Thinking of upgrading to ARP 134-6005 Rod bolts in my 95 LT1 (powder metal rods). Anybody ever change the rod bolts while the engine is still in the car? Is it even possible? Gonna use a bolt stretch guage. Any room for it? Oil pan is off anyway for a new(stock) timing cover. Current cover is modded for an EWP.
I figured the ARP`s would be some cheap insurance.
Thanks!

you really should not swap rod bolts unless you have the rods out and get them resized........

I have change them with out taking the bottom end apart. I dont think you can in the car. I had the motor up side down on a engine stand. I used arp as well.

You have to take a hammer and a punch and knock out one bolt at a time. Do not knock out the other side , you dont want the cap to come off!

Tools needed
Go to Lowes and pick up the smallest C-clamp they have, and round up a washer/ spacer 1/2 long, but big enough for the arp bolt to pass threw, hammer, punch


FREZZE THE ARP BOLTS, They will not go in if not frozen.
Put the lube on the bolt and push it in, it will only go so far, then use a c-clamp(leave the cap on)

Work fast you dont want the bolts to warm up till you are done. Once the bolt bottoms out againts the c-clamp , use a tall washer, look close in pick three. (you will need a washer 1/2 inch think) ( I had to grind on the side of the washer to it would sit correctly on the rod caps.)

Now thinken the c-clamp again using the washer as in pic one.

The bolt will stop going in all the way if i remember correctly, it doesn't bottom out.

Now here is the fun part. Take Your arp nut and screw it on the bolt, and thighten it up. MAKE sure that you have at least two or three threads before you tighten up the nut. The nut will suck the bolt up into the rod NOTE- Because of the clockwise motion of the nut it might turn the head of the arp bolt, so when you start this procedure place the arp bolt a little counter clockwise, so it will end up straight.

Finsihed product should end up like this


I thightened the bolt two or three times to get them to strech, then i torqued them to specs.

This was my first time so i took pics for when some one might ask.

I'm not sure if you could do all of this inside the car. There is not that much room, you have to turn over the crank some. I bet you could just lift the motor, with a cherry picker and drop the k-member down to get more room, if not just take it off.

Good luck , hope this helps.

I DID NOT RESIZE MY RODS, and i just dynoed 400rwhp two days ago, car just got back running three days ago.

Good write up B-rad

Noticed this one on your site too, but it wasn't included in your write up?



Bret

Leave well enough alone, the risk far exceeds any gain.

LOL, ya thats the kind of help i get around my shop.

I just sent you a email of my dyno graphs, im about to go change out the opti right now.

You should not change rod bolts without resizing or at least checking the bore for distortion. ARP bolts need to have the rod reamed to fit.

haha Bret doing a little directory surfing.

Hey, Thanks everyone.
I think I`ll just forget this mod. I`m just concerned of the high revs (6800 redline) that I spin this engine to. And someday I`m going to get to some open track days= sustained high rpm. I`ll just have to keep the revs low.

Actually I don't think it's a bad thing especially on PM rods. LS1 guys using the same design rods do it and get lots of RPM out of those shortblocks with a longer stroke (but lighter piston)

Bret

Fit just fine to me, still beating mustangs

I always contemplated this but kept forgetting to post about it. Seems like a thoughtful idea, but perhaps not the best approach. Good thread.

-Dustin-

It is my understanding the clamping load changes with ARP rod bolts, which means the bearing clearances.

If you don't resize the rods for the ARP rod bolts, you're effectively changing the bearing clearance and making the rod clearance tighter than spec.

Am I wrong on this?

I agree my machinist recommended the same thing when i installed rods bolts and when i studded the mains he linehoned with the studs

Depends on the rod and the bolts.... There are a lot of times when you measure this it doesn't change.

Bret