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Stronger engine frame rods
Posted by: Mike Clark (IP Logged)
Date: September 27, 2003 05:55PM
<HTML>
Have recently broken an engine frame rod ( the original, presumably extremely fatigued, 3/4 “ mild steel ) on my H engine which has the dry 3 and 5/8th by 5 inch 20hp type common to both the H and the Model F Stanley I am wondering if anyone has experience of using higher grade steel for frame rods?
I am thinking of either a straight 0.4% carbon steel (UK EN 8 / US SAE 1040) or an alloy steel such as EN24 / US SAE4340 – a nickel chrome molybdenum alloy which is approved for helicopter rotor shafts – can’t get more critical than that! I would use the “T” grade which is supplied heat treated to the maximum reasonably machinable hardness (55 Tons tensile per square inch).
My concern is whether the brazing of the joint to the crosshead brackets leads to either embrittlement if cooling is too rapid or just to a soft area in which bending stresses will congregate. Has anyone tried? We will use silver solder rather than brass braze to keep the temperature down to 650C instead of 900.
The rod broke on the cylinder side of the crankshaft bearing block, actually, as one would expect, through the thread, between the threaded collar and the bearing block. I propose to machine my new rods from thicker bar so that this collar can be an integral part of the rod with a nice filet radius. Made like this the thread only needs to start at the other end of the bearing block and the rod will be much stronger where it goes through the bearing block. I also wonder whether to stiffen up the rod by carrying a thicker diameter through as far as the crosshead bracket. Any views on this?
I have tried as much as possible to keep original 1907 bits in use but there comes a point where this is impossible as they are just plain knackered! The block repair which I did last year is holding up fine, although I have had patterns made to cast a new stronger block which I shall fit to my spare engine just in case.
The car has now done getting on for 2000 miles since I finished it, 1600 of which has been on the welded block. I usually push it reasonably hard when near home to find any defects, rather than having a breakdown on tour and so far have succeeded in this as it has only once packed up on tour (broken perch rod). I should say that the road to my house has a short stretch of uphill 25% grade where I am forced to go slowly past my neighbour’s front door – this is the critical test of block and frame rods.
Mike</HTML>
Have recently broken an engine frame rod ( the original, presumably extremely fatigued, 3/4 “ mild steel ) on my H engine which has the dry 3 and 5/8th by 5 inch 20hp type common to both the H and the Model F Stanley I am wondering if anyone has experience of using higher grade steel for frame rods?
I am thinking of either a straight 0.4% carbon steel (UK EN 8 / US SAE 1040) or an alloy steel such as EN24 / US SAE4340 – a nickel chrome molybdenum alloy which is approved for helicopter rotor shafts – can’t get more critical than that! I would use the “T” grade which is supplied heat treated to the maximum reasonably machinable hardness (55 Tons tensile per square inch).
My concern is whether the brazing of the joint to the crosshead brackets leads to either embrittlement if cooling is too rapid or just to a soft area in which bending stresses will congregate. Has anyone tried? We will use silver solder rather than brass braze to keep the temperature down to 650C instead of 900.
The rod broke on the cylinder side of the crankshaft bearing block, actually, as one would expect, through the thread, between the threaded collar and the bearing block. I propose to machine my new rods from thicker bar so that this collar can be an integral part of the rod with a nice filet radius. Made like this the thread only needs to start at the other end of the bearing block and the rod will be much stronger where it goes through the bearing block. I also wonder whether to stiffen up the rod by carrying a thicker diameter through as far as the crosshead bracket. Any views on this?
I have tried as much as possible to keep original 1907 bits in use but there comes a point where this is impossible as they are just plain knackered! The block repair which I did last year is holding up fine, although I have had patterns made to cast a new stronger block which I shall fit to my spare engine just in case.
The car has now done getting on for 2000 miles since I finished it, 1600 of which has been on the welded block. I usually push it reasonably hard when near home to find any defects, rather than having a breakdown on tour and so far have succeeded in this as it has only once packed up on tour (broken perch rod). I should say that the road to my house has a short stretch of uphill 25% grade where I am forced to go slowly past my neighbour’s front door – this is the critical test of block and frame rods.
Mike</HTML>
Re: Stronger engine frame rods
Posted by: David K. Nergaard (IP Logged)
Date: September 28, 2003 02:38PM
<HTML>I have had the much thicker rods of the type 7 engine fail in the same place. My response was to stiffen the frame with plates taking the diagonal forces. The plates are fitted vertically and clamped, not welded, to the frame rods. See Steam Automobile Bulletin vol 12 #4 and vol 13 #2 for details.
