Reuse main bolts and rod bolts? Machining? Please help.... wise men welcome

[packinkimber45]

I was wondering since I am going to be changing my main bearing and rod bearings, is it okay to reuse my main and rod bolts? I also read that when replacing rod bolts with new ones there is some machining that has to be done to the rods since new bolts are being used and has something to do with the bolt deforming and such. If I do take off my rod bolts just to do the plastigage do i still need to get the rods machined or resized? I really dont want to take out the rods and pistons. I just want to replace main and rod bearings. Does this same procedure apply to the main crank, is there any machining that has to be done for taking off the main bolts and re-installing them? I'm reading more and more things that is making my objectives get more complicating. Please help, I am confused and I am starting to feel that I am way over my head. I just want to replace my bearings and do it right.

 

[Locke]

Like headbolts, you can reuse rod and main bolts assuming they are in good condition. Check them for excess stretching at the threads and where the head meets the bolt shank.

Bolts are inexpensive, though. If you are intending on making a lot of power, consider new or upgraded bolts/studs.

 

[pj91gsx]

dont take the rod bolts out unless you are putting in better ones, like arps. the main bolts are reusable. if you spun a bearing you may need to align hone the journals. Its really not that difficult as you are making it sound.

 

[packinkimber45]

Like headbolts, you can reuse rod and main bolts assuming they are in good condition. Check them for excess stretching at the threads and where the head meets the bolt shank.

Bolts are inexpensive, though. If you are intending on making a lot of power, consider new or upgraded bolts/studs.

I know they aren't that expensive. I do plan to get new bolts.

dont take the rod bolts out unless you are putting in better ones, like arps. the main bolts are reusable. if you spun a bearing you may need to align hone the journals. Its really not that difficult as you are making it sound.

I do plan to replace my rod bearings so I figured since I am taking them out I might as well replace them. I dont really want to get the arp's if I have to do any machining on the rods at this time since I dont plan to run higher than 16-18 lbs boost. But as far as the machining on the rods that I have read, does that apply to only replacing with arp hardware or anytime you replaced the rod bolts. Through searching, I have read due to the head part of the bolt flexing it deforms once you torque them down so you have to get some machining done on the big end of rods. By taking the bolts out of the rods in order to do my clearance check, will I need to get the rod machined or only if I replace the bolts with new ones or arps? Thanks.

 

[pj91gsx]

anytime to take the rod bolts out an put them back in the bolts go in differently so you would need to get the rods align honed.

 

[packinkimber45]

anytime to take the rod bolts out an put them back in the bolts go in differently so you would need to get the rods align honed.

I was hoping for a different answer but it is what it is. I didnt really want to take the rods out, that would mean I have to take off the head to get the pistons and rods out. On that note, in order to measure my main bearings correctly I have to take the crank out and clean off all the oil from the upper bearings so my measurements are accurate. So this would mean I have to undo the rod bolts therefore I have to get them align honed. I was hoping to take the crank out to get it polished too and get it inspected by the machine shop. There goes that idea. Am I understanding this right, if I touch the rod bolts at all I will have to get it align honed which I would also have to take out the whole rod assembly? Is there anyway around having to align hone the rods and taking them out with being able to change out my crankshaft and rod bearings?

 

[->PrOjEcTGS<-]

No, what he's saying is that if you were to remove the bolt from the rod and replace it with an ARP rod bolt you would need to get them honed out. Since the rod cap could potentially be in a different position with the new bolts. I assume you are trying to do this without taking the engine out of the car. In that case, just replace your bearings, reuse your original fasteners and make sure to use plastigauge to make sure your still in spec. And call it done!!

Andrew

 

[pj91gsx]

anytime to take the rod bolts out an put them back in the bolts go in differently so you would need to get the rods align honed.

I see where you are misunderstanding. I ment when you take the rod bolts out of the rods. not when you take the nuts off.

 

[packinkimber45]

Sorry like I said I have never done this type of procedure before. So to clarify....

1. When I check my clearances with plastigage and I take the nuts off the rod bolts I can take the caps off and the bolts will stay in the rods?

2.So as long as I dont take those bolts off the rods I wont have to do any type of machining?

3.Will the rod bolts stay in there or is there something I will have to do in order to keep them from falling out?

4.The motor is currently on the engine stand with the motor upside down. Also when I take the nuts off the rods will the pistons just fall toward the head.... is there anything I have to do to make sure that does not happen?

