WWGRMD: Bad Verdict on my S2000

I has a sad.

Just spoke to the mechanic about the low compression on cyl 4 of my S2000. Things don't look good. I took it to a reputable local mechanic recommended from this board. Basically the engine would need to be torn down and rebuilt just to find the problem. Even if it's "only" a valve, that's more work than he wants to do and he's warning me that these are very complicated engines. Sounds like too big a job for me.

I'm looking for serious suggestions on what to do about this.

I could try to tackle the task of rebuilding the engine. This would be lowest cost, but highest labor.

I could try to source another used AP1 engine and swap that in. That would be about >$3000 + labor.

I could really go all in and get a team of guys to tackle an LSx swap. Although I love the idea of LSx Miatas, it feels a bit wrong to ditch the gem of an engine from the S2000.

I could say "berkeley it" and clear the engine codes and sell/trade it to a car dealership for... something... else. I don't know what I'd want to replace my wonderful S2000 with though.

Do you have someplace to take it apart? They're not any more complicated than an R63 engine and we know how easy that is.

Hmm. I just got a cheap borescope camera. We could try poking it in the #4 cylinder to see what we find.

If the motor is done I think you should either rebuild it or swap it for a used one. A crazy motor swap is cool but not if you're depending on the car and not if you're unable to spend a long time debugging it.

The s2000 is your only car right? I was going to suggest you could use my lift to swap the motor yourself but you'll want to take your time on that one so it might not be the best plan.

I am sorry to hear it.

In reply to dculberson:

S2000 is NOT my only car. I have a Chrysler minivan that I use as my winter beater/keg hauler. I am totally fine having this down for an extended period of time.

If you've got a borescope camera, that would be really great for figuring out how buggered things are. I can bring by growlers of beer as thanks.

Book time for r&r cylinder head is about 9 hours. I'm use to BMWs that are 20+ hours, so it doesn't seem like it's that horrible of a job. Of course you could pull the head and find it's something on the bottom end.

In reply to Beer Baron:

Best times for me are around 9pm weeknights or Sundays. Email me at my user name at gmail dot com. How hard is it to get to spark plugs on that? It won't take long once we have the plug out.

In reply to dculberson:

Sundays are pretty good for me. Spark plugs are easy to get to. Just a cover plate and coils on top. Will we actually be able to inspect the valves with the borescope? Or would we just be able to see if the piston is messed?

These engines are very similar to Honda K-series, and I know those are very popular with Honda tuners and enthusiasts. I used to be involved with a lot of Honda guys when preference just started shifting from the H-series to the K-series engines for swaps. People would build or have them built very frequently. Is the F20C that different from a K20 from a rebuilding perspective? I'd imagine there might be some additional cost for divergent parts, but someone familiar with Hondas and specifically the K- and later F-series engines should not find it to be a particularly complex job.

I don't know! I just got the camera a couple days ago. But it's tiny and has a mirror. It's possible we could get a glimpse at the valves with some creative use.

No way that we'd know less than we do now. We could at least determine if there was damage done to the pistons or cylinder walls. I figure if those are in good shape, that's a good sign this is only valve and seat. I doubt it's rings because I'm not seeing signs of the oil looking bad.

Do you want to keep it or not? If you want to keep it, you might pull the head first just for the hell of it. Then if it's not a top end issue, buy that three large motor and put it in.

Double_Wishbone wrote: These engines are very similar to Honda K-series, and I know those are very popular with Honda tuners and enthusiasts. I used to be involved with a lot of Honda guys when preference just started shifting from the H-series to the K-series engines for swaps. People would build or have them built very frequently. Is the F20C that different from a K20 from a rebuilding perspective? I'd imagine there might be some additional cost for divergent parts, but someone familiar with Hondas and specifically the K- and later F-series engines should not find it to be a particularly complex job.

I figured this wouldn't be too crazy of a job for a mechanic. Not sure how far I'd have to look to find one who specializes in fancy Honda engines. I have no idea how different the F series engine might be from the K series.

I found a service manual pdf online. The head removal is pages 6-25 through 6-31 (pp139-145). Doesn't actually look too crazy. Looks like most of the work is removing things from around the sides and front, like intake and exhaust manifolds. That's not overly technical. Where it starts getting into wholly new territory for me is what happens with the rocker arms and dealing with those when pulling the cams out. It also isn't clear if there's something weird or special I need to do for like VTEC solenoid stuff or anything when reassembling everything.

