latelifecrisis

I've decided to take B serious's advice and purchase a used complete motor to resurrect my 2007 S2000.

I looked into this 2007 motor carefully:
https://www.ebay.com/itm/29486792519...is&media=EMAIL
I've looked into what are acceptable leakdown numbers (this engine: 8, 10, 10 & 6%) and these seem decent, but not great. I ran the VIN and I've attached the report. The engine is from a stolen car, it was driven by thieve(s) for over 2 months with final mileage unknown. Stated mileage on ebay listing is 92,650 which was the mileage 8 months before the car was recovered. On the plus side, it's a DBW AP2 engine so plug and play with my car.

The other engine I'm considering (strongly) is this one:
https://www.ebay.com/itm/11550869605...is&media=EMAIL
Positives: Documented 68k miles before car was totaled in a collision (per a carfax report I ran). Stated 240 psi compression test on all four cylinders.
Negatives: No exhaust manifold, clutch or flywheel, 2005 engine with throttle cable, more expensive (by about $650 including shipping) than other contender ap2 motors from taeusedautoparts813
I would plan to use my existing 2007 engine exhaust manifold on this motor, a lightened ACT flywheel, OEM clutch disk, OEM T/O bearing and OEM pilot bearing from my bad engine all with under 900 miles. I would buy a new OEM pressure plate for $250 from another ebay seller.

Per this previous s2ki post, it looks pretty straightforward for me to swap out my 2007 intake manifold and the other listed required changes to use this 2005 engine in my 2007 car with parts from my 2007 engine.
https://www.s2ki.com/forums/s2000-un...8-car-1114947/
I would plan to tap and plug my intake manifold to avoid exhaust gases escaping from intake manifold per post #10. With my current engine dissambled, it shouldn't be too hard to make the required changes.
Do I need to swap my 2007 wiring harness onto this 2005 motor or can I reuse the 2005 wiring harness?

I'm interested in what you all think. My ultimate goal is to restore this car to stock condition (with maybe my CAI), but never to run it FI. I'd like to get 50k relatively trouble free miles out of the engine/car.

First, how good/acceptable are the leakdown numbers for the 2007 engine? I assume they are done with the engine cold.
Second, 240 psi seems to be the new condition compression test numbers for the AP2 engine. Can I trust that these numbers are real from this ebay vendor (with near perfect feedback)?
Third, if these compression numbers are indeed legit, do they indicate with a high degree of confidence that the engine has rings and valves that seal well in lieu of leakdown numbers?
Finally, I'm I making a mistake by trying to buy a throttle wire engine and convert it to DBW?

Thanks to date for all of the constructive forum feedback I've received on this journey from B serious, Slow_Crash101, Jub and others on this long and ardous journey to bring my S2000 back to life.

B serious

You want your 2007 harness.

One plain difference is the throttle body wiring that doesn't exist on the MY05. There are quite a few not so plain ones too.

These engines don't tend to lose much/any compression over 100K miles, if they're just driven normally, with good maintenance. That's one of the advantages of an FRM wall and low friction pistons/rings, etc.

The leakdown numbers from the DBW engine are good...not stellar. But quite good. Yes, it would have been done with the engine cold. I do share your sentiment regarding the thieves. Presumably, they did some joyriding. But they wouldn't have done so much that it would damage the engine...since its worth money (assuming they planned to use/sell the parts from the stolen car).

Or maybe it was totaled due to theft of the seats/other parts...and never actually stolen. That's best case scenario. Because only a pleb would let the insurance take their seat theft S2000 in this day and age.

Jub

If changing the stuff on the engine isn't a big deal to you, I'm partial to the 05 engine. I'm also familiar with ordering from Lee C. Parts and feel they're a trustworthy business. I've called them up to ask about specific condition of parts but nothing major. If someone knowledgeable like Billman can 100% confirm what you need and you're fine with doing the work, that'd be my choice. It's roughly a 10% premium compared to the other. That being said, the leakdown on #1 doesn't look bad. 10% is not great but it's certainly ok.

Compression gauges vary. My 06 with a refreshed head read 255/260/265/255 warm after having the head replaced. I bought a Bosch gauge thinking it'd be greatly calibrated but that is oddly high based on most readings. I think my gauge just reads high. I'd compare to what other engines are reading from the same vendor. Lee C Parts has an 04 block listed with 126k miles @195/175/230/190. I'm assuming they're using the same gauge. Therefore, the engine you listed is significantly more healthy than that engine. Generally, I'm suspicious of anything under 210 but gauges do vary. If all cylinders are in the same range (spec is within 28 psi), typically things are all good. The more variance, the less you assume it to be different gauge calibration and start looking for issues.

latelifecrisis

Just bought the 2005 motor listed above. I've read what's required to use the throttle cable AP2 engine in my DBW car and I'm confident I can do it. Assuming I'm right, having an engine in what looks to be great shape will make it worth this long journey. The (re)resurrection begins (again)...

Slowcrash_101

You can always part out stuff from your old motor.

latelifecrisis

I've already begun...

Save the Manual Wagons!

Shirley there must be someone in the US that can competently rebuild a Honda F engine? You're the person who installed a new OEM engine that quickly blew up, yes? After all that, putting in a random used engine seems like setting yourself up for even more disappointment...

My junky NB Miata is on its third engine (all were installed before I bought the car, so no idea where they came from). That engine burns a lot of oil and has low compression in #4. If I ever get around to putting a fourth engine in that car, it's going to be one I build myself or one built + installed from a shop that will guarantee their work.

B serious

Used longblocks are the most numerically successful option.

Rebuilt engines are among the least likely options for long term use. OP already tried. Remember?

This isn't the same as a Miata engine. I could put a Miata engine together in a room full of swarming bees and it would be fine.

F series were hand built. Bearings, bores, etc are all sized per engine. Factory built ones are generally bulletproof unless someone does something stupid while the engine is in use (save for the 06+ engines that were discovered to have thrust bearing install issues).

I'm sure there's a handful of people who can rebuild them. Idk where or who they are. Rebuilding also depends on the base you start with.

latelifecrisis

Yeah, I'm the one. If an OEM new short block self destructs in 900 miles, I'm not buying another one. Have you looked at the tolerances for rebuilding a short block in the SM? Some are less than .001". I searched carefully to avoid a "random used engine". The one I bought has under 70k miles (documented by Carfax report) and 250 psi compression on all four cylinders. Nothing is guaranteed, but this is a far from random purchase. Wish me well...

Save the Manual Wagons!

You could buy another one and have Honda install it, with a stock clutch, and get a warranty in writing. Anyway, I understand how you feel.

I wish you all the best, seriously. Going though two engines in such rapid succession must be depressing.