Nakinto

Well I am fairly certain no water got into the crankcase because it all came out the other side of the engine as in radiator side I always do a run of 'used' oil as in I just let the oil flow in and flow right back out no engine running with some used but not BLACK oil. just golden brown then I do an oil change within 1000 miles and another 2k after.

That is what I did each Rotary rebuild not that the rotary ran 'well'... still need to fix her as soon as I got a grand I am gonna buy a new rear rotor and apex seals/springs again and see about another rebuild lolol

ezone

In my experience, draining the radiator alone doesn't get the block emptied to below the head gasket parting line on these. Coolant still comes out when I lift the head.

I prefer to drain the block either by pulling the actual block drain (PITA) or by pulling the water pump.

Even then, there are still coolant dribbles left that come out of the head when I pull it up.
Any dribbles of antifreeze on the deck surface means there's the possibility that it got into the crankcase through the drainback holes.

If there was coolant standing on top of the pistons when the head came off, then I can bet there's coolant that got into the crankcase too.

(I have also done them like, just pull the head up and let 'er splash, figuring I gotta change oil a couple times anyway....but now I'll take the extra time to drain the block.)

It only takes a trace of antifreeze in the oil to cause damage to engine bearings....and I don't know for sure how big the 'trace' would have to be, or how long it would have to run with traces in it to make damage known, but I really can't afford to find out.

If I know it got a lot of coolant in it, I drain and fill the crankcase before running, then change oil again (and filter this time) after it's warmed up. (If the block is drained first, I only change it after it's warmed up.)
No matter what: after it's warmed up the first time, it gets oil and filter changed at least once before it leaves.
I might write like 500 miles on the oil change sticker on the windshield too, so the owner brings it back.

Better safe than sorry, and oil is cheaper than another engine IMHO.

Used oil, that's a great idea since it's just going to be a flush, of sorts.

I'd put in fresh oil before returning it to a customer though.


I'd like to build/drive a SBC/LSx or SBF repower....An RX with gobs of torque would be an interesting ride...
We had a 1st gen RX7 running around my 'hood for a short while that was poorly done (scary dangerous looking up close), but it could roast tires at the blip of a throttle.

I know a 5.0 in a Miata is HELLA fun!