Head question

[The datsun kid]

Hey guys gotta question how can you tell if a head is good or not I got a head from my cousins friend and he said it was off a running motor but we all have heard that one so I guess is they're anyway to tell cuz my head is toast

[KC Phirus]

Is it chicken fried crispy?

Any noticeable cracks?

If it's clean and straight, and all the valves are functional, you're good to go. Could always get it surfaced and bu,p up the compression ratio a bit.

[EricJB]

Are the valves and seats clean? Are the ones that were hold open by the cam rusty? Pull the cam and towers off so all valves are closed. Set it on the the bench chambers up. Fill the chambers with solvent and let it sit awhile. if the solvent runs out the ports, that valve is not seating.

 

Now flip it over springs up. Push and pull on the retainers to see if the valve stem is loose in the guide. If all is well, run it.

[ggzilla]

+1

[datzenmike]

Don't remove the cam and towers. Because they are line bored they may not go back into the exact right spot. Probably very close but why bother. Also the sall bolts are always over-torqued by owners and stripped. Quicker to pry the spring down and lift the rockers off to get the valves closed (keep in order) Or simply turn the cam with vice grips until on compression stroke for each one.

 

Turn cam till each valve is at max lift and push sideways on valve. If it moves 0.008" or more the guide is worn. Look for any valve that has sunken into the head

 

Look for obvious rust on wear surfaces.

The cleaner