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4.8l cam and bearing failure. Help determining cause?
This is a Gen III 4.8 that was going to be mated to a 4L60/Atlas combo and go into a buggy project. Upon futher inspection it appears to have connecting rod bearing wear, and pitting/failure on a cam shaft lobe, cyl 8 exhaust. There was also some rust one cylinder where it looked like water had pooled there...... Any help determining the cause of this, and maybe a realistic estimate of a cost to rebuild this engine stock/mild upgrades? I am also considering purchasing a low mile pull out 5.3 and hope to have better luck with that.
The cam died first... wouldn't hurt to know what it was, and what valve springs were in it, and what oil pump. (and whether the O-ring was any good)
The rest is just collateral damage from the metal chips from that.
maybe a realistic estimate of a cost to rebuild this engine
About 4 times what you can get another for from yer local buzzard. Gotta be about the stoooooooopidest way of handling the situation. I like the 5.3 idea: about a 10.4% increase in ... EVERYTHING ... for pennies on the project as a whole though, altogether A Better Idea.
As far as the cause, tell us the history, and we can guess at which event was the cause.
Just out of curiosity what heads were on that motor? 706 castings or 862 castings? Is it really sludged up? Pictures aren’t super conclusive but everytime I’ve seen some come apart like that water/coolant was involved.
As for the cost to rebuild you gotta figure close to 2k at an absolute minimum provided you don’t need pistons and the crank is fine etc. If you need pistons that’s $500ish plus the machining costs.
Rebuilding doesn’t make sense if all you are looking for is to get something going. I’ll usually rebuild my motors but I’m not rebuilding to stock specs.
I am not sure of the history. I purchased it in this condition, as it was supposed to be a cleam low mileage engine. Everything appears to be factory, 862 heads, unsure of cam, stock pistons and rods. As far as engine cleanliness, I was suprised at how clean everything was. My current thoughts are to bolt the heads back on and use this block for mockup purposes and buy a new/different engine when I am getting ready to fire her up.
4.8l cam and bearing failure. Help determining cause? 
