Short Block Assembly Continued

New rings, this along with the double roller timing set were the only upgrades to this Z390. Rock Auto just happened to have a clearance on these Moly rings.... so why not.

Checking the ring gaps per instructions.

Using the piston to square up the ring in the bore.

I set the feeler gauge to a couple thousandths more than the minimum limit and just used it a go-no-go gauge.

So I took apart each piston assembly, degreased, walnut blasted, then scraped the carbon out of the ring lands, then did a final rinse. This was tedious.

New rod bearings.

Dry bearing clearance.

Well within limits.

Takes about 45 minutes per piston for all that. Only 7 more to go.

All the connecting rod bearings are hammered like this. This is the 2nd FE I'd had with lead on the valves and it was a detonation monster. I'd wager a large sum the Y390 currently in the golden XL is the same way, so that would make 3.

So far so good, tis a V4 now.

All 8 piston assemblies installed and everything in tolerance. For a DIY home refresh it feels like a properly rebuild engine as the drag from the rings is very noticeable, even on worn bores.

Taped up and in the paint booth.

No ugly shades of Ford blue will be on this one.

Note 1:

On the cylinders there was taper, so I straight stoned hone them till the taper was under 0.005". Of course that meant opening up the bottom of the cylinder by removing material. Each cylinder is around 0.008" oversize now. Once that was done, I used a ball hone to finish them off in 320 grit for the moly rings I bought. Actually Rock Auto had a clearance on them and they were the cheapest in standard size.

For a temporary engine I think it should be alright. The heads came out factory fresh, the only thing really is the worn cylinders and I don't think 0.008" is detrimental. The crankshaft came out pretty good, the pistons are a bit beat up from detonation but that should cease with the new clean valves. Otherwise with new bearings, cam, lifters, oil pump, etc it should last a while. Besides when this engine gets replaced eventually, this will sit in one of the parts cars and probably never run again.

Note 2:

nothing would make me happier than not to have done this at all and toss this old engine. But I need an FE that runs for my golden '68 XL. Otherwise, might as well scrap the golden XL as well as it's currently useless. It will be a long while before parts, a machine shop I can trust and funds become available to build a proper 390 like I did for the two 1966's.

At least this old Z390 turd will work and if it consumes a bit of oil and has some extra blowby that's fine at least the golden XL can be enjoyed and driven for a while. Anything is better than the current Y390 that's in there now. When I have a proper 390 engine built for this golden XL I'd be happy to toss this Z390, but because we are so remote it's actually far less work just to stick it in a parts car and leave the parts car parked in one of the garages for most likely perpetuity.