Cylinder head slightly pitted
 

Hi folks,

I drive a 940 Polar SW, B200FT of 1997 - 283000 Km and my head gasket had to be replaced.

So I removed everything and took the cylinder head to resurface.

Now, I have only one big issue left, there is a point that is pitted, and I need advice on the best way to repair it.

Please see some images below, no need to circle the small pitted area in photo #1:

https://i.postimg.cc/876YH8jW/IMG-20220518-171600.jpg

https://i.postimg.cc/4KvFDzvx/IMG-20220518-171811.jpg

https://i.postimg.cc/GBn5gMyf/IMG-20220518-172024.jpg

https://i.postimg.cc/PptFTPKz/IMG-20220518-172033.jpg

Some people suggest to use stuff like JB-Weld metal, but I think I need another level of professional welding here, it has to last at least another 25 years (in the meantime I will make it electric) :)

Your advice is always appreciated.

Thank you!
Alex

That needs building up with weld and machining back.

Looks like watermarks to me. If it's been skimmed flat ( as it should've been ) it will be fine in that area.

Hi
That area of pitting is where there is a hole in the gasket which allows the coolant from the block to contact the cylinder head. This is quite common and shoudn't be anything to worry about in your case.
Looking at your first photo, there seems to be a blemish under the intake valve of number 3 cylinder. Is this oil/grease or something? If it's a ripple in the aluminium I would worry more about that as it is where the cylinder gasket will sit.
Tim

Hi
I have just done my head and it was much worse than that
it will be fine
the reason it happens is not enough antifreeze

As the others have said it is very common on these cylinder heads and is nothing to worry about. I had a patch like that on my 531 head still after I got it skimmed and it has been absolutely fine for about 10k miles now.

It is well away from any oil or coolant galleries, so theres a good change it would never cause a problem.

Conversely, I built race engines for a living for near on 40 years and if it were mine I'd ert it sorted on the basis that its only a few hundred quid to fix, so theres not a compelling financial argument for taking even a slight risk with it.

That's near enough perfect, far worse out there. Run it.
Use correct coolant. Might need attention by the year 2050.

My vote would be to just fit it and accept the slight pitting as a minor imperfection.
The pitting indicates a "designed cutout" in the head gasket where water has been in contact with the Alloy head, over the years the antifeeze strength may have been suspect and corrosion has caused pitting BUT even if you had it "repaired" it would still be part of the open aperture of which there are many in a Volvo Redblock gasket.
How do l know?........l've just replaced my 940 Wentworth gasket and had to replace the head as corrosion had crept through to No1 cylinder but in fairness the original head had a repair done in 2009 so l assume that before l had the car the owner/s did not use the correct mix of antifreeze and it had more pits than a Welsh mining town .......but we are currently talking 210,000 miles here.
Fit a graphite head gasket NO sealants, new stretch bolts and the jobs a good un'.........................trust me!!

Hi folks,

Thank you very much for reassuring me on that little pitted area.

With the exception of the first 4 years, where I think I only used water, the last 21 years I have used 50/50 concentrate antifreeze + distilled water.

I cannot say what might have caused this, but after 25 years, I think she did well, and I hope she will continue that way :)

Thank you,
Alex