View Single Post
spuggy spuggy is offline
Registered User
 
Join Date: Jul 2003
Location: Glorious Pac NW
Posts: 3,413
Quote:
Originally Posted by Rodsrsr View Post
The bottom ends are fairly robust and you may not even need to touch it.
Factory rod bolts are probably the weakest link in the stock 3,2/3,3 bottom end. They stretch if you over-rev. And then they're not under tension and just come undone.

Sometimes, they do this even if you don't over-rev. 3,2 bolts do this as well. Because they're the same bolts. Week after my 3,3 did it, 3,2 was in the same shop because it threw a bolt on the same rod (#6). 160,000 mile car, same owner for the last 15 years or so. Shop owner said "they just do that; sometimes. I can guarantee the owner didn't over-rev it".


That will cost a rod, guaranteed. Probably a crank journal. And you may find (like I did) that a good used std/std crank with matched rods is almost the same price as a set of undersize big end bearings - and you avoid a crank regrind/re-hardening (which apparently is not as good as the original). But you're still splitting the cases either way.

ARP rod bolts are an investment/cheap insurance if you're lifting the cylinders anyway; no real need to split the cases just to fit them. Although you have to go by torque if you don't - and measured stretch is arguably better (and manufacturer preferred/recommended).

That's just the very top of the slippery slope....
__________________
'77 S with '78 930 power and a few other things.
Old 05-08-2013, 04:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)