Author Topic: Chris's Build of a Stanley 735 Engine  (Read 44309 times)

Online crueby

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Re: Chris's Build of a Stanley 735 Engine
« Reply #150 on: January 16, 2020, 12:05:49 AM »
I think the naming convention is spools in hydraulic valves, piston valves for steam. Also pi$$ed-on valves for the leaky ones I have made before I learned the tricks about PTFE rings on piston valves, and radii at window corners in port openings on sleeves for piston valves.   ::) :lolb:
I like the leaky valve name!

On the valves for this engine, the original used steel rings, I was thinking of not using any since o rings and such would tend to get cut by the openings, and they would need to be in pairs to work right with the openings designed for the original. Had not thought about PTFE rings though. Would they work better for going past the openings? They used a row of 'windows' around the circumference, rectangular with rounded corners. I have no experience with that kind of setup, was just going to use a bronze piston (with two sections riding on the sleeve inner wall, thinner above/below/between them to allow steam/air flow). Always an issue to get a decent enough seal while allowing it to move, thats why I like slide valves better for most engines. The sleeve ID will only be around 3/8" or so, the ports are .078" tall as scaled from the original.

Offline Johnmcc69

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Re: Chris's Build of a Stanley 735 Engine
« Reply #151 on: January 16, 2020, 02:35:55 AM »
 :ThumbsUp:
 Looking good Chris!
 Why did you use the metric (Not that there's anything wrong with
 that... 8) ) threads on the cylinders & caps? Did the size just work out better?

 John

Online crueby

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Re: Chris's Build of a Stanley 735 Engine
« Reply #152 on: January 16, 2020, 03:18:32 AM »
:ThumbsUp:
 Looking good Chris!
 Why did you use the metric (Not that there's anything wrong with
 that... 8) ) threads on the cylinders & caps? Did the size just work out better?

 John
Hi John,


Its a function of the gear set. The sherline thread cutting attachment comes with gears that will do both imperial and metric pitches, but with the riser block in place only the metric combination will reach that high. You can buy additional gears to do inch pitches with the riser, but I didn't want to take the time and expense to get them. As a one off set of parts that only have to match each other, I just picked a combination that would be coarse enough to be strong and fine enough to fit the space. Many choices would have worked.
Normally I use both systems in taps and dies, picking what fits the parts, so no real difference here.

Online cnr6400

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Re: Chris's Build of a Stanley 735 Engine
« Reply #153 on: January 16, 2020, 01:33:48 PM »
"On the valves for this engine, the original used steel rings, I was thinking of not using any since o rings and such would tend to get cut by the openings, and they would need to be in pairs to work right with the openings designed for the original. Had not thought about PTFE rings though. Would they work better for going past the openings? They used a row of 'windows' around the circumference, rectangular with rounded corners. I have no experience with that kind of setup, was just going to use a bronze piston (with two sections riding on the sleeve inner wall, thinner above/below/between them to allow steam/air flow). Always an issue to get a decent enough seal while allowing it to move, thats why I like slide valves better for most engines. The sleeve ID will only be around 3/8" or so, the ports are .078" tall as scaled from the original."

For a 3/8" sleeve ID probably a lapped sleeve and a lapped-to-match solid bronze piston valve would be best option. Rings of any kind on such a small bore would be difficult to do with enough gap to work but not too much clearance, and getting a scarfed / angled split in the ring that didn't catch the port openings. The PTFE rings I mentioned I have experience with were on 1" and 1 1/2" dia piston valves, much bigger than 3/8" dia and easy enough to do - no watchmaking needed!

Are you thinking a steel sleeve or could you do a cast iron one? The self lubing properties of cast iron would make for a very low friction running fit to a lapped bronze valve. Probably be very smooth in operation.

Note to any of Chris' elves reading the above - I said lapping, not lap dancing! and egg nog is NOT a good lapping compound, with or without Navy rum - don't even go there!  :hellno:  :Lol:
"I've cut that stock three times, and it's still too short!"

Online crueby

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Re: Chris's Build of a Stanley 735 Engine
« Reply #154 on: January 16, 2020, 02:25:33 PM »
Thanks CNR, great info. I was thinking of using the 303 for the sleeve with bearing bronze for the valve, had not thought of cast iron. Machining a very thin wall in cast iron, 1.25" long with holes in the side sounds like it might be tricky? Might be safer to use the steel.

Online cnr6400

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Re: Chris's Build of a Stanley 735 Engine
« Reply #155 on: January 16, 2020, 02:37:52 PM »
Hi Chris, if you wanted to make the sleeve in cast iron, just get a small piece of Meehanite or other continuous cast iron bar. The sleeve will be a walk in the part with that stuff. My suggestion - turn it to be say .188" wall per side outside your finished ID, bore, cut the port windows, turn OD to finish size, lap would be my suggested order of ops. Just food for thought, there are are many materials and methods that will work fine.
"I've cut that stock three times, and it's still too short!"

