m117.984 Casting Issues

[Toren]

Hello Folks,


I've removed the heads from my M117.984 and only broke one bolt in the block... success! I sent the heads to Metric Motors in Los Angeles for a refresh and now I'm preparing the block surface. I noticed one of the coolant passages has a significant proud spot from the deck. I did not have head gasket issues before disassembly. Has anyone seen this before?


https://postimg.cc/gallery/mWyKQRW4

[Tony H]

How are you preparing the block surface?

[Toren]

Scraping it until it's clean.

[Sugar Bear]

Can it be carefully filed smooth?

[gmog220d]

That raised up area looks like it wasn't covered by the old gasket. Does it interfere with the new gasket?

Also, it looks like rusty scale. If so it should come off relatively easily.

[Frank Reiner]

Originally Posted by Toren

Hello Folks,


Now I'm preparing the block surface. I noticed one of the coolant passages has a significant proud spot from the deck. I did not have head gasket issues before disassembly. Has anyone seen this before?
https://postimg.cc/gallery/mWyKQRW4

Corrosion of Iron (rust) involves bonding of Oxygen atoms to the Iron atoms.
Iron (Fe) + Oxygen (O) > FeO
The iron oxide molecule, FeO, is of greater volume than the iron alone, hence a bump.

Scraping, filing, and block sanding will restore the surface.

[Toren]

Thanks to everyone for the contributions. I was able to carefully file the bump.

[Toren]

Thanks to everyone for the contributions. I was able to carefully file the bump.