Using a larger rod with a shoulder to fix the bearing cap ia a good idea IF you have exactly the right dimension to match your bearing caps and cylinder block. Else, you will have pstons hitting cylinder heads, and no way to adjust them. I am sure that is why Stanley threaded the rods as far as they did.</HTML>
Using a larger rod with a shoulder to fix the bearing cap ia a good idea IF you have exactly the right dimension to match your bearing caps and cylinder block. Else, you will have pstons hitting cylinder heads, and no way to adjust them. I am sure that is why Stanley threaded the rods as far as they did.</HTML>
Re: Stronger engine frame rods
Posted by: Mike Clark (IP Logged)
Date: September 29, 2003 08:09PM
<HTML>David
Thanks for your advice - not a lot of room to fit bolted plates on the H engine although I already have a pair of bars just in front of the crosshead and can just about get a bracing plate in there too. I will solve the problem of cylinder position adjustment by using nuts in place of the brazed collars at the block end of the rods, a slight increase in the length of thread here is much less harmful than by the crankshaft bearings.
Could you put a picture of your rods and the plates on the website - I don't have the bulletins?
Mike</HTML>
Thanks for your advice - not a lot of room to fit bolted plates on the H engine although I already have a pair of bars just in front of the crosshead and can just about get a bracing plate in there too. I will solve the problem of cylinder position adjustment by using nuts in place of the brazed collars at the block end of the rods, a slight increase in the length of thread here is much less harmful than by the crankshaft bearings.
Could you put a picture of your rods and the plates on the website - I don't have the bulletins?
Mike</HTML>
Re: Stronger engine frame rods
Posted by: SSsssteamer (IP Logged)
Date: October 14, 2003 03:43AM
<HTML>Dear Mike, In another thread, Coburn Benson of Maine, had reccomended a type of steel for use in replacing Stanley engine frame rods. It was was very successful fix and I hope that either Coburn or someone else can remember which thread it was on. Pat Farrell</HTML>
Re: Stronger engine frame rods
Posted by: Peter Brow (IP Logged)
Date: October 14, 2003 06:12AM
<HTML>Was it 4140 Chromoly?
Peter</HTML>
Peter</HTML>
Re: Stronger engine frame rods
Posted by: Caleb Ramsby (IP Logged)
Date: October 14, 2003 03:19PM
<HTML>Peter,
4140 Carbon: .35 - .45 Maganese: .60 - .90 Phosphorus, Max: .040 Sulphur Max: .050 Chromium: .80 - 1.10 Nickel: none Molybdenum: .15 - .25
4140 is actually a Molybdenum Steel.
S.A.E 4140: This steel is used extensively for rear axles, front axle tubing, propeller shafts, transmission shafts and forgings for aircraft work.
Heat treatment: 4140: Normalizing Deg. F. 1,600 - 1,700, Annealing Deg. F. 1,450 - 1,550, Hardening Deg. F. 1,525 - 1,625, Quenching Medium is Oil, Tempering Deg. F. To desired hardness.
This information is from The Machinery's Handbook 1942 edition.
Actually I recently bought some 4140 to make some tongs for a company. They needed the jaws to be tough but also pliable. I think that these will work much better than the straight 20 point carbon tongs I made tham before.
If you want more detailed information I can give you some out of my Metals Handbook, but that gets pretty deep.grin
Caleb Ramsby</HTML>
4140 Carbon: .35 - .45 Maganese: .60 - .90 Phosphorus, Max: .040 Sulphur Max: .050 Chromium: .80 - 1.10 Nickel: none Molybdenum: .15 - .25
4140 is actually a Molybdenum Steel.
S.A.E 4140: This steel is used extensively for rear axles, front axle tubing, propeller shafts, transmission shafts and forgings for aircraft work.
Heat treatment: 4140: Normalizing Deg. F. 1,600 - 1,700, Annealing Deg. F. 1,450 - 1,550, Hardening Deg. F. 1,525 - 1,625, Quenching Medium is Oil, Tempering Deg. F. To desired hardness.
This information is from The Machinery's Handbook 1942 edition.
Actually I recently bought some 4140 to make some tongs for a company. They needed the jaws to be tough but also pliable. I think that these will work much better than the straight 20 point carbon tongs I made tham before.
If you want more detailed information I can give you some out of my Metals Handbook, but that gets pretty deep.grin
Caleb Ramsby</HTML>
Re: Stronger engine frame rods
Posted by: Mike Clark (IP Logged)
Date: October 14, 2003 09:13PM
<HTML>Caleb,Peter, Pat,
Steel for frame rods.