Online crueby

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Re: Chris's Build of a Stanley 735 Engine
« Reply #156 on: January 16, 2020, 02:40:27 PM »
Hi Chris, if you wanted to make the sleeve in cast iron, just get a small piece of Meehanite or other continuous cast iron bar. The sleeve will be a walk in the part with that stuff. My suggestion - turn it to be say .188" wall per side outside your finished ID, bore, cut the port windows, turn OD to finish size, lap would be my suggested order of ops. Just food for thought, there are are many materials and methods that will work fine.
I'll get some and give it a try, thanks! I take it that it has a different grain structure and strength properties?

Online cnr6400

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Re: Chris's Build of a Stanley 735 Engine
« Reply #157 on: January 16, 2020, 02:55:49 PM »
The Meehanite or similar continuous cast bar has very even grain all across and through the bar, and grain size is consistent and medium size. There are no chilled areas or voids in the iron, in my experience, unlike many cast-to-shape iron parts done by sand casting. I've carved many engine cylinders, covers, steam chests etc from the continuous cast bar with every success. On valve faces a careful sanding with the paper laying on a surface plate , and figure 8 polishing motion, gives a perfect finish for bronze slide valves to seal on. Lapping piston valve bores in this type of CI gives a perfect finish for many types of piston valves. It is dirty to machine though - the graphite in the iron, that gives it the self lube property, gets everywhere while machining. You join the black finger club right away.  :Lol:
"I've cut that stock three times, and it's still too short!"

Online cnr6400

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Re: Chris's Build of a Stanley 735 Engine
« Reply #158 on: January 16, 2020, 03:02:00 PM »
By the way, there is no secret handshake, and no dues fee payable, in the black finger club. Members worldwide too.   :Lol:

People with itchy ears also get free membership in the black ear-'ole club too.  :shrug:
"I've cut that stock three times, and it's still too short!"

Offline zeeprogrammer

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Re: Chris's Build of a Stanley 735 Engine
« Reply #159 on: January 16, 2020, 03:05:46 PM »
By the way, there is no secret handshake, and no dues fee payable, in the black finger club. Members worldwide too.   :Lol:

People with itchy ears also get free membership in the black ear-'ole club too.  :shrug:

 :lolb:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Online crueby

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Re: Chris's Build of a Stanley 735 Engine
« Reply #160 on: January 16, 2020, 03:09:18 PM »
By the way, there is no secret handshake, and no dues fee payable, in the black finger club. Members worldwide too.   :Lol:

People with itchy ears also get free membership in the black ear-'ole club too.  :shrug:

 :lolb:
:)   :ROFL:
Here is the shop elves dog before and after machining cast iron...


 
« Last Edit: January 16, 2020, 03:40:37 PM by crueby »

Online crueby

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Re: Chris's Build of a Stanley 735 Engine
« Reply #161 on: January 16, 2020, 03:48:43 PM »
Looking around for Meehanite - is that basically the same as 'Durabar'? And are they different than 'Gray' cast iron rod? Lots of names, not sure what to look for. I dont see Meehanite at my usual sources here in the US. Suggestions?

Offline Brian Rupnow

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Re: Chris's Build of a Stanley 735 Engine
« Reply #162 on: January 16, 2020, 04:23:22 PM »
My metal supplier carries round bars of grey cast iron. Beautiful stuff to machine, no voids, no hard spots and no particular grain to it. As CNR says, it's dirty stuff, but a real pleasure to machine. I make all my i.c. cylinders from it.---Brian

Online crueby

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Re: Chris's Build of a Stanley 735 Engine
« Reply #163 on: January 16, 2020, 04:43:54 PM »
My metal supplier carries round bars of grey cast iron. Beautiful stuff to machine, no voids, no hard spots and no particular grain to it. As CNR says, it's dirty stuff, but a real pleasure to machine. I make all my i.c. cylinders from it.---Brian
So the grey cast iron is the continuous cast type CNR is talking about? That I see at a number of suppliers, sounds like it is worth a try for this valve sleeve. The only cast iron I had used before was from sand castings, sounds like quite a different beast.
I see Speedy Metals has some 5/8" gray cast round bar at a great price, says it is 'class 40', my searching shows the higher the class number the higher the strength. Would that be suitable for this?

Offline Brian Rupnow

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Re: Chris's Build of a Stanley 735 Engine
« Reply #164 on: January 16, 2020, 05:18:04 PM »
The grey cast iron I get doesn't have "class numbers" that I know of. I just tried to call my supplier but he's on lunch. i will call him again after 12:30 and see if he knows anything about "classes" of grey cast iron.

 

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