Discussion: Cryoing Engine Parts
03-27-2003, 04:42 PM
#41
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Re: Discussion: Cryoing Engine Parts </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pro Stock John:
<strong> Great posts!!!
So cryo the crank yes? And before balancing it then I take it? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I cannot yet recommend that. When we determine how much retained austenite is in the LS1 crank I'll have a better idea.
As far as straightness is concerned, you should accurately check runout on the center mains using a good dial indicator when supporting and rotating crank on the outer mains. You could use the engine build up method of assembling crank in block with outer mains only torqued, and turn the crank by hand noting torque to rotate. Tighten center main and remeasure. This should give you some idea of how straight crank is as long as bearing clearances are good. Do this before cryo and after. Torque should be the same. If it increases, crank was probably bent, and should be straightened.
Also, it doesn't appear that the stock journals are hardened. My metallurgist/heat treater is doing the analysis; we'll discuss the pros and cons of nitriding and/or sub-zero treating the entire crank. If you'all can wait a week or so we should have a more informed opinion.
Remember, nitriding produces a brittle white layer from a few "tenths" (.0001 inch is a "tenth") deep on up which isn't what you really want your bearings working against. Ionitriding AKA Glow Discharge Nitriding does produce a thinner white layer and a more ductile and fatigue-resistant case, and is what folks are doing, I believe.
PacerX, thanks for the support. This is the basic stuff of metallurgy and heat treating, but you sorta have to be involved with it to know about it. A little knowledge is still a dangerous thing.
Guys, listen to PacerX's comments, and not just because he agrees with me. His points are excellent.
Bottom line is that possibly cryo and ionitriding might be helpful on a stock LS1 crank, but I just don't know yet. For the cost involved, I'd suggest starting with a new-from-GM crank rather than one you've hammered on for many thousands of miles.
Metal, like a woman, remembers every time it was ever stressed, and when it's limit is reached it may react violently without any warning.
My $.02
<strong> Great posts!!!
So cryo the crank yes? And before balancing it then I take it? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I cannot yet recommend that. When we determine how much retained austenite is in the LS1 crank I'll have a better idea.
As far as straightness is concerned, you should accurately check runout on the center mains using a good dial indicator when supporting and rotating crank on the outer mains. You could use the engine build up method of assembling crank in block with outer mains only torqued, and turn the crank by hand noting torque to rotate. Tighten center main and remeasure. This should give you some idea of how straight crank is as long as bearing clearances are good. Do this before cryo and after. Torque should be the same. If it increases, crank was probably bent, and should be straightened.
Also, it doesn't appear that the stock journals are hardened. My metallurgist/heat treater is doing the analysis; we'll discuss the pros and cons of nitriding and/or sub-zero treating the entire crank. If you'all can wait a week or so we should have a more informed opinion.
Remember, nitriding produces a brittle white layer from a few "tenths" (.0001 inch is a "tenth") deep on up which isn't what you really want your bearings working against. Ionitriding AKA Glow Discharge Nitriding does produce a thinner white layer and a more ductile and fatigue-resistant case, and is what folks are doing, I believe.
PacerX, thanks for the support. This is the basic stuff of metallurgy and heat treating, but you sorta have to be involved with it to know about it. A little knowledge is still a dangerous thing.
Guys, listen to PacerX's comments, and not just because he agrees with me. His points are excellent.
Bottom line is that possibly cryo and ionitriding might be helpful on a stock LS1 crank, but I just don't know yet. For the cost involved, I'd suggest starting with a new-from-GM crank rather than one you've hammered on for many thousands of miles.
Metal, like a woman, remembers every time it was ever stressed, and when it's limit is reached it may react violently without any warning.
My $.02
03-27-2003, 07:13 PM
#42
Re: Discussion: Cryoing Engine Parts One good thing about having Old SStroker around as the ME here is that advertising from companies speaking over most of our heads about material strength doesn't get by him.
From what I have seen most Cyro recomendations are advertising. It does have some uses, but to actually know what it's good for requires a real understanding of metalurgy. One thing I see alot of around the shop here is that we get parts to quote that have the wrong material speced out for them. Old SStroker helps out the ones he can to save them money and have get the part they need.
