gm guys in here
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gm guys in here Got a question but not sure where to go to ask so here we go. we have a 97 4.3 motor out of a gmc pick up, stupid us we did not mark the rods when we dropped them out of the motor, no big deal we thought, now that we are putting them back in we get them in torque them down to about twenty pounds or so and the crank will not turn over locked tight. we know its not the crank, we thought it might be at first so we got another one, now question is this, theses rods have gma and gmb stamped on them is there a certain order they have to go in or do you think that since they use heat to put the valve head back on the rods they warped the rods.
Valve heads on the rods? Hmmm.
Look on the big end of the rod, there should be a bevel on one side, this goes toward the crank, there is no to little bevel on the other side of the rod big end, this side goes toward the other rod on the journal. Make sure the mark on the pistons still face forward.
This is assuming everything is right. You might have the wrong size bearings. Did you check the clearance?
Look on the big end of the rod, there should be a bevel on one side, this goes toward the crank, there is no to little bevel on the other side of the rod big end, this side goes toward the other rod on the journal. Make sure the mark on the pistons still face forward.
This is assuming everything is right. You might have the wrong size bearings. Did you check the clearance?
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Originally Posted by 8a8mfh
Valve heads on the rods? Hmmm.
Look on the big end of the rod, there should be a bevel on one side, this goes toward the crank, there is no to little bevel on the other side of the rod big end, this side goes toward the other rod on the journal. Make sure the mark on the pistons still face forward.
This is assuming everything is right. You might have the wrong size bearings. Did you check the clearance?
Look on the big end of the rod, there should be a bevel on one side, this goes toward the crank, there is no to little bevel on the other side of the rod big end, this side goes toward the other rod on the journal. Make sure the mark on the pistons still face forward.
This is assuming everything is right. You might have the wrong size bearings. Did you check the clearance?
Last edited by Nemo02Z; Aug 27, 2006 at 08:02 PM.
GMA and GMB mean nothing to you, me, anyone except for the people who forged the rods in the factory.
AGAIN did you check the bearing clearance? Did you make sure the bevel on the side of the rods big end faces the crank and not the other rod?
What about the caps? you say they are not marked any other way right? no stampings?
Do you know if the caps are on the rods they came off of?
The caps have to be on the rods they were originally on, in fact you should not have a disassembled engine in your presence that doesn't have the rod caps AND rods numbered.
If you have the caps and rods mixed up you are going to risk damaging the pistons getting them back off the rods, and the rods are going to need to be reconditioned.
AGAIN did you check the bearing clearance? Did you make sure the bevel on the side of the rods big end faces the crank and not the other rod?
What about the caps? you say they are not marked any other way right? no stampings?
Do you know if the caps are on the rods they came off of?
The caps have to be on the rods they were originally on, in fact you should not have a disassembled engine in your presence that doesn't have the rod caps AND rods numbered.
If you have the caps and rods mixed up you are going to risk damaging the pistons getting them back off the rods, and the rods are going to need to be reconditioned.
Last edited by 8a8mfh; Aug 27, 2006 at 09:45 PM.
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rods are all the same! they can go into any cyl. you need to check 'all the clearence's. do you have a spec sheet from machine shop? this will tell you what everything is at.
if your not sure how to read the sheet? go to any performance shop or online and get a manual! "how to rebuild your small block chevy" the best 30 bucks you'll ever spend.
if your not sure how to read the sheet? go to any performance shop or online and get a manual! "how to rebuild your small block chevy" the best 30 bucks you'll ever spend.
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well your right rods are all the same but after looking at the caps they are different, three have a tall bevel and three have a short bevel. Now all we have to figure out which caps go to which rods. All parts are new all other parts have been machined. The info on the caps might have given us the break we needed will let you know, thanks 
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Thread Starter
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Thanks got them figured out, until now did not know it made a big difference when you get the caps mixed up.... Let this be a lesson to everyone make sure you stamp the rods and caps when you pull them from the motor
Last edited by Nemo02Z; Sep 1, 2006 at 04:55 PM.