I have used 1040 for lots of things, spring U bolts for example and have proved to my satisfaction that it can be heated up, bent hot, silver soldered etc without going too hard - seems to retain its hardness well even after silver soldering. I think 4340 is the top, strongest grade for this kind of thing and have made half shafts and engine cranks from it, but have not done a test piece for brazing yet. Both of these steels can be machined and threaded without difficulty.
I have used 4140 but found it very hard to cut threads and it seems to go banana shaped if you have to reduce the diameter of a bar as you would if making integral collars on the frame rods. I'd hate to have to cut the threads for frame rods
Mike</HTML>
Steel for frame rods.
I have used 1040 for lots of things, spring U bolts for example and have proved to my satisfaction that it can be heated up, bent hot, silver soldered etc without going too hard - seems to retain its hardness well even after silver soldering. I think 4340 is the top, strongest grade for this kind of thing and have made half shafts and engine cranks from it, but have not done a test piece for brazing yet. Both of these steels can be machined and threaded without difficulty.
I have used 4140 but found it very hard to cut threads and it seems to go banana shaped if you have to reduce the diameter of a bar as you would if making integral collars on the frame rods. I'd hate to have to cut the threads for frame rods
Mike</HTML>
Re: Stress proof frame rods
Posted by: C Benson (IP Logged)
Date: October 15, 2003 03:22PM
<HTML>Hi,,,I dont recall that post,,,But i probably would have made mentoin of a steel called ''stressproof'' a trade name,,,,this was the suggestion of Dan Fay,,,one of the engineers at Morgan Construction of Worcester,,,,they design steel [and other] rolling mills,,We talked a lot on steam and Stanley problems,,,this steel is a bit expensive,,,and i'm not sure how well it likes a 60d tool bit,,,,but from a strength and fatigue point of view ,, Dan said it was the choice,,,,Dan did a lot of machining himself so if it was real ugly ,,,I think he would have given me a clue it was hell hinge stock,,,which as you all know is off the chart,,,worse 'n sash weights,,,or chevy cast camshafts, I bont recall any coment on gettin brittle if it was brazed etc I'd be curious on that,,,,XXXXXX Many [lots] of new steels are vastly superior to the antique stuff,,,,Flexing is the culpert,,,larger rods and/or Davids stifner plates are both a good idea,,tho he comments the engine has a bit more viberation in short cutoff,,,as its not so flexable,,,,but thats not a problem I think,,,Don't forget Dave has done a lot of experimenting w/Stanley cutoff,,,,XXXXX On the other side // what ya can get away with,,,,Carl would just make up a steel shaft,threaded,,an weld it onto the broken rod,,,,Dont recall a failure on this fix,,,any comments here??? XXXXX Another cause of failure would be the loostning of the MAIN BEARING NUTS,,,,a lose nut on one side will raise havoc on side opposite,,,think about this one and what it would look like in motion,,,,The nuts on the rearend also loosten,,,,what else is new,,,Hope this is helpful,,,,Good luck all,,,Cheers Ben /ps I included the note on Dan as I thought it might be good that it be known ,the source,,,,,cb</HTML>
Re: Stronger engine frame rods
Posted by: Peter Brow (IP Logged)
Date: October 16, 2003 12:15AM
<HTML>Caleb,
Thanks for the metallurgical data. I have a Machinery's Handbook too, 1952 ed, and just found 4140 on p. 1549 under "Molybdenum Steels". Everything from 4119 to 4340 has chrome in it. Not sure if all of this is the stuff usually called "chromoly", I'm just in the habit of using the term from reading about and watching dune buggies and sandrails. This kind of stuff takes amazing loads in the tubular frames of those vehicles, flying 20 feet in the air off a sand dune, crash-landing on the other side, and keep going ... kidney belts recommended ... Makes Starsky & Hutch look like wusses ... :)
Mike,
Sorry to hear about 4140's machining problems. I was planning on using the stuff for frame rods, hoping to avoid "banana" problems by using a fresh bit and "peeling" it with a travelling rest, but I bet you already tried that, so it's back to the drawing board. Haven't machined the stuff myself yet. Last thing I need is funky alloy machining problems (not much stainless in my design, the old-school machinists have been working on my head), too many other problems already. Maybe I'll just use 1040, which I have worked with, and thicker rods and/or sleeves @ cross members to mellow out stress concentrations. Will also look into 4340, if it machines nice and doesn't cost a fortune. Even "plain" steels today are much better than their equivalents from 80-90 years ago, and should last much longer. Just using the "same" stuff is often a big improvement!
