Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Steam technology, On mine I have what looks like 4 cracks where the bolts hold the head on.  It looks like the bolts were overtighted
And cracked the head. After seeing your pictures I noticed yours also has a crack.  Do you have 4 cracks on yours? One for each head bolt?  Perhaps its supposed to be that way?
Mine seams to run ok. Thanks

Yes, I had noticed that before but they seem to be too uniform to be cracks. I think the part is laser cut and the slots are part of the process or they are there to relieve any stress from the bolts.
The bolts do not need to be super tight, just enough to seal the cylinder.