opinions on straightening bent rods?

[StuttgartDavid]

Any opinions on the wisdom of having a bent con rod for an early 911 straightened?

2 of my 2.0 S rods (black, nitrided) are visibly bent. No sign of why -engine was running fine on teardown, no evidence of other damage. P+c s looked good, but both bent rods measured excess sideplay and only those 2 had rod bearing wear. May have been this way for years since last overhaul?

I know V-8 hotrodders have rods straightened all the time, and some of those guys really know what they are doing.

If they can't be saved or replaced with 2 others, need I replace the set with nitrided 'S' rods, or will rebuilt standard rods work for a stock rebuild that will be held to the stock 7200 rpm redline?

[pjv911]

post the part #`s and I will check a box of rods I bought at the hershey swap meet from an ex racer. Its a box of about 40 rods all mixed and to the eye look serviceable . If I have them there your for free.

Kurt Williams

[Wayne 962]

You didn't mention which year you had, but all the documentation I have says that all the rods were the same for all the cars (at least in 1967, which I checked)...

-Wayne

[Superman]

In answer to your question, I guess I would have no faith in a rod that had been bent. Perhaps they are rare, but my feeling is the same. Those things change direction twice per revolution with a bit of mass (piston) at the end. At 6000 rpm that's 100 revolutions, and 200 direction changes PER SECOND. I still don't believe engines can do that, except for the fact they DO. When it comes to those parts (crankshaft, rods, bolts, pistons, wrist pins), take no prisoners.

Oh, and you ask how they might have been bent. Surface ignition can do it. If the engine had been 'dieseling' (running on after the key is turned off), this can bend a rod.

[john walker's workshop]

malleable rods are straightened every day. they clamp the big end in a soft jawed vise and twist the top end with a long tapered bar. then it's put back into a holding fixture and checked for straightness. but yours are nitrited, (hardened), so you's out of luck.