Bent valves after cambelt failure

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KimH
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Thu Jun 21, 2012 11:09 pm

I picked up a very clean 885 cylinder head at the scrappy that had been involved in a cambelt fail and there are a couple of bent valves and a snapped rocker arm. Would this be a scrap head or would a simple replace the duff bits rebuild sort it?

Has anyone recovered from a snapped cambelt by just replacing the valves?
maggspower
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Thu Jun 21, 2012 11:30 pm

Hi there, its very hard to say without seeing it. Get it cleaned upand give it a good check over by eye looking at the seats and the part of the guide that is in the port, also check where the rocker shafts run through for cracks. If it passes this you could rebuild it, replacing the damaged parts, but I would be geting it pressure checked, skimmed and rebuilt properly. I'm sure it was a bargain, so get it sorted and you'll have a cheap rebuilt head :)
HairyScreech
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Thu Jun 21, 2012 11:34 pm

Tricky and needs proper assessment, at its simplest then its a case of a few new valves and run it.
However the rockers may have been damaged, i wouldn't want to run ANY of the rockers from the head, just not worth the hassle of one going due to impact damage.
The vent stems may have damaged the valve guides, these will need checking.
The seats may also have been damaged and require replacement or recutting.
All of the valves in the head will need checking as its possible they all got bent before the bottom end stopped and the cam will need to be checked as it is possible to twist a cam in this manner.

Best thing to do may be strip it right down, bin the rockers and valves, and get a head shop to check the seats and guides for you, if they are ok then keep it as a spare casting.
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