Swap vs rebuild
 

So my rings on my 95 just gave way with in a week of running turbo, now do I A. Pull the motor, machine everything, , maybe even do rods and some other "insurance" mods, or B. Switch to a bp4w, I would go vvti but I don't want to upgrade my ms just yet. What would be the most cost effective way to reach the 250 whp before other components become reliable to break. This will be my first engine rebuild on a Miata. I know a lot of things will need to be replaced from just pulling the motor, I am prepared to spend the $ and shell out the time. I'm not expecting spoon feeding, I know this is the wrong forum for that but what are some pros and cons about both

Swap = unknown
Rebuild = known

If you are willing to spend just rebuild. If you want a quick fix search for a cheap motor.

He pretty much summed it up. Buy a trackspeed bottom end and enjoy life.

I'm biased, but yeah, I agree with this. :)

I'm not ready to say anything for sure, but we've made some changes to our engine program that will substantially reduce our leadtimes on our "standard" turbo-spec bottom end. I'll reveal more in an official announcement when it's nailed down.

whatever you do, fix what you did to blow the first so it doesnt happen to the second as well in another week.

As much as I thought it was me, I think this car was left sitting for a long period of time and wasn't maintained. Like I said before, compression tests before turbo was good not great, I guess we will see when I pull it apart. It was only running 8 psi on a retarded timing map, with det can headphones, and ve analyze going.

Retarded timing maps melt things. No?

I guess they do, but also I do remember getting some wiffs of gasoline doing my last NA oil change. I'm sure my retarded map didn't help

I bought a 2000 1.8 a few years back that had 78,000 miles on it and a blown head gasket. A few months ago I finally cleaned it up, measured the clearances, honed it and put new rings in it. I'm going to be listing it for sale soon...interested?

What's the car doing? Why do you think it's the rings? You can break anything, but these motors are pretty solid.

I've beat the crap out of several sets of "mystery" stock pistons/rings with a lot of miles on them, for a long time, and done pretty much everything wrong and never gotten more than a little blue puff when I lift. It'd be a shame to tear down a motor over some simple, cheap issue, especially if you just made some major changes that could potentially be what's causing the problem.

Last two cylinders 140 psi, oil poured in, 175 psi

Forgot to mention...it will be a short block that I'll have for sale. Which is. 9.5:1 compression.
If you do choose to rebuild your own motor, I highly recommend it just for the learning experience. It's fun too.

So i can still drive the car, and I will, come maybe next week when I have to do the clutch. I'll pull my engine and trans, pull head, remove oil pan, punch pistons up from bottom, diy hone, and re assemble. Estimated time with 2 people? And any objections to this?

Better not make any plans at all next weekend...

Got all week :dealwithit:
So entire engine gasket kit, piston rings, motor mounts? And timing belt and water pump?
Should the head have anything done to it?

Oil Pan gasket maker...valve seals. Torque everything correctly. Use a stone hone not a ball hone. Watch a YouTube video about honing. Don't stay in it too long, just enough to make the appropriate angle of the cross hatch marks. Pull the oil squirters, cause if you hit em with the hone...bye bye stones.
Hope that helps. Just my 2 cents.

nissan sr20
 

Is the sr a viable swap for the miata

Yes. Do it.

Yeah the BP (miata motor) is actually a shortened version of the SR. The SR bolts right up to the motor mounts/tranny/etc,