Old Bill

Gordon M " You are right - you might be over-solving this one. What's the compression ratio on the engine, then? Nothing too high, I assume. " I think it is about 4:1 or at least, it was before we lined the bores. I think we have lost 500cc of swept volume so the ratio will have dropped a bit. Steve

Very many thanks for all of your thoughts, Chaps. I bought the rings from a ring specialist after telling him what sort of engine it is and the dimensions of the current rings. I am simply planning to fit what he supplied, relying on his expertise. Unfortunately, he didn't provide any guidance notes! Looking at Chris' website, it appears that if the rebate is upwards, it is used as the top ring for dodging the step at the top of a worn bore and if it is downwards, it is a scraper ring. As we have new bores I think I might assemble them all with the rebate downwards. That way, if ever we need to replace them without reboring, we can put the new top ring in the other way up to dodge the step. Will I get any lubrication problems if I assemble them all as scraper rings? The originals are just plain compression rings. Perhaps I am being too clever! Steve

I wish! I have just remembered that I need to machine the ends of the gudgeon pin bosses as well. There is a lot of work in a piston and these are relatively simple. Now, please may I have some advice? The top rings are all 1/8" thick but they are stepped such that the contact surface is only 1/16". The question is, which way up should they go or does it even matter? Your thoughts would be appreciated. Cheers! Steve

How will you transfer the logo to the hub cap? Photo etching or engraving perhaps? It does look good! Cheers! Steve

Well, that's interesting. Doesn't look like a Thorny to me but I can't Identify it. The driving position looks very well forward from the hand brake position and I have never seen anything like those wheels before. None of the fittings have a Thorny look about them so I don't think it is. We need Doug or Tim or Runflat to have a look! Steve

Thanks Richard. Punching is an interesting thought. The sleeve, if I remember correctly, is 5/8" outside diameter and 1 1/2" long with a wall thickness of 1/16". The brass centre has a piece of tube pressed through it crossways to secure the sleeve. I drilled the PTFE through, fitted it to the spindle and then turned the outside afterwards. It hasn't leaked at all which I count as some success but not being able to turn it on is a bit of a downer! Steve

Over the bank holiday and when we put the lorry into store, it has become apparent that the fuel tap has become very stiff, to the point where I am concerned that I will either break off the handle or worse, break it out of the bottom of the tank. You may remember that I made it up to represent the one in the fuel tank drawing but I took the liberty of using PTFE for the liner sleeve instead of cork. This may have been a mistake! Well, I had the great good fortune to meet the delightful Sarah at the rally at Old Warden over the weekend and she worked for some years in an organo-fluorine chemical laboratory. I asked about the sleeve and she told me that petrol will not corrode or degrade it. However, she did explain that the octane molecule, a major constituent of petrol, is of a similar length to the ethylene molecule such that inter-molecular Van-der-Waals forces will securely attach it to the PTFE. (Gosh, I wish I had paid more attention to my chemistry at school!). The net effect of this is that the PTFE grows which explains why the valve has tightened up. Now that I understand the problem (more or less...) I must find a solution. At the moment, I think that a cork sleeve may provide the answer but does anyone have any suggestions how I should make one? Do I use a lump of whole cork or some reconstituted crumb material? How do I turn it? Any advice would be gratefully received! Steve :embarrassed:

I think the centre lorry might be an FWD. The others are certainly Quads though. Steve

Nice pic again Tom. Difficult to identify the lorries but I would suggest that they are Peerless. They certainly have the look about them. Did the RFC have any? Cheers! Steve

You've stolen my thunder Barry! Yes, that is part of the plan. My intention, at the moment, is that the right hand lump will be turned to the outside dimensions of the onion with the big core print at the bottom and the little one at the top. The centre lump will be turned to the inside dimensions to become the shape of the core. The left hand lump is to be turned to the outside dimensions of the main pattern in the area of the hole. This, I plan to cut to the profile of the hole and glue to the core block giving a section, raised by about 1/4", in the area of the hole. That will support the core in the hole in the sand. Now, the clever bit. I shall make up two core boxes as empty wooden boxes. The wooden core will be supported half into the box and the box filled with resin around it. It will then be reversed and the same done for the other side. This should give me two core boxes, one for each half of the core. The moulder can glue the core halves together before placing them in the mould. Well, that's the theory anyway. I have not done this before but will keep you posted with progress! Steve

Thanks Chaps. Just what I wanted! Cast iron is lovely to machine but the swarf is filthy. I shall have rusty handkerchiefs for a week! Steve

I am just getting prepared to machine them now, just as Barry described with the draw bar through the headstock of the lathe. I will face both ends and clean up the inside ready for the gudgeon holes to be bored by a friend with a bigger mill. One particular question arises, though, and that is how much clearance should I give them on the diameter? I have asked around and been given figures from 0.005" to 0.010". The bore is 4 5/16" and it is an iron piston. I plan to make the land above the top ring about 0.004" smaller in diameter than the rest of it which will remain parallel. I would value your thoughts please! Cheers! Steve

Quite right. The challenge is everything. If it was too easy, we wouldn't do it! I hadn't thought of Dental resin. That has worked well with a lovely result. How did you obtain the materials? Perhaps I am just being dim and should ask Mr Google. One other thing intrigues me and that was how you set all of those rivets? I have found using such large rivets in thin plate troublesome as they tend to roll over in the snap and twist the plate locally. Nice job. Keep it up! Steve

