what are the consequences of this!!
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Re:what are the consequences of this!!
I think a clue here is a misinterpretation of what is actually going on - I have NO doubt that heating the WHOLE gear will enlarge whatever center bore is present - and suspect what is being done with the liquid nitrogen is *SPOT* cooling to shrink the bore metal only in a limited, LOCAL area - possibly a completely DIFFERENT physical phenomena!
This would be quite similar to over heating an engine block, then causing it crack by too quickly pouring in cold water - WHY? - because it causes the metal in contact with the cold water to CONTRACT faster than the hotter surrounding metal can adjust, so a crack is formed...
I can visualize how under specific, controlled conditions that MIGHT work on a gear/shaft situation, and it might be easier and more cost effective to COOL a relatively SMALL area to shrink the metal in a local area, than to HEAT a much larger one to do the same thing- but if we're talking about heating or cooling the WHOLE piece, I'll stand by my original opinion...
;D ;D
And I think most of us WERE talking about heating/cooling the WHOLE material, rather than smaller local areas...
This would be quite similar to over heating an engine block, then causing it crack by too quickly pouring in cold water - WHY? - because it causes the metal in contact with the cold water to CONTRACT faster than the hotter surrounding metal can adjust, so a crack is formed...
I can visualize how under specific, controlled conditions that MIGHT work on a gear/shaft situation, and it might be easier and more cost effective to COOL a relatively SMALL area to shrink the metal in a local area, than to HEAT a much larger one to do the same thing- but if we're talking about heating or cooling the WHOLE piece, I'll stand by my original opinion...
;D ;DAnd I think most of us WERE talking about heating/cooling the WHOLE material, rather than smaller local areas...
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From: The "real" Northern CA
Re:what are the consequences of this!!
I can visualize how under specific, controlled conditions that MIGHT work on a gear/shaft situation
YES, by ALL means, you WOULD heat the gear to gain a better fit over the shaft!
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Re:what are the consequences of this!!
"You are saying what you said earlier is wrong?"
NO - what I *am* saying, and follow me here, there MAY WELL be a different physical phenomena between heating a WHOLE large diameter gear with a center bore to change the size of that bore, and rapidly CHILLING *only* the center area of that same gear to do the same thing!
Capeesh?
"YES, by ALL means, you WOULD heat the gear to gain a better fit over the shaft!
I believe this topic is about a hole not a gear."
I think it's pretty clear he IS talking about the "hole", and heating the gear to GET the hole to fit on it's shaft - at least *I* didn't have any problem with that assumption.
NO - what I *am* saying, and follow me here, there MAY WELL be a different physical phenomena between heating a WHOLE large diameter gear with a center bore to change the size of that bore, and rapidly CHILLING *only* the center area of that same gear to do the same thing!
Capeesh?
"YES, by ALL means, you WOULD heat the gear to gain a better fit over the shaft!
I believe this topic is about a hole not a gear."
I think it's pretty clear he IS talking about the "hole", and heating the gear to GET the hole to fit on it's shaft - at least *I* didn't have any problem with that assumption.
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From: The "real" Northern CA
Re:what are the consequences of this!!
Man you seem to get all worked up about silly stuff. And like I said earlier, the topic is about a hole in the manifold not a gear. The theory is that the hole will enclose with heat not enlarge. You follow me? <br><br>And if you're implying that by cooling the gear the center will get smaller, than your right. capeesh? 
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From: Rising Sun, IN (out in the woods)
Re:what are the consequences of this!!
Ok....<br><br>Gary, when you install a gear on a shaft with a tight fit, heat the gear and freeze the shaft.<br><br>Katoom, when you install a gear on a shaft with a tight fit, freeze the gear and heat the shaft.<br><br>Note: One of these methods won't work. One of these methods will indeed make the assembly impossible to put together. I, from experience, know which one works.<br><br>Flame off.....<br> >
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From: McKinney, TEXAS
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Re:what are the consequences of this!!
