Continental metallurgy specs?

[Edwin Otha]

Re: Continental metallurgy specs?

I was wondering the same thing.
If it's a 4 ring it's the old p/n 4544 piston. This can be verified with the pin diameter, should be .895. But it doesn't end there, there's an AD that put in a heavy wall pin, each pin has slip fit plugs but each are different part numbers and different I/D's.
If it has a .912 pin it shouldn't be a 4 ring piston. The later pistons had the .912 pins, but 3 rings for the 65, 5 rings for the 75 but ALL 75 pistons have a.895 pin.
The latest and greatest pin is the .912 diameter with the pressed in plugs, due to the fact that the other pin plugs would wear and put metal in the oil and wear the cylinder walls.
EO

[45 Tcraft]

Re: Continental metallurgy specs?

Rob,

Getting back to your original question - our lab has the capability to analyze and identify the aluminum alloys in the plug and piston you have. For something like that we could use spectral analysis, or maybe a Scanning Electron Microscope. However, looking at all the chips to identify them would be more time consuming - and to be honest, would be a bit more time (man hours) than I would be willing to volunteer for. Also, our lab is a research lab for an engine manufacturer - so, I would not offer a certified report as you would get from an independent lab for hire.

Given your situation, and what you are looking for, you're probably better off working with a local lab. Good luck with your investigation.

Randy

[Robert Lees]

Re: Continental metallurgy specs?

Thanks for the responses to date. I am awaiting a quote from a local independent certified lab.

It may be more than I am willing to pay, but I have a bee in my bonnet.

Rob

[Hank Jarrett]

Re: Continental metallurgy specs?

IF you have some fairly large chips you might be able to tell them apart by conductivity or hardness. Problem is that takes some larger chips.

Hank

Wish I still had access to the lab near me. They closed the facility years ago.

[Guest]

Re: Continental metallurgy specs?

Thanks for the responses to date. I am awaiting a quote from a local independent certified lab.

It may be more than I am willing to pay, but I have a bee in my bonnet.

Rob

Hi Rob,

Was there any remnant of the pin plug inside the pin?

What I am getting at is that if the plug had been present and wore down I would expect that the portion of the plug that fit in the pin i.d. would retreat into the pin and be salvaged. I think this because there is no force to push it out once the flanged end of the pin is gone.

Lack of residue (from plug) or remnant inside the pin might suggest the pin was never there.

Dave

[Robert Lees]

Re: Continental metallurgy specs?

Hi Rob,

Was there any remnant of the pin plug inside the pin?

What I am getting at is that if the plug had been present and wore down I would expect that the portion of the plug that fit in the pin i.d. would retreat into the pin and be salvaged. I think this because there is no force to push it out once the flanged end of the pin is gone.

Lack of residue (from plug) or remnant inside the pin might suggest the pin was never there.

Dave

The folks in Oregon who stripped the engine said that there was no remnant inside the pin.

[3Dreaming]

Re: Continental metallurgy specs?

Hi Rob,

Was there any remnant of the pin plug inside the pin?

What I am getting at is that if the plug had been present and wore down I would expect that the portion of the plug that fit in the pin i.d. would retreat into the pin and be salvaged. I think this because there is no force to push it out once the flanged end of the pin is gone.

Lack of residue (from plug) or remnant inside the pin might suggest the pin was never there.

Dave

The one that we had fail left very little in the pin. There was a small unrecognizable piece of aluminum that was still in the pin. When one fails I think it is in the bore of the pin, and then it just rolls around eating itself up.

[Guest]

Re: Continental metallurgy specs?

Thanks, good info.

I wonder about how much residue is left.

I bet that even when it bounces around and eats itself up that at some point the mass becomes so small that it stops "decaying" and remains at a fixed small size that is visible on teardown?

In other words even though you run it for a zillion hours the mass never completely disappears and does leave some residue.

Just a thought.

[PA1195]

Re: Continental metallurgy specs?

How did the side face of the piston in this thread get chewed up if the wrist pin plug was absent to begin with?

Gary

[Guest]

Re: Continental metallurgy specs?

Hmmm, good question Gary.

My tractor had all 8 plugs missing and had cylinder damage but no piston damage like Rob's pictures.

I assumed that the metal flakes from the cylinder caused the damage on Rob's.

However the tractor had much much worse cylinder damage that produced a lot of metal but not similar piston issue.

Dave

[Robert Lees]

Re: Continental metallurgy specs?

As I write, the errant piston is next to me, I brought it back from Oregon (so for 52 hours I was a 5-piston Taylorcraft!)

There is a chunk missing/deformed from the piston, between the fourth ring and the piston pin. That fourth ring is jammed in its groove due to deformation of the piston. Maybe that was the cause of my original high temperatures? The rectangular as-cast "flat" of the piston, where the pin fits, is almost polished by the hammering action of errant material. It's smoother than shot-peining.

That rectangular area around the piston pin is if course captive inside the cylinder bore, so any loose material in there cannot escape; hence I assume the hammered/polished surface.

I attach some more pics.

Rob

[PA1195]

Re: Continental metallurgy specs?

Just some amateur comments and questions that's all.

I'd check the fit of the wrist pin to piston pin bore on both sides to see if the worn side varies significantly. Any excess rocking to the pin and the plug if installed may have been compromised. If so and present it may have developed when the pin contacted the cylinder wall (note the two line damage to the wall and rolled pin end) and end friction on the pin increased, however.

The ring face wear-in looks exceptionally good even penetrating through the fourth ring. In my limited experience on some engines the third ring if present is lucky to have 50% wear due to decreasing combustion pressure down the piston away from the combustion chamber. Do these engines typically do that in the time it was run?

Looking at Post#9 the remaining cylinder cross-hatching seems excessive and rough (any expert opinion here?). I wonder if whoever did the cylinder build really hone scored the liner beyond recommend specs (via a coarse ball hone for example) and that contributed to early plug wear? Once the missing plug wore (if it was actually there) the pin would slide sideways and relieve wear from the remaining plug which appears normal.

The piston top above the rings and the skirt below on the burnished side appears scored more than the opposite. What's up with that?

Gary