bongva

iTrader: (7)

So a local guy told me awhile back that you can replace your stock rod bolts with arp ones while the motor is still in the car. Is there any truth to this? Anybody ever done it? If so, then I will consider doing it. I don't want my stockers to stretch :/

95ONE

iTrader: (1)

Sales3@Texas-Speed

iTrader: (2)

There is some truth to this, there are even several people here on the board that have successfully completed the swap with the motor in the car, I just assume it would be rather difficult

Although, I wouldnt recommend doing the ARP rod bolt upgrade without resizing the rods (as ARPs are not only a stronger bolt, but have a higher clamping force), but the Katech rod bolts can be installed without having to resize the rods (as they offer the same clamping force as stock bolts, but in a stronger material).

SS10Tech

There was a recent thread showing Katech's indeed distort the big end even though Katech claims otherwise. This of course causes serious bearing problems and also takes the rod out of true. I would say this finding was within the past week or so.

For this reason i would not recommend doing it as you're asking for trouble. But that is not to say it has not been done. I would never do a bottom end upgrade with the motor installed for this reason. As always, YMMV.

mark21742

Yes you can do it, but I do not recomend it...you need to support the engine from the top with either a hoist or big bar laying over the struts, then drop all your front suspension with the k member....but like said, I wouldn't do it

Sales3@Texas-Speed

iTrader: (2)

This is good info, I will try to find that thread. I can say that we have used Katechs in the past, and the rods checked out (we recommend at least checking, even if you dont need to resize), but there may have been material changes by the manufacturer, or who knows. I will look into this further and post back if I find anything.

bongva

iTrader: (7)

Ok I see. Guess I will just be pulling the motor instead then. Thanks for the help guys. Feel free to update the thread when you find out about the kaltech rod bolts.

mark21742

When pulling your motor don't forget about the 3 ground straps on the back of the drivers side head!

95ONE

iTrader: (1)

I don't think you will. It disappeared.

machinistone

Ha ha, good old IB putting vendors interests above those of the people who populate their boards.

Mattyfresh89

I'd thought about doing this, but wasn't 100% on what was involved....sounds like pulling the motor would be more beneficial

ScottyBG

I'd like an Engineering explanation of why an improved bolt from manufactuer A is different from manufacturer B. Maybe one of the sponsors will chime in. To the best of my knowledge, the bolts are the same dimensions, and torqued to the same specs? so the only difference can be the yield strength of the steel? How can 1 of them increase the yeild strength, not distoring the rod and the other increases the yield strength and they do? The clamping force is a function of the stretch, and yield strength, is it not? Would 2 bolts stretched to the same spec, and the same hardness not give the same clamping force? Are there other properties I'm unaware of that effect the clamping force?

Conventional wisdom (ok mechanics of solids) would say that putting a stronger bolt in there and stretching it the same amount would put more clamping force on the rod and distort it. It's been about 25 years since I did these calculations back in my engineering undergrad days, so maybe I'm a little rusty? It sure sounds like marketing, not mechanics of solids, and the engineering, thats making the statement that one manufactuers bolts distorts and another doesn't.

Unless you plan on turning it over 6500 for extended periods of time the stock bolts do hold up decent.

wildcamaro

iTrader: (15)

Yea I read the thread about the katech rod bolts distorting, but that thread disappeared like the same day it came out...the man at work

bww3588

iTrader: (49)

It was active for a week or so, I haven't seen it since. After seeing that thread, I wouldn't recommend any upgraded bolts to anyone with out at least checking for o-O-r.

Sales3@Texas-Speed

iTrader: (2)

Unfortunately I have yet to find that thread, for whatever reason... I don't have a set in stock at the moment, nor do I have a spec sheet here, but Im sure a quick call to them would most likely answer your questions.

redbird555

iTrader: (14)

I read it when it was posted and it's still up in the sponsor feedback section for those intersted. It was a good read and I dont disagree with the op's findings but the fact that people blow their motors with arp's and no one has had a failure with katechs makes me take it with a grain of salt ya know? I'd be curious to see a set of arps roundness on those same rods....

95ONE

iTrader: (1)

It kills me every time. Which set of ARP's are you talking about? There are at least 2 styles of ARP available for that Rod. One of which will certainly make the rods out of round if you torque it to stretch. The other most likely will not.

bww3588

iTrader: (49)

Bullshit.

Both arp bolt sets will put the rod out of round. I had the 8740's and ended up .003 out of round. I can only imagine what the 2k series would have done the same.

95ONE

iTrader: (1)

^^^ because it happened to you it happens to everyone? Then I say bullshit to you because mine didn't? No.. I don't say bullshit. I say check every set. Sometimes it will, sometimes it doesn't. World isn't absolutes Mr. Bullshit.

bww3588

iTrader: (49)

Look around outside your world Mr perfect and see some of the instances. You think I only checked 1 set of rods? This is not my first rodeo with these rods and bolts. Out of 5 sets I have personally done, one was very close to spec. Still out, but very close. The rest were all out in left field somewhere.

I also know that I'm not the only one who has experienced this, so saying "one set will most likely not make them out of round" is false information.