RB30 Cylinder Head Question

[dom14]

Hey Guys,
I've got hold of this used cylinder head from an R31 skyline, which has apparently
had issues with bottom end bearing(s) blowing up. And the guy said it had head
gasket blowup before that and the head reconditioned after that incident(then bottom end blew up).

I saw lot of crud and staining on cylinder head outside as well, not just inside.

I am wondering if you fellas can tell me what that can be?

I've posted pictures of both the head and rocker cover.
Both units have been through degreaser spray, plenty of scrubbing and water spray to remove as much crud as I could. But, you can still see a significant amount of crap, especially under the rocker cover, which will need a more thorough cleaning job, when I get time for that.

What can cause the kinda staining on the side of the cylinder head?
Can the oil+crud leaks alone can create such stubborn staining?
The crud under the rocker cover is probably oil/water mixture binding on to metal for too long??!!

Thanx

[dom14]

More pictures

[garett]

thats oil inside the rocker cover and on the valve train. its a normal occurrence when the oil isn;t changed often enough and it sorta burns leaving a stain. saying that it dosn't mean the engine is cactus but if it goes further it can form large chunks and block oil galleries, (astra's and bmw's are good for this when the oil isn't changed)

[dom14]

thats oil inside the rocker cover and on the valve train. its a normal occurrence when the oil isn;t changed often enough and it sorta burns leaving a stain. saying that it dosn't mean the engine is cactus but if it goes further it can form large chunks and block oil galleries, (astra's and bmw's are good for this when the oil isn't changed)

Thanx mate. The amount of oil crud that was gathered under the rocker cover was unbelievable.

What do you think about the staining outside of the cylinder head surface?
I can't get my head around to understand the way such bad staining can develop!?

[dom14]

This is under side of the rocker cover after I removed the "guard plate".
There's a fair bit of crud as you can see.

I don't need any definitive information about this guys.
Anything that comes off the top of your head would be good.

[garett]

at a guess i'd say it had a leaky rocker cover gasket and it never got fixed.

[dom14]

at a guess i'd say it had a leaky rocker cover gasket and it never got fixed.

Yeah, probably had lot of blow-by leakage as well. Guy probably kept driving it until the bottom end completely blew up.
Pretty horrible way to treat a good engine like RB30.