How To: Restoration of Ford M8 armoured car US Ordnance number 7373

[Big D]

Hi all,

I am still waiting for the axles to be done which is getting quite frustrating now. If it is going to be too much longer, I’m inclined to go in and pick them up and do them myself now that my hand is right.

As well as doing a few odd jobs on the M8, most of my time over the last week has been spent stripping the three engine blocks. All three blocks are pretty tired with quite a bit of pitting on the tops of the block in and around the valve seats. The pistons and valves are all stuck so there is some work to break them all down. I’m not sure if any of the blocks will be up to the job but my aim is to get them all apart so that they can be assessed by someone with more knowledge than I have.

I have taken out the other two crankshafts that were still in the blocks. One crankshaft looks quite good and still had plenty of oil on the surfaces, but the other two will need some tidying up. I’ve had the pistons soaking with penetrant for some months in these blocks and now that I have all the crankshafts out, I’ve started the process of giving the pistons a good smack with a big hammer and a solid piece of wood shaped to fit in the bore. Out of the 18 pistons in the three blocks I’m working on, 1 piston has moved about 10mm so as I expected, this is going to be a long process.

As you can see, the tops of a number of the pistons are actually so badly pitted they can’t be saved so I am experimenting with another method of removal recommended to me. This involves drilling the top of the piston with the aim of breaking up the piston and or getting to the rings. I have plenty of valves and pistons and these are easily obtained, but good bores are not, so if I can get the pistons out and save the bores and rods it maybe worth a go. I’ve been told an air chisel is the way to do this but I don’t have that so I will progress with a drill and die grinder and see how that goes. I need to get penterant into the rings which will be what is sticking in the bore.

I’ve tidied up the bellhousing, engine mounts and timing cover along with a few other parts in preparation for a rebuild. It took me a couple of go’s to get the paint to my liking. I think it looks pretty close now.

For Oz and others rebuilding Hercules JXD engines, one of the photos shows the two seals for each end of the block. One seal has the unique rubber ring that goes around the seal in the block. I got these from Linda and Jerry at Hercules Parts, along with some other engine parts.

That's it for this week.