1.8 Rebuild Questions
 

I just bought my first Miata (97 1.8 5spd) and intend to use for spirited street driving, some autocross, and maybe someday some track days. This thing will never be a daily driver, so I'm not in hurry to rush through a build. I got, what I belive to be, a decent deal but the car is going to need some work before I can drive it. The previous owner believes he spun a bearing and as a result I'm probably in for a rebuild or engine swap. I'm bringing the car home on Saturday and will pull the engine and get it on a stand so I can disaasemble it and inspect the damage. I would have prefered to do chassis and suspension mods first, but since I don't have a working engine I'll need to address that first. So here's what I'd like to know:


1. What's the least expensive, sensible engine option? Rebuild or replace the engine with a salvage one? I'd like to have a driveable car to mod, as oppposed to one that spends all of it's time on jackstands. LOL


2. If I do the rebuild, can I get away with a hone (bore and/or line) if I really do have a spun bearing? If not, what machine work should I expect to do?


3. If I rebuild, I'd probably do Ebay rods, stock pistons, new rings, new bearings, and ARP fastners. Am I on the right track?


4. Is there a reputable machine shop near Chattanooga or Atlanta (I'm in NW Georgia) that knows Miatas? I'm a recent transplant from the midwest and I'm still figuring out where my "go to guys" are down here.


Sorry for the "noob" post. I've done some research, but wanted to get some advice before I start spending money.

There is a lot of info out there, so you have plenty of searching to do, but I'll summarize:

1. least expensive is finding a used engine from a reputable seller. Avoid anything over 120k-ish miles, any rusty/corroded engines, and make sure they come with good compression numbers. Miatas aren't high comp, so as long as they're +/-5ish psi from each other in the 170-190 range, you're good. Get any 94-05 that meets this criteria, as you can make it work with your '97 ecu with some changes. Ideally you get a 99-00, since they're MUCH better than any 94-97. 01-05 (VVT) is higher comp, and you can just leave the VVT uncontrolled, or eventually buy a standalone ECU or VVTuner to control it. Clean the egine, replace the rear main seal, front main seal, cam seals, valve cover gasket, and CAS o-ring, replace all rubber hoses, get an aluminum radiator, and change your oil with a quality oil consistently.

2. If you rebuild, you'll need to possibly replace the head, definitely the oil/water cooler, oil pump, and at the very least grind the crank for over sized bearings. ANYTHING that touches oil needs a really good cleaning, including all passages, jets, and all galley plugs need to be removed. If a piece of the old bearing is left, it'll get back to the new bearings, chew them up, and repeat the process.

3. That's a perfect plan, although personally Manley rods are name brand and not that expensive. I've had good luck with them out of the box, where as last I heard Ebay rods required a little machining.

4. can't help you there.