Red12secZ28

iTrader: (2)

I have arp rod bolts on my stock LS1 rods. They where made in 99. I was worried because every said check the connecting rod big end with the arp rod bolts final torqued to 45 ft-lbs. I took my connecting rods to the machine shop and they all checked out fine with no bore distortion. I still recommend if anyone is going to install them check the clearances. But more than likely the rods will be fine without checking.

Scalpel

iTrader: (4)

Great info. Thanks for posting!

Fireball

iTrader: (21)

I've been running ARPs on stock unmodified rods for 2 years with no ill effects

LS1derfull

They are bolts that thread in thru cap, they are not like factory SBC rod bolts that press in and use nuts. BTW Fireball do you have PRO series rod bolts or the cheaper ones?

Orange Peel

iTrader: (20)

Great info, I have my Pro Series ARP rod bolts sitting here at home waiting to get installed, just not sure when I want to do them. But good to know they will just go in as a replacement and not have issues!!

Hysteria

The big end on the rods are supposed to be 2.2242-2.2252 I believe. I am going to use the std ARP's in my next build up. I wish you could get a bigger bearing for a rod resize like you can for some of the Ford rods with the cracked cap.

ArKay99

iTrader: (1)

This is great news. I just did this on my 99 LS1 vette with the crank in the car. Lots of guys told me I was nuts and would ruin my bottom end. Other guys, and a couple of tuners, told me it was a great mod to do. I checked the rod side clearances but not the journal clearances obviously, but the side to side did not change at all. Just to be safe I am running the car in about 300-500 miles before any trips to redline. I was looking for threads of people that have done this and reported the results. Thanks!

J-Rod

Glad you had no deformation.

Jason @ Thunder saw .002 deformation and the big end was no longer round when they swapped bolts. So, they re-size when they do bolt swaps. I commend you for checking, many folks just assume that everything will be the same when it has been shown in some cases to deform the rods.

I don't disagree that you can do it, and get away with it. But, if the big end is out of round when your done, your motor will still run, your motor is going to create its own clearance. In that case you get some ugly bearing wear, and a bunch of bearing material in your motor that doesn't need to be there, and unless you tear the motor down you'll never know it...

Anyhow, its just a good practice to re-size rod when doing swaps like this. If you choose not to, so be it. I'd be interested in seeing the bearing out of a few motors to see what the rods bearing look like after a few miles (10-20K)are on them once the bolts have been swapped.

Hysteria

Awesome on the bearing availibilty!! I know what I'm going to do now! Thanks for the information.

guadofreak

iTrader: (1)

SO now the word is not just to swap out the bolts? I am new to this and was giong to do this next week(if i still have a house and car-tampa, FL)

I have a set of the std ARP rod bolts. Do those cause the same deflection as the pro series? And what should I use to make sure everything is in check? please help. I read all of the above but it is still confusing to me.

thanx. ~Eddie

Jason99T/A

iTrader: (21)

Jarrod, I saw some deformation when installing the ARP Pro-series rod bolts in the factory rods. I would have to check the built sheets to see the exact amount, but it definitely was not .002" Not sure where you got that number. I'll try and get this info this week. Based on this, every stock rod motor we build has the housing bores resized .002" larger than factory. To do this, you need to use a special bearing from Clevite for use with this larger housing bore.

You motor is not going to instantly blow up if you don't re-size the rods. Heck, the motor I built that was in my car with the TReX cam/stock heads had the ARP bolts installed without any re-sizing. It is still running just fine after 10k HARD miles and probably over 100 dyno runs and quite a few track passes turning 7200+ rpms. However, it is very important to have to have a housing bore than is within spec, not out-of-round, and free of taper. This is very important for long bearing life.

Another thing to point out is measuring the housing bore with the rods bolts streched to the required amount, not just torqued to spec. Having the ARP pro-series bolts torqued to 45lb-ft very, very rarely gets you within the recommend stretch for this particular bolt. On the motors I have built, this generally takes 55lb-ft or so. This number will vary based on the type/amount of lube used, condition of the threads, and the calibration of the torque wrench.

Also, the bearings TR has listed on their webpage are for a rod using the factory housing bore diameter (stock or aftermarket SBC connecting rods). The Clevite bearings I mentioned above are not currently listed, but are available.

Jason

Fireball

iTrader: (21)

Pro series

J-Rod

Sorry, I think I remeber how much you re-sized and transposed that for deformation. Sorry about that. If you can provide what you saw, that would be cool.


As for the torque required, you bring up a good point about how much torque is required to get the proper stretch on the bolt, and once that is done, what does the bore end up looking like.


I think many folks don't understand and appreciate proper bolt stretch and its importance.

My90Iroc

iTrader: (26)

Can rod bolt swaps be done correctly with the motor in the car? This is probably not something I'd do myself so if I were going to pay someone for it I'd like to have an idea of what the labor should cost.

I've never been to the track but do take the motor to 6k once in a while. The car and motor right now only have 13.5k miles and I'd like it to last as long as it's supposed to. This is my only concern for the motor because it doesn't sound like something I really want to do myself with my limited experience with motor internals.

Thanks.

MyLS1Hauls

iTrader: (2)

If you rarely rev the motor to 6k, you'll be fine with the stock bolts. The stockers can be safely revved to 6500.