bent spark plug

[endlss]

hoping for some advise
haven't posted in a while car has been undercover for a more than a year,
thought i would start working on it again, tried to get my efi kit on it but did my head in so went back to the webber, seemed to run fine once the timing was set up how it used to be .
but today went to take it out and started miss firing went back home and put a timing light on each lead found #1 wasn't firing right pulled the plug found the tip had been bent to the side,
the engine was built by the previous owner to do hill climbs just before i got it so i thought it couldn't be the motor maybe i bent it when i installed it...., either way changed the plug with a spare went for a drive no misses
parked looked over everything took it out again and started missing again, checked #1 perfect thought i would look at the rest #4 bent like #1 was
so this is where i am.
i am guessing the bearings on the crank are stuff or could it be a valves hitting the plugs

[Sigmaproject]

I would assume that it is physically impossable for a piston to hit a spark plug...unless the plug was way too long.

[Scorpma82]

To which the piston\engine would be destroyed in a matter of moments....... Far too quickly for a spark plug to bend

[endlss]

Same plugs that have always been in the engine prior to being parked up

[Scorpma82]

the plug isn't crossthreaded into the head is it?

[brendon]

I've had a very bent spark plug electrode in my scorpion previously.
only happen once (2 months ago at a khanacross) in the 7 years I've had it and never for the previous owner who built the motor.

put in new plug and haven't had an issue since

[endlss]

Put another plug in #1 ran well did a 10mins drive then it started missing again.. and yep took it out bent.