem like they would originally have been set at around 0.012" but what would be a sensible limit before replacement? I used a dial bore gauge to check the bores. At the worst point they barrel by 0.05mm which seems perfectly fine. Whilst messing with the pistons I noticed that the gudgeon pin retaining rings are actually deliberately in two halves (cut with a hacksaw) rather than broken in two. That still leaves me with one that is actually broken but that may have been done by the same mechanic that broke all the tappets. Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 15, 2015 Share Posted September 15, 2015 The engine bore is 75mm and this piston ring end gap is 0.022". From the limited information I have managed to find it would seem like they would originally have been set at around 0.012" but what would be a sensible limit before replacement? If it was me, I would arbitrarily decide 25 thou. :-) My interpretation of https://www.hastingsmfg.com/ServiceTips/ring_gaps.htm is that 22 thou is fine. In fact it seems to say that you could start at .020 and allow a further .009 as wear limit. Quote Link to comment Share on other sites More sharing options...
Ted170 Posted September 15, 2015 Share Posted September 15, 2015 (edited) I've been told one old simple calculation for the ring gaps - cylinder diameter/3000. So, 75/3000=0.025 mm gap. That's a starter gap for a fresh repair, with time that would increase a little with the engine wear Edited September 15, 2015 by Ted170 Quote Link to comment Share on other sites More sharing options...
andypugh Posted September 15, 2015 Share Posted September 15, 2015 I've been told one old simple calculation for the ring gaps - cylinder diameter/3000. That comes out at less than 1 thou? That can't be right. Quote Link to comment Share on other sites More sharing options...
Ted170 Posted September 15, 2015 Share Posted September 15, 2015 You are right, I should have thought a little while writing It's 300. For 75 mm cylinder that would make a quarter of a millimeter. Quote Link to comment Share on other sites More sharing options...
David Herbert Posted September 15, 2015 Share Posted September 15, 2015 For 75 mm cylinder that would make a quarter of a millimeter. Which is 10 thou. I would have thought that was as tight as one would want to be. I would be happy with anything up to 25 thou on a modern engine. WW1 engines run slower and at much lower pressures and will never do the mileages that we expect of a modern vehicle so I would have thought that if everything else was ok, ring gaps up to about 40 thou would be fine. I certainly wouldn't worry about 22 thou. But that's just my opinion ! David Quote Link to comment Share on other sites More sharing options...
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