Well, if your not going to change the balance shaft bearings, there's no need to pull them really, but if you do (to clean the block up good) just leave the gears on them, that will tell you which goes where. I'm not putting new BS bearings in this one.....the engine sounded fine, had lots of power and was quiet running....just had water in the oil, so I think it will be just fine for what we're going to use it for.
Get some micrometers and measure everything to see what you've got, and go from there......this one is not bad at all....I'll post all the clearances on it as I have it all recorded in a notebook as I'm putting it together.
The biggest wear area is the ring end gaps......when you use the new rings in the worn bores, just the slightest amount of cylinder wall wear will increase the ring end gap quickly, but it's not that bad really. You'll lose a couple of points/PSI in compression......maybe 3-4 PSI at the most compared to if they were right on where they should be, but it won't smoke nor use any oil.......I've done this too many times, and they work perfectly and last another 100,000 miles to boot.
Look at the top of your cylinders, where the upper compression ring reaches the top of it's stroke, if you have a noticeable ridge there, then you will want to have it bored and buy new pistons to match. It's my experience that these Mazda blocks are damn good metal and they don't wear like some other blocks will.
Here's a few more pics!
Checking the oil clearance on the mains.
Getting ready to drop the crank in.
Got the mains torqued down and checking the crank end play.
It was .006" so all is good there......should be .0031" to .0071 if I remember correctly.
And no, it didn't go all the way around to .094"......I just set it up where it was zeroed at the forward most position and then shifted the crank to the rear most position.
MMMMMM Beer!
And just like that......all the pistons were in!
I was explaining to my buddy and he was helping me install the pistons and I forgot to stop and take pics! Plus we were getting hungry and trying to get it done so we could go across the street to the pub for a big ole hamburger and a couple more BEERS!
And we were using.......