So needless to say, it is extremely helpfull to have real engineering talent here.
As for the block being cryo treated.
The material strength like mentioned above is has very little to do with the strenght of the block, it's the shape of the block that gives us the strength. As for the cylinder bores. Unless you want to do alot of R&D for a ring company to come up with the proper surface finish on the bores to work with that surface hardness and grain structure of the new cylinder bores after the cryo I wouldn't do it. Hell most people who do Cryo a block could gain so much more by just putting the right surface finish Ra and Rz on the cylinder walls through use of the right stones and the proper hot honing techinique.
On the crank side, I hope that after a cryo or a Ionitriting you are going to polish all the journals at the very least.
We are working on the best way to get a stock crank to take as much power and rpm for as long as possible. Hopefully soon we will have a lightened, profiled, treated and Teflon Coated crank available soon. Hopefully half the price of a Forged crank for the Big Bore and stock discplacement guys who want a lower cost alternative to the Lunati, Cola, Scat cranks out there.
Bret
From what I have seen most Cyro recomendations are advertising. It does have some uses, but to actually know what it's good for requires a real understanding of metalurgy. One thing I see alot of around the shop here is that we get parts to quote that have the wrong material speced out for them. Old SStroker helps out the ones he can to save them money and have get the part they need.
So needless to say, it is extremely helpfull to have real engineering talent here.
As for the block being cryo treated.
The material strength like mentioned above is has very little to do with the strenght of the block, it's the shape of the block that gives us the strength. As for the cylinder bores. Unless you want to do alot of R&D for a ring company to come up with the proper surface finish on the bores to work with that surface hardness and grain structure of the new cylinder bores after the cryo I wouldn't do it. Hell most people who do Cryo a block could gain so much more by just putting the right surface finish Ra and Rz on the cylinder walls through use of the right stones and the proper hot honing techinique.
On the crank side, I hope that after a cryo or a Ionitriting you are going to polish all the journals at the very least.
We are working on the best way to get a stock crank to take as much power and rpm for as long as possible. Hopefully soon we will have a lightened, profiled, treated and Teflon Coated crank available soon. Hopefully half the price of a Forged crank for the Big Bore and stock discplacement guys who want a lower cost alternative to the Lunati, Cola, Scat cranks out there.
Bret
03-28-2003, 12:54 AM
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Re: Discussion: Cryoing Engine Parts Old SStroker,
I am glad your voice of reason entered into this discussion.
"One of the primary advantages of sub-zero treatment, whether it be -120F or -300F is the conversion of retained austenite to martensite in the steel (or ductile iron) structure. Without getting too boring, a nearly 100% martensitic structure is preferred for strength over one with some untransformed austenite which occurs during heat treating."
This is almost verbatim from the steel "bible", The Making, Shaping and Treating of Steel (10th Edition, pgs 1264-1265).
The caveats added by the "bible" are that this process, when used on steels, is only truly effective on high carbon content steels (such as the cast iron used for our cranks), high alloy steels (4130, 4340 and such...) and tool steels involved in wear applications.
Cryo-treating of steels is only worthwhile in materials (such as those above) that have a tendency (as SStroker mentioned) to retain austenite due to the quenching process not achieveing a low enough temperature to transform all of it to martinsite. Eventually, as the part ages, this austenite will tend to transform itself into martinsite and cause embrittlement, cracking or distortion. Some alloy steels are intentionally alloyed to take advantage of this (they are called maraging steels and are used as warhead penetrators or armor in many cases).
According to the "bible", temperatures below -100F are generally not required to accomplish this transformation.
"If there is 1-3% or so retained austenite, there won't be much gain, but if there were 2-3 time as much, you might expect more gains. We'll know more about LS1 cranks soon."
Absolutely spot on. PREACH IT BROTHER!
"Anytime you cool or heat metal parts, especially over a 600F range, you may change size or configuration. I worry most about straightness of things like cranks and cams during post-machining heat treating."
I would NEVER reinstall a part like a crank or cam after this type of treatment without blueprinting. Cast parts can have voids that will greatly affect dimensional stability during and after heat/cold treatment.
