brendasue555
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posted December 12, 2008 12:25 PM
 Edited By: entropy on 13 Dec 2008 22:56
head ache
ok, so what do ya'll have to say about these? I am sure to learn something now. Any thoughts?
http://www.flickr.com/photos/brendasue555/sets/72157610889961702/show/
The valves were both found lodged in the exhaust port.
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Brenda
  
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brendasue555
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posted December 12, 2008 04:43 PM
correction. both valves were lodged in the intake port.
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Brenda
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entropy
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posted December 12, 2008 06:48 PM
i'd say you got very lucky, some seat work and you'll be back in Biz!
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brendasue555
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posted December 12, 2008 06:55 PM
I hope so. You should see the pistons. I know that it is in the best hands it can be in and I am lucky to have the help of some of the best people in the business. I can only count my blessings and do my best to be worthy.
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Brenda
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posted December 13, 2008 09:57 AM
ok maybe its this computer but the "link" doesnt work
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brendasue555
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posted December 13, 2008 02:41 PM
try copy and paste.
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aliveagain
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posted December 13, 2008 04:17 PM
assist
http://www.flickr.com/photos/brendasue555/sets/72157610889961702/show/
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brendasue555
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posted December 13, 2008 06:08 PM
OK at the risk of sounding dumber than a box of rocks, I had it right the first time, both valves were lodged in the exhaust port. Now I have to figure out why I thought that exhaust valves were bigger. Hmmm, maybe I have overloaded my brain with too much detonation. LOL! At least I am younger than a box of rocks. Ok maybe not the box.
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Brenda
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dougmeyer
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posted December 13, 2008 07:40 PM
Brenda,
Intake valves are almost always bigger because the incoming air is forced into the cylinder only by the atmospheric pressure filling the cylinder as the piston descends, while the exhaust gases are exiting under a great deal of pressure after the combustion process. Because of this high pressure the opening area can be smaller.
At the risk of sounding a little "know it all", the correct name for the "intake" valves is really "inlet valves" and you'll find this terminology in many engineering texts and used often by serious engine guys. This is the correct term because that's really what they do, they merely "let in" the air when the descending piston creates a lower pressure in the cylinder (a vacuum).
Doug
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brendasue555
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posted December 13, 2008 07:59 PM
Thanks, seems so logical.
brenda
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entropy
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posted December 14, 2008 05:52 AM
everything seems logical in retrospect 
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chavcat
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posted December 14, 2008 01:19 PM
Who would be a recommended shop/person to repair this?
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entropy
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posted December 14, 2008 02:21 PM
quote:
Who would be a recommended shop/person to repair this?
Jim (Y2K) in Connecticut does GREAT porting, seats, and any kind of head work.
I send heads to Jim (he has one right now for porting) = great results, and for local stuff I use Andy at Metric in Houston, again great results, just no CNC porting.
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whitehendrix
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posted December 14, 2008 02:26 PM
wow..
this is the second case of broken valves i've seen this weekend now.. the other was on a roadrace-spec ZRX400 in spain somewhere.. it's bad, too..lol
you think you can salvage that head?
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Y2KZX12R
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posted December 14, 2008 03:06 PM
Yea I just looked at the pics. It can be fixed.
Doug, what brand valves are those? Are they stock seats? Stock guides?
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chavcat
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posted December 14, 2008 03:28 PM
Jim - would you replace the guides with OEM?
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dougmeyer
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posted December 14, 2008 04:38 PM
Jim,
Stock valves, stock guides. (When N/A, I don't think there's anything better to use.) I'm pretty sure the seats are BeCu. I'll double check my records.
Brenda is sending me the pistons just so I can review the whole failure.
Doug
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Y2KZX12R
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posted December 14, 2008 06:56 PM
Chavcat, The OEM guides are fine in this application. Bronze transfer heat better but we can do whatever.
With stock iron guides I prefer coated stems like KW black diamond valves or factory valves. With bronze guides Ferrea uncoated are fine. If its a low mileage application it doesnt really matter coated or not, the stems wont wear much anyway.
Doug, I agree stock valves are good in most applications. I dont like stock exhaust valves in turbo or nitrous applications thou. But thats just me. Theres plenty of guys running nitrous and stock exhaust valves.
From what I remember reading it didnt sound like the engine was being stressed when the failure occured. If I remember right he was at low speed with it no?
Brenda can you verify this?
If so, the valves were most likely compromised prior. Molecular creep, crystalization could be setting in. The last owner could have over heated them, in which case I wouldnt trust any of them anymore.
