When Things Go Wrong!!!

[c.o.]

Just the messenger... this is a thread brought to you by Slojo.....

This exhaust valve head fell of at a traffic light while idling. The valve appears to have a black hard coat stem and a part number stamped on the stem by the keeper groove as an identifier the number is 56012. Does anyone know who the manufacture is?

joe

[c.o.]

Whoops..... I neglected to mention that we're talking about a '48 EL.... and that busted valve in the top of the piston is a horrific shot!!!!

[Jerry Wieland]

Actually for dropping a valve that is relatively minor damage. It probably just locked the engine up. At RPM it is a totally different story. It never is good but the head is repairable and the cylinder looks undamaged.

Looks like the engine was burning oil or running rich. One valve wasn't seating very good.

I cannot help ID the valve but Rowe is a big producer of valve hardware.

Jerry

[Tom Lovejoy]

My brother in laws Sportster did that at speed, 30 years ago. It's still in his shed, he has not fixed it yet.

[Slojo]

I bought the bike about ten years ago and the motor already had been rebuilt . It has a Jim's main shaft sticking out with his name laser etched on the end. Although it ran well I never liked the sound of the motor, (to much top end noise) and figured eventfully it would come out for a rebuild and conversation to hydraulic lifters. The valve guides are Rowe but the valve has not been identified yet.

joe

[exeric]

I'll be following this thread with great interest as I have to do the heads on my '48 motor. Is there a consensus on who makes the best valves, guides, and springs?

[Slojo]

I have not experienced spring failure using stock springs. These are not Indy motors. The material fatigue with this valve must have been a faulty manufacturing process. Either the friction weld or the subsequent heat treat, I believe the heat treat machine/process is at fault. Typically these problems are caught during manufacturing and this valve probably slipped by Q.C.

Heat treating valves is most likely accomplished by an induction heat treat process. "Basically", a valve stem is inserted into a coil and a high frequency charge of electricity is pushed through the coil for a few seconds exciting the molecular structure of the valve stem to a point where the metal lights up from friction (Atoms bouncing of each other) within the make up of the metal followed by a quenching process.

I am not a qualified metallurgist !

joe

[Robert Luland]

Heat treating valves is most likely accomplished by an induction heat treat process. "Basically", a valve stem is inserted into a coil and a high frequency charge of electricity is pushed through the coil for a few seconds exciting the molecular structure of the valve stem to a point where the metal lights up from friction (Atoms bouncing of each other) within the make up of the metal followed by a quenching process.

Joe, that is pure sex to a motor head!

[T. Cotten]

I am haveing trouble viewing the pics Folks,
so please set me straight:

You blame the valve?

....Cotten

[mcarver]

At least that valve head didn't pass into the lower end..... that would have made a noise. Was it the valve that failed or did the valve spring fail and drop the valve onto the piston which then broke the head off the stem?

[c.o.]

. Is there a consensus on who makes the best valves, guides, and springs?

Eric,

I'd have to try and find the paperwork but if I recall correctly headhog used Rowe valves when he restored my heads.

Joe, that is pure sex to a motor head!

That got ya revving did it Bob?

Was it the valve that failed or did the valve spring fail and drop the valve onto the piston which then broke the head off the stem?

Mike, that was my first thought when I saw the photo.

I am haveing trouble viewing the pics Folks,
so please set me straight:

You blame the valve?

....Cotten

Cotten,

Does this make it easier?

[T. Cotten]

Thanks Cory,

Now I can see them all on a modern PC,
but it takes forty to seventy seconds to open something, and right now the "reply with quote" has been continuous spinning for about twelve minutes, even though I clicked "reply" after a minute, and the window popped up immediately.
And then "submit" didn't work, so I went "advanced".
This site has more bugs than a stray cat.

Back to topic,
Its a two-piece valve, Folks.
Except for Kibblewhite, I cannot think of any that are not.

Rowe is defunct, by the way.

The valve is a victim, like the piston.
The question is where the fuse was lit.

(The example in my photo was stamped "ENGLAND", and I installed it new. It had a fuse that I consider admirable.)

The other valve should be inspected for knicks at its margin from a collision, and both guide-to-stem clearances inspected.

Photos are tricky, but the valve looks pretty white, and there seems to be a shadow at the top of the first pic that suggests the head has warped a skosh.
These are excessive heat signatures.

Excessive heat makes things come-from-together, one way or another; I smell a vacuum leak.

.....Cotten

[gary.h]

now i know to some this is not a big deal,but if that was my bike like that,the ole arse woulda puckered so tight,that if i farted only dogs would hear it!
joe i send you outmost my sincere condolences to valve and piston.........and other than a pan down,i hope all is good with you!,,,all the best to you joe.

[duffeycycles]

running too low octane gas causes flash burns creating heat.the valve stem swells, sticking in the guide.the cam goes away and the valve slams shut[pinging]the valve face tries to weld to the seat both from the heat and slamming closed,and the cam breaks the valve trying to free it from the seat. Or intake leak like Cotton says

[T. Cotten]

running too low octane gas causes flash burns creating heat.the valve stem swells, sticking in the guide.the cam goes away and the valve slams shut[pinging]the valve face tries to weld to the seat both from the heat and slamming closed,and the cam breaks the valve trying to free it from the seat. Or intake leak like Cotton says

Or the sticking valve gets clipped by the other valve, which calls for inspection of the stem-to-guide clearances:
A valve can stick in a wallowed guide just like a tight one.

....Cotten
PS: Gary H! I can recount the experience of my photo's example explicitly.
My sphincter was not involved.