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Like your plan, I always 'dry-crank' the engine prior to starting it after a re-build ---plugs out, 'king' lead disconnected from the coil, ignition on and crank until the oil-pressure warning light goes out. If your engine is still on the work-bench, may I suggest that you remove the timing cover and the top cover of the oil-pump and then pack the oil-pump with 'Vaseline' (petroleum jelly)--NOT grease, which will not be absorbed into the oil, whereas the Vaseline will. This will give the pump something to initially 'suck on' and bring the oil-pressure up quicker.
No disrespect to Tom, (the hobbler)(for whom I have the greatest of :worship: :worship
but I don't think I would disturb the timing cover on your professionally rebuilt engine.
If you watch old videos of engines being assembled in car factories, it's amazing how little lube is applied during assembly, they just seem to quickly throw them together, fill the sump with oil and towards the end of the assembly line, fire them up (I've never seen factory oil pumps being filled with petroleum jelly but have seen it being recommended in aftermarket workshop manuals e.g. Haynes).
With the coil lead disconnected (i.e. ignition system disabled) there is little load on the crank bearings or the piston skirts, so minimal risk of any damage being caused by spinning the engine over to prime oilways and build up oil pressure - assuming a little oil was applied to these areas during the assembly. I know some time has passed since your engine was built, but the oil applied won't have disappeared.
If I was concerned, I'd remove the oil pressure warning light sender unit (oil pressure switch on the main oil gallery on the side of the engine/crankcase) and use one of these 'oil suction guns' :-
https://www.drapertools.com/product/47812 (NOTE:- Similar suction guns are available from other sources at much lower prices, possibly circa £10)
filled with engine oil and a suitable adaptor to inject oil under a little pressure, thus priming the oil galleries, crank bearings, oil pump, centrifugal oil filter, camshaft bearings, rocker gear etc.
A suitable adaptor might be available from an industrial plumbing supply company/ commercial/truck motor factors/ or as part of a kit of adaptors supplied with an automotive oil pressure test gauge. (bring the oil pressure sender unit with you to get one with the correct thread size/pitch). Or make your own - remove the innards from an old sender unit, fit a metal pipe (sized to suit the plastic pipe of the oil suction gun) using soldering/epoxy resin. Or maybe you could just have someone hold the plastic tube firmly against the sender unit hole in the crankcase and inject some oil, (if the plastic tube fits into the crankcase hole, fit a washer and 'O' ring over the tube, applying pressure to the washer will cause the 'O' ring to form a good seal).
The above 'oil suction gun' can do both suction and pressure. It's a very useful tool to have - can be used to fill gearboxes, flush solvent through oilways, drain brake fluid from fluid reservoirs etc. lots of uses.
Talking of gearboxes - if fitting the engine and gearbox as one unit (much easier), just support the combined unit front and rear at a suitable height on some timber blocks, then roll the car back over the power unit. By leaving a space between the wood supports, you can roll a trolley jack in from the side to do the final raising of the power unit. The rear panel can be easily fitted to support the engine, you can then reach in under (if you have longish arms)(without jacking up the car) to fit the bolts that secure the gearbox support cradle if you have everything lined up.
Great attention to detail. I'm most impressed. :worship::worship:
But.....
I haven't seen any mention of any rust-proofing having been applied. :devil:
Before any trim is installed, is an ideal opportunity to spray something suitable (Waxoyl or your preference) in all box sections ,on the reverse-side of all the window/screen openings, up inside doors, engine lid/bonnet frames - anywhere you don't want rust to start/get worse (there's probably some hiding right now in some of the hidden sections :bang: ).
Tip:- some of these rust-proofing products stink (and will continue to stink for a very long time, including fragrancing your garage....) so you might consider adding a few drops of some nice fragrance/essential oil? to your chosen treatment before application. (many such treatments can continue to drip from drain holes for some time afterwards, so take appropriate action to protect your garage floor/driveway).
Hth,
Al.