1978 Mercury 402

[dilleyo]

Long story short....I decided to replace the piston heads on my motor (the PO had mismatched heads). I am in the process of puting the motor back together. When my brother and I took it apart, we don't remember if the crank was a little tough to turn by hand or not. Does anyone know if the crank should be fairly easy to turn by hand? My brother said that there should be a little resistance due to the motor creating a little compression. I would hate to get it back together and find out that I did something wrong when I can fix it now. I appreciate all and any insight. Thanks.

[boatfixer]

To answer your question, Yes it should rotate relatively freely. As far as compression? You have spark plugs out?

Also, curious as to what you are refering to when you say heads. Mercs don't have heads.

[dilleyo]

Yes--spark plugs are out and I was thinking that they should move more freely than they do, but couldn't remember when we tore it apart. My brother was the one that was all for tearing it apart and now he ran into some issues where he can't come over to help put it back together and I am stuck puting it back together. He knows a little more than me about engines in general, but not much.

When i said heads, I basically meant the actual pistons themselves, sorry, incorrect term.

Thanks for the response and it looks like I have some more work ahead of me.