2G 2 cylinder head gaskets - Need advice

[Heryst78]

Hi everyone,

I'm writing to you because I have a real problem with my engine, a 4G63 NA that we're converting to turbo.
It just blew two cylinder head gaskets in quick succession.

For the first head gasket, we did everything by the book:
- Complete removal
- Inspection of the cylinder head, stress test on the cylinder head, and leak test
- Rectification of the flatness of the cylinder head
- Original Mitsubishi head gasket
- ARP studs

The first time, it was a failure on cylinder 3, with compression passing into the coolant.
Today, there is compression in cylinder 4.
Has anyone else experienced this?

I saw a post where someone mentioned a blockage that had formed over time in the coolant pipes.

The only thing I haven't done but have checked is the flatness of the block.
For the turbo assembly, we plan to blow at 0.8B, and the block is not decompressed. Original pistons and connecting rods (slightly different from the 4G63T).

Thank you,

 

[pauleyman]

You need to check the block. Also is it clean? Ive seen blocks that were "scraped clean" but in reality they werent. Also did you completely clean and blow out the head bolt holes and make sure all the studs were bottomed out?