old Henry's engine

[40 Deluxe]

Quote: "That fourth ring helps stabilize the long skirt on a 4-ring...."
Not so! A piston ring, any ring, has to float freely in it's groove to do it's job-a stuck ring causes blow-by and/or high oil consumption. Since the ring is free-floating, it cannot impart any force to the piston, "stabilizing" or otherwise. Actually, the piston is stabilizing the ring, holding it square to the cylinder for the best ring-to-wall contact. Excessive piston clearance allows the piston to rock, "tipping" the ring thus causing it to lose full contact with the cylinder wall and wearing the ring face.
Again, a ring can't stabilize a piston. Now, some old school one piece oil rings had a thin 'zig-zag' type expander behind the ring; usually found on re-ring sets for worn piston skirts and/or cylinder walls, as I remember. Could this little strip of metal "stabilize" the piston, holding it centered in the bore (the piston skirt not touching the cylinder wall)? I doubt it. At mid-stroke, with the rod angled 1 7/8"-2" from center, and several hundred pounds of combustion pressure on the piston, I think the skirt is going to contact the cylinder wall! Same when the crank is pushing the piston up on the exhaust and compression strokes. If all that force on the piston skirt is transferred to the ring (to"stabilize" the piston), we're going to have some extremely short ring life!

[Ronnie]

Originally Posted by 40 Deluxe

Quote: "That fourth ring helps stabilize the long skirt on a 4-ring...."
Not so! A piston ring, any ring, has to float freely in it's groove to do it's job-a stuck ring causes blow-by and/or high oil consumption. Since the ring is free-floating, it cannot impart any force to the piston, "stabilizing" or otherwise. Actually, the piston is stabilizing the ring, holding it square to the cylinder for the best ring-to-wall contact. Excessive piston clearance allows the piston to rock, "tipping" the ring thus causing it to lose full contact with the cylinder wall and wearing the ring face.
Again, a ring can't stabilize a piston. Now, some old school one piece oil rings had a thin 'zig-zag' type expander behind the ring; usually found on re-ring sets for worn piston skirts and/or cylinder walls, as I remember. Could this little strip of metal "stabilize" the piston, holding it centered in the bore (the piston skirt not touching the cylinder wall)? I doubt it. At mid-stroke, with the rod angled 1 7/8"-2" from center, and several hundred pounds of combustion pressure on the piston, I think the skirt is going to contact the cylinder wall! Same when the crank is pushing the piston up on the exhaust and compression strokes. If all that force on the piston skirt is transferred to the ring (to"stabilize" the piston), we're going to have some extremely short ring life!

You need to read the following info pages on piston being stabilized by the rings.

Rings
Piston rings perform a number of important functions. They seal the gap between the piston and cylinder wall to prevent combustion gases from blowing by into the crankcase. They stabilize the piston as it travels up and down in the bore. They help cool the piston by transferring heat into the engine block. And they scrape oil off the cylinder walls. That’s a tall order, and in recent years the theory on how to make rings best carry out these tasks has undergone revision.

Read more: http://www.carcraft.com/techarticles...#ixzz2UyCnIfzv

The overall purpose of the ring package is to stabilize the piston in the cylinder, lubricate the piston and pin, keep the oil in the crankcase, and maintain compression in the combustion chamber. We want a ring as small and thin as needed to control the issues of the package.

Read more: http://www.circletrack.com/techartic...#ixzz2UyEfb6EH

http://www.costex.com/Library/articles/IT05.pdf

R

[rotorwrench]

Pistons rock each and every time they change directions. They will move around even more if there isn't something there to act as a buffer. The oil control rings (for tha lack of a better term) squeegee a film of oil each time they go down. This oil film has to go somewhere. Just look at an oil control ring and its corresponding ring groove in the piston and you can see where they want it to go. This oil film also acts as a cushion between the ring and the piston as well as the piston and the cylinder wall. What seem simple to some can be complex for others.

