Any luck, jMx?

 

Rod bolts do have a affect on rod bearing bore shape when all is tight, therefore depending on the rods structual integrity it could be risky just changing bolts since they werent machined with the better bolts. My question is didnt GM replace early LS1 rod bolts with upgraded ones ? Any factual info on this would be greatly appreciated. Keep in mind a nice alternative to replacing stockers would be to check and retorque them for proper spec. This alone could be why people have had failures in the past. A robot prolly torqued them and may have botched settings? <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

TTT, ? <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

 

Sorry guys, I haven't even ordered the bolts yet. This will be a good month off at the minimum and needs more research before I go messing with them.

LS1derfull, you cant just check the torque readings on the stock bolts as they are torque to yield.

 

A better Q might be to ask Where/When the rod bolt failure myth started and how seriously we should take the issue. Also, has GM addressed the rod bolts over the years? When did the change start?

How in the hell do you go back and diagnose a rod bolt was the culprit of a bottom end failure when everything turns to mush?

Is it worth the risk of changing the bolts without disassembling, sizing and re-balancing? The sales staff at Katech will say, 'Go for it!', but what to machine shop people think? Both sides are probably biased.

Maybe someone could ask an independent tuner or two about changing just the bolts without disassembling, resizing, etc.

 

You cannot resize a cracked cap rod btw. What you do is bore out the big end to for a special bearing that has a larger OD.

Eric

 

Ahh, thx. Would changing rod bolts specifically designed for that rod force you to do that? Sounds like a PITA to have to change the bore & bearings? Makes sense, but I haven't heard of anyone doing that before. I have heard them say check the big end or whatnot.

So maybe they are just bolt-ins?

 

I changed the rod bolts on mine yesterday. I took one out at a time and installed the new ones.

Make sure to use the supplied lube from ARP. Instructions say to torque to 45 ft lbs. Loosen bolt then torque to 45 ft lbs. Loosen again and torque to 45 ft lbs.

After I torque all this way I went over them to double check the torque. They were all perfect.

 

Always resize the rods after changing the rod bolts. Changing the rod bolts changes the clamping force, which then changes the big end bore. Remember that with only .002"-.003" oil clearance, it does not take much distortion before you have major problems.

Unless you are making some crazy horsepower, I would recommend that you stay with the GM Bolts. Normally if a GM rod bolt breaks it is becuase something else broke first and placed an extreme amount of pressure on the bolt.

 

so with a motor spinning 7100rpm or so, the rod bolt won't break? i have an 00 and was thinking about spinning about that high in the future

 

damn you ressurrected this post from the dead.

 

01 and newer engines used redesigned rod bolts. I do not think they are torque to yield. They are supposedly much better then the 00 and older ones. I also remember reading that the katech rod bolts are the exact same size as the factory ones, where the arp are a bit longer i think. Someone was saying that the longer arp bolts could contribute to the rod end getting out of round. Not sure on how true this is though.

 

I just did this on my 99 C5. I built a steel frame around the car after it was on the lift. The steel frame was a pallet rack a buddy of mine has at his warehouse. We put a crossmember up at the top across the center of the engine and removed the front wheels. Then I took 2 Kevlar 10,000lb tie downs and slung them under the middle two pipes of my headers and put them over the crossmember above. Them I removed the motor mount bolts and cranked the ratchets untill the motor came up evenly about 1/2". The only thing I removed was the fuel rail covers! I also put a 1.5 ton under hoist stand under the rear crossmember for stability. I let it stay like this overnight and when I came back in the morning the motor hadn't moved so I knew the straps were fine to hold it.

Then I put a transmission jack under the left front bottom arm and removed the bolt and steering rack arm connection. Then I unbolted the shocks at the bottom and lowered the transmission jack. Then did the same to the right one. At this point the crossmember was disconnected from the wheels.

I then removed the two steering rack bolts and the four bolts holding the ABS controller to the crossmember and the power steering cooler.

I then unclamped all the hard lines and the harness that runs along the front crossmember.

Then I removed the four bolts holding the crossmember up with the transmission jack under it and slowly lowered it and got it out of the way.

For the most part the oil pan mounting bolts were easy to get to except for one on the passenger sid in the middle. It was a bear because it was between two aluminum strengthening bars and was up behind the headers and right above the sump horn. I was able to get it with the a ratchet wrench kind of wedged in there and got one click at a time. It took about 30 minutes to get out but I kept at it and it finally came out. Putting it back was just as bad.

Once I removed all the bolts (and had the oil drained and filter removed previously) The pan came right down. The gasket was ruined when I removed it. It broke in several places and remnants were caked to the block an pan and had to be removed with a plastic scraper.

The windage tray and pickup tube came next. I removed the pickup tube first which meant I had to remove the two bolts from the oil pump. Make sure you also have a new oil pump O-ring. Then the windage tray can be removed.

Once the tray is out of the way you can get to the bolts. The rods are right there. I got a 24mm socket and put it on my long ratchet handle and rotated the motor slowly with that to get to each rod.

I used the ARP pros. I put some moly lube that came with them on the bolt threads and a little under the cap. I remove one stock bolt at a time and replaced it with one ARP bolt at a time and torqued them to 40lb/ft 3 times with the 3rd time the clamp as per the instructions. I checked my rod side play with a feeler and it didn't change and I was able to get a thin .002 plastic-gauge in btween the rod and bearing and it didn't change with the ARP's installed. I know that isn't the best way to check them and is not accurate but it showed me the caps didn't go out of round enough to change the bearing clearance, at least where I was able to measure with the guage.

After they were all in, I went over the whole bunch again to make sure they were all at the correct torque.

I then replaced the windage tray and pickup tube.

Then I cleaned and prepped the pan mating surface and the block mating surface. This was harder that you might think because doing it from the bottom I had to put the RTV bead in the corners after I dried it off and also the whole mating surface, as GM specs the gasket to be mounted dry. Once we had the rtv inplace on the block and the gasket placed on the pan, a friend and me got the pan up and put bolts into the corners finger tight. Then we got the rest in finger tight and kept checking the pan alignment. Once all the bolts were in we tightened them to spec in 2 passes on alternating sides.

Then we put back the crossmember, etc. I have a bunch of pics if you would like I can send them to you. It might help you visualize what you will need to do.

One thing I noticed was the ARP Pro's were longer than the stockers so the torque load is spread out over a longer distance. They were also slightly heavier but that hasn't been an issue for me. No vibrations, etc.

I have just finished putting about 400miles on them and have nailed it few times and all seems weel so far.

 

sry bout that, iwas using the search feature

 

how do you do it for an f-body?

 

TTT please

 

dont the rod bolts have to be pressed out of the rods?

 

No, LS1's are just threaded in. No pressing needed.

 

Congrats and Good Luck!
How many times did you/should you TQ, Loosen and Re-TQ to properly stretch the rod bolts during install?

 

According to ARP's instructions use moly lube on the threads torque to 40lb/ft. and loosen 3 times with the third time being the final clamp. The sequence you highlighted was for reinstalling the oil pan. Also, keep in mind for the external procedures I decsribed, I was doing it on my 99 C5.

BTW, I have about 450 miles on them now and have been woking the motor more and more. I took it to the rev limiter yesterday and all had been well. This week we are doing AFR 205's, cam, and LS6 PCV conversion. If all goes well, dyno next weekend and I'll post the results.