Here's my situation; I replaced my original 222k mi 13b from the -SE last year and put in a lower mileage untouched -SE engine from the same year. That engine is now running really well (have 227k mi on the car now) and I'm just enjoying driving it.

The original engine that I pulled out of the car is now bolted to my engine stand and in a position to take it apart for a rebuild. Eventually, I'd like to put a mildly tuned and rebuilt 13b in the -SE with maybe some porting (stock RE-EGI and EFI will remain), but was wondering if it's better if I wait until the engine that's in it now starts to show signs of losing compression then pull it, disassemble both engines and pick the best parts from what I've got to do the rebuild. At least with this method, I'm using the best parts from 2 engines for the motor that will eventually go back in the car and stay there for the foreseeable future. I've owned this car 20+ yrs, my dad bought it new from the stealership before he sold it to me, and I took my driving test in this car - so it's not leaving my sight.

Alternately, if I rebuild the original engine now while I have the parts from only one engine to work with, it will sit on the engine stand in the corner of my garage until it's needed. I don't mind keeping a spare engine around, but wanted to get the forum's thoughts on the best approach to rebuilding, based on having 2 engines at my disposal. As an aside, the original was pulled due to loss of compression on both rotors and wouldn't hot-start, had to be pull-started to run, but once running, ran well. This leads me to believe it's probably just the oil control rings or side seals badly worn, as it drank a lot of oil before I replaced it.

Current engine (now in the car): http://oi65.tinypic.com/2n0sc9d.jpg

As always, I appreciate the opinions of those of you who've rebuilt these amazing little engines,

 

It depends on how you feel about downtime on the car. If you don't rebuild the original now and wait until you pull the other one when it needs it, then you car will be down for whatever time it takes to pull the engine, disassemble it and get the rebuild complete. Personally, I would go this route in your situation. If you rebuild the original now, you will have to make sure its lubed, sealed up good, and gets monthly rotations done to keep it fresh. Plus you won't really know if the build is good until you finally swap it in.

 

I'd pull the original engine apart now. Take a look at your parts and decide what you want to keep or not. Slather all the bare metal pieces with a bit of grease (to keep them from corrosion) and store the individual pieces in a bin.

Then when your engine in the car kicks the bucket you have everything (or at least most) ready for assembly. And assembly takes all of 20min.

But you might get lucky and find that your original engine only needed soft seals and apex seals; housings, and rotors are fine. In that case assemble your original engine with new parts and keep it lubed till needed. (like Tim said)

 

This one.

 

Yeah pull it apart already, I got a new engine once and I waited until like 8 months to take apart my old engine and a lot of the parts where corroded.

 

Thanks, guys. Living in the Sonoran desert, we don't see much corrosion, and I drained this engine of everything and sprayed in MMO before storing it. I'll plan to get it apart and go from there. Thanks for the opinions,