[Old Henry]

Here's a picture comparing the newer three ring pistons Doc put in 30,000 miles ago to my original 4 ring. The newer three ring is 17.1 oz. compared to my original that's 17.8 oz..



Inside the three ring:



Inside my original 4 ring



What meaningful differences do you see in them?
Can anyone tell the brand of the newer three ring?

The three ring that came apart:




Here's the newest 4 ring Doc just put in compared to my original from post # 22 so you can compare the newer three ring to the new four ring. The new 4 ring weighs 19.3 oz.

[al's28/33]

Thanks for these updates Professor!! I hope you get the ol' gal out for your next adventure, looking forward to seeing and reading your next posts!

[Old Henry]

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One thing I see right off is that the newer three ring is missing a bunch of metal around the pin hole. Don't know if that's good or bad. What do you think?

And the slot for the oil ring looks way too wide for it. What's with that?

[Old Henry]

Originally Posted by al's28/33

Thanks for these updates Professor!! I hope you get the ol' gal out for your next adventure, looking forward to seeing and reading your next posts!

Dropped in to Doc's yesterday to check status and he was just putting the last coat of paint on the engine and bolting the intake and oil filter on. I'm picking it up today to put in some night next week when Chuck can come down and help me.

I'm still counting on the trip to Glacier/Waterton National Park in two weeks.

[cmbrucew]

Prof.

Good luck on your new rebuild.
May you get many miles of pleasure from it.
We are all looking forward to more of your tour pictures.

Bruce

Works good
Lasts long time

[rotorwrench]

Originally Posted by Old Henry

One thing I see right off is that the newer three ring is missing a bunch of metal around the pin hole. Don't know if that's good or bad. What do you think?

And the slot for the oil ring looks way too wide for it. What's with that?

With pistons, its all about expansion under heat. The old 4-ring piston has a split in the skirt to allow for expansion. The later 3-ring has the area around the pin holes relieved to allow for expansion. The later 4-ring was designed to get expansion in other ways. One being the fourth ring groove.

The slot in the oil control ring grooves allow oil to pass through when it builds up during the down strokes. That later 3-ring may have had a bit too much relief in there. You can see in the new 4-ring design that the drain back reliefs are smaller to give more structural strength at that point.

The latest technology of high silicon aluminum castings, (Hypereutectic) allow for much less expansion due to the later type material used. Many pistons that are made this way are nearly as strong as forged and they expand less than any standard aluminum casting prior to that technology application. The only hypereutectic designs for flatheads that I am aware of were marketed by Speedway Motors but I don't think thay are available any longer. They are a modern 3-ring design that should work well. I just don't know why they stopped marketing them. If well designed & manufactured, they would be a superior design for street motors.

Here is a wiki link: http://en.wikipedia.org/wiki/Hypereutectic_piston

[Old Henry]

Doc Roger and my engine I picked up today.



Gotta comment about this guy. He is a dying breed. As I said before, he retired 3½ years ago and wasn't going to do any more engine rebuilding. Mine was the last. He was going to work on his own cars that he'd had for many years and drive them - take some road trips. My memories of him saying that put me in deep despair when my engine broke and needed his service again. I had no idea of anyone else that I could get to do it and was so relieved when I found out that he was still rebuilding flatheads. He had worked on some of his cars some but had not driven them much and no road trips as he'd dreamed of.

So, why is still living at his dark dingy shop when he could be out playing? Here's how he put it as I visited with him today, "If I just turned off the lights and closed my doors forever a lot of people would be hurt." He's talking about all of the people like me that still need his very valuable service and couldn't get it done as well or as near as he does and is. He doesn't need to keep slugging away at flatheads. But he keeps on keeping on because there's no one else to do it and it's a job that still desperately needs doing.

I told him several times today that he was my hero. (I had to keep reminding him because he'd read this thread and thought I was critical of him. I hope that I was not. I did not intend to be.) It is him and his very fine skills honed over a lifetime of experience that has made it possible for me to enjoy the passion that I have to drive my time machine every chance I get and share that passion with others that I love.