[quote author=rattle_rattle link=board=7;threadid=16839;start=#157944 date=1057720512]<br>Ok....<br><br>Gary, when you install a gear on a shaft with a tight fit, heat the gear and freeze the shaft.<br><br>Katoom, when you install a gear on a shaft with a tight fit, freeze the gear and heat the shaft.<br><br>Note: One of these methods won't work. One of these methods will indeed make the assembly impossible to put together. I, from experience, know which one works.<br><br>Flame off.....<br> ><br>[/quote]<br><br> ;D ;D <br><br>Gotta LOVE it! ;D ;D ;D
<br>[/quote]<br><br> ;D ;D <br><br>Gotta LOVE it! ;D ;D ;D
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Re:what are the consequences of this!!
"The theory is that the hole will enclose with heat not enlarge. You follow me?
And if you're implying that by cooling the gear the center will get smaller, than your right. capeesh?"
Now, indulge me here a bit - I'm gettin' old and sorta senile, but are you saying the hole in a heated GEAR would get LARGER - but a hole in a heated manifold would get SMALLER?
I really DO wanna "capeesh", even if it DOES seem "silly" to some... ;D ;D ;D
Shucks, I may have been installing tight fitting gears on shafts the WRONG way for all these years - and succeeding only by dumb luck...
And if you're implying that by cooling the gear the center will get smaller, than your right. capeesh?"
Now, indulge me here a bit - I'm gettin' old and sorta senile, but are you saying the hole in a heated GEAR would get LARGER - but a hole in a heated manifold would get SMALLER?
I really DO wanna "capeesh", even if it DOES seem "silly" to some... ;D ;D ;D
Shucks, I may have been installing tight fitting gears on shafts the WRONG way for all these years - and succeeding only by dumb luck...
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From: The "real" Northern CA
Re:what are the consequences of this!!
Gary, when you install a gear on a shaft with a tight fit, heat the gear and freeze the shaft.<br><br>Katoom, when you install a gear on a shaft with a tight fit, freeze the gear and heat the shaft.<br><br>Note: One of these methods won't work. One of these methods will indeed make the assembly impossible to put together. I, from experience, know which one works.
Now, indulge me here a bit - I'm gettin' old and sorta senile, but are you saying the hole in a heated GEAR would get LARGER - but a hole in a heated manifold would get SMALLER?
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From: Colorado
Re:what are the consequences of this!!
[quote author=hotdram link=board=7;threadid=16839;start=0#157889 date=1057712637]<br><br>Two dis-similar metals heated to the same temperature will expand to different dimensions (and in different directions) due to their different CTE's.<br><br>[/quote]<br><br>I'll stick with this one, having played with LIN here and there. :
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From: Marietta SC
Re:what are the consequences of this!!
;D I've been in maintenance for over 10 years. This argument always comes up. Here is the solution we have came up with to solve this discussion. Men get naked go into the shower with the water on warm. Then turn the water to ice cold and look down. You will have your answer, regarding heat and cold
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From: Eldersburg, MD
Re:what are the consequences of this!!
Keep it simple, The hole is going to both expand and contract. Over time the probe is going to get loose, and fall out. Also where did all his shavings go from drilling that small hole? I would guess he could not get a magnet in to fish out the particles. Where did he get the probe? They should have also sold him the 1/8 or 1/4 MNPT to compression/swage fitting, along with instuctions on how to install.<br><br>Ken
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From: yardley, PA
Re:what are the consequences of this!!
he said he DID get the tap and didn't see the point in drilling that big of a hole..didn't ask about the shavings though....i wonder if the egt's are the same w/o the tap??? i remember reading when i installed mine that the tap was set to "ambient outside temperature" or something on those lines :
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From: Windsor, Colorado
Re:what are the consequences of this!!
I fell through the ice on a frozen lake once and all I can say is that sure made some things shrink. 
<br><br>I agree with Kenny, both the hole in the manifold and the probe are going to go through cycles of expansion and contraction. (Don't care to argue when and why) At some point, the probe will get loose. <br><br>There is no way in the world I would leave the probe in the truck that way. But some people are happy with Duct Tape and Band-aids. :
<br><br>I agree with Kenny, both the hole in the manifold and the probe are going to go through cycles of expansion and contraction. (Don't care to argue when and why) At some point, the probe will get loose. <br><br>There is no way in the world I would leave the probe in the truck that way. But some people are happy with Duct Tape and Band-aids. :