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"Mad" Member
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Discussion Starter #1 (Edited)
Why would the same journal get killed every time?

The journal(Rod nr 5) that gets damaged sits just behind main bearing cap no 4.

First time around it was with stock rods, I imported aftermarket rods, had the machining done on a different crank, same journal gets spun.

All clearances were machined as per Mondello and Bill Trovato.

Is the problem the oil feed to that specific journal?

All the other journals are fine.

I have run out of Nodular "N" spec cranks, both are trashed.:mad:

Wikus
 

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Huh?

Why would the same journal get killed every time?

The journal(Rod nr 5) that gets damaged sits just behind main bearing cap no 4.

First time around it was with stock rods, I imported aftermarket rods, had the machining done on a different crank, same journal gets spun.

All clearances were machined as per Mondello and Bill Trovato.

Is the problem the oil feed to that specific journal?

All the other journals are fine.

I have run out of Nodular "N" spec cranks, both are trashed.:mad:

Wikus
Just behind main cap #4? Wouldn't that be cylinder number 7 or 8?? 5 & 6 would be between the #3 and #4 main caps..Regardless of where, your question is WHY... The rods feed from the mains, is there any signs of wear on the main bearing that feeds that rod? Is there any signs that particular piston is tighter in the bore than the others? Any chance that cylinder is leaning out and detonating which will hammer a bearing fairly quickly. These are just guesses and questions about your question, not really answers, sorry. I haven't experienced anything similar with 455s, but maybe others have....It could have something to do with oil restrictors. Just what, I don't know, but I do know the Olds oiling system is very finicky compared to some others.... BTW, which brand and type bearings are you using?.....
Ray
PS I haven't bought the sailboat yet, so I can't smuggle in any Olds parts for you, but I do have 2 "N" cranks. One std/std, and one 20/20..........Man, the shipping to South Africa will murder you, again....
 

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"Mad" Member
Joined
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769 Posts
Discussion Starter #3
Just behind main cap #4? Wouldn't that be cylinder number 7 or 8?? 5 & 6 would be between the #3 and #4 main caps..Regardless of where, your question is WHY... The rods feed from the mains, is there any signs of wear on the main bearing that feeds that rod? Is there any signs that particular piston is tighter in the bore than the others? Any chance that cylinder is leaning out and detonating which will hammer a bearing fairly quickly. These are just guesses and questions about your question, not really answers, sorry. I haven't experienced anything similar with 455s, but maybe others have....It could have something to do with oil restrictors. Just what, I don't know, but I do know the Olds oiling system is very finicky compared to some others.... BTW, which brand and type bearings are you using?.....
Ray
PS I haven't bought the sailboat yet, so I can't smuggle in any Olds parts for you, but I do have 2 "N" cranks. One std/std, and one 20/20..........Man, the shipping to South Africa will murder you, again....
Ray,

I don't even want to think what it will cost me to bring in a crank. I will probably have to mortgage my farm:D

The block has been rebored to .40 to fit new pistons as well. No lean out or detonation, piston looks like when i put them in.

Here is a pic of a block, the black dot marks the cylinder I have the problem with.
 

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