Billman, I have lots of Honda experience, but most of which is s2000's. I worked a Honda dealer and was ase certified, just to clarify I was not referring to a DIY or enthusiast type experience.

Anyhow, I always am the first to admit to not knowing an answer but am intrigued to learn that as soon as I can. Now that you mention that center bolt being loose, I could agree it would bleed pressure off so that the head will not get any oil basically at all. I am pulling the engine from this car this afternoon/tomorrow, so I will be checking that center bolt. But where are you at on the absolute lack of oil? Owner said he changed it 2 months ago with royal purple. Lets assume this is true and it was filled properly. Could we assume it was burning massive amounts of oil (control rings and maybe even valve seals?), but at the same time the center bolt bled off head pressure? And I am still in awe that this car was running on such little oil, was mis shifted, then basically babied home when he heard a tapping noise, and then given to me.

Very intrigued to see the cylinder walls on this engine given the circumstances.

 

Just to clarify, not my s2000. A customers. And I am with you, especially ap1's, CHECK THAT OIL!

 

tamadrummer1120, My feeling from Billman's post is checking the oil level was NOT the problem --- if that center bolt backed off the head. Under high oil pressure, you'd have seconds to stop engine from having major problems.

Kinda like a major hemorrhage, like aortic artery busting. You have minutes to live.

 

On 100% of all the S2000s I've seen that had engine damage due to low oil, all off the top ends were perfect.

If you were to drive with your foot to the floor at 120+ and drop the drain plug while in motion, the bottom end would starve, spin bearings, lock up. The top end would show zero damage. It takes oil starvation for a sustained period cook the top end.

When you disassemble the engine, follow the oil pressure path to the top end carefully. You may even find a little piece of silicone blocking the pathway. This is why I stress so much no silicone on the Vtec valve or TCT.

 

Oh no I agree with him. It is just mind blowing that all at once, there was 3 problems that could have blown this engine.

1. Center bolt to back out and scorch the head (supposedly our issue here)
2. Total oil inside engine between oil pain drain and oil filter = 3/4 qt
3. Owner mis-shifted, over revved the engine and started heard loud ticking noise, which could have easily turned into a retainer letting go if it was cracked before.

It appears it was never in the cards for this engine to make it past 70K

 

Correct. Oil pressure was lost up top but remained down low. If you are careful during disassembly you should find the underlying cause.

 

Will do. I plan to thoroughly go through the disassembly of the engine, up to the rotating assembly coming out. That part is up to inline pro. But I want to make sure, from my visual inspections and prior knowledge, this block is a good candidate for sleeving and rebuilding. Now if there is excessive side to side play with the crank (maybe thrust washer or main cap wear), we may be scrapping this and find a good donor. A lot cheaper than needing to line bore.

 

One more question for ya billman.

Lets say this owner was just cruising along, and make sure we keep in the back of our head the lack oil available to the lubrication system, and then he did misshift, and the engine over revs, but the center bolt being loose (or maybe came loose then) caused the loss of pressure to the head. You say the head would be toast almost immediately, how is it then the car still drove home and was able to started up later? Only curious here, I am not disagreeing. Just want to make that part clear.

I guess maybe enough residual lubrication. So crazy the cam caps snapped too.

 

I think the problem is your basing things on what the owner is telling you and I don't think he is being truthful for whatever reason. I can't see anyway that engine ran after those caps snapped and I highly doubt they waited till he pulled in his driveway to snap.

Are you sure he didn't miss shift, try to investigate on his own and royally screw crap up in doing so, then blow the head to pieces on startup?

 

I wouldn't disagree that I am getting 100% truth. But I did see the engine running at cold idle ticking its ass off on the top end when he asked me to come out and look at it. After I said to shut it off immediately he then told me he mis shifted and over revved. So I know for a fact it did run, but whether he messed with it prior to bringing it over is beyond me. But everything we began to take apart looked factory sealed. So who knows.