In any machine, sometimes the overall best materials or designs (weight, cost, machining, sourcing, etc, balanced together) just have a certain service life, and need replacing now and then. But even the pros blow it in the design tradeoff dept.. Example, 200,000-300,000+ mile valve trains have been around for decades, yet some of the world's top carmakers now use ohc drive belts that shred as soon as 60,000. They call this "progress". Some of those engines are even valve-interference designs, where the engine goes if the belt does, so smart owners change belts at 40-50,000 -- which is not even made an easy job in some engines. Yet many of those are considered desireable performance engines, and sell like crazy.
Personally, (no recommendations here, & mainly for new designs), I think that 60,000 mi is unacceptably short service life for major automotive powerplant components. As the Coneheads say, "Un-acceptable!". 150-200,000 minimum for anything on the car that can't be R/R'd with a screwdriver or wrench in like 5 minutes. If it goes fine for 150-200,000, and if getting 300-400,000 or more is a giant hassle or really expensive, then it's time for some serious head-scratching. Antique/classic preservation adds the problem of balancing in originality and likely extremely long vehicle life (many of these cars will be running for centuries, mind-boggling), and each owner has to have his own priorities.
Ben,
Interesting notes on checking other possible problem sources. "Improving" something "here" sometimes causes more problems "there" (been there done that for sure), and the best combo of solutions may be far from obvious, and may vary from one user to the next. Maybe Amsley had it right with "plain" steel frame rods.
Peter</HTML>
Thanks for the metallurgical data. I have a Machinery's Handbook too, 1952 ed, and just found 4140 on p. 1549 under "Molybdenum Steels". Everything from 4119 to 4340 has chrome in it. Not sure if all of this is the stuff usually called "chromoly", I'm just in the habit of using the term from reading about and watching dune buggies and sandrails. This kind of stuff takes amazing loads in the tubular frames of those vehicles, flying 20 feet in the air off a sand dune, crash-landing on the other side, and keep going ... kidney belts recommended ... Makes Starsky & Hutch look like wusses ... :)
Mike,
Sorry to hear about 4140's machining problems. I was planning on using the stuff for frame rods, hoping to avoid "banana" problems by using a fresh bit and "peeling" it with a travelling rest, but I bet you already tried that, so it's back to the drawing board. Haven't machined the stuff myself yet. Last thing I need is funky alloy machining problems (not much stainless in my design, the old-school machinists have been working on my head), too many other problems already. Maybe I'll just use 1040, which I have worked with, and thicker rods and/or sleeves @ cross members to mellow out stress concentrations. Will also look into 4340, if it machines nice and doesn't cost a fortune. Even "plain" steels today are much better than their equivalents from 80-90 years ago, and should last much longer. Just using the "same" stuff is often a big improvement!
In any machine, sometimes the overall best materials or designs (weight, cost, machining, sourcing, etc, balanced together) just have a certain service life, and need replacing now and then. But even the pros blow it in the design tradeoff dept.. Example, 200,000-300,000+ mile valve trains have been around for decades, yet some of the world's top carmakers now use ohc drive belts that shred as soon as 60,000. They call this "progress". Some of those engines are even valve-interference designs, where the engine goes if the belt does, so smart owners change belts at 40-50,000 -- which is not even made an easy job in some engines. Yet many of those are considered desireable performance engines, and sell like crazy.
Personally, (no recommendations here, & mainly for new designs), I think that 60,000 mi is unacceptably short service life for major automotive powerplant components. As the Coneheads say, "Un-acceptable!". 150-200,000 minimum for anything on the car that can't be R/R'd with a screwdriver or wrench in like 5 minutes. If it goes fine for 150-200,000, and if getting 300-400,000 or more is a giant hassle or really expensive, then it's time for some serious head-scratching. Antique/classic preservation adds the problem of balancing in originality and likely extremely long vehicle life (many of these cars will be running for centuries, mind-boggling), and each owner has to have his own priorities.
Ben,
Interesting notes on checking other possible problem sources. "Improving" something "here" sometimes causes more problems "there" (been there done that for sure), and the best combo of solutions may be far from obvious, and may vary from one user to the next. Maybe Amsley had it right with "plain" steel frame rods.
