4.2 L connecting rods

A little while ago while driving the engine pushed out two connecting rod bearings in # 3 and # 4 piston. I’ve included a picture of # 3 connecting rod. A noticeable change in colour is evident. What would be the appropriate action? Would I need to replace the connecting rod or would it be ok to reuse it?Love the site, been using it throughout my home rebuild of 69 e type. Engine was not rebuilt by me but by previous owner of the project, hence no history file.

Hi Mark, I suspect you didn’t include the picture that you intended.

i.e. I see no picture at all.

Well, if it became so hot that the heat discolored it I wouldn’t like it in my engine. It is probably unlikely that it deformed or the properties changed significantly, so if it is still straight it should work in normal driving. If it breaks, the engine is scrap and you are in there now - however, the rods must be balanced so swapping in a generic one is not a good solution; the others must be looked at,…

IMG_2768%5B23920%5D

I’d replace that rod.

Yeah, I concur with Wigs.

What do #3 and #4 crank journals look like?

Not good I’m taking it to get resurfaced shortly but it really is scored at 3 and 4

Undersized mains in your future. The failure was likely triggered by loss of lubrication from a sludge buildup in the crank, so backing out the plugs for a cleanout should also be on your to-do list.

Thanks Nick

Im taking the crank to Cdn chrome and crank in concord to get it taken care of and the block at cdn cylinder head for resurfacing , honing and anything else it needs

Don’t forget to include the timing cover bolted to engine if the have to block the deck.

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Got it, thanks!
I guess I would have to also skim the mating surface of the cylinder head as well? There was no issue with sealing before all this happened.

I would have it checked for flatness, with a machinist’s bar and feeler gauge: if it’s not needed, don’t just automatically plane it.

Replace all with a set of series 3 XJ6 rods.
Reconditioned of course.

I assume you will give them your pistons to let them assess/adjust the bore work?

Yes will be doing that as well. Thank you for your comments, really helping to get my mind around the whole process.

Mark, you mentioned Concord. Are you in Ontario?
If so, stop in and see us guys in Niagara.
Cheers,

Rob

Hi Rob, where are you located in Niagara. I’m in Toronto, Yonge South of the 401.
Would love to take a drive,
Mark

Stop by in Oakville on your way down!

Post withdrawn, thanks