Engine head wont screw down, any ideas?

[GTnitro]

This is a 21 hobao engine from an old hyper 7 sport. I've just rebuild the engine and now the head wont sit flush with the block. The piston sleeve isn't flush with the engine block, it's sitting a little below the engine block which means its should have enough room to sit flush. Any ideas what I've done wrong?

The piston sleeve is extremely tight to the block and was a b**** getting it out in the first place.

 

[fstnd]

This is very normal, it's always like this, the purpose is to make it easier to get the sleeve out.

To be sure, check if the exhaust hole of the sleeve matches the exhaust port of the engine block

 

[GTnitro]

This is very normal, it's always like this, the purpose is to make it easier to get the sleeve out.

To be sure, check if the exhaust hole of the sleeve matches the exhaust port of the engine block

Understood thanks for the reply. So is the picture above (header screws visible) showing the gap between the head and the block normal?

 

[fstnd]

Understood thanks for the reply. So is the picture above (header screws visible) showing the gap between the head and the block normal?

It's totally fine