What bolt is the right bolt.
 

Been about 6 months about time to do some work on the MSM build.
Putting a 949 twin disk on the built 1.8 and over the years I have put many of the parts in very safe places, that I can no longer find.
Question is what is the right bolt for a 1.8 miata flywheel and does it use a washer or not. The longer ones have no washers and the shorter ones have washers, No idea what Miata they came from.
Thanks!

https://cimg4.ibsrv.net/gimg/www.mia...286cd0274c.jpg
https://cimg5.ibsrv.net/gimg/www.mia...fb71183301.jpg

After some research the short ones came from a 1.8 Auto car..

it is the short one

You can tell it is the long one because it has a shank or shoulder to locate the flywheel precisely.

In a sample size of a grand total of three sets of flywheels I've pulled, they've all looked like the shorter one. These were from manual cars too.

Though I think sonofthehill has more flywheel pulls under his belt than I do, so YMMV

When in doubt, the basic bolt requirement is engagement depth should be min. of 1 1/2 the bolt's shank size; as in a 1/2 bolt needs to be threaded in at least 3/4in. Subtract for the flywheel bolt area's thickness, and see if you have enough depth.

I'll go ahead and start the debate by saying flywheels are hubcentric not lugcentric. Fairly certain the flimsy piece of metal auto owners call a flex plate uses the shorter bolts, thicker manual flywheel uses the longer ones. I will say that I'm fairly certain I've used them (a full set) interchangeably.

Fair enough. However the bolt shanks could be used to index the flywheel for say, timing marks, if our cars did that sort of thing, which they don't.
So how about this, I would much rather have 6 of those partially threaded bolts holding my flywheel on. I would ditch the ones that are threaded all the way to the head. :dunno:
Curly definitely has about a billion more flywheels under his belt than I do.

Yes the longer ones are for a flywheel and shorter are for flexplate. Looking sexy now.