The DOD tick finally got to me

[Fernando Escobar]

Is that a rebuilt engine? Factory cam bearings would show copper in the worn area. That cam bearing is in great shape if it's original.

View attachment 420793

I don't think its rebuilt although I did see some weird initials on the cylinder heads

 

[Dustin Jackson]

I see nothing of concern here, I would put it back together with an AFM delete

 

[Fernando Escobar]

I don't think its rebuilt although I did see some weird initials on the cylinder heads

I see nothing of concern here, I would put it back together with an AFM delete

These responses are reassuring guess its time to rebuild and time to cancel my cam/mains and rod bearings

 

[iamdub]

I don't think its rebuilt although I did see some weird initials on the cylinder heads

I'm betting it's rebuilt and they just reused the original cam.

 

[Fernando Escobar]

I'm betting it's rebuilt and they just reused the original cam.

i did not find those heat tabs they put on it, but I'm guessing it it is rebuilt it came from a dealership then.

 

[Fernando Escobar]

Here are the picture of the only lifters that had some shiny spots almost like a shiny polished look. There the onky ones that stood out.

 

[Dustin Jackson]

The valley cover and valve covers are painted?

This isn’t the first time this motor has had a lifter problem and it was probably rebuilt and put back together using AFM parts but didn’t properly address the cause of the failure.

There are electrical anomalies that can cause the AFM system to malfunction resulting in lifter failure. I understand this a mostly overlooked subject and I’m not well versed in it so I’m mostly speaking from memory but that can be a cause of reoccurring AFM lifter failure.

Those cam bearings look incredibly good so maybe it was rebuilt recently.

 

[Fernando Escobar]

The valley cover and valve covers are painted?

This isn’t the first time this motor has had a lifter problem and it was probably rebuilt and put back together using AFM parts but didn’t properly address the cause of the failure.

There are electrical anomalies that can cause the AFM system to malfunction resulting in lifter failure. I understand this a mostly overlooked subject and I’m not well versed in it so I’m mostly speaking from memory but that can be a cause of reoccurring AFM lifter failure.

Those cam bearings look incredibly good so maybe it was rebuilt recently.

I painted the Valley cover and valve covers during COVID because I had an oil leak and the VLOM bolts were so loose i could turn them by hand.

Then my dumb a$$ broke a plastic connection on the VLOM so i had to buy new one and had extra paint.

I bought this car with about 80k miles and now has a bit under 180k. So I wonder if the previous owner had to have been a slob if that engine blew on him before me.

I even painted the 4 pot brake upgrade gm blue. Remember I mentioned I can be extra sometimes.

When I reconstructed my 02 Tahoe engine the mains and rod bearings had 285k and my Mechanic neighbor who tutored me couldn't believe they looked almost new.

So i guess its time to reassemble the rest and not mess with the bottom end. Although the wife gave the green light to redo the rest. "I know its going to bug you" is what she said. Thats as close to yes honey spend the money and buy the new bearings and ARP bolts

 

[Dustin Jackson]

I think that pretty much debunks my theory, but the cam bearings look good. I've heard that main bearings are boring to look at because they always look perfect even with 200k

 

[j91z28d1]

when I was searching around for cam bearings a few years back. I saw pics of what was supposedly a zero mile ls3 gm crate motor they pulled the cam to put a bigger one in and the cam bearings look worse than yours.

literally the best gm cam bearings I've ever seen pics of. your Toyota guy is right if it was anything else, I'd say change them.. an ls, not so much. one theory that kinda makes sense is gm has so much block shift, they line hone the cam tunnel after installing the bearings before assembly. I've seen pics of the crazy amount of core shift around the cyl liners, so it seems possible.