Good Heads Gone BAD !!! : V-Twin Forum: Harley Davidson Forums

springer- · 12-22-2007, 07:58 PM

What happens when a valve and piston hit each other and then the head of the valve breaks off ??

The valve head bounces around and destroys the piston and cylinder. It also bends the valve seat !! It bends the exhaust valve as well as breaks the valve guide.

Mtclassic · 12-22-2007, 08:05 PM

ouch!! What caused the piston and the valve to come to such an untimely meeting? Did it end up trashing the lower end too?

springer- · 12-22-2007, 08:11 PM

Quote:

Originally Posted by Mtclassic

ouch!! What caused the piston and the valve to come to such an untimely meeting? Did it end up trashing the lower end too?

I don't have that information, this head was sent to us for repair. It is an STD Panhead. It was cheaper to replace than to repair.

hdmarsh77 · 12-22-2007, 08:20 PM

That's gory!

bbrowncods · 12-22-2007, 08:35 PM

I guess they found the damage with a leak down test.

ViennaHog · 12-23-2007, 12:32 AM

Any chance that the rods survived the ordeal?

HDMD88 · 12-23-2007, 01:28 AM

Quote:

Originally Posted by ViennaHog

Any chance that the rods survived the ordeal?

When a piston hits anything in the combustion chamber like you see here the rod bearings suffered Trama....lower end needs to come apart and get rid of the rod bearings that now have several flat spots on them.
I've seen a lot of Manily Stainless Valves drop of at the weld like this in my day....but I don't know what valves these where in this head.

claydbal · 12-23-2007, 07:33 AM

Quote:

Originally Posted by springer-

I don't have that information, this head was sent to us for repair. It is an STD Panhead. It was cheaper to replace than to repair.

STD panhead-------accurate engineering motor by chance???????????

Ed Y · 12-23-2007, 08:02 AM

That's definitely nasty. Used to see a few of those many, many years ago.