Head Damage

[mossyboy6]

Pulled my head the other day, and found this:

http://tinypic.com/view.php?pic=11hs0pk&s=4

Pretty bad damage in cylinder #2.

Also my spark plug holes' threads are messed up. (ill just re-tap them, not a biggie)

Will I see any future problems from this damage? Will it hurt performance?

And finally is it worth replacing the head?

[c.d.iesel]

you got a broken spark plug ?

or maybe the P.O. fuched up a plug at some point

and "TAG" your it now?

Stands to reason - prior screw up with the plug and damaged

hole - fragments fell into the chamber = what you got now.

what caused those marks ?

anything embedded in the piston top ?

Will I see any future problems from this damage? =yes

Will it hurt performance? = yes

And finally is it worth replacing the head? = yes

[mossyboy6]

Plug threads in that cylinder is fine, otherwise that scenario would make sense. I have no idea what caused the marks. No, nothing is embedded that I can find. What problems do you see? And how much performance deduction are we talking?

[Guest Anonymous]

The intake valves in the two pictures look pretty beat up as well. I would take the head to someone with experience with BMW 2002 engines and have them look at it. As long as there isn't damage elsewhere (water jacket erosion, cracks etc.,) and it pressure tests OK, a good engine builder will fill those pock marks with aluminum (again depending on how deep they are) and then surface the head. I would say new valves and guides for sure - and while your at it replace the rest of the valve train stuff (keepers, retainers springs etc.,) as it is pretty cheap any way. Bottom line is get a knowledgeable opinion before you start to throw cash. Good luck.

[TobyB]

Interesting.

You ingested something. And it gave the car indigestion...

If there aren't any marks on the piston crown, then it was done before

someone fixed the bottom end...

I've seen very similar marks on a head that had the compression ring break up-

little chunks of ring pounded the head, and the piston crown.

It looks like that head's been surfaced in the not- too- distant past,

and that it's not seen enough antifreeze (or at least, anti- corrosion protection)

But the valves do look pretty well- used-

I agree, professional eyes would be good.

However, I disagree that it's a real performance problem on a street car-

I ran one that looked worse for a few years, and it really didn't cause any

problems. Now, it wasn't any rocket, but it worked OK.

We have low- compression engines...

t

[PatAllen]

i opened tons of engine in my life with similar marks on the head, most of them were still runing like champ.

the nature of the flat top pistons and flat head surface dont allow anything thicker than the cylinder head gasket to stay there.

something got suck into the engine, or a piston ring is broken and played there.

unless the cylinder walls are ok and piston too, check the valves and call it a day.

Will it hurt performance ? in fact, it may help to create more turbulence ito the combustion chamber and then more hp !!

the 121 head into my turbo engine was worse than yours when i opened this engine first time...it holds 250hp since year 2000.

...lol, CD, c'mon, give up on those wrong pills.