"Before I'd cryo treat a block, I'd want to know how the cylinder bore structure and hardness changed because different structures require different surface conditions for best ring seal. What works for a normal gray cast iron isn't necessarily optimum for cylinder liners which were made and heat treated differently. I suspect the same thing with treated blocks."
I'd simply stay away from cryo treating a block unless it is going to be bored, decked, line bored and honed afterwards.
Blocks get their strength from shape, not really material. This is one of the reasons that aluminum works well for blocks and heads.
"If I were building a street engine, I would be sure that the treatment was helping rather than hurting before I'd use it. IMO, this is especially true with cast, or PM, and subsequently heat-treated engine parts like cranks and rods."
I shudder to think about what could happen to a PM connecting rod with voids. A billet or forged rod made from the right material may benefit, but a PM rod may be fatally weakened. PM, by definition, has voids.
"We produce many bearing rollers, and impact parts from high carbon, high chrome bearing steel which are always sub-zero treated. This is done before the finish machining/grinding operations, however."
I completely concur.
Other notes...
It was mentioned that this could help cylinder heads. I would strongly disagree. Cylinder heads crack because of voids, core shifts causing thin walls, and machining and casting induced stress risers. If you are generating enough cylinder pressure to blow a non-cryo treated cylinder head apart, you've got bigger problems...
Aluminum alloys can approach the strengths of the weaker steels (low carbon steels, 050-060 HSLA's, etc...). Aluminum has no chance, regardless of treatment, of approaching the strength of the ultra-high strength steels. Furthermore, aluminum alloys have a weakness that steels do not - long term fatigue failures caused by thermal cycling and loads considerably below the yield strength of the material.
<small>[ March 27, 2003, 01:03 PM: Message edited by: PacerX ]</small>
I am glad your voice of reason entered into this discussion.
"One of the primary advantages of sub-zero treatment, whether it be -120F or -300F is the conversion of retained austenite to martensite in the steel (or ductile iron) structure. Without getting too boring, a nearly 100% martensitic structure is preferred for strength over one with some untransformed austenite which occurs during heat treating."
This is almost verbatim from the steel "bible", The Making, Shaping and Treating of Steel (10th Edition, pgs 1264-1265).
The caveats added by the "bible" are that this process, when used on steels, is only truly effective on high carbon content steels (such as the cast iron used for our cranks), high alloy steels (4130, 4340 and such...) and tool steels involved in wear applications.
Cryo-treating of steels is only worthwhile in materials (such as those above) that have a tendency (as SStroker mentioned) to retain austenite due to the quenching process not achieveing a low enough temperature to transform all of it to martinsite. Eventually, as the part ages, this austenite will tend to transform itself into martinsite and cause embrittlement, cracking or distortion. Some alloy steels are intentionally alloyed to take advantage of this (they are called maraging steels and are used as warhead penetrators or armor in many cases).
According to the "bible", temperatures below -100F are generally not required to accomplish this transformation.
"If there is 1-3% or so retained austenite, there won't be much gain, but if there were 2-3 time as much, you might expect more gains. We'll know more about LS1 cranks soon."
Absolutely spot on. PREACH IT BROTHER!
"Anytime you cool or heat metal parts, especially over a 600F range, you may change size or configuration. I worry most about straightness of things like cranks and cams during post-machining heat treating."
I would NEVER reinstall a part like a crank or cam after this type of treatment without blueprinting. Cast parts can have voids that will greatly affect dimensional stability during and after heat/cold treatment.
"Before I'd cryo treat a block, I'd want to know how the cylinder bore structure and hardness changed because different structures require different surface conditions for best ring seal. What works for a normal gray cast iron isn't necessarily optimum for cylinder liners which were made and heat treated differently. I suspect the same thing with treated blocks."
I'd simply stay away from cryo treating a block unless it is going to be bored, decked, line bored and honed afterwards.
Blocks get their strength from shape, not really material. This is one of the reasons that aluminum works well for blocks and heads.
"If I were building a street engine, I would be sure that the treatment was helping rather than hurting before I'd use it. IMO, this is especially true with cast, or PM, and subsequently heat-treated engine parts like cranks and rods."
