This past summer I did a major overhaul of the car and rebuilt the transmission and 3200 stall. also did cam and heads, lifters, oil pump, and much more and replaced almost all the gaskets of the motor. i was reading about the failure rates of the stock rod bolts with high miles. so i decided to do arp rod bolts. i did the torquing sequence (2 passes at 30ft/lbs and a final at 50) and used the supplied lubricant. i did strip the last bolt and had trouble getting it out, but eventually was able to get it out. i also took out the ferrules.

fast forward about 3000 miles later, and about a month and a half later, im goin WOT to tune the car and i hear a clunking; i knew right away that i had spun a rod bearing. i didnt have time to rebuild it myself cuz of work and school so i let my mechanic tear it apart. i had 2 spun rod bearings and one of the rod bolts completely backed out and was sitting in the oil pan.

now before anyone says anything, i didnt use the stretch gauge to check since i didnt have the tool, and i was running out of time before school started up again. and ppl on here have done the torque sequence before and i guess i was the unfortunate one.

i may have installed them incorrectly so im not bashing ARP bolts, but i want everyone to know what happened with me so they wont make the same mistakes. if i did do everything over again, i would have spent the extra 100 bucks and got the katech. and if i got the arp bolts, i would for sure have got a machinist to do and check with a stretch gauge.

it was very disappointing, but i like to look at the brightside of things. even though the old motor failed, the car is back up and running with an LQ9.

 

Don't you also have to resize the rods when you do the ARP bolts also?

 

typically yes.. some get away without it though.. as cheap insurance you might as well do it while its apart like that

 

My understanding was since the rods were a cracked cap design you cant resize them but, IDK though???

 

if it was going to spin a bearing from the rod sizing being off, it wouldn't take 3000 miles for it to happen

 

OP, dont feel bad, I had a motor last 1350 miles with the ARP rod bolts. Found 1 bolt torn completely in half and the one across from it hanging on for dear life. The aftermath:



The engine is installed in the car WITH the oil pan:



Cracked sleeve:

 

yea but i really didnt go hard on it at all for the first 2000 miles. i just babied the **** out of it and daily drove it. i didnt start going WOT until the last 700 miles of its life. but u maybe right.

 

It's actually easier to resize the rods with the cracked cap design. The old style rods had to be cut down at the parting lines first to reduce the bore diameter and then honed back out to spec. The cracked cap rods are just honed out .002" without having to cut them down to a smaller diameter so it's a lot faster to do. Clevite, ACL, etc. all make bearings specifically for these rods honed .002" larger.

Sorry to hear the bad luck! If the bolt actually backed out, it's most likely improper installation. **** happens. At least there's a bigger engine in there now, lol.

 

yea i remember seeing ur thread, which is what concerned me in the beginning. but i saw so many ppl have success; i guess we are just the unlucky ones.

btw, did u file a complaint with ARP or anything like that?

 

Why do the rods need to be re-sized just to change rod bolts? If the rod bolts are changed one side @ a time without loosening the adjacent rod bolt per rod, the bearing seat should not be affected. Am thinking that you guys are discussing the need to re-size only once the rod cap has already been removed or both rod bolts loosened. Just wanted to clarify.

 

Bearing seat?

I really don't think it matters whether you take out one rod bolt at a time or two, the increase in clamping force from the upgraded bolts are going to distort the bore to some degree.

 

It matters.

 

How do u know that?

 

x2

Katech has been building engines forever, and I'm sure they've done their fair share of research. I went with Katech's for my build, and they say I can do it inside the car, then I will.

 

Sorry to hear about this OP. I went with the Katech rod bolts, so hopefully their claim of unneeded rod honing holds true.

 

Very unfortunate disaster. GL with your next build

 

I'm sorry that you had the bad experience. But as you mentioned "most" get away with it. You're obviously not in the "most people" category! I'm sure you'll build an even better engine - goodluck!

 

Those of us who "get away with it" do so because the bolts are swapped correctly. One @ a time while the other side remains torqued.

 

Yeah Id have to agree. If you are planning on not honing after and checking the work you have performed on your expensive motor then at least install them this way as it would be the most proper in keeping the true bore size and not throwing it off as much as completely removing the bolts first. Also, make sure your torque wrench is accurate, its an easy thing to forget

PS LS1450, it is incredible that theses engines are monsters hidden in small blocks but its also even more incredible that racing teams are creating 1200+hp out of little 2.0l engines N/A.

 

So just to be sure, with Katech rod bolts, theres no machine work involved with the rods? Even with a complete disassembly/rebuild?