andypugh

I am guessing it is too complete and not enough of a challenge for your team?

I am more confused about why the spark plugs are located almost randomly on the head. With the larger engines it was common to have a trembler coil ignition and a mageneto, with the trembler for starting and the magneto for running. There is just no way to crank a 9 litre engine fast enough for a magneto to kick-in. So you pull the engine over TDC a few times to fill the cylinders with mixture, and then turn on the trembler. With any luck the engine will kick round a few turns fast enough for the magneto to start working, at which point you can turn off the trembler. Here is asciidv using the same idea to start an engine which doesn't have a trembler.

I see conflict in the future where your "Got to collect them all" on White and Poppe runs up against Barry's "got to collect them all" with fire engines.

The remaining metal is probably a bigger diameter than you would find on a modern valve. though I still don't think I would risk it.

Looks pretty good to me. I wonder if you could metal-spray it with aluminium to make it look like solid metal again?

http://www.bodgesoc.org/thread_dia_pitch.html Says none of the standards there. So, another "Special". Maybe there was a reason to enforce a specific nut design in that position? Is the seating area particularly small, for example?

Not to be confused with the similar German “Panzergewinde” https://en.m.wikipedia.org/wiki/Panzergewinde

That looks close to M8 again, you know.

If you try to interlock the original and the M8 thread do they fit? 25tpi is starting to look like a possibility. I think that the fact it goes in as far as it does implies a pitch error rather than a profile difference (eg ISO v SI or NF v NFJ) 25.7 TPI (0.99mm) pitch Holtzapfel thread? you have the nut, so hete is how to measure the pitch very accurately: Run the nut dow to near the head and mark one flat. Measure the gap with a calliper and zero it (or note the reading ) run the thread down 20 turns or more, using the marked flat to ensure an exact number. Measure the head to nut gap again, divide by the number of turns. I have a CNC lathe. I can make _any_ pitch of thread. Even if it turns out to be an 80DP thread (25.46479089470325TPI)

The engine was designed in metric, but they were aware that UK mechanics only had imperial spanners.

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.

One way to repair pinholes that pretty much can't fail is to rivet in aluminium rivets. It's not the neatest or tidiest, but it is easier to reverse than some other ideas. AC Mig seems like it ought to work, though I seem to recall it's been tried, and failed, on Dennis castings.

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.

You typically have a lever with 20 degrees of timing adjustment in that period. So, no, the mechanical timing wasn't critical at all considering what the driver could do.

I think I would try a couple of turns of self-amalgamating tape tight around the stub before fitting the hose. It might not work, or it might prove impossible to fit the hose over the top, but it's quick to try and then quick and clean to un-try if its a failure.

Could it be a steam charabanc? I don't know how you would tell from a photo. The White steam cars look exactly like IC engined vehicles.

Cartainly similarities, http://www.kfzderwehrmacht.de/Homepage_english/Motor_Vehicles/Germany/NAG/NAG_KL8/nag_kl8.html except that it seems to be flat at the bottom. A not-exhaustive search of the round-radiator marques mentioned here didn't turn up anything definitive for me: https://www.prewarcar.com/round-radiators-revisited

I was just reminded of this machine. How is it going?

It is very odd that the windings are missing. If they had been taken for scrap then I would not expect the set to be re-assembled. There is a fair chance that my flywheel magneto remagnetiser can refresh the magnets, if there are any.

An alternative for filling rust-pits is knifing putty. I think it is really intended for scratches, but it works OK for pitting and can be used straight out of the tube without mixing. It's more like a very thick paint than a hard-setting filler. It is one of those things that has many names, knifing putty, stopper, glazing putty (and that last one can really cause confusion...) You can get Holts Cataloy from Halfords, though I have a huge tube of something else picked up at an autojumble that seems rather better.

It looks like a weakness caused by the number 9!

It looks to be right-hand drive too. (unless that is a passenger-operated horn)

Modern Technology makes it possible to fit a replacement condensor inside the points housing. http://www.brightsparkmagnetos.com/easycap/index.htm

Are the front wheels the same size? (I know one has a tyre and one doesn't, but the left wheel also looks bigger)

Never skimp on anything that comes between you and the ground. That includes shoes, beds, sofas and tyres. But not, you will notice, cookers. Incidentally, when cooker-shopping you might want to consider those that offer pyrolytic cleaning, the higher temperature is likely to be more useful for tempering and annealing parts.