andypugh

I am surprised you are not suggesting machining from solid with some extreme thread cutting on a Myford :-)

I have always found Lee Spring to be helpful. They advertise that they make custom springs. I got a wave spring from them, they insisted on sending a sample, and when I pointed out that I would only ever need one, they said that was fine. I assume from what you say that you have tried putting your parameters in their spring finder? https://www.leespring.co.uk/uk_compression_spec.asp?springType=C&subType=H&forWhat=Search You could consider buying oversize and grinding down on a mandrel.

I would have no qualms putting that back in to service. Not that I am any kind of expert. But, what fraction of the bearing surface is missing? 2%?

Probably post WW1, but I just saw this on a Youtube video: https://youtu.be/MbIlBZmZ4Xs?t=333

Cast iron crank-case? I was surprised by that, so far I have only seen (or noticed the material of) Aluminium (Dennis, for example) or Bronze (FIAT) crank-cases of that period.

It seems likely that it could be made, though one might expect it to decompose again (200C, again according to Wikipedia) https://en.wikipedia.org/wiki/Phosgene And that would lead to the emission of CO and Cl, neither of which are particularly good for you either. Though all three gasses probably beat being on fire.

I think it's worse than that, the gas created is Phosgene. Though Wikipedia suggests that the direct toxicity (to the liver) is just as bad, and it's an ozone-depleting gas too.

All authentic features of a WW1 truck 🙂

My own opinion (and it is worth exactly what you paid for it) would be that if you have the early pistons then they should be kept precisely because of that. I doubt that oil consumption is a significant expense in the context in which you will be operating the vehicle.

I think that it is normal for the ring lands to taper a few thou (in steps). The area above the top ring runs a lot hotter than the skirt.

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?