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Okie doke, got the head off and found the missing valve
Thoughts and questions.
The valve snapped at the base of the stem, inside damage seems minor ( far better than some Panhead I have seen )
1.. What would cause such a break ?
2 ..Should the guide be replaced could it be bent ?
3.. Based on damage chamber and piston seem to look like a good wire wheeling would clean them up... yes / no ?
4, Is the head still usable after this type of injury ? ( was hoping rebuild head toss it back on and fly )
Last edited by HumblePie68; 07-20-2012 at 7:02 AM.
depending on at what RPM this all happened at will be relative to what damage you have. look hard at the movement of the pistons and see it they move exactly the same. you may have rod damage, that broken off valve did not have much room to hide in. and yes do a complete head rebuild this is likely caused by a valve seizure and the piston hit it and snapped it off.
Sorry, but If this was my motor I would take it as an indication of a motor that needs a complete overhaul.
depending on at what RPM this all happened at will be relative to what damage you have. look hard at the movement of the pistons and see it they move exactly the same. you may have rod damage, that broken off valve did not have much room to hide in. and yes do a complete head rebuild this is likely caused by a valve seizure and the piston hit it and snapped it off.
Sorry, but If this was my motor I would take it as an indication of a motor that needs a complete overhaul.
Motor was not running when it broke, they were trying to start it.
Yes I had thought bent rod,,but think its ok,,stock bore so gonna go 10 over and redo the head
ok that's a good thing, the damage may be minimal and it was likely caused by a valve being rusted stuck and then gettin hit by the piston and you might be ok with that plan.
you can do a top end rebuild now and even if you go with a total rebuild later you are not wasting any money.
Standard bore indicates it's an old unmolested motor, that's both good news and bad news.
ok that's a good thing, the damage may be minimal and it was likely caused by a valve being rusted stuck and then gettin hit by the piston and you might be ok with that plan.
you can do a top end rebuild now and even if you go with a total rebuild later you are not wasting any money.
Standard bore indicates it's an old unmolested motor, that's both good news and bad news.
Bad as in now, oh so many moons later stuff is gonna start to fail
um....there is this thing called a sludge trap in Triumph engines, this is a ticking time bomb in the middle of the crank shaft, If your motor is still std. bore and it looks like a 65 or so motor, then the odds are it has never been apart and had the sludge trap cleaned out, then if you combine the fact it may have sat for a while the oil that was inside the crank turns into a sludge further plugging the trap up.
this broken valve could have saved you from throwing a rod through the sides of the crank case.
you are half way rebuilt by just doing the top end...you may want to go all the way.
when you got it apart, think mmmmsludge trap ,,below that ,,,,main rollerbearings for crank,,,better check em too,,,, if, one lets go ,, then you gotta tear it down again,,,safe then sorry,,happened to me once .
they never fixed it ,the thing is,,,, if it hasn,t ever been pulled you may have crap in there thats unwanted , think,, very old fasioned ,oil filteration,It should be cleaned in a triumph rebuild,,,
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