Hi all,
I have a seized 30hp block that I'm rebuilding and I have become stuck (excuse the pun) whilst removing the first of the heads.

Loosened and removed all head stud nuts, tapped the head gently with a rubber mallet (without damaging anything) to get it loosened from the barrels.

My problem is, No. 3 barrel is stuck to the head, so when I try to withdraw the head, the barrel gets tight on the piston rings and generally stops me removing the head. I tried a little to tap the barrel to loosen it from the head but not having any luck. Twisting the barrel would work if the case studs weren't in the way...

I've isolated where the seizure is, No. 4 is completely rusted & sludged up, but that can be sorted (already got the crank moving slightly).

What tips would you guys have for loosening No. 3 barrel from the head?

Penetrating fluid such as Penol has worked for me before especially if you stand the engine so the fluid will seep into the counterbore.Deisel is good to .if you can immerse the whole engine or at least the head they normally come off with the help of a nylon hammer but obviously avoid breaking the fins.

If you think that you will be able to twist the cylinder off, why not remove the case studs around that cylinder? Just put two nuts on the thread, lock them together and wind the studs out?

Good luck