Uh Oh my rod is cracked, any advice on new hardware?

[nreed]

When installing my crank I noticed that one rod seemed to spin easier on the crank than the others.

Glad I noticed or it would have gone out the side for sure!

It's cracked on both sides.

Now I'm hunting for new rods. Any advice...?

[350HP930]

If you had the engine apart you really should have all the rods examined and resized if neccessary.

Before you put it all back together have all the rods inspected and machined if its needed.

[nreed]

I agree, I had them all inspected and resized and bushed. Not sure why this happened. I'm glad I bought ARP bolts now...

[350HP930]

I would raise hell with the shop that 'inspected' them.

[john walker's workshop]

that's real strange. you could bend those rods into a pretzel and they probably wouldn't crack. glad you saw that!

[Wayne 962]

Can you post a pic? Not that I don't believe you, but it's way unusual to have them crack, particularly on both sides?

-Wayne

[nreed]

This is the best I can do for now. My camera is having trouble focusing up close and I did not have the macro lense with me.

The crack on the other side is almost in the same place but is a little longer. I have not taken the rod off the crank yet.

I guess I should invest in 6 new rods. I'm leaning toward Carrillo rods. I'm not willing to take the risk on the other 5. I also assume a new set of rod bearings is a good idea.

[beepbeep]

...check out with company that machined them. They might have fixated them in unappropriate way, leading to crack.

[Jim Sims]

Did this engine suffer an over-rev episode and then was run for a while after that? Hard to see the crack in the provided image but it looks like it may be a fatigue crack resulting from loss of joint preload. Jim

[garibaldi]

tough to tell from your pic, but are you sure its a crack and not a surface flaw? The proper way to verify the condition of rods , cranks, etc before you reuse them is to have them magnafluxed, it cheap insurance, and if it were a crack, that blatant, it woudl show up right away, but it can pick up smaller non visible surface fissures as well. Not saying you shoudl use theses without checking them, but I may try grinding down that area to see how deep the "crack" goes it may be a tooling nick. None the less, surface flaws should be minimized to help prevent stress risers.

[nreed]

Please forgive me for panicing and posting this problem...

You guys were right. Under a microscope they are not cracks but surface scratches and slight flaws.

I will double check the rod bolts now and try and discover the real reason behind this easier spinning rod. I will check them again with plastigage and recheck my ARP rod bolt stretch. I took good notes on the before and after torque lengths.

Thanks for your patience!

I wonder if the moderator should delete this whole topic?

[Fishcop]

Don't delete! That's the whole point of these postings...