I shudder to think about what could happen to a PM connecting rod with voids. A billet or forged rod made from the right material may benefit, but a PM rod may be fatally weakened. PM, by definition, has voids.
"We produce many bearing rollers, and impact parts from high carbon, high chrome bearing steel which are always sub-zero treated. This is done before the finish machining/grinding operations, however."
I completely concur.
Other notes...
It was mentioned that this could help cylinder heads. I would strongly disagree. Cylinder heads crack because of voids, core shifts causing thin walls, and machining and casting induced stress risers. If you are generating enough cylinder pressure to blow a non-cryo treated cylinder head apart, you've got bigger problems...
Aluminum alloys can approach the strengths of the weaker steels (low carbon steels, 050-060 HSLA's, etc...). Aluminum has no chance, regardless of treatment, of approaching the strength of the ultra-high strength steels. Furthermore, aluminum alloys have a weakness that steels do not - long term fatigue failures caused by thermal cycling and loads considerably below the yield strength of the material.
<small>[ March 27, 2003, 01:03 PM: Message edited by: PacerX ]</small>
03-28-2003, 07:21 AM
#44
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Re: Discussion: Cryoing Engine Parts "So cryo the crank yes? And before balancing it then I take it?"
John, has anyone broken a crank with a failure not due to detonation?
I'm just asking because I don't know. I've heard of rod bolt, rod and piston failures, but never a crank blowing apart.
Harlan is making sick power on what I thought was a stock crank.
"Hopefully half the price of a Forged crank for the Big Bore and stock discplacement guys who want a lower cost alternative to the Lunati, Cola, Scat cranks out there."
I'm glad some folks are working on this.
Concurrently, I'd like to see somebody working on a less expensive rod.
The $1000 rod sets are just silly.
I'm sort of wondering whether there is an effective post-treatment for the PM rods that GM might have left off for cost reasons.
Another idea would be to look carefully at rod failures and consider replacing the lower end of the rod with a stiffer billet piece instead of replacing the entire rod assembly.
<small>[ March 28, 2003, 07:42 AM: Message edited by: PacerX ]</small>
John, has anyone broken a crank with a failure not due to detonation?
I'm just asking because I don't know. I've heard of rod bolt, rod and piston failures, but never a crank blowing apart.
Harlan is making sick power on what I thought was a stock crank.
"Hopefully half the price of a Forged crank for the Big Bore and stock discplacement guys who want a lower cost alternative to the Lunati, Cola, Scat cranks out there."
I'm glad some folks are working on this.
Concurrently, I'd like to see somebody working on a less expensive rod.
The $1000 rod sets are just silly.
I'm sort of wondering whether there is an effective post-treatment for the PM rods that GM might have left off for cost reasons.
Another idea would be to look carefully at rod failures and consider replacing the lower end of the rod with a stiffer billet piece instead of replacing the entire rod assembly.
<small>[ March 28, 2003, 07:42 AM: Message edited by: PacerX ]</small>
03-28-2003, 08:48 AM
#45
6600 rpm clutch dump of death Administrator
Re: Discussion: Cryoing Engine Parts I'd like to thank both of you guys for stepping in and providing us with some good information. My dad does a bunch of stuff with metalurgy in the NDT field, but I don't have the level of expertise you guys have.
Again, all I can tell you is that one of the local shops has invested in a cryo setup. They are treating just about every part of an engine that folks bring in.
As for the blocks, All I can tell you is that when boring identical blocks one treated, and one not, there is a different sound. Also, the treated blocks bore better...
With that said, I do look forward to hearing the results of your testing.
As for rods. that is one thing I tend to always go overboard on. Just about every engine failure I come across seems to be rod related. Rods tear in half or the big end comes apart. I know good bolts can keep alot of this in check. But I think rods are one thing to put some attention into. But thats just me...
Again, all I can tell you is that one of the local shops has invested in a cryo setup. They are treating just about every part of an engine that folks bring in.
As for the blocks, All I can tell you is that when boring identical blocks one treated, and one not, there is a different sound. Also, the treated blocks bore better...
With that said, I do look forward to hearing the results of your testing.
