Polishing stock rods?

Discussion of the 331-354-392 HEMIs.

Moderators: scottm, TrWaters, 392heminut

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Moparlee
Posts: 144
Joined: Thu Jul 22, 2004 6:38 am
Location: Carthage, MO

Polishing stock rods?

Post by Moparlee »

Has anybody here done this on a set of 392 rods? Did you like results, did they last longer? Thanks in advance.

Lee
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
392heminut
Posts: 488
Joined: Sat Nov 30, 2002 2:16 pm

Post by 392heminut »

I polished the beams on the rods in my 392. I like them, but don't know about the longevity of them as I only have a few thousand miles on the engine. I do have about 60 1/4 mile passes on the engine also with no problems.
Owner of the Poor Man's Hemi Cuda
Bailiesdad
Posts: 433
Joined: Sat Dec 01, 2001 6:00 pm
Location: Maryland

Re: Polishing stock rods?

Post by Bailiesdad »

Moparlee wrote:Has anybody here done this on a set of 392 rods? Did you like results, did they last longer? Thanks in advance.

Lee
Anytime you cut excess casting ridges off cast iron it strengthens the underlying material. It elimnates the areas that have a tendency to crack/fail under stress.
mart
Posts: 536
Joined: Tue Mar 22, 2005 2:06 pm

Re: Polishing rods

Post by mart »

Polishing is good, but also, you asked "did they last longer?" Hmm?? How would you know if they "lasted longer"???

mart
Moparlee
Posts: 144
Joined: Thu Jul 22, 2004 6:38 am
Location: Carthage, MO

Re: Polishing rods

Post by Moparlee »

mart wrote:Polishing is good, but also, you asked "did they last longer?" Hmm?? How would you know if they "lasted longer"???

mart
Was just wondering if a person had done an experiment with two build ups or just opinions. Either way, thanks for the reply's.

Is it true that if you do this, they have to be shot peened afterwards. There is a lot of people around here that blast rods, but don't have a shot peening machine. If I'm not mistaken there is a difference isn't there? Thanks again for your time.

Lee
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
mart
Posts: 536
Joined: Tue Mar 22, 2005 2:06 pm

Post by mart »

Yeah. Ideally the rods should be shot peened after poloshing. Not everybody does it though. Polishing alone should (does) in reduce the likelihood of cracks starting or spreading , but shot peening after polishing is better because it improves the surface hardness of the metal as well. As you have noted, it's hard to find a shop equipped to do actual shot peening. The more common, glass beading, media or sand blasting is good for cleaning the rods and making them look pretty but has virtually no effect on surface hardness or durability.

mart
challengerman

polishing stock rods?

Post by challengerman »

Hi, thought I'd get my 2 Cs worth in. I can't think of a machine shop that wouldn't tell you to shot peen the rods. People make mistakes and polish across the beam and so forth. Any marks across the beam instead of with it (length wise) is like asking for a crack to start & it will go cross wise. You can imagine what happens next.
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