Cylinder head repair


14 replies to this topic
  • ctorrider

Posted May 27, 2004 - 01:41 PM

#1

I saw where someone had a cylinder head repaired after a cam seized in it.I was wondering if anyone has info on this company or knows of someone who does this type of repair.Any help would be appreciated.---thanks shane :thumbsup:

  • MN_Kevin

Posted May 27, 2004 - 03:09 PM

#2

http://www.enginedynamics.com/

I JUST got my head back.

  • ctorrider

Posted May 28, 2004 - 03:12 AM

#3

How did you like their work? What kind of savings did you get versus buying a new head? Thanks for the info---shane

  • R_Little

Posted May 28, 2004 - 06:56 AM

#4

I went the whole 9 yards, valve job and blueprint, cost me $600 but I could have done it cheaper. Head is working fine but I did find the valves out of spec and a badly nicked cam bucket that neede dcleaning up.

All in all, a good job.

  • x2smoker

Posted May 28, 2004 - 07:17 AM

#5

Broke a valve and reaked havoc with the head (and piston and cylinder). EdCo fixed the head for 1/2 the cost of new. I am 100% satisified with the result, I have put about 200 miles on since the repair and the bike has never run stronger.

  • terrymc

Posted June 14, 2004 - 01:47 PM

#6

Any ideas how the valve broke or what caused it to break? I just experienced similar failure, and might try to send my head off to be repaired. You can see the damage here.


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And here
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  • Hamish

Posted June 15, 2004 - 02:25 AM

#7

Very hard to say......
If the tensioner/camchain/big and little end bearings are all in tact a piston to valve collision is unlikely the cause. The fact that the other 2 inlet valves are ok supports this theory.
Titanium valves do have a 'service life'. Although they are strong and light, they do suffer from faitigue more than SS valves. May have been a simple componment failure, with a rather devistating effect.

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  • TWSimpson

Posted June 15, 2004 - 03:48 AM

#8

My son has an 04 YZ250F and it did the same thing. The valve broke off right at the flang and turned 90 degrees and the piston jammed it into the head. We're in the process of replacing the head, piston and cylinder. :thumbsup: Lot's of $s. The crank still meet specs but, we're going to replace it also. I'm concerned there may be some fracture that we can't detect.
I'm hoping that we have the bike back together this week. He made the Loretta Lynn qualifier and he needs that bike for the regionals. He's one unhappy camper over this one.
Tom

  • terrymc

Posted June 15, 2004 - 03:50 AM

#9

I haven't cracked the case yet but there is evidence of serious valve to piston interface, as the conrod is bent and contacting the crank.

Heres a few more pics.

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  • SFO

Posted June 15, 2004 - 04:11 PM

#10

Rod replacement is SOP after dropping a valve.
The shock imparted to the rod tends to cause the small end to seperate from the rod.
You can use a Falicon rod for a stroker CR-F.
It is .060" longer than the stock yz-f rod but more durable and it is ampco45 bushed on the small end.
I get my deck height w/2 base gaskets.
Please all you TT'rs when you call EDCO tell them you saw them here on TT, it is still my goal to get them as sponsors.
They have performed many a commmunity service here and would be a very welcomed part of our community.
Mike at EDCO was a factory triumph tuner/mechanic in the early 70's and his weld repairs are amazing.
Jinny his wife answers the phone and is very helpfull.
Their turnaround is very quick as well.
I would also replace the cam chain in addition to checking the indexing on the cam sprockets.
When rebuilding I would check the cams with a degree wheel and double check the valve to piston clearance just for safeties sake.
I would also double check the bottom end bearings and their respective bores to make sure all was kosher.
Good luck!

  • SFO

Posted June 15, 2004 - 05:32 PM

#11

just for clarification,
EDCO = http://www.enginedynamics.com/

  • Hamish

Posted June 15, 2004 - 10:01 PM

#12

I haven't cracked the case yet but there is evidence of serious valve to piston interface,


The interference is generally after the valve has snapped and there isnt enough room for it to be in the combustion chamber at TDC. WR/YZ rods are suspect at the best of times, so replacement is required.

  • BIGMatt

Posted June 16, 2004 - 12:00 PM

#13

The wear marks on the face of the valve indicated that it was 'floating', then the piston hit it, bent it slightly and the rest is history. Did this happen when you were redlined at 80mph??? Get stiffer valve springs while you have the head off too.

  • terrymc

Posted June 16, 2004 - 05:12 PM

#14

The wear marks on the face of the valve indicated that it was 'floating', then the piston hit it, bent it slightly and the rest is history. Did this happen when you were redlined at 80mph??? Get stiffer valve springs while you have the head off too.


I've got a new head on the way and I'll probably send this one off to be repaired (and loaded with SS valves)

I had been running for about 1 minute WFO, backed off, got back on it and then backed off again (twisty gravel road) and when I backed off that second time it let go. :thumbsup:

  • captain_S

Posted June 17, 2004 - 10:52 AM

#15

Have you checked out your carb slide to see if it is still intact?,it may have broken up under the on off throttle time and held the intake valve open if a piece got stuck in the valve!,just a thought! :thumbsup:




 
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