LS Rod Swap.... How To
02-13-2008, 05:10 PM
#82
3.0 BAR
Join Date: May 2006
Posts: 1,967
Re: LS Rod Swap.... How To
So I should probably tell them to make the bushing to these specs:
.936 wide
.748 ID ....or should I go with pressing the pins in? (.7475) The Vitara piston already floats on the pin anyways, but it's also held with C-clips so it's not like the pin is going to move side to side if I don't press it in. .748 would make assembly easier for me.
.8285 OD (pressfit into rod) The catalog says .827 for part #90926-1. I'm assuming I need to tell them to oversize it right?
.936 wide
.748 ID ....or should I go with pressing the pins in? (.7475) The Vitara piston already floats on the pin anyways, but it's also held with C-clips so it's not like the pin is going to move side to side if I don't press it in. .748 would make assembly easier for me.
.8285 OD (pressfit into rod) The catalog says .827 for part #90926-1. I'm assuming I need to tell them to oversize it right?
02-14-2008, 03:58 AM
#83
0.0 BAR
Join Date: May 2005
Posts: 0
Re: LS Rod Swap.... How To
Originally Posted by E-b0la
So I should probably tell them to make the bushing to these specs:
.936 wide
.748 ID ....or should I go with pressing the pins in? (.7475) The Vitara piston already floats on the pin anyways, but it's also held with C-clips so it's not like the pin is going to move side to side if I don't press it in. .748 would make assembly easier for me.
.8285 OD (pressfit into rod) The catalog says .827 for part #90926-1. I'm assuming I need to tell them to oversize it right?
.936 wide
.748 ID ....or should I go with pressing the pins in? (.7475) The Vitara piston already floats on the pin anyways, but it's also held with C-clips so it's not like the pin is going to move side to side if I don't press it in. .748 would make assembly easier for me.
.8285 OD (pressfit into rod) The catalog says .827 for part #90926-1. I'm assuming I need to tell them to oversize it right?
Press fit is 0.003" over. So get them that much larger. Also, get them slightly wider too, the machine shop will mill the small end down (along with the big end of course) and ream it to free float the piston pin.
02-22-2008, 01:52 AM
#88
0.0 BAR
Join Date: May 2005
Posts: 0
Re: LS Rod Swap.... How To
Originally Posted by civiceggturbo
i can guarentee they were not .003- probably .0003-thats three ten-thousanths not 3 thousanths
crower must just have superior machining abilities than the rest of the world
crower must just have superior machining abilities than the rest of the world
The bushings I ordered were 0.003", that's 3 thousandths larger than the hole in the rod. The machine shop did not have an issue.
It's supposed to be an interference fit.
02-24-2008, 12:45 AM
#89
0.0 BAR
Join Date: Oct 2007
Posts: 0
Re: LS Rod Swap.... How To
seriously...if you did the math from the specs given the ls rod hole dimension should be .827 and he said make the od of the bushing .8285
.8285
-.8270
----------
.0015 = oversize of the bushing
not .003 i would like to see that pressed in when the wall of the bushing is aroud .030
not trying to be a complete dick but you are wrong, you even said you didnt do it/ obiviously have no machining experience so why try to defend your misunderstood specs
read up
http://www.engineersedge.com/class_v.htm
.8285
-.8270
----------
.0015 = oversize of the bushing
not .003 i would like to see that pressed in when the wall of the bushing is aroud .030not trying to be a complete dick but you are wrong, you even said you didnt do it/ obiviously have no machining experience so why try to defend your misunderstood specs
read up
http://www.engineersedge.com/class_v.htm
02-24-2008, 01:48 AM
#90
0.0 BAR
Join Date: May 2005
Posts: 0
Re: LS Rod Swap.... How To
The information from that page is nice info to have, but it doesn't even take into account of the materials used, thus it is not accurate by any means.
It states that at that size, 2 thousandths is maximum for an interference fit. 3 thou is not much larger and silicon bronze will deform if it needs to. That's okay though, since the bushing is going to be reamed for a good fit on the piston pin.
The most important thing to remember is that most people are going to be using used rods, which may not have the exact 0.827" diameter. It is always better to have extra room than not. Otherwise your out $40 on useless bushings or worse, the bushing is too loose and grabs the pin and boom, you're out a motor.
Crower is not stupid, obviously they do this for a living and are very good at it. Don't knock what they have to say. No offense, but I'll take their word over yours.
It states that at that size, 2 thousandths is maximum for an interference fit. 3 thou is not much larger and silicon bronze will deform if it needs to. That's okay though, since the bushing is going to be reamed for a good fit on the piston pin.
The most important thing to remember is that most people are going to be using used rods, which may not have the exact 0.827" diameter. It is always better to have extra room than not. Otherwise your out $40 on useless bushings or worse, the bushing is too loose and grabs the pin and boom, you're out a motor.
Crower is not stupid, obviously they do this for a living and are very good at it. Don't knock what they have to say. No offense, but I'll take their word over yours.
