Cylinder head repair
Posted May 27, 2004 - 01:41 PM
Posted May 28, 2004 - 03:12 AM
Posted May 28, 2004 - 06:56 AM
All in all, a good job.
Posted May 28, 2004 - 07:17 AM
Posted June 14, 2004 - 01:47 PM
Posted June 15, 2004 - 02:25 AM
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.
Posted June 15, 2004 - 03:48 AM
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.
Posted June 15, 2004 - 03:50 AM
Heres a few more pics.
Posted June 15, 2004 - 04:11 PM
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.
Posted June 15, 2004 - 10:01 PM
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.
Posted June 16, 2004 - 12:00 PM
Posted June 16, 2004 - 05:12 PM
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.
Posted June 17, 2004 - 10:52 AM