One pharked 71 FLH motor

[Hep]

Gretings from Australia,
Riding at 70 MPH my 71 FLH stopped running and coasted to a halt. No compression on either cylinders. Pulled it down and found unbelieveable damage. Hole in rear piston (new KB Pistons), All valves bent (4) Cracked valve guides. I just rebuilt it using quality American parts.
The cam timing seems to be OK, but the valves have hit the pistons hard!!!The only thing I can think of is that the moulton alloy from the holed piston jammed the oil pump relief valve and pumped up the lifters which lifted the valves?? I and others don't understand what went wrong.
I had just fitted new points and possibly it was too far advanced. The carby is an S&S Shorty and souldn't be running lean. Bores weren't damaged.
Any ideas? As you can imagine, I don't want it to happen again.

Andrew, Geelong, Victoria, Austraila.

[xxxflhrci]

If it wasn't the timing, it was an intake leak that melted the piston. Since it was only one piston, I'd guess on a leak.

[Hep]

Thanks for your suggetion xxxflhrci

Just lifted the motor out after taking the timing cover of. Cam timing is correct. Possibly there could have been an air leak that holed the piston but what lifted the valves, bent them, push rods & broke one lifter??
Help

Hep

[newultraclassic]

Hello,

I think you may have hit on the correct answer to the bent valves. It had to have been something that caused excess oil pressure and pumped the lifters. It wouldn't take all that much.

The only other thing that I can think of is that perhaps the lifters were adjusted a bit too far down. Isn't it four turns down and 1-1/2 back?

Sorry about your problem.