Peter</HTML>
<b>Re: SEARCH for - Stronger engine frame rods</b>
Posted by: JW (IP Logged)
Date: October 17, 2003 03:18AM
<HTML>Hey Pat- Try the "SEARCH" option located in the top navigation bar. It will find any word, phrase or author that has ever been posted here.
JW
</HTML>
JW
</HTML>
Re: Stronger engine frame rods
Posted by: George Nutz (IP Logged)
Date: October 17, 2003 10:22AM
<HTML>4130 is the first "supersteel" with 4340 just a tad better--nowdays the 4140 is more available(just has .1% carbon than 4130). Etremely strong and great toughness to resist those millions of fram rod flexures. It is easily machinable in the annealed state. I believe Daves framerod stiffeners worked well to reduce the amount of torsional twisting of the cylinder block but the resulting torque moments are just moved someplace else---I believe Dave has busted a framerod anyway after he installed them, I could be wrong as memory is failing! Dave could inform us of such breakage. The use of a high strength 4130 steel would not reduce the infernal frame rod twisting as that is a function of the Modulus of Elasticity and all steels are about 28-30 million psi modulus. An off note 4130 is what aircraft tubing is made of and is an excellent Chrome Moly high temperature boiler tube, in some ways better than stainless if burning diesel fuel.
George</HTML>
George</HTML>
Re: Stronger engine frame rods
Posted by: Peter Brow (IP Logged)
Date: October 17, 2003 09:41PM
<HTML>Hi George,
I think it was you who recommended 4140 to me. Annealing is not hard to do, and if this makes it easily machinable then I won't count it out after all. Test cuts seem to be in order. As I recall (I have a "phonographic memory" but the needle skips sometimes), you also advised that 4140 isn't much more expensive than 1000-series steel.
What I need to do is check the local (& LA) metal suppliers and see what's available. We still have an aircraft industry in San Diego, so I may be able to get 4130 too. Not to mention all those SoCal dune buggy builders, though they usually use tubing instead of rod.
If I can get good straight rod in the right diameter, I may not have to do any turning at all, just cut to length and thread it. The Stanley 'prints show stock rod sizes; may just go up an eighth or sixteenth from comparable Stanley specs, cut, and thread. Cold-rolled steel usually mikes dead-on (not just "nominal"); don't know about the alloys. I think all the mil-spec stuff is metric now, but who needs it exc for $4000 toilet seats. :)
Every 100,000 miles or so with these kinds of engines, you add another million flex cycles. As my Chinese history professor used to say, "That's lots." (There's lots of lots in Chinese history).
Peter</HTML>
I think it was you who recommended 4140 to me. Annealing is not hard to do, and if this makes it easily machinable then I won't count it out after all. Test cuts seem to be in order. As I recall (I have a "phonographic memory" but the needle skips sometimes), you also advised that 4140 isn't much more expensive than 1000-series steel.
What I need to do is check the local (& LA) metal suppliers and see what's available. We still have an aircraft industry in San Diego, so I may be able to get 4130 too. Not to mention all those SoCal dune buggy builders, though they usually use tubing instead of rod.
If I can get good straight rod in the right diameter, I may not have to do any turning at all, just cut to length and thread it. The Stanley 'prints show stock rod sizes; may just go up an eighth or sixteenth from comparable Stanley specs, cut, and thread. Cold-rolled steel usually mikes dead-on (not just "nominal"); don't know about the alloys. I think all the mil-spec stuff is metric now, but who needs it exc for $4000 toilet seats. :)
Every 100,000 miles or so with these kinds of engines, you add another million flex cycles. As my Chinese history professor used to say, "That's lots." (There's lots of lots in Chinese history).
Peter</HTML>
Re: Stronger engine frame rods
Posted by: George Nutz (IP Logged)
Date: October 18, 2003 10:05AM
<HTML>Peter,
Try adding another 900 million cycles per 100,000miles! I believe McMaster Carr and others sell 4130-40 in several rod diameters and lengths, can't find my blasted catalog to check!
George</HTML>
Try adding another 900 million cycles per 100,000miles! I believe McMaster Carr and others sell 4130-40 in several rod diameters and lengths, can't find my blasted catalog to check!
George</HTML>
Re: Stronger engine frame rods
Posted by: Caleb Ramsby (IP Logged)
Date: October 18, 2003 02:24PM
<HTML>Peter,
When I purchased my 4140 from my local steel supplier, Express Metals. It was $52 for 80' of 3/8" diameter stock. It was supplied in the annealed state. That sort of helped out because then the reins(handles) of the tongs which I didn't forge any are already in the annealed state and after I forged the jaws I then in the normalized state.