When this engine gets fired up again, it needs to have the exhaust temps monitored, I'm thinking that the one carb might have a circut partially pluged. Even if its just a hand held IR temp unit it will show a hotter pipe in relation to the others.
Are stock zx11 valves friction welded 2 piece? Looks like a perfect seperation in one of the photos.
Dont worry Brenda, Dougs on the case.
You could have a better person looking at it and giving advice.
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brendasue555
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posted December 16, 2008 12:19 AM
omg, I couldn't sleep so I decided to check my email and check in on bike land. Noe I really can't sleep. I just got done running around my chair jumping up and down screaming and now I can barely type. Ya'll are talking about my bike. If I am not the luckiest girl in the whole world then I don't know who is! Well maybe the girl with the brand new zx14 is a little luckier. Nah no way, I am the luckiest by far. I would not trade any of this for the world. Thank you Doug for so much I can't even begin to show my appreciation for you and your willingness to help me. And Jim Your knowledge just amazes me also and for Doug to speak so highly of you he must think you are pretty smart too.
Now as far as the bike goes, I think probably all the valves need to go, I know that all 4 pistons had pieces broken off and they were all the top edge closest to the exhaust valves. The night before it broke Paul road it pretty hard. And for him to say that, I am sure that he road it real hard. This was the first time it had been started the next afternoon. He was going to the conveinence store and made it about 100 yrds, He said it was like running on three cylinders or something so he cut it off, he knew it wasn't good but I am not sure why. I will get his input for sure.
Here are a few more things that might or might not matter. All of this before Doug saw it at Texas mile. One of the spark plug wires was burned up about 4 or 5 inches on the inside of the wire. The middle part! We dont know why or how it got like that, Also there were 2 times that I was starting it that it backfired so loud and so metalic that i thought it blew something right out of the motor. Also I think it might have been running hot at one point I will have to ask paul but I think I remember him checking the thermostat or something like that. Also the bike was so hard to keep running when I got it and it would kinda like bog down before it would start going kinda. I dont know how the guy put 9000 miles on it with the stock ignition and no air box. But what ever we need ot do just say the word and consider it done. Thank you both so much for taking time from your busy lives to look into my bike I wish there was some way that I could show how much i appreciate everything. Doug thank so much I will always be your biggest fan. And Jim I am still in awe at you. And I bet your wife is too.
Brenda
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posted December 16, 2008 11:50 AM
quote:
assist
http://www.flickr.com/photos/brendasue555/sets/72157610889961702/show/
thanks !
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posted December 16, 2008 11:56 AM
quote:
Yea I just looked at the pics. It can be fixed.
Doug, what brand valves are those? Are they stock seats? Stock guides?
how can some of those dings & prangs be fixed
weld & grind ?? ? ? ?
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VincentHill
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posted December 16, 2008 01:24 PM
Y2K, What made me think that you lived in Virginia?? OR have you moved??
1 piece valves are USUALLY Better than 2 piece because when they let go, they break near the Welding process! I think the reason for 2 piece valves is mainly COST! The stem is cheaper than the Head and one piece would be all the same!
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Y2KZX12R
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posted December 16, 2008 06:42 PM
FL, yes welding.
Vince, I've always lived here in CT. The tax capitol of the world. Except for when I was going to school in Denver in the early 80's.
I think your right on the cost issue.
Almost all Titanium Valves are 2 piece (head and stem) and are friction welded. Most stainless valves have some kind of hardened tip on them. Both two piece but in different places.
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dougmeyer
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posted December 17, 2008 10:41 AM
Brenda,
I's my opinion that the stock ignition and the lack of an airbox is exactly the reason that the engine lasted 9000 miles on pump gas. That was a 15:1 C/R engine and there's no way it should have held together on pump gas. But because it was running so badly it was not able to develop enough cylinder pressure to hurt itself. After Paul did such a great job of getting it back right it was pretty easy to to hurt it. When I rode it on the access road at Goliad there was no way I could lean on it very hard so all I could tell you was that it felt strong and had good response. Again it took a hard run to get it into terminal detonation. I'm sorry I didn't think about that and warn you before I left, although I think we briefly talked about being careful with the timing.
Rest assured that when we get it running again it will be fine to ride on the street.
Doug
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posted December 17, 2008 11:30 AM
i pc or 2
ive never seen stems torn like that b4
usually the valve heard will get popped off anyway
yet ive never seen longitudinal tears
would have been nice to see pix of the pistons from their respective holes
so unusual to lose 2 valves same cylinder
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