zx6r engine exploded

This is for an 09 zx6r. So I was racing CCS the other weekend, and my motor let go on me. Felt sudden loss of power, and rear wheel locked up. Pulled in clutch and coasted it off track. I took apart the motor and found the timing chain was destroyed, all valves bent, and some broken connecting rods. I had my ECU flashed and dyno tuned, and the factory rev limiter was increased by 500 RPM's. Could this have caused such a disaster? I have a fresh backup motor to install, but I don't want the same thing to happen.

 

shit happens. 09 motor, how many times have the con rod BOLTS been used ? or was it original or 1st build ? had that bite me in the ass last year. Perfect motor, bolt broke after 5 rebuilds. Know better now.
Everything was junk when the piston/rod stayed up and didn't let valves come down, the cam shaft lobes broke a couple of buckets in half ruining the head (can't repair the bucket bore).

rev limiters don't work on downshifts, not that that's what caused issues. did ya happen to have an on-board camera going when this occurred ? look at where your bike stops making power too, on an r6 you are going slower shifting close to rev limit (or 500 rpm more). It's just handy to have a bit of overrev at a particular corner where it's faster to let it scream than upshift then real fast downshift again..

 

I do have video, (haven't posted it to youtubes yet). It did happen going into a turn while downshifting 2 gears. This was the original (entirely stock) build, engine had 11000 (street) miles, maybe 8-10 track days, and 3 race weekends on it. Oh well. Head might be ruined (cracked valve guide), block is trashed (has hole through it). Just glad I didn't spill oil all over the track!

 

Wow! I am shocked that the engine failed so soon...but maybe it did over-rev on your multiple downshifts. I had this happen to me once when I switched to GP shift pattern and went the wrong way - instant broken connecting rod and big hole in the engine. Is it true that the bike having a slipper clutch is supposed to be protective from downshifting over-rev? I thought I heard this from an SV racer once. If so, the zx6r has a slipper....

 

Slipper will not prevent over-rev on down shift, but it will help reduce how often/severe they are. I still believe that people blow up motors more now because they think slippers are a protect all(06 R6 for instance).

 

Why did you bump the rev limiter and extra 500 RPM? The bike stops making more power before it even gets to the stock redline. I'm assuming you left the valve-train stock w/ the extra 500 rpm?

 

we covered that .. but it's still not likely the higher rev limit in and of itself caused any damage, unless he was riding on the limiter a bunch. Hence why i would be interested in seeing the on-board vid

 

with more info, posted vid, and maybe more pics of the damaged stuff.. some of the top builders may shed some light on what happened.

 

The Kawasaki 600 keeps making power with the additional rpm. However, aftermarket rods are a must when you do this. I build these for micro sprint guys and see this quite often.

 

Wednesday and I want to see some motor carnage

 

Now you tell me! Guhl motors is the tuning shop that dyno flashed my factory ECU (highly recommended) and they mentioned they do a lot of work for the micro sprint cars that use this motor frequently. They also mentioned they use a lot of over rev most of the time with the tune, but didn't mention if they keep the factory rods. I would've stuffed in some carillo rods and opened the intake/exhaust ports up on this beast if I wasn't planning on racing superstock Here are some carnage pics:

http://nofadz.com/~sonic/blewthefuckup01.jpg
http://nofadz.com/~sonic/blewthefuckup02.jpg
http://nofadz.com/~sonic/blewthefuckup03.jpg
http://nofadz.com/~sonic/blewthefuckup04.jpg
http://nofadz.com/~sonic/blewthefuckup05.jpg

I'm not sure what happened first, broken timing chain or broken rod/bearing. I do remember feeling the power disappearing (valves) and then I heard what I thought was the rod letting go (clunk rattle rattle). So maybe the timing chain or tensioner let go first. I was lucky I didn't crash the bike or grease up the track (bike was completely dry somehow). Oil pan didn't have any damage either. Already have a brand new engine installed, ready for the next race weekend.

 

damn.. whatta mess. bummer.

 

Woah, is this something to worry about with a kit ecu and a tune? The place that tuned it I specifically requested them to keep the limiter at the stock RPM. With running stock RPM limit would this be an issue? (same bike). Don't mean to thread jack Sonic!

 

Bearing failed first, melted the big end. Everything else was collateral.

 

would do ya think a better rod have helped in this situation Rick ? (with just the photos to go off of ).

 

Rods plus coated bearings definitely help. Good oil helps. That bike has priming issues with the oil delivery as well - doing this correctly during oil changes helps.

There are easier and safer ways to make power on that engine as well. Sprint car guys want rpm - they use it like changing gearing. Bikes, not as much. Bikes are about acceleration.

 

Nah you should be ok at stock rev limit + proper maintenance, as long as you aren't running really lean (detonating). You don't hear about too many zx6r engines blowing up like this, unless you are revving to the moon like I am.

 

I agree with this, looking at the big end, the surrounding metal is completely blue, so this definitely supports the bearing failing first. Hopefully my new engine doesn't suffer the same fate. What do you recommend for oil? Currently using Amsoil 10w40 motorcycle oil, this is what I used exclusively for the engine that exploded as well (not that I would blame the motor oil for the bearing failure).

 

Motul 300v 10w-40. I don't use anything else unless it's a big twin or a single.

 

yep just as RM says, not uncommon for rod failures on these. I hate building ss types as they make great hp but imo not the most reliable (rods!) but in SBK type or track day trim we use Carrillo;s 100% of the time and never a Rod issue yet..