As for rods. that is one thing I tend to always go overboard on. Just about every engine failure I come across seems to be rod related. Rods tear in half or the big end comes apart. I know good bolts can keep alot of this in check. But I think rods are one thing to put some attention into. But thats just me...
03-28-2003, 09:04 AM
#46
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Re: Discussion: Cryoing Engine Parts "As for rods. that is one thing I tend to always go overboard on. Just about every engine failure I come across seems to be rod related. Rods tear in half or the big end comes apart. I know good bolts can keep alot of this in check. But I think rods are one thing to put some attention into. But thats just me..."
I think I tend to agree with you. That's why I'd like sometime to see the small half of the big end and the rod bolts replaced and not the rest of the rod. The concept is kind of like how billet main caps help the lower end.
Might save tons of bucks and give us a 1000hp rod. I'm just guessing that no one has done it, and I think it's worth a try.
I think I tend to agree with you. That's why I'd like sometime to see the small half of the big end and the rod bolts replaced and not the rest of the rod. The concept is kind of like how billet main caps help the lower end.
Might save tons of bucks and give us a 1000hp rod. I'm just guessing that no one has done it, and I think it's worth a try.
03-28-2003, 09:10 AM
#47
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Re: Discussion: Cryoing Engine Parts I am going to run a centrifrugal supercharger pulleyed for 20 lbs of boost and I want to see if it's worth cryoing the crank in an effort to make the crank snout stronger.
03-28-2003, 03:28 PM
#48
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Re: Discussion: Cryoing Engine Parts </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by PacerX:
<strong>
I'd like sometime to see the small half of the big end and the rod bolts replaced and not the rest of the rod. The concept is kind of like how billet main caps help the lower end.
Might save tons of bucks and give us a 1000hp rod. I'm just guessing that no one has done it, and I think it's worth a try. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hmmmm. I don't see it like that, Pacer. Here's why:
The power loading on a rod puts it in compression which basically unloads the cap and bolts. It's the g loads of stopping the piston at the top of the (exhaust) stroke that loads the cap and the bolts. The g loads are proportional to reciprocating mass (piston, pin, rings and the upper portion of the rod) and rpm. [F=ma]
The power loading on the block is into the main bearing caps. Early Model T Ford engines didn't have upper half bearings (babitt) in the center main! The main caps need to be strong enough not to distort or move about under the (1000) hp loads, and distribute the load into the block. IMO, those are just about opposite requirements from a rod cap.
We can minimize the rod cap loading by lowering the m in F=ma. Lighter pistons, pins etc. goes a long way. Upgrading the rod bolts is also a big help, as is keep the r's below 7K or so.
From a manufacturing point of view, adapting billet caps to an LS1 rod would be a challenge. You'd need to face off the "fracture" surface at the split line, and determine a new way to locate the cap. This would involve moving the rod bearing bore up the rod a tad, so by the time you got done, you'd be close to the cost of decent aftermarket rods.
Also, I don't think a PM LS1 rod is ever going to be made in to a 1000 hp rod. The beam will go bye-bye long before that, as will even SStrokerAce's modified LS1 crank. If we assume 600-650 hp as a reasonable LS1 number with a basically stock crank, then $600 or less for rods should hold it. The next step is a $2K-$3K billet crank and more costly rods if you are going for 650+++.
In other words, How fast do you want to go...? You know the rest.
<strong>
I'd like sometime to see the small half of the big end and the rod bolts replaced and not the rest of the rod. The concept is kind of like how billet main caps help the lower end.
Might save tons of bucks and give us a 1000hp rod. I'm just guessing that no one has done it, and I think it's worth a try. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hmmmm. I don't see it like that, Pacer. Here's why:
The power loading on a rod puts it in compression which basically unloads the cap and bolts. It's the g loads of stopping the piston at the top of the (exhaust) stroke that loads the cap and the bolts. The g loads are proportional to reciprocating mass (piston, pin, rings and the upper portion of the rod) and rpm. [F=ma]
The power loading on the block is into the main bearing caps. Early Model T Ford engines didn't have upper half bearings (babitt) in the center main! The main caps need to be strong enough not to distort or move about under the (1000) hp loads, and distribute the load into the block. IMO, those are just about opposite requirements from a rod cap.
