Motor failure on the dyno today
Thread Starter
Registered User
Joined: Oct 2006
Posts: 2,507
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From: Westchester NY
Motor failure on the dyno today
I was tuning my car at NRG tech today (well miller was tuning it) and we did a few pulls after he setup everything.
Off the WG spring (10.5lbs) the car made a few pulls fine. Then we started to hear a rattling noise only when VTEC engaged, so we pulled the valve cover and inspected everything, all seemed okay. Put the VC back on, started making a louder rattling noise, but then it went away. I thought it could have just been the TCT when vtec engaged because both are oil activated.
So since the noise was gone, we went to do another pull. With VERY conservative timing and fuel, the car let go of cylinder number 4 (around 7700rpm). The dip stick blew out and oil/smoke shot everywhere. We stopped there and inspected the inside of the cylinder that blew with a pretty cool snap on tool lol
Piston does not appear to be cracked on top. I'm guessing it's the ringlands. Anyway, is this a common failure for s2000 motors? The motor was fine all it's life as NA. Compression was perfect, oil level was fine etc. I don't understand because so many bone stock motors make a ton of power. This was a conservative pull on 10lbs.
MY setup is:
2002 f20c
60-1
aem
ID 1000cc injectors
walbro intank
9 series plugs
93 octane
blah blah
Here are the pics finally...warning they are sad!
This is the one that let go....It melted all the way down to the top compression ring and lost all compression in that cylinder:
Number 3 cylinder...pretty melted on the intake side, yet exhaust side is perfect. That's how it is on all the cylinders..idk why!
First cylinder...
And here is the crater I was talking about on cylinder number 4... It is deeper in person. But there is no way this happened before the car was on the dyno. The motor would just not run right with it this way.
Here are the maps from the dyno:
Off the WG spring (10.5lbs) the car made a few pulls fine. Then we started to hear a rattling noise only when VTEC engaged, so we pulled the valve cover and inspected everything, all seemed okay. Put the VC back on, started making a louder rattling noise, but then it went away. I thought it could have just been the TCT when vtec engaged because both are oil activated.
So since the noise was gone, we went to do another pull. With VERY conservative timing and fuel, the car let go of cylinder number 4 (around 7700rpm). The dip stick blew out and oil/smoke shot everywhere. We stopped there and inspected the inside of the cylinder that blew with a pretty cool snap on tool lol
Piston does not appear to be cracked on top. I'm guessing it's the ringlands. Anyway, is this a common failure for s2000 motors? The motor was fine all it's life as NA. Compression was perfect, oil level was fine etc. I don't understand because so many bone stock motors make a ton of power. This was a conservative pull on 10lbs.
MY setup is:
2002 f20c
60-1
aem
ID 1000cc injectors
walbro intank
9 series plugs
93 octane
blah blah
Here are the pics finally...warning they are sad!
This is the one that let go....It melted all the way down to the top compression ring and lost all compression in that cylinder:
Number 3 cylinder...pretty melted on the intake side, yet exhaust side is perfect. That's how it is on all the cylinders..idk why!
First cylinder...
And here is the crater I was talking about on cylinder number 4... It is deeper in person. But there is no way this happened before the car was on the dyno. The motor would just not run right with it this way.
Here are the maps from the dyno:
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Joined: Aug 2004
Posts: 946
Likes: 1
From: Planet Earth....Welcome!
That sucks dude. I know the feeling. My motor let go with 7.5 psi. But it just forced me to build it and make it really strong. I think some of the guys making tons of power have just been getting lucky with there motors.