It would be the best if you could find a supplier that would provide the steel in the annealed state at the start.
If you want to do it your self, take the metal up to about 1,500 deg. F., leave it there for a few hours, then cover it in a container full of vermiculite or sand for a day or two to cool off SLOWLY. Preferably you would bring the temperature of the steel up very slowly, about 50 - 100 deg an hour, depending on how thick they are. You can get a tempil stick at a local welding supplier for 1,500 deg. F. that will melt when touched by something that is at 1,500 deg. F.
By the way, I don't remember it being mentioned how thick these bars are going to be. Could you enlighten me?
Hope this helps a little.
Caleb Ramsby</HTML>
When I purchased my 4140 from my local steel supplier, Express Metals. It was $52 for 80' of 3/8" diameter stock. It was supplied in the annealed state. That sort of helped out because then the reins(handles) of the tongs which I didn't forge any are already in the annealed state and after I forged the jaws I then in the normalized state.
It would be the best if you could find a supplier that would provide the steel in the annealed state at the start.
If you want to do it your self, take the metal up to about 1,500 deg. F., leave it there for a few hours, then cover it in a container full of vermiculite or sand for a day or two to cool off SLOWLY. Preferably you would bring the temperature of the steel up very slowly, about 50 - 100 deg an hour, depending on how thick they are. You can get a tempil stick at a local welding supplier for 1,500 deg. F. that will melt when touched by something that is at 1,500 deg. F.
By the way, I don't remember it being mentioned how thick these bars are going to be. Could you enlighten me?
Hope this helps a little.
Caleb Ramsby</HTML>
Re: Stronger engine frame rods
Posted by: Caleb Ramsby (IP Logged)
Date: October 18, 2003 02:43PM
<HTML>I just checked out <www.mcmaster.com> they sell 4140 with a few different heat treatments. It is around $60 for a piece 3' long and 2" diameter.
Caleb Ramsby</HTML>
Caleb Ramsby</HTML>
Re: Stronger engine frame rods
Posted by: Mike Clark (IP Logged)
Date: October 18, 2003 08:16PM
<HTML>
I just spoke to my steel supplier to understand why I had found 4140 harder to thread and generally machine than 4340. He says that although the specification for both materials (which are known as EN19T and EN24T in the UK) gives a hardness range of 55 to 65 tons per square inch tensile strength, they are usually supplied at the top end of this spec. He felt that my experience was simply that I had received 4140 in a harder sample than the 4340 I was used to. So I guess either would do but for our purpose a batch with hardness at the lower end would be easier to work with.
Both materials can be purchased in what is described in the UK as the “T” condition meaning 55 – 65 tons tensile which is about as hard as can comfortably be machined without annealing and gives a finished component which is considerably harder and tougher than mild steel whose usual tensile strength is about 35 tons. The “T” grade is used without further heat treatment and is supplied as bright bar.
4140 and 4340 can also be supplied in the annealed condition when they are no harder than mild steel and so can easily be machined (this is the result you would get from your home annealing process). The annealed grade is a rough finished “black” bar. However the annealing takes away just those qualities of hardness and toughness you were looking for and in order to recover this the normal industrial procedure is to carry out a further heat treatment process followed by tempering to the required finished hardness. 4340 can be taken up to a tensile strength of as much as 100 tons in this way. Any finishing operations after heat treatment are done by grinding and at this point it is common to find that some straightening is needed, by press or in the grinding.
I think that it is a mistake to anneal the 55 ton material to ease the machining problem as you would lose the benefit of using a stronger steel – if you have a choice look for some with a 55 ton tensile rather than 60+. I think this level of tensile strength would make a huge improvement in Stanley frame rods so this is what I propose to use.
The brazing temperature (about1600 F) needed to fit the crosshead brackets would have been no problem for the original mild steel but it could be for the alloy steel which might be annealed and softened. However silver solder melting at 1200F should be OK and I have tried this on sample bits of alloy steel and believe me they are still tough. Any heat you apply to these steels must be allowed to cool out slowly – quenching causes them to go glass hard. They absolutely must not be welded to repair in the Amsley fashion!
I am still thinking whether to beef the thickness up between the crankshaft bearing and the crosshead – it seems a good thing at first but perhaps it would concentrate all the bending just at the weakest point. I do intend to make the locating collar in one piece with the rod so I can have plain rod through the bearing block and keep the threaded part as short as possible.