Dr. Hess wrote: Do you want to keep it or not? If you want to keep it, you might pull the head first just for the hell of it. Then if it's not a top end issue, buy that three large motor and put it in.

Yes. I would like to keep it. I really like this car. I can't think of anything I would like more that wouldn't be significantly more expensive.

If it's just the head it's really not too bad. Not that I've done it on this engine, but I've pulled apart a few Hondas and they're really well engineered for disassembly. Figure out it if you need any special tools first (probably for holding cams) and then tear into it.

Needs more diagnosis. Doesn't take a teardown quite yet. Try a leakdown test and see if you can isolate the source. Thought there had been issues with valves/valve springs on these. Borescope to check cylinder wall(s). Manually test valve action.

What I'm most intimidated and unsure about is: what happens with the rocker arms after pulling the cams off?

Looking at the manual... holy crap... do all the rocker arms come out as a single assembly along with the lower races for the cams? That looks really simple. Not having to keep track of 16 separate rocker arms and a special VTEC solenoid assembly that all need to be put back together just so.

I just downloaded and looked at the book and the rockers all come off as a unit. Cardboard organizers are your friend when taking off bolts of different lengths.

oldtin wrote: Needs more diagnosis. Doesn't take a teardown quite yet. Try a leakdown test and see if you can isolate the source. Thought there had been issues with valves/valve springs on these. Borescope to check cylinder wall(s). Manually test valve action.

I'll double check, but I'm pretty sure the mechanic said he did a leakdown and couldn't determine anything for certain. He figured it was unlikely to be the head gasket, couldn't say for certain about rings or valves.

How does one manually check the valve action?

I think I've also been reading about cracked valve seats being not uncommon on these.

It already doesn't work. It's not gonna not work anymore than it does already if you take a look inside. 'Scope it, if that's inconclusive, yank the head and go to work...

You'll feel better if you do, I promise.

sure he was a good mechanic? A leakdown test should tell you EVERYTHING you need to know about that cylinder. Lock the engine at TDC, run your compressor to the sparkplug hole and pressurize.

If you hear air leaking out the exhaust, it's one of those valves, same for the intake. Check the radiator for bubbles and pop the oilcap to listen for air there.

I cannot imagine an f22 (that's what those are, right?) Being any harder than an r63 motor.

Beer Baron wrote: I could really go all in and get a team of guys to tackle an LSx swap. Although I love the idea of LSx Miatas, it feels a bit wrong to ditch the gem of an engine from the S2000.

A gem of an engine would have compression in all its cylinders.

mad_machine wrote: sure he was a good mechanic? A leakdown test should tell you EVERYTHING you need to know about that cylinder. Lock the engine at TDC, run your compressor to the sparkplug hole and pressurize. If you hear air leaking out the exhaust, it's one of those valves, same for the intake. Check the radiator for bubbles and pop the oilcap to listen for air there.

This all correct. Another thing to do is a "wet test". You take a compression reading as usual, then put a little oil in the spark plug hole (i do two squirts from an oil can) and see if the compression goes up. If the rings are bad the oil helps seal them. I think the spec is you want less than a 20% increase, but you need to double check that part. So that will tell you how the rings are sealing. Then do the leakdown test as described above. That should tell you where your compression is going.

If the engine does need rebuilt and you dont want to tackle it you could save a lot by pulling the engine yourself and taking it to a rebuilder.

If I was rebuilding it, I'd probably go this route:

http://www.superstreetonline.com/how-to/engine/0609turp-honda-f20c-stroker-build/

Considering it uses stock Honda parts with a a little machining here and there, if you are tearing down the block and throwing new parts in, might as well gain some cubes.

I had to rebuild mine last year due to failed thrust bearing. A new short block from Honda was ~$6000CAD, so I did some upgrades and rebuilt. Here are my posts on my local forum, it should give you an idea of what is involved. I think the engine has a undeserved reputation as being complicated, if I can do it, anyone can.

Tear down: http://www.mrheavyfoot.com/forum/viewtopic.php?f=8&t=3170

Rebuild: http://www.mrheavyfoot.com/forum/viewtopic.php?f=30&t=3215