I finally got around to removing the engine from the crapcan miata this weekend, and despite the heat, everything went really smoothly. No stuck connectors, fluids all looked decent, and I ended the day with no seized or broken fasteners! I did however notice something this morning as I was leaving for work. I’ll try to convey my discovery process in pictures.

That’s a short nose crank 1.6... which is prone to breaking the crankshaft keyway and was replaced with a much better design in mid 1991 (the “big nose crank” version)... and it just came out of my ‘93.

Advertisement

Despite spending hours working on it, and probably looking half mindedly at the pulley a couple dozen times, it never actually clicked until this morning as I was heading out. I thought “That’s weird, shouldn’t that pulley have 8 slots?” Turns out, yes, that pulley should absolutely have 8 slots if it were actually a 93 engine. For those who don’t know there is a great technical article that goes over the issue here

http://www.miata.net/garage/cranksh…

But long story short, this

Is good

This...

Is not

So now the decision I’m left with is to either fix the oil pan leak, reinstall the engine, and bury my head in the sand on this issue... or dig deeper hoping that I have an updated “long nose crank” or that the damage isn’t too bad to attempt the “loctite fix”. In either case, I’ll probably be running it without A/C or power steering connected to lower the bending forces on the crank pulley as much as possible.

Any Miata experts on here that have dealt with the issue?