Upgrading Rod bolts on stock bottom-end - post if you've done it

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Nov 15, 2009 | 07:33 PM

#46

evo8fl

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From: hunting v8s

I did drop in pistons and rods at 80k wish never done it, my car was fine for a few months but after a few races drag and road course start to burn oil, right now 1qt per 100 miles this is bad

, do your self a favor doit right the firt time take the block to a machine shop

Nov 15, 2009 | 07:35 PM

#47

scheides

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From: Minneapolis

Did you diagnose the problem at all? Leakdown and/or compression tests? Sounds like the rings were installed improperly or something? idk. Good info though, thx.

Nov 15, 2009 | 10:45 PM

#48

batty200

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I am not sure about power levels and legth of time the motors lasted but none of the motors I have ever worked on has issues because of the BS Elim or the rod bolt upgrade. The EVO I worked on actually the t-belt tensioner failed and was making a rod knock like sound so I daignosed it and one check was I pulled the oil pan off and removed the rod ends to see the rod bearings to make sure they were OK and they were perfect. I have seen many motors get the rear B/S that locked up (DSM would be front shaft on EVO) and destroy the whole motor and turbo from lack of oil pressure. That risk is way larger than any issues from removing them.

As far as install of the rod bolts I just used molylube and torqued to arps specifications and that was it. I would really be surprised if you were torquing the arps to a high enough torque using any method to distort the rod.

I will be doing this to my own evo when installing a big turbo and 272's so I will let you know how it likes 8500-9K rpms through the traps in 4th gear hopefully. I will not be revving that high regularly as it is unnecessary with our short gearing to stay in the powerband even when racing on the street just when you are at the top of 4th in the 1/4 we would lose too much shifting into 5th.

Quote:

Originally Posted by scheides

Interesting addition of doing BS elim at the same time as rod bolts. What kind of mileage have you seen out of a stock bottom end after doing these mods, and at what power level?

More and more I'm hearing that yes, doing rod bolts on stock bottom-end could be worth it and an even be reliable if done properly, but not guaranteed. BUT if you are doing this, you're probably already at the power or torque level of putting the stock rods in jeopardy, so doing the rod bolts on stock rods ultimately brings no peace of mind, because if a rod bolt were to fail a spun bearing would be the result, but if a rod let's go, the damage is much more catistrophic.

Let's keep this discussion going! If you've done this, how long and at what power level ? Did a rod eventually break or did you build the motor?

Nov 15, 2009 | 11:49 PM

#49

Aby@MIL.SPEC

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From: San Elijo Hills, Ca.

Quote:

Originally Posted by ryno529

We have done a few sets of rod bolts at the shop . To be honest it is a waste of time and money. All the rod failures we have seen when a stock bottom end is "pushed" is not from the rod bolts failing but instead the rods usually fails in the center of the beam. Most of the time the big end of the rod is still bolted together on the crank. We had a car in a few weeks ago with ARP rods bolts in it where the rod put a nice window in the block ,this was at 500 WHP. It is not a bolt issue but a rod issue. You would be better off saving more money and putting in a set of eagle rods.

+1

when i tore my motor apart after rod #3 wanted out...

i discovered a bent rod in another cylinder.....

all rod bearings & pistons / ring lands looked fine....

hey, some people are lucky with making big power on the stock bottom end & others are not....

do you feel lucky