We can minimize the rod cap loading by lowering the m in F=ma. Lighter pistons, pins etc. goes a long way. Upgrading the rod bolts is also a big help, as is keep the r's below 7K or so.
From a manufacturing point of view, adapting billet caps to an LS1 rod would be a challenge. You'd need to face off the "fracture" surface at the split line, and determine a new way to locate the cap. This would involve moving the rod bearing bore up the rod a tad, so by the time you got done, you'd be close to the cost of decent aftermarket rods.
Also, I don't think a PM LS1 rod is ever going to be made in to a 1000 hp rod. The beam will go bye-bye long before that, as will even SStrokerAce's modified LS1 crank. If we assume 600-650 hp as a reasonable LS1 number with a basically stock crank, then $600 or less for rods should hold it. The next step is a $2K-$3K billet crank and more costly rods if you are going for 650+++.
In other words, How fast do you want to go...? You know the rest.
03-28-2003, 10:41 PM
#49
6600 rpm clutch dump of death Administrator
Re: Discussion: Cryoing Engine Parts I have to agree also. A PM rod is fractured, that fracture line is what makes the rod fit together. To make a rod any stronger would require you to simply replace the rod, not just a part of the rod.
As for billet mains, we are finding that cast mains if cast with a proper ammount of material are just as strong as billet mains. Look at the new Dart blocks as an example. Also look at the big caterpillar engines. All cast mains. The big thing is to cast in an intergrated dowel to center the main, and have enough meat in them.
Also, if your mains are the same material as you block the rate of expansion is the same, so your bore stay straighter. Try to avoid dis-similar metals whenever possible.
As for billet mains, we are finding that cast mains if cast with a proper ammount of material are just as strong as billet mains. Look at the new Dart blocks as an example. Also look at the big caterpillar engines. All cast mains. The big thing is to cast in an intergrated dowel to center the main, and have enough meat in them.
Also, if your mains are the same material as you block the rate of expansion is the same, so your bore stay straighter. Try to avoid dis-similar metals whenever possible.
03-28-2003, 11:49 PM
#50
Re: Discussion: Cryoing Engine Parts Damn, I'm out of town and no printer! I've got to get some sleep... keep this thread at the top so my feeble mind doesn't forget to delve into this stuff!!Thanks to all-very interesting. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
03-29-2003, 01:21 AM
#51
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Re: Discussion: Cryoing Engine Parts Great thread.
Military special forces cryo-treat certain weaponry, mostly blades.
I have a Katana sword which has a cryo-treated blade that will cut into an engine block.
Will cryo-treating make the crank stronger and last longer? . . . As mentioned above due to shape etc. . . I'd imagine a great deal more research is needed <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Again, great thread and keep this going <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
<small>[ March 29, 2003, 01:24 AM: Message edited by: The Dragon ]</small>
Military special forces cryo-treat certain weaponry, mostly blades.
I have a Katana sword which has a cryo-treated blade that will cut into an engine block.
Will cryo-treating make the crank stronger and last longer? . . . As mentioned above due to shape etc. . . I'd imagine a great deal more research is needed <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Again, great thread and keep this going <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
<small>[ March 29, 2003, 01:24 AM: Message edited by: The Dragon ]</small>
03-29-2003, 03:04 PM
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Re: Discussion: Cryoing Engine Parts are you reving to 8 grand?
running over 15psi boost?
if the answer is no , why waste money ,
any money engine builders can get out of you they will, by saying it cant hurt, ya the only thing it hurts is your pocket book.
i think that alot of aftermarket parts and
some machine practices are a joke, if a guy wants a real engine, spend the big bucks and get a pro build then you will know for sure what you are getting, a huge bill and more horse power than the car can hook up with!
running over 15psi boost?
if the answer is no , why waste money ,
any money engine builders can get out of you they will, by saying it cant hurt, ya the only thing it hurts is your pocket book.
i think that alot of aftermarket parts and
some machine practices are a joke, if a guy wants a real engine, spend the big bucks and get a pro build then you will know for sure what you are getting, a huge bill and more horse power than the car can hook up with!