Mike</HTML>
I just spoke to my steel supplier to understand why I had found 4140 harder to thread and generally machine than 4340. He says that although the specification for both materials (which are known as EN19T and EN24T in the UK) gives a hardness range of 55 to 65 tons per square inch tensile strength, they are usually supplied at the top end of this spec. He felt that my experience was simply that I had received 4140 in a harder sample than the 4340 I was used to. So I guess either would do but for our purpose a batch with hardness at the lower end would be easier to work with.
Both materials can be purchased in what is described in the UK as the “T” condition meaning 55 – 65 tons tensile which is about as hard as can comfortably be machined without annealing and gives a finished component which is considerably harder and tougher than mild steel whose usual tensile strength is about 35 tons. The “T” grade is used without further heat treatment and is supplied as bright bar.
4140 and 4340 can also be supplied in the annealed condition when they are no harder than mild steel and so can easily be machined (this is the result you would get from your home annealing process). The annealed grade is a rough finished “black” bar. However the annealing takes away just those qualities of hardness and toughness you were looking for and in order to recover this the normal industrial procedure is to carry out a further heat treatment process followed by tempering to the required finished hardness. 4340 can be taken up to a tensile strength of as much as 100 tons in this way. Any finishing operations after heat treatment are done by grinding and at this point it is common to find that some straightening is needed, by press or in the grinding.
I think that it is a mistake to anneal the 55 ton material to ease the machining problem as you would lose the benefit of using a stronger steel – if you have a choice look for some with a 55 ton tensile rather than 60+. I think this level of tensile strength would make a huge improvement in Stanley frame rods so this is what I propose to use.
The brazing temperature (about1600 F) needed to fit the crosshead brackets would have been no problem for the original mild steel but it could be for the alloy steel which might be annealed and softened. However silver solder melting at 1200F should be OK and I have tried this on sample bits of alloy steel and believe me they are still tough. Any heat you apply to these steels must be allowed to cool out slowly – quenching causes them to go glass hard. They absolutely must not be welded to repair in the Amsley fashion!
I am still thinking whether to beef the thickness up between the crankshaft bearing and the crosshead – it seems a good thing at first but perhaps it would concentrate all the bending just at the weakest point. I do intend to make the locating collar in one piece with the rod so I can have plain rod through the bearing block and keep the threaded part as short as possible.
Mike</HTML>
Re: Stronger engine frame rods
Posted by: Peter Brow (IP Logged)
Date: October 20, 2003 07:37AM
<HTML>Hi George,
Okay, math test. 100,000 miles times say ~ 1000 revs/mile = ... add the zeros together ... 100000000 eight zeros ... 100,000,000 revs per 100,000 miles. Whoa.
McMaster catalog check. (#105, latest paper version which I have). Huh. Page 2999, 4140 square bars and hex stock, all in the right size range (and considerably smaller and bigger sizes too) ... ah here we go, page 2977, 4140 alloy steel rounds! Wee hoo, cold-rolled _and_ annealed already. 6 foot length of 5/8 is $13.43; 6' of 3/4 is $18.23; 6' of 7/8 is $22.08. Well, make that "was". 1999 prices. Current prices probably slightly higher. Not bad at all, and they sure are easy to order from online ( [www.mcmaster.com] ) via old Pentium laptop (also acquired per your advice, needed for their incredible pdf format online catalog). My experience is McMaster has stuff on my doorstep the next day at the latest, same day if I order early in the morning. "Your results may vary", that's LA to San Diego shipping. And is there anything they _don't_ have?
Thanks George, you're indispensable as usual. 4140 frame rods it is.
Peter</HTML>
Okay, math test. 100,000 miles times say ~ 1000 revs/mile = ... add the zeros together ... 100000000 eight zeros ... 100,000,000 revs per 100,000 miles. Whoa.
McMaster catalog check. (#105, latest paper version which I have). Huh. Page 2999, 4140 square bars and hex stock, all in the right size range (and considerably smaller and bigger sizes too) ... ah here we go, page 2977, 4140 alloy steel rounds! Wee hoo, cold-rolled _and_ annealed already. 6 foot length of 5/8 is $13.43; 6' of 3/4 is $18.23; 6' of 7/8 is $22.08. Well, make that "was". 1999 prices. Current prices probably slightly higher. Not bad at all, and they sure are easy to order from online ( [www.mcmaster.com] ) via old Pentium laptop (also acquired per your advice, needed for their incredible pdf format online catalog). My experience is McMaster has stuff on my doorstep the next day at the latest, same day if I order early in the morning. "Your results may vary", that's LA to San Diego shipping. And is there anything they _don't_ have?
