4g64 block/4g63 head headgasket concern

[Verdant]

While installing the head gasket on my 4g64/4g63 engine I went with the 4g64 gasket since that's what everyone was saying to use.

When I put the 64 gasket on i noticed it covers 2 oil holes (64 gasket pictured in blue)

The 63 gasket had these holes cut out for the block (63 gasket pictured in green)

And both gaskets didn't have the holes cut out in one picture (pictured in red)

Everyone says use the 64 gaskets but I wanted some insight behind why these holes are covered with these gaskets.

 

[ErikTande]

Following, I might be doing this in the future as well.

 

[ThunderChild]

Those are oil drain back holes in green. Technically you could block them, but I'd recommend marking them and having the gasket punched for them.

The red holes are coolant holes, and you'll notice the 4g63 gasket you have doesn't have those exact holes either. Depending on application, certain coolant holes are blocked/restricted to limit or direct coolant flow a certain way. Look at rwd 4g64 info and you'll run across info pertaining to this.

The coolant holes I wouldn't worry about. The drain backs I would address.

Or you can see about getting a gasket for a 91-92 Mitsubishi expo with a 2.4, as they had a 6 bolt 4g64 that should have the correct drain back holes punched.

 

[Verdant]

Great information, thank you!

 

[ErikTande]

Those are oil drain back holes in green. Technically you could block them, but I'd recommend marking them and having the gasket punched for them.

Is that something a machine shop has to do? Or can you just get a punch set and hack it up?

 

[ThunderChild]

Is that something a machine shop has to do? Or can you just get a punch set and hack it up?

I would recommend getting a shop to do it, but you can get circular punches too if you feel confident diy'ing it.

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Also remember, not all gaskets have the kickouts for the drain backs, so make sure your gasket does.

 

[miguelmcv]

You got the wrongs head gasket, I’m not sure but I want to say, that’s a 3g gasket.

The galant 2.4 DOCH head gaskets has the exact same oil galleries as the 4g63, the galante 7 bolt 4g64 block doesn’t need the oil galleries to be plugged (like yours), the reason is because they never got them, it does have the surface to be drilled IF you want to open it, but they are sealed from factory. You can stack a 4g64 on top of a 4g63 gasket and you won’t know which is which (unless you pay attention to the piston ring seals).