Seized engine '50 Panhead

[loch]

Tops of the pistons look fine. I mean they're intact. Just covered with carbon. Not thick. But then I'm not sure how a piston in healthy engine is supposed to look. pretty much like the pictures shown. The rings are intact.

[dukekleman]

What does the other thrust face of each piston look like?

[loch]

Good morning, T, Duke,

I used my palm, makes more sense. I only questioned the mallet for clarity. No clunking sounds at the 90-degree positions starting at BDC. No twist-play in the pistons. Piston rings are intact. Expected carbon buildup on top of pistons and what might be burning along portions of the top edge of the piston. Could also be carbon though. The rear connecting rod is forked.


The front piston is first.



FrontPistonPanhead.jpg



RearPistonPanhead.jpg

[T. Cotten]

I always used my palm, too, Duke!

Its hard to listen for something if the mallet makes the noise.

When fitting rods, I measured the sideplay of the wristpin end with a dial indicator. But wear and stretch quickly widens the arc of play, so we have no baseline, really. But if there's noticeable play on the female rod top, I declared them 'tired'.

Once again, running rich can be agravated by carb issues, but usually it is because the motor demands it, usually because of extra oxygen.

....Cotten

[dukekleman]

Loch,
I would suggest you do not strike the rod with a mallet as you questioned. Doing so can cause surface issues with the bearings. Instead use the palm of your hand. Keep in mind that the crank pin will surface wear on the peak pressure portion of the pin. Meaning you should perform this check in 4 places, every 90 degrees...
As far as motor oil turning so dark in as little as 80 miles I would question a few things. 1) Was it contaminated by the previous oil ? 2) Excessively rich air fuel ratios, which sadly is to common, build carbon quickly, wash the cylinder walls and carry the black soot in the fuel wash through the cross hatch of the cylinder walls, past the piston rings and into your oil sump. This not only lessons the oils ability to lubricate, seal, cool and clean your piston skirts and rings but greater increases the darkness of your motor oil.

[joe fxs fxr]

You can try twisting the front piston/rod, if it moves, you have too much play. That's the forked one, right?

[loch]

Thanks, Fred.

I guess you mean to pull up on the rods individually and then strike them with a mallet? Is this to check for free play in the shaft bearings?

[PanheadFred1]

Take off the gear case cover...if you haven't already and make sure it's clean inside there. One way to check out the crank is to pull up on each rod pretty firm and while holding upward pressure, smack down on the rod. If you hear any kind of clunk... you'll need to investigate more

[loch]

So what I started to ask a few posts back and don't think I was clear in my question;

Is there a definitive reason to crack open the cases and rebuild the bottom end?

I see the benefit of basically having a rebuilt engine at the end of it all. But is it necessary? Looking for some advice here.

Follow on:

Is there a telltale sign, some obvious indicator that cracking the cases is warranted? What should I be looking for?

Personal history, I learned, or was told, a long time ago, with my first shovel, not to get into the lower end unless it was necessary. That most of the time, when engine work is warranted, beyond the carburetor, it most likely would be the top end. If ain't broke, don't fix it. The antithesis of: if it's broke, we can fix it, if it ain't we can fix that too. Trying to avoid the latter here.

I'm going to drain the remaining oil into a clean pan. The cylinders are off and look pretty good. Could use a honing and with that new rings.

- Loch

Update:

I drained the remaining oil from the crankcase. There was a lot more than I expected would be in there. Filled a 9in pie pan and then some. And black. Which is still concerning to me because it only had about 80 miles of service. I also realized that I was using the incorrect weight oil. I had 20W 50 in the garage for my brother's Softail. I believe that's what I used when I changed the Panhead oil last summer.

[loch]

Thanks, T!

That's actually hilarious! And makes perfect sense. Yes, I figured the oil level in the tranny was too high. That was my first thought. But while I've got engine out I might as well take a look at the shaft and replace the seal.

Loch

[T. Cotten]

...To seal kicker arm: replace bushings if loose & replace the seal between the 2 bushings.
Note: if you are leaking that much out of the kicker arm bushing, your tranny oil level is way too high.

Don't forget the kickerarm shaft can be worn oval, Knucklehead61!

(They never wear round...)

....Cotten

[knucklehead 61]

By way of an update:

Drained the oil tank, the engine oil is black (only about 80 miles on the oil). I'm thinking it shouldn't be black. Maybe dark with a slight hint of its original amber color. But not pitch-black. Found tiny metal shavings (used a magnet to check sludge caked on rocker blocks) near rocker arm oil holes. Not just a few, but caked with what looks like wet carbon or oil gunk or something.

Looking for the best way to pull engine sprocket. I tried tapping with a mallet but it's not wanting to come off very easily. I'm thinking gear puller. But I'm concerned it might damage primary chain or gear teeth.

The sprocket nut is off. And I found a recipe for creating a chock-block with an old plastic cutting board. Worked like a champ! Chock + socket-on-breaker bar + WD40 + 20min soak time = easy removal.

I also discovered the [seal?] on the kicker is definitely leaking oil - unexpected puddle on the floor under kicker. Not coming from the transmission cover, but from the kicker shaft.

To remove gear: use a 3 jaw puller, apply tension & give the center bolt a sharp blow with a hammer or tap the edge of the gear with a hammer.
To seal kicker arm: replace bushings if loose & replace the seal between the 2 bushings.
Note: if you are leaking that much out of the kicker arm bushing, your tranny oil level is way too high.

[loch]

By way of an update:

Drained the oil tank, the engine oil is black (only about 80 miles on the oil). I'm thinking it shouldn't be black. Maybe dark with a slight hint of its original amber color. But not pitch-black. Found tiny metal shavings (used a magnet to check sludge caked on rocker blocks) near rocker arm oil holes. Not just a few, but caked with what looks like wet carbon or oil gunk or something.

Looking for the best way to pull engine sprocket. I tried tapping with a mallet but it's not wanting to come off very easily. I'm thinking gear puller. But I'm concerned it might damage primary chain or gear teeth.

The sprocket nut is off. And I found a recipe for creating a chock-block with an old plastic cutting board. Worked like a champ! Chock + socket-on-breaker bar + WD40 + 20min soak time = easy removal.

I also discovered the [seal?] on the kicker is definitely leaking oil - unexpected puddle on the floor under kicker. Not coming from the transmission cover, but from the kicker shaft.

[T. Cotten]

Just a word of advice for your leaking nipples; check the rivets for leaks also. I had to turn oversized ones for my ULH. Been there but I don’t envy your leaky nipple problems.

For oversized rivets, Otis,

I soaked large nails in hot coals and let them cool overnight, and then cut to fit the minimum the original holes would clean up round.

The important thing was to make the head conical instead of flat, so it would squeeze in and plug the hole, when pressed outward with a cam-shaped "buck", as Knucklehead61 mentioned.

A flat head rivet is difficult to seal upon the curved ID of the nipple!

....Cotten

[otis71]

Just a word of advice for your leaking nipples; check the rivets for leaks also. I had to turn oversized ones for my ULH. Been there but I don’t envy your leaky nipple problems.