Popular Mechanics 1962 PM38 Build [SPLASHED 2017]

[archbuilder]

The style I have would work if you put the crank on later. And the crank end of the rod is smaller than the piston. It is from Summit racing, but I doubt they would have one that small. Most of them are for around 3.75" and larger.

 

[pekstrom]

The ring compressor was too tall?

Poor man's ring compressor - Grease, a strip of aluminum flashing and a hose clamp. Smear some grease on the piston and rings, single wrap the flashing around the piston and hold it all with the hose clamp around the rings. Tighten the hose clamp until the piston barely moves inside flashing, insert the piston into the bore and lightly tap the piston through the flashing.

I've done it with just the hose clamp and grease. but the flashing protects the clamp from scratching the piston. I would insert the pistons first and install the crank after both pistons are in the bore.

No, not too tall, but it just didn't seem to compress the rings very well. It didn't stay round. And it didn't fit all that great in the bevel of the cylinder so the rings popped out when I tried to push the piston into the cylinder. Now that I have thought about it some more, there are two slots in the cylinder wall at the bottom where those claw compression tools would go. So now I am wondering if I can just compress the rings enough with my fingers and insert them while my fingers go into those slots. I'll have to look at it some more. It wouldn't be the first time I've overthought something. :facepalm: :lol:

I also like your suggestion of flashing and a hose clamp. I'll have to keep that one in mind too. Thanks for that!

In the service manual they show how they insert both pistons at the same time while attached to the crank shaft using those claw tools. I'm thinking you are right though, inserting them first and then attaching the crank chaft does seem like it should be much easier in my case.

 

[pekstrom]

The style I have would work if you put the crank on later. And the crank end of the rod is smaller than the piston. It is from Summit racing, but I doubt they would have one that small. Most of them are for around 3.75" and larger.

I looked at yours and found it on the interwebz, but like you said, unfortunately they don't have one for my bore size. They have one slightly smaller but it would be too small. The next one up was for a 3.something bore which would be way too big.

I'll see what I can come up with.

 

[pekstrom]

Well now...



So, turns out it was user-error that caused my issues the other day. :facepalm: :mad-new: (No real surprise.) I am sure other ring compressors work better, but once I figured out why the ring broke last time, it went so much easier. I had been thinking it was a little strange that the rings could just rotate around the piston so there's a chance of the gaps lining up, which would cause problems with compression I would think. So while I was looking at things today, I noticed they had thought of that. I'm sure y'all seasoned engine tinkerers already knew this but this newbie didn't. :wave: There are little nubs in the grooves where the rings sit, preventing them from rotating! So once I figured that out, I was able to get the compressor to properly compress the rings, and viola! So now my theory is that the ring broke because I was putting pressure on it with the compressor while the nub was in the wrong place. Live and learn. Luckily a new ring isn't expensive, but I do have to wait for it.

A question though, I realize there should be a rather tight fit in the cylinder, but should I be able to pull the piston back and forth easily, or should there be quite a bit of resistance? I used some assembly lube on the walls and piston, and later added some 4-stroke oil on the cylinder walls. But it takes both hands and quite a bit of force to move it. Would this be an indication I need to hone the cylinders?

 

[GA_Boater]

The locating pins stop rings from rotating so the gap isn't caught on the ports. Catching on a port leads to broken rings.

New rings are pretty tight in the bore. I would hone a used block to break the glaze on the cylinder walls so the rings break-in sometime during your lifetime, not because the pistons are hard to move by hand.

 

[pekstrom]

The locating pins stop rings from rotating so the gap isn't caught on the ports. Catching on a port leads to broken rings.

New rings are pretty tight in the bore. I would hone a used block to break the glaze on the cylinder walls so the rings break-in sometime during your lifetime, not because the pistons are hard to move by hand.

Ah, that makes much more sense than losing compression. Broken rings would most likely also lead to badly scratched cylinder walls I can imagine.

Ok, cool, so tight fit isn't necessarily a sign of problems then. I'm thinking friction building heat. This is the first time I have worked with an engine to this level so, lots to learn. What type of hone would you recommend? I have seen the ones that look kinda like a dish drush with balls on the ends of the bristles. I have also seen a 3-armed deal with a stone at the end of each arm. The arms are springloaded. So would either work? I believe I saw Arch use the one with the balls on the ends.

 

[pekstrom]

Ah, that makes much more sense than losing compression. Broken rings would most likely also lead to badly scratched cylinder walls I can imagine.

