mattinker

I very much doubt that it was to prevent cracking, boiling water will still crack an engine! More for better flow in the rad. Matthew

A word of encouragement! I've been following you for years, first the Denis and now the Thorny. I saw you in Brighton with the Denis, but, I won't be able to make it this time. The best of luck! Thank you! Regards, Matthew

Hi Steve, I haven't posted in a while, but I've been following along! Enjoying it as much as ever. With this kind of capillary tube oil pressure gauge, it is customary to include a couple of coils to render the pipe more more flexible. Engine vibration quickly work hardens copper, I'm afraid that without coils, you're running the risk of a broken oil pressure pipe! Regards, Matthew

Andy, Properly forged, (Sorry Steve!) it would have been possible to open up the bend a little bit without cracking, had it been hardened any form of carbon steel would have broken not cracked. Regards, Matthew.

Steve, Mild steel is just that, not enough carbon to make harden-able. You would not have been able to introduce enough carbon to make it brittle (otherwise, it would be a known technique for making harden-able steel!). So the only thing left is forging too cold! Still following along and enjoying the ride! May be see you in Brighton next year! All the best, Matthew.

Just a word to say how much I enjoy this thread. Thank you for taking the time and trouble to keep us informed of your progress by recording this interesting restoration! Regards, Matthew.

Just a quick word of encouragement! I know it's nice to know there are people out there following on! Thank you for this great thread!! Regards, Matthew.

It is perfectly feasible to drill square holes using a rotary broach. The attached video is for drilling hex holes, but a square, hole is done using a square tool! Something went wrong... Regards Matthew

Steve, I don't know whether or not I'll get across the channel for the next Brighton run, I hope so! Thanks again, Matthew

I don't have much to say apart from how much I enjoy and apreciate your rebuild and the associated thread. Thank you for making all this available. Thanks again, reegards, Matthew

I don't think there would be a strength problem, the Denis one seems to work. How about a crash test to see! ;-} Regards, Matthew

It's nice to see your back at! looking forward to the Thorny rebuild Regards, Matthew

Nice to see you back at it! I've never seen cast Iron pistons before, all that mass flying backwards and forwards, the mind boggles! Enjoying the progress as always, Regards, Matthew

I would go so far as to say the look like they've been made of old cotton reinforced tyres! Regards, Matthew.

Hi, The whole thing will become clear when there are holes drilled in leather. The washers go on the leather so that The two forks will be coupled by the leather. Six holes in the leather will be bolted to one of the six holes in the two forks, the forks won't touch each other. Give me a shout if I'm not clear! Regards, Matthew

I'd be very keen to see all the bits cleaned up. It may be there shims to take out between theouter screw casings. Regards, Matthew

Using the whitemetal approach, I would start y looking at the actual wear. If your good enough with the lath to take the wear out then your in. Have you done a file test on the thread? When making leadscrews for a lathe, you use an unworn part of the lead screw. It would be possible to turn up a dummy shaft. Youtube film on making babit. Is there a "split line? Babit is usually poured with shims toi to allow for adjustment. Regards, Matthew

Notice the big “silver” spots on the steering nut shell. They are of white metal and the whole of the big thread inside the shell is white metal. Goodness knows how this is done but there are “ silver spots” like this on the four sides of the shell. Presumably the white metal is poured in through these holes and the outside of the casing is then cleaned up afterwards. But how is the thread inside made? The threads would "smoked" with lamp black (acetylene torch burning without Oxygen, or a candle) to stop the white metal sticking. Dams would be made to stop the babbit leaking out and they would be poured in the same way as a smooth babbit bearing. This is a method that is sometimes used to refurbish worn half nuts on old lathes. Regards, Matthew

I agree with David about the cause. I would be very surprised if it is hardened steel. It's after all running in a warm environment! I'm not sure that adding a ring and tacking it on isn't just putting a weakening ring of welds further out. I would suggest, if it "passes" the file test for steel, to avoid deformation, either heat up the whole thing before welding, or weld short lengths and let it cool between welds. You have nice weed burner and I seem to remember a forge! I think, a good weld repair would be sufficient for your uses! Just don't blame me if it breaks! Regards, Matthew

Side valve engines have a short valve train therefore 12 thou would seem reasonable as an engine hot clearance. I doubt there is much overlap on this engine, and it won't be too sensitive to valve timing. Try it and see! Regards, Matthew

I just thought I'd point out in passing that a star is in fact an easy punch to make, a drill dimple in the middle and filed grooves around the outside, temper and it's done. Regards, Matthew

Great, I always look forward to new pictures! Regards, Matthew

I was wondering if the governor wasn't used in convoys? I am assuming that these are governors that can be set to a specific engine speed, not only over-speed. Did these vehicles have power take-offs? I used to own an old Fordson Major tractor, the accelerator set a given speed and after that it would try to maintain that speed. I have a feeling that the Thornycroft would be more like a tractor than a lorry! Regards, Matthew

The get you out of trouble method that I was taught was to set the N°1 piston to TDC using a dial gauge, measuring from say 10 thou below, going past TDC (top dead centre) to 10 thou below and dividing the distance between the two on the fly wheel. Working without the pistons, with the engine up side down, (bearing in mind that it's a fixed head!)N°2 journal at BDC (Bottom dead centre) might be easier. Find a convenient place to mark the flywheel for future reference. When N°1 is at TDC, the valves on N°4 cylinder should be "on the rock", the point where the inlet valve is opening and the exhaust valve is closing. With the valves in place, with the correct tappet clearances at the point where the cams just start to touch or come of the followers should be right! It's easier with a single cam shaft engine! My method should be sufficiently close to get the teeth into mesh. If the cams have no adjustment on the cam shaft, this method should be spot on. The Cams being marked in degrees could have been that when the engine was first set up, they had a selection of pinions to fine set the timing. Regards, Matthew