Ad0911

In another thread someone wrote that the con-rod bolts are one use only. I know this is definetly the case with the aircooled 911 engine. The 911 workshop manual also mentiones that these bolts cannot be re-torqued. The 928 manual doesn't say these bolts are one use only. Anybody with bad experience on this point?

BC

What I have heard is that they are one use. The issue here is that the rods need to be resized when you press in the new bolts. ARP has them and its about 250 for two sets of four.

AO

The WSM does say to replace...

Jim bailey - 928 International

rod bolts.... workshop manual 13-16 Checking conrod Bearing Play.." Install bearing cap and tighten to specific torque.....remove cap width of flattened Plastigage ....." no mention of changing rod bolts or nuts for that matter BUT I recommend new nuts.

Ad0911

If I read correctly, the WSM says here to replace the nut, not the bolt.

Mike B

My understanding is you can use the bolts again but the nuts are a one use only.

RyanPerrella

SINGLE USE NUTS!

REPLACE THEM, bolts are fine

BC

Guys, Guys - bolts are NOT fine 100% of the time. They are possibly "usable" after one torquing - but its just as possible that they already are done and you don't know it.

I had to tighten and retighten some rod bolts on a previous engine I built, and it turned out that the third time I went to the torque spec, 3 out of the 8 rods had bolts that were gone - meaning they were permanently stretched and continuing to stretch at the torque rating.

RyanPerrella

was this on a 928 engine Brendan? Or something else?

Its my understanding that the nuts will stress and fail before the bolts do.