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Can I reuse the rod and main bolts

B

Bob V

New member
Doing a rebuild on my 1998 GTP. Is it safe to reuse the rod and main bolts if they tighten correctly? I have searched and cant find the answer and cant find the stock bolts ANYWHERE. ARP are about $170. I really don't want to spend that much if the stock will hold. Also having problems finding the rocker bolts locally. has anyone had any luck reusing these?
THANKS!!
Bob V
 
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Never re-use rod bolts. Rods....if you didn't have a violent engine failure my be ok but for the amount of work involved in a lower end rebuild, I suggest new/reconditioned rods.
 
I have heard of people re-using rocker bolts...but I wouldn't take the chance on my engine. ZZP sells Comp reusable rocker bolts for $20.
ARP rod and main bolts are $150 plus shipping
 
You can't install ARP hardware in the bottom end without machine work. So, unless you are getting the rods and mains resized, you should avoid these.

I've reused original hardware in the bottom end without issue. But, it's probably not a bad idea to get new bolts, even though I've yet to find anything about replacing them in the manual.
 


Factory rod and main bolts are TTY.

The mains need line bored for running ARP studs...rods need the bosses where the TTY bolt to sit machined out because the ARP rod bolt is larger, along with the face of the bolt.

I didn't run ARP rod bolts in my setup, just got new L32 rod bolts...only TTY bolt I'd re-use is the crank bolt.
 
To the OP, if you're re-installing everything without having the mains line bored...be in for a few hundred mile wonder though...
 
Thanks All. It just seems that if EVERONE was replacing the rod and main bolts I would be able to find them. I will have two full sets to use so I will compare length and not use any stretched ones and if any of them get soft while torquing them i will know. Now, Why do I have to line bore the engine that had no problems before and now it wont last 200 miles? what is going to fail? Will I bust the crank? why would a problem not show up while plasta gauging the mains?
 
Most people that I've talked to won't rebuild an engine, they just find a replacement.

"When you align bore the main bearings, you are making sure that the center of each main bearing hole is aligned with the other main bearing holes. It is a good idea to make sure that you bring the studs to the machinist with your block because they install the mains and torque them down when they machine the block thus accounting for any distortion caused by the studs. "

"I had mine aligned bored when I installed studs. My machinest told me I had to because when he torqued the mains down it pulled them out of round. "
Courtesy of 3800Pro.com
 


bob, what did you do to the engine,

mark all you mains and rods, dissassemble, clean, reassemble with new bearings and check with plasti gauge?

if your clearence is good the engine is probly fine, but in reality the houseing bore might be 1/2 thou outta spec but you wouldnt know cause you didint measure it

the houseing bore, has a min-max spec
crank has a min-max spec
bearings of the same part no. measured in the same houseing bore at the same torque, can vary as much as a thou, (allways swaping bearings or half shell at work)
between all these variances its hard to be sure with plastigauge that your truley in spec, its just a blur between it all

ive reused tty bolts on rods and mains on a few different engines and have never had a problem, howerver professionally i wouldnt recomend it
 
Its a 10/10 crank kit. My machinist and I both agree that if it gages out good and still spins over fine with the mains torqued down I will be fine. Its not like the line bore stays dead on as an engine heats and cools anyway. The only thing wrong with this engine was a spun rod bearing. I really need to find a service manual. does anyone know if the torque specs are for dry or oiled fasteners? If I cant find it I will go with lightly oiled- other than the ones that need sealant
 
i only have 07 spec at home (20ftlbs + 50deg), im sure someone can let you know or i will tomarrow

if you lost a rod bearing i wouldnt use the rod bolts over, but that me.


yes torque your fastners with engine oil
 
I will be using a rod from my other motor that has good rods. The weight EXACTLY the same so no problem there. I would have changed the bolts but the only bolts I could find are ARPs, just cant justify the cost of the bolts AND machine work (and the time). I need to get this together this weekend.
 


Problem with ARP rod bolts is machining is needed on the cap to fit the head of the bolt, as it is larger than the stock one...so good call getting the stockers, they're more than enough.

That's the only reason why I didn't go with ARP rod bolts...and waited for my stockers...I couldn't justify it either...spent the money on the main/head studs instead.
 
Thanks ALL! got it together and so far so good. Very happy with how the car runs and drives so far. Was a little nervous since I bought the car with not being able to drive it. I do have one small problem you might be able to help with. The previous owner kept the after market intake and gave me the stock stuff. Not sure if I got everything as far as mounting the PCM. How does it mount in the are cleaner housing? it just kind of sits in there now. Is that how it is supposed to be?
Thanks!
 
UPDATE
About 1200 miles now and all is well. Some things I found out while researching the rod and main bolt re-use
#1 there is a LOT of bad information out there!
#2 ARP rad and mains will fit without machining. They recommend checking the journals for roundness because the difference in clamping force. if they are still found with the ARPs you are fine.
#3 Should have gotten the factory service manual first (go back to #1)
The manual does state that the head, cam sprocket, and rocker bolts permanently stretch when tightened and should not be reused. There are NO such statements for the rod and main bolts, the manual does say to check for stretch and replace if they are.
#4 There is a LOT of bad information out there. Just because the tightening procedure has and torque and turn method does not mean the fasteners are torque to yield. It's actually a more precise way of tightening because it eliminates a lot of the friction variable in torquing (up to 80% of the turning effort is overcoming friction, and the tighter you go the higher it gets). If you look at the manual almost all fasteners on the engine are torque and turn. However, it is always a good idea to replace critical fasteners with new.
Again I would like to thank those who helped with this and i hope that some of this info is helpful to others.

The total cost of the non-rebore rebuild was about $900, 700 for parts (crank kit, rings, gaskets & seals, oil pump kit, timing chain, head bolts, timing chain dampener, etc) and $200 for machine work ( tanking and cleaning heads and block, cylinder honing, cam bearings and install)
 
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