5.Also in order to check the clearance on the rod bearings do I need to make sure the crankshaft main caps are installed and torqued or that is irrelevant?

Sorry I have lots of questions. I just want to make sure I dont screw anything up and that I did not spend all this money for all the maintenance parts and result in engine breakage. I really appreciate it. Thanks in advance.

 

[pj91gsx]

Sorry like I said I have never done this type of procedure before. So to clarify....

1. When I check my clearances with plastigage and I take the nuts off the rod bolts I can take the caps off and the bolts will stay in the rods?

2.So as long as I dont take those bolts off the rods I wont have to do any type of machining?

3.Will the rod bolts stay in there or is there something I will have to do in order to keep them from falling out?

4.The motor is currently on the engine stand with the motor upside down. Also when I take the nuts off the rods will the pistons just fall toward the head.... is there anything I have to do to make sure that does not happen?

5.Also in order to check the clearance on the rod bearings do I need to make sure the crankshaft main caps are installed and torqued or that is irrelevant?

Sorry I have lots of questions. I just want to make sure I dont screw anything up and that I did not spend all this money for all the maintenance parts and result in engine breakage. I really appreciate it. Thanks in advance.

you are asking all of the right questions. The rod bolts are pressed in so they dont move unless you press them out. The piston rings should hold the pistons in place but im not for certain, I never messed with a motors internals with miles on it. very importantly, dont mix up the rod caps. each cap goes with each rod, and each cap goes on a certain way. The indentions that hold the bearings in should be on the same side. The caps for the main need to be in the same spots too. the arrow points to the timing belt. torque the bolts in the correct sequence. do a 3 step torqueing sequence.

 

[->PrOjEcTGS<-]

Well, since the engine is already out and sitting on a stand, why not go the full nine yards? You might as well take the head off, pull the pistons, and re-ring them. To do this you will have to take the block to a machine shop to have the cylinders honed so that the rings will seat. When you reassemble it put all new gaskets and timing components on and you should be good to go. Then, aside from the head you would have a completely rebuilt engine.

 

[pj91gsx]

how many miles are on this motor?

 

[packinkimber45]

you are asking all of the right questions. The rod bolts are pressed in so they dont move unless you press them out. The piston rings should hold the pistons in place but im not for certain, I never messed with a motors internals with miles on it. very importantly, dont mix up the rod caps. each cap goes with each rod, and each cap goes on a certain way. The indentions that hold the bearings in should be on the same side. The caps for the main need to be in the same spots too. the arrow points to the timing belt. torque the bolts in the correct sequence. do a 3 step torqueing sequence.

In regards to the torque sequence, when uninstalling or loosening of main caps do I do reverse of the torque sequence or same torque sequence? For example
10 6 2 3 7
9 5 1 4 8

or

1 5 9 8 4
2 6 10 7 3

when loosening main caps bolts?

 

[packinkimber45]

Well, since the engine is already out and sitting on a stand, why not go the full nine yards? You might as well take the head off, pull the pistons, and re-ring them. To do this you will have to take the block to a machine shop to have the cylinders honed so that the rings will seat. When you reassemble it put all new gaskets and timing components on and you should be good to go. Then, aside from the head you would have a completely rebuilt engine.

As much as I would like to do that, I just dont have the money. I have bought a lot of oem parts to do this little maintenance that has expanded to close to a rebuild. I will have to wait unfortunately until later. I just need the car running.

 

[packinkimber45]

how many miles are on this motor?

130k mi's. Rotated the crank last night and on journal closest to piston #1 I see what looks to be a hairline crack. I will be taking it to the machine shop today, hopefully they will tell me it is ok. Fingers crossed because these things are freaking expensive.

 

[pj91gsx]

why did you take the motor out? When torqueing the bolts down for the head and the mains I always do the corners and work inward. though I dont if that is exactly right but I havent had a problem with my motor yet.

 

[packinkimber45]

why did you take the motor out? When torqueing the bolts down for the head and the mains I always do the corners and work inward. though I dont if that is exactly right but I havent had a problem with my motor yet.

I decided to do a bunch of parts replacement for maintenance. I just got back from the machine shop and it doesn't look good. There is a gouge on one of the main journals closest to the crank pulley. The machinist said that it is bad enough that he would not recommend to put it back in the motor with just getting the crank polished. He recommended getting it reground down to .10 under. But researching these cranks cannot be machined due to being nitrate coated. So it sounds like I have to get ahold of another crank or a new one which happens to be $692 my cost just for oem ones.