Wing nuts can be clearly seen in the drivers' manual so we have continued their use. Those I found twenty years ago are of a modern pattern. Since then, the internet has come along and Dad has found the correct pattern quite easily so we will replace them in due course. The Dennis box was secured with nuts and washers (Again visible in the manual). However, it also has a filler on the front of the case with a cover. That is fixed using wing nuts. I would suggest that this would allow the driver to top up the box with no tools to hand. Regarding the 'gate' this is just the same as the Dennis with reverse through first and a trigger to allow the lever to move to that position. I'm not sure how common this was but I have seen it elsewhere. Cheers! Steve

Trailer wheels I should think. What do you think Hedd? You are the Eagle trailer expert! Steve

What I really wanted to do was to just skim the original pistons to fit. However, we have lost 3/16" on the bore and the piston walls are just too thin to allow us to take enough off, hence the new ones. Our aim is to have a 100 year old lorry that looks to have been cared for using factory parts. The factory would have used iron so we are doing the same. Now, we bend the rules a bit with our silver soldered fabrications but we generally try to follow the original process wherever we can. I am still pondering as to how the factory would have machined the pistons. Possibly, they may have started with the bottom of the skirt, facing and boring and then by cutting the gudgeon-pin holes. Next, using a dummy gudgeon pin and a draw bolt through the lathe headstock, the piston could be pulled back onto the faceplate or a locating disc to turn the outside and face the crown. They would not have had a chucking piece like ours as it is a wasted piece of metal. We don't have the facility to bore the gudgeon pin holes and that job will have to be put out. Using the chucking piece, I can complete all of the other machining processes before having the hole bored. Steve

Glad you enjoyed the Dennis. The pleasure of it is what this is all about and we love to share it with all of our friends! Welcome! Steve :-D

That's some lovely timber you have used there, Mark. What other things did you have to make? Looks like a new radiator and bonnet too. Well done. It's great to see another one out! Steve

When I made our first piston patterns for the Autocar many years ago, I did them like this and they worked well. It was only afterwards that I thought about the cores floating off! I hadn't thought about putting a large flange on the end of the core to trap it but it is an obvious solution now. Never mind. Father can take these to the foundry and we can hear what they have to say. Mother took the last ones in and she ended up with a guided tour of the foundry! If I have to remake them, sobeit but I hope they can manage. We shall see. I still have the onion pattern to make and then the water outlet as well so there is still plenty of opportunity to practice. Steve

So that is how it is done! Proper colours too! I see that the core hangs down into the cavity whereas mine has the crown at the top. That way, the dross will end up in the skirt rather than the crown. I think I will get away with it as any dross will end up in the chucking piece on mine. It is very nice to see something professionally made. I'm afraid that I just make it up as I go along! Thanks for sharing that with us Barry. Steve

Is that the Albion from Farrall's Transport of Chester? If so, they have been working on it for a good few years. Nice to see another one out! Steve

Yes, that's right. A classis 'cone-clutch'. They are very common on early vehicles, sometimes with leather linings and sometimes just metal to metal. They work well but can grab a bit if you are not careful. It says in the manual to apply oil to the friction material if it does! The leaf springs are a bit unusual though. We are fortunate to have a refurbished set in stock. It is amazing what you can pick up if you spend long enough on a project! Steve

Hi Chaps. Many thanks for all of that. I hadn't thought of using a plastic but it would work. I don't think I want to, though, as it wouldn't be 'as built' which is the standard we have set ourselves. Thanks for the suggestion though. I am sure we can straighten the worm but am still thinking on the most reliable process. It will certainly want heat as it is quite hefty and to get the bend where I want it, the pressure points are going to be very close together. I have the remains of the original column which I could use to lean on it in the vice but that will take a bit of control on my part to get the right amount in the right direction. I would like to use the press but it is going to be at its limit cold. It does have the advantage of much finer control than the tube. I am thinking that if I make two half bearings and mount them on a plate, say 4" apart, I could put that on the press to support the worm either side of the bend before giving it a push in the middle. It would make the setting up process when hot a lot easier. A two man job though! Tim??!! The white metal is interesting. It is a very coarse two start thread so the backlash might not be significant. At the moment, I feel inclined to reassemble it all and see how bad it really is and then re-metal if necessary. Dad has cleaned it up today and says that it looks a bit rough in the middle so a bit more thought is needed. Thank you all very much for the procedure suggestions. That takes some of the fear out of the job! I have only done big ends before so this is really quite different. I shall ponder this job a bit longer before tackling it. In the mean time it is back to pattern making. There should be some pics of that by the weekend. Cheers! Steve :-)

As Dad says, that is not my lounge. I keep my railway wagons in the lounge along with an air horn from a ship! The back-lash in the arms and bearings is negligible but in the white metal, it is about 1/16". I'm not sure whether I want to do anything with that for the moment. It depends on how brave I am feeling! I must admit that once you get more than 90° of slop at the wheel, keeping the machine on the road becomes a bit of a challenge. This will give us about 30° I think which is pretty borderline. I think I will make up all of the other bits first and then see how it feels. Do you think that the metal was simply poured in to fill the space between the worm and nut? Assuming it doesn't stick to the worm (smoking is a good idea) would not the wear in the middle of the worm prevent the nut from moving to the ends? Have any of you chaps ever done this as I am finding the thought of it a bit daunting! Straightening the worm will be fun too. it is straight between the bearings and runs OK. Therefore, I need to unbend it at the point where it bent in the first place. Currently, I am thinking of making a split block which I can use to clamp the worm in the vice at the bearing seat. Then I will heat it with oxy-acetylene (borrowed) and lean on it with a piece of pipe. Does anyone have any thoughts about this? More challenges! I will think about them further whilst making my piston pattern. Cheers! Steve :-)