rob.ok

Most of you guy know that I just recently lost a new motor. For the full write up with all the details check the original thread.

rob.ok documented motor build and failure




For those of you that want to get right down to the brass tax..........


Spoon 2.2L stroker kit with .25 oversized pistons.
Approximately 12.5:1 CR
100 octane race fuel
AP1 cams



The motor was built by Ace Engine Machine in Fresno, CA. There were multiple problems with the build as it got rushed. However after an extensive investigation with 3rd party professionals I came to the understanding that while it wasn't perfect, it had noting to do with the failure and would have more than likely had no negative effects over the long run.

I put about a total of 8XX miles on this motor. About 400-500 break in miles with less than half throttle and the rev limiter set at 4000rpms and maybe another 200 miles on the street before going to the track. I did step on it a few times but I'm not one to speed or drive crazy on the streets...I save that for the track.

The car was tuned by Blacktrax in Milpitas, CA. I felt really confident especially after hearing that Rylan's #8 ITE monster of an S2000 had been there for their services. The car was on the dyno for a total of about 2 hours and everything was looking pretty good.

On 9/26/09 I took the car out to Buttonwillow for its first shakedown. The first session went pretty good and everything looked like it was ready for some hot laps. I opened the car up and did a few hot laps but always with 2 or 3 cool laps since everything was still new. I was experiencing excessive blow by and filling up my catch can well before the session was over. During the fourth session I got meatballed for smoke. The dipstick popped up from all the excessive crank case pressure from the blow by and pumped about a quart and a half of oil out. I did not notice any loss of power (since I really was not pushing it that hard at the time) and it sounded and ran like a champ before, during, and after. However, I shut the car down and towed it home. My brand new motor that I dumped a good deal of time and money into only lasted 23 laps


I tore the motor apart and this is what I found.


All 4 top rings were broken due to heavy detonation. 2 of these rings were literally smashed into 15 plus pieces!!! All four pistons are trash and the cylinder walls are scored. I found an excessive amount of metal in the oil pan and it was circulated through out the entire motor (the metal is from the broken rings). Essentially...its all trash considering it was all brand new, balanced, and micro polished.
I explored multiple avenue and scrutinized every every piece of the motor. I received professional opinions from engine builders, piston manufactures, and tuners and I have received what could be considered a unanimous decision as to what caused the failure. All have either suggested or agree that the tune has about 7-10 degrees too much timing in the map. The main reason being that severe detonation was occurring in all four cylinders and everything including the fuel octane and compression ratio checked out ok. I have to put some sort of stock in what these professionals have to say and I can only agree with them that the reason my motor failed was simply cause I got a poor tune.

If any of you have had a similar experience or suffered a similar failure I'd love to hear about.


For those of you that are that are rather technical here is some photos for you to review.







Notice the light "frosted" coating above the top ring of each piston and at the top of every cylinder. This is the product of detonation. It simply is basting away the aluminum and leaving this frosted look.











Here is a copy of my timing map. This is what has been speculated as the ultimate cause of the detonation.





I do not think that anyone in the S2000 community has ever suffered a failure like this and most have never seen a motor simply detonate to the point where it destroyed all 4 top rings in the manor that mine did. I can only hope that other don't end up having a similar experience or failure.



Best of luck to all,
-Rob

TubeDriver

I guy I know went through 2 Cobb built motors due to improper tune. That is all it takes. Hope you get things settled and fixed as soon as possible.

Voodoo_S2K

Good seeing you yesterday Rob. Best of luck with the car in the future. If you need any help, lmk.

blackey

I would send the map to Asura and Church and see what they say. They'll know right away how much timing you can safely run.

Bill

PS - Remind me not to get on a flight with you. Together with our luck on motors...

CKit

So sorry to hear about your engine. That must be very disappointing to lose the motor so soon. Is any part salvageable?

Asura

Definitely due to improper tuning. It's not just the ignition map either.

The log file on the knock sensor will tell us more.

Broken piston rings, black death on the piston skirts, and your ring lands are toast.

Asura

Oh really??? That's certainly news to my ears along with several S2Ki locals who were present while I was tuning Rylan's car on their dyno.

That's actually hillarious if they are claiming to take credit for MY work on Rylan's car.

For the record the last time we (S2Ki Race Team) rented their dyno was in Feb. 2008.

ou818

That's a hell of a loss. Sorry to hear it.

Did you talk to the tuners about this? Can you hold them liable in any way?

And thanks for sharing.

rob.ok

[QUOTE=Asura,Nov 12 2009, 11:40 AM]Oh really???

nexus

That sucks about your motor. I'd seriously take them to task over this. I'm sure they will bitch and moan and argue but thats a pretty significant failure.

They've never had a very good reputation that I'm aware of so this doesnt surprise me.

Good luck getting them to make right of this.