Thanks George, you're indispensable as usual. 4140 frame rods it is.
Peter</HTML>
Re: Stronger engine frame rods
Posted by: Peter Brow (IP Logged)
Date: October 20, 2003 08:25AM
<HTML>Caleb and Mike,
Thanks guys, very informative and useful info. I wrote the reply to George before reading your posts. The round sizes I mentioned in that post are in the size range we're looking at, Caleb. What dia are you considering, Mike?
Schick blueprints for the 20 hp (#7, later 4x5 w/2pc conrods) engine show 7/8" "CR" steel, CR = oopsie. I don't think stainless is what we want here. Some details in almost all prints need to be taken with a grain of salt, eg Schick sez "CR" for early 10 hp pistons and I know that's wrong!
The Bruce Green prints (don't have yet) are prob good dimensions as he told me lots of tiny details turn out to be essential. He apparently didn't know about self-aligning bearings in the late '80s as he said bearing screwups were a major flaw in the engine, I said there were ways to fix that, dead silence was his reply. I think he was being polite and thought I was loopy or fantasy-prone. Wish we'd talked longer and got into details. At the time I thought that self-aligning bearings were untried in Stanley-type engines and my own hot new experimental idea, but I think others were already using them unbeknownst to me. Things like that don't slip by unsaid in internet discussion boards.
Schick for 10 hp (earlier type 3x4) show (shuffle shuffle riffle riffle) "steel 5/8 stock". "Light Steam Power" English prints for later 10 hp (3.25x4.25) Stanley, mislabeled (?) "type 735B, 10 hp 1909" (735 was a 20 horse, much later, and late 10hp started 1910 I think?) state "Four 3/4" dia steel bars 2'7" long [etc]". If dimensions are correct, Stanley did some beefity work from early to late 10 hp, of course there's more bore & stroke in later 10hp too.
Wanted to finish the Stanley line with 30 horse frame rod specs, but can't find them now. No 30 hp prints exist as far as I know. Also don't have early 20 horse specs (3 5/8" bore), but I think Mike already mentioned them.
Peter</HTML>
Thanks guys, very informative and useful info. I wrote the reply to George before reading your posts. The round sizes I mentioned in that post are in the size range we're looking at, Caleb. What dia are you considering, Mike?
Schick blueprints for the 20 hp (#7, later 4x5 w/2pc conrods) engine show 7/8" "CR" steel, CR = oopsie. I don't think stainless is what we want here. Some details in almost all prints need to be taken with a grain of salt, eg Schick sez "CR" for early 10 hp pistons and I know that's wrong!
The Bruce Green prints (don't have yet) are prob good dimensions as he told me lots of tiny details turn out to be essential. He apparently didn't know about self-aligning bearings in the late '80s as he said bearing screwups were a major flaw in the engine, I said there were ways to fix that, dead silence was his reply. I think he was being polite and thought I was loopy or fantasy-prone. Wish we'd talked longer and got into details. At the time I thought that self-aligning bearings were untried in Stanley-type engines and my own hot new experimental idea, but I think others were already using them unbeknownst to me. Things like that don't slip by unsaid in internet discussion boards.
Schick for 10 hp (earlier type 3x4) show (shuffle shuffle riffle riffle) "steel 5/8 stock". "Light Steam Power" English prints for later 10 hp (3.25x4.25) Stanley, mislabeled (?) "type 735B, 10 hp 1909" (735 was a 20 horse, much later, and late 10hp started 1910 I think?) state "Four 3/4" dia steel bars 2'7" long [etc]". If dimensions are correct, Stanley did some beefity work from early to late 10 hp, of course there's more bore & stroke in later 10hp too.
Wanted to finish the Stanley line with 30 horse frame rod specs, but can't find them now. No 30 hp prints exist as far as I know. Also don't have early 20 horse specs (3 5/8" bore), but I think Mike already mentioned them.
Peter</HTML>
Re: Stronger engine frame rods
Posted by: Peter Brow (IP Logged)
Date: October 20, 2003 08:35AM
<HTML>Yep, Mike already mentioned stock(?) 3.625x5 frame rod dia: 3/4". Looks like Stanley just upped frame rod dia's an even eighth from early to late 10 & 20 hp.
Peter</HTML>
Peter</HTML>
Re: Stronger engine frame rods
Posted by: Arnold Walker (IP Logged)
Date: October 21, 2003 01:41PM
<HTML>I think you would have steam SUV fans interested in your prints if you find any for the 30 hp stanley.</HTML>
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