Ok, cool, so tight fit isn't necessarily a sign of problems then. I'm thinking friction building heat. This is the first time I have worked with an engine to this level so, lots to learn. What type of hone would you recommend? I have seen the ones that look kinda like a dish drush with balls on the ends of the bristles. I have also seen a 3-armed deal with a stone at the end of each arm. The arms are springloaded. So would either work? I believe I saw Arch use the one with the balls on the ends.

I actually like the Flex Hone tool. I believe that's what Archbuilder used on his engine. What I am unsure of though is if silicon carbide would be hard enough for the cylinders in my engine? Does anyone know?

 

[GA_Boater]

All I ever used was the 3 stoner, but the ball hone may good too. Who has used a ball hone? Guys?

 

[Baylinerchuck]

I used the three stone glaze breaker. A little oil, cordless drill, and a minute or less is all it takes. Tried to use one on a chrome bore one time......learned a lesson that day, lol.

 

[pekstrom]

I decided on the ball hone after reading some folks having good luck with it, and also reading about some folks who had problems trying to use the 3-stone hone. In the end it probably doesn't matter but we'll see. I haven't gotten it yet.

But another issue that has me perplexed... I have a 732-2735A2 piston kit. Per the parts list I have I found that the rings are 39-32921, so I ordered one. Turns out one meant a set of 3, since the piston is a 3-ring piston I guess. But the problem is that the rings are a tiny bit too thick, so they don't fit in the groove on the piston. Not sure what I am missing?

 

[pekstrom]

So I’m not sure what’s up with those rings but they definitely don’t fit the piston. So I opted to just get another NOS piston kit. I found one for $40 which isn’t bad. I have been in the hospital for about a week and just found out I need a pacemaker. So that’s getting installed later today. Hopefully be back home tomorrow. Can’t wait to get this engine together!

 

[GA_Boater]

I hope the Doc doesn't run into a stuck rod nut like you, Pek. I should say connecting rod nut, but the heck with it.

Take care of yourself and don't over do it when you get home.

 

[archbuilder]

Hope all goes well and you are back at it soon!

 

[kcassells]

Hey Perk, Only the best to you and your situation. Just take it easy. Boats always there! Take care of YOUR engine first.

 

[Baylinerchuck]

Take care of YOUR engine first.

Definitely!!! What he said.....

 

[pekstrom]

Thanks for the kind words guys! They are greatly appreciated!

It is good to be back home. Of course now I have to stare at the hone and soon the new piston kit as well. It'll probably be at least 2 months before I can get back to working on it. But it'll be ok. For now I'm just going to enjoy the Admiral's care.

 

[Pcolafisher]

Just back on from Sally. Sorry to hear about your timing issue. Spend the time to fully recover! The engine will wait!
Best wishes!
Cheers

 

[pekstrom]

Just back on from Sally. Sorry to hear about your timing issue. Spend the time to fully recover! The engine will wait!
Best wishes!
Cheers

Thank you Pcola, I appreciate the kind words! Perhaps I should have gone for a new set of points! :lol:

I was watching the weather channel quite a bit during the hospital stay and it looked like Sally hit the coast pretty hard. It amazed me to see the reporters standing in waist deep water! I take it you are in the area that got impacted? Hope everyone is ok!

 

[Pcolafisher]

We’re all okay. I have the trees off the house,garage,and shop. I completed the two worst roof repairs, but still have to replace a lot of roof cap shingles and a few others that have missing tabs. Then, there is a good size area of the garage roof to repair, but it isn’t leaking yet. Tomorrow ceiling replacement in front of the fireplace where flashing and roof failed. Still have a lot of chainsaw and hauling work.
Cheers

 

[pekstrom]

We’re all okay. I have the trees off the house,garage,and shop. I completed the two worst roof repairs, but still have to replace a lot of roof cap shingles and a few others that have missing tabs. Then, there is a good size area of the garage roof to repair, but it isn’t leaking yet. Tomorrow ceiling replacement in front of the fireplace where flashing and roof failed. Still have a lot of chainsaw and hauling work.
Cheers

Oh wow! It's been a while. The new timing system seems to be working out so far.

Pcola, I'm glad y'all are ok. I know there's been a bit more rough weather in your area sinc last time so I hope y'all are still ok?

I'm looking to pick back up soon on the motor assembly. During my adjustment to the new electronic ignition system I have been sidetracked on one of my vintage (home) comupter projects... Too many hobbies.

I hope everyone who celebrate it has a great Thanksgiving!