What causes cylinder wear like this?

[squaredeal91]

Changing head gasket on a 1989 supra 3.0 inline 6 non turbo with my nephew, Supposedly blew because it's supposed to be retorqued? I did check torque before removing and got a quarter to half a turn on exhaust all except the end ones took almost nothing and may a little on some intake side. Even though I've been paying my bills on toyotas lately I'm still definitely not a toyota guy.
Engine was rebuilt 8 months ago By reputable machine shop but they said themselves they didn't know what they were doing because it's a toyota bahahah...
Anyway check out these score marks ricko, What do you think?

 

[Ricko1966]

Is it an illusion or is there ring ridge at the top of the cylinders?

 

[squaredeal91]

@Ricko1966 I just cleaned the top of one and it's so hard to tell but I honestly think it's starting to make a ridge. It looks like maybe the honed it and did rings but I Don't think they bored it out but not totally sure. Has 1.00 on piston. You can see water marks on walls too.

 

[DoubleDingo]

Looks like they just honed it and didn't clean it up like they're supposed to

 

[fast 99]

To me it appears improper bore and or hone finish. Could be ring flutter or excessive ring land wear? The good part, does not appear to be using oil by rings. Unless you want to start over and rebuild again bolt the head on.

Re-torquing head bolts is a joke. I think manufacturers put that in for a way to get out of a warranty or lawsuit, doesn't happen. Engine compartment access today makes that unreasonable to impossible.

 

[Ricko1966]

Reason I asked about ridge,from the pic I can't tell for sure if the scars are from forever ago and just honed, poorly I would add. If so run it or but a new block and start over. Unless those blocks can go .060 safe. If you think it was bored and it looks like this already,pull the pistons,see what the look like,and check the bottoms of the bores for a chamfer,Toyota so I can't say for sure,but some blocks if you bore them and don't chamfer them,when the transition from down to up at the bottom of the bore the piston tips a little and that sharp edge scuffs material off the piston skirts,that material gets drug up the bore,sticks rings all kinds of cool of stuff. It's had trash up and down those cylinder walls at some point IDK when or why. If the sides of the pistons look galled up possibly to tight piston clearance, we had that problem with some pistons that weren't making it with manufacturer recommended clearance, after a coupe of failures we loosened up the clearance,no more problem. We're you running a thermostat? What temp, that was part of the problem with the tight clearances run hard cold,pistons were sticking because they were expanding faster than the cylinders.

 

[squaredeal91]

I found a 180° thermostat in it. Wasn't smoking. We're going to put a gasket on and run it. I'm going to straight edge check head but he said he noticed it was pushing fluid and brought it over but wasn't getting hot according to the gauge.

 

[PrairieDrifter]

I would be curious of ring gap and if the ring gaps are staggered. Since it's a non turbo the gap is probably fine, but you never know.

 

[squaredeal91]

I would be curious of ring gap and if the ring gaps are staggered. Since it's a non turbo the gap is probably fine, but you never know.

I was thinking ring gap when I first saw the wide lines. Hard to say exactly but hoping for the best.

 

[DoubleDingo]

 

[85 Squarebody76]

 

[squaredeal91]

Got a new cometic gasket. The old gasket was sprayed with copper. Like the spray one would use when using a shim. Not sure if I should find the spray and do it or not. Probably though

 

[Doppleganger]

A long time tech friend of mine used to spray Hylomar on every HG he did. Something that Rolls Royce supposedly came up with. I used copper spray but he swore by the Hylomar.

 

[squaredeal91]

@Doppleganger I'll look it up what you said. At my very first job I worked for an old timer mechanic/maxhinest/ equipment repair in a very small farm town. He was the guy. He sprayed his head gaskets with high metallic paints. Once we reused one at least 3 times on a 3 cylinder diesel and it had wet sleeves and one cracked. We're were doing repairs on the 1 sleeve and kept reusing it till we got it right.

 

[squaredeal91]

@Doppleganger I've Never heard of that stuff before. Is this it?