Doc has had a lot of young guys working with him in his shop that he hoped would learn the trade and take over the mission to keep flatheads running. Most have not had the stamina to make it and the good ones ended up getting jobs in mechanic shops working on newer engines. As Doc put it: he is one of the youngest (at 70) of the "old guys" that do what he does and he fears that when he and his kind are gone there will be fewer and fewer that really know and care about flatheads, what really makes them tick, and how to get them to tick better than most.

I sense that there are other "heroes" out there still slugging away at the flatheads as well - not just their own but other's as well. My hat is off and I salute each and every one of you, and especially my own personal hero, Doc Roger.

[Old Henry]

More about the Doc and the kind of guy he is that I think is dying in the world:

When he called me after taking apart my broken engine and told me of the damage to the cylinder we discussed what to do. He wondered whether I just wanted to try to "patch it together" with a new piston and cylinder sleeve or what. From my experience with him before I knew what a mechanical perfectionist he was and how much it would bug him to do such a minimal job. Fortunately, we were on the same page as far as that went. I drive Old Henry A LOT and wanted the engine as good as he could possibly make it. It started with replacing all of the pistons as I've said before. But, as he was "cleaning up" the valves to reuse them, some were so dirty that by the time he cleaned them up there was not much left of the edge between the face and the top (something I just about had to use a microscope to see - couldn't even get a good picture of it) so they all had to go and he replaced all of the valves, lifters, springs, and guides, using the improved 49-53 solid guides instead of the original split guides because no one made them to the tight tolerances that he required any more. Here are the two kind of guides he was talking about:



Also, the color of the top of the valves was not right. They were supposed to be a light brown and mine were something else.
(Correctly "toasted" valve on the left. Mine on the right)



We discussed the excessive carbon on the tops of the pistons as well as the improperly "toasted" valves and decided that the larger carburetor jets I'd been using to reduce pinging were too rich so I'll be stepping those down to the next smaller size.

Doc found a lot of other surfaces and clearances that were not up to his specifications and fixed all of those as well so that now I've got an engine better than new and maybe even a bit better than the last time he rebuilt it. That's the kind of guy he is - passionate about his work and continually learning and improving it all that he can. My hero - Doc Roger.

[El Rat]

After 30K it isn't reasonable that the piston pin rod had clearance issues. Most likely is the piston cracked and ultimately garbaged the deal! Just saying...

[Mtn Wudy]

I wished I lived closer ,,,I'd come over and help you put that "Blue Beauty" back in .....A lot of us would just to get you and your camera back out on the road...Keep us posted..!! Carl

[Old Henry]

Originally Posted by Mtn Wudy

I wished I lived closer ,,,I'd come over and help you put that "Blue Beauty" back in .....A lot of us would just to get you and your camera back out on the road...Keep us posted..!! Carl

Old Chuckles from up the street came down tonight and helped me put the "Blue Beauty" in. Now if I can just find the other engine mount bolt!!!

[Old Henry]

Originally Posted by El Rat

After 30K it isn't reasonable that the piston pin rod had clearance issues. Most likely is the piston cracked and ultimately garbaged the deal! Just saying...

Agreed. That's my take on it too.

[AlDeBear]

Lookin' good Professor! Best of luck on your next 80,000 miles! Larry

[Admiral]

Lookin' good! Following your engine saga is fascinating, Old Henry. It's an unfortunate story but one that's very interesting nonetheless. Thanks for sharing and I hope your beautifully rebuilt flathead lasts much, much longer than 30,000 miles. Is that the correct blue color? It seems quite bright but it could just be the camera or my computer screen... or my eyes.

[Old Henry]

Originally Posted by Admiral

Is that the correct blue color? It seems quite bright but it could just be the camera or my computer screen... or my eyes.

It's the correct color. It doesn't look that bright in real life. The lighting and increased contrast brightened it up a bit for the "Blue Beauty" photo.