Miata 1.8 block
 

I have read that all 1.8 blocks are all the same. mabie someone can tell me more . I dont know alot about this platform.

I have a 99 NB1. That i want to rebuild the bottom end for boost and do it the right way.

My question.

I have read that all 1.8 blocks are the same. What year would be best to swap Everything from my 99 including the head/alt/starter/manfold/wiring ect..... the whole works will bolt right up according to my knowledge?
Are the cranks the same in all 1.8s? I know the Comp changes but that wont matter due to forged internals.
What year block do you recommend. Is it worth just finding a 99 block. I cant find any in my local area at all

Thanks

If you are building for a turbo, get an early 1.8 block with the threaded boss for oil feed.

I know that will work. But was do i have to change? Nothing? Dont have to worry about sensors fitting or anything along those lines? Crank P Sensor different location?
As long as i have the the NB1 accessories i should be good?Nothing will change? What year had the oil feed? 94-96? Wont have to tap anything?

Thrust bearing surfaces on the block are machined differently between NA and NB 1.8 blocks. Not a significant performance difference but you need to know what you have so you can use the correct thrust bearing. All miata 1.8 cranks are interchangeable.

94-95 and MSM blocks have the oil feed on the driver side of the block. It's 1/8 bspt if I remember correctly. I use a 1/8 bspt to -4an fitting there for my 95. If you don't have the hole there you have to source it from elsewhere, FM t's off of the oil pressure sender and runs a feed line around the back of the block. Some people here use a sandwich plate between the oil filter and the block and run a line from there. There are a couple other ways that people have gotten oil for turbo that may or may not work but I'll let you find those yourself. Looking for a 94-95 block just for the feed sounds like more trouble than its worth but if you can get one easily it is more convenient having the feed there. If you have a 99 block just run a line around the back. I think FM will sell just the feed for their kit that does just that for <70$.

Oil feed on the block is M10x1.5, oil pressure sender port is 1/8" BSPT

Crank sensor mount is on the oil pump, which I would presume you are at least getting an NB2 pump if not a Boundary pump for your build?

The thrust bearing width changed around the '00 model to combat the crank walk issue that the late 97's-99's had because a bad machining tolerance.

NB2 VVT blocks have MBSP, bigger thrust bearings, the oil pan is different and might have more motor mount points IIRC. Bigger oil pump, different oil feed thread size, BSPP instead of BSPT. If you use VVT the oil feed line is tapped for BSPT. If not, running an oil feed off BSPP would be fun.

Might just be because I've got three, but I wouldn't use anything other than a VVT block.