04-07-2003, 09:46 PM
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Re: Discussion: Cryoing Engine Parts Originaly posted by Jrod </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">A conventional heat treatment must be done prior to the cryogenic process, The cryogenic treatment improves the wear characteristics in metal fatigue, especially in short track pinion gears; abrasive wear in brake rotors and cylinder bores; and adhesive wear or galling in racing engines. One Cryo also treats crankshafts, connecting rods, camshafts, pistons, valves and valve springs, heads, rocker arms, spark plugs, engine blocks, intake manifolds and rear ends.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Does this mean that I should heat cycle my valve springs before I send them for Cyro? It's bad enough just changing them, much less doing it twice. Do you believe I could take a set of heat cycled 918's cyro them and get them to run a couple of years with a .588 lift cam?
Dale
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Does this mean that I should heat cycle my valve springs before I send them for Cyro? It's bad enough just changing them, much less doing it twice. Do you believe I could take a set of heat cycled 918's cyro them and get them to run a couple of years with a .588 lift cam?
Dale
04-08-2003, 01:07 AM
#54
Re: Discussion: Cryoing Engine Parts Don't worry about the heat cycling.
The 26918's can handle .600 of lift, but they are not going to handle a XE-R lobe doing that to them. I strongly doubt that the cryo is going to help the valve springs at all, but that might be a good question for OldSStroker.
Bret
The 26918's can handle .600 of lift, but they are not going to handle a XE-R lobe doing that to them. I strongly doubt that the cryo is going to help the valve springs at all, but that might be a good question for OldSStroker.
Bret
04-08-2003, 03:08 AM
#55
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Re: Discussion: Cryoing Engine Parts After this winter we just came through, my whole car was cryo traeted I think! <img border="0" alt="[jester]" title="" src="graemlins/gr_jest.gif" /> and my trans still broke! Seriously, when I was down South doing work for a few Cup teams, Cryo treatment was being experimented on spindles and brake hardware, Ray Evernham told me that they did last longer after the treatment.
Joe.
Joe.
04-08-2003, 10:13 AM
#57
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Re: Discussion: Cryoing Engine Parts K, I have been in Germany for a week so I haven't been able to follow up on this thread...
Anyhoo...
My theory on the rod goes like this:
1) I need to see an actual, real-life rod failure. My guess is a fracture at the big end is the usual culprit - but that's a guess on this rod. Anyone actually broken a rod?
2) If my failure mode is correct, what I am trying to do is stiffen the rod bolts from the other side to counteract a "splaying" force applied to them by the rod and piston assembly on the downstroke. As the rod is compressed, I believe that the rod bolts will tend to try to move away from each other and the rod itself will try to twist. If that is the case, the other end of the rod can be used to hold them in place and mechanically counteract any displacement. I kind of doubt a purely compressive failure of the rod itself - things will bend up under stress, a bending moment results and the rod snaps.
3) The PM rods would require a facing operation to clean up the fracture area to try my theory. This may or may not be possible.
This is only theory and a silly idea. I'd like feedback though.
Anyhoo...
My theory on the rod goes like this:
1) I need to see an actual, real-life rod failure. My guess is a fracture at the big end is the usual culprit - but that's a guess on this rod. Anyone actually broken a rod?
2) If my failure mode is correct, what I am trying to do is stiffen the rod bolts from the other side to counteract a "splaying" force applied to them by the rod and piston assembly on the downstroke. As the rod is compressed, I believe that the rod bolts will tend to try to move away from each other and the rod itself will try to twist. If that is the case, the other end of the rod can be used to hold them in place and mechanically counteract any displacement. I kind of doubt a purely compressive failure of the rod itself - things will bend up under stress, a bending moment results and the rod snaps.
3) The PM rods would require a facing operation to clean up the fracture area to try my theory. This may or may not be possible.
This is only theory and a silly idea. I'd like feedback though.
04-21-2003, 10:51 PM
#58
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Re: Discussion: Cryoing Engine Parts So is it actually worth cryoing the crank or not because i want to throw 20 lb of boost into my motor but i want to know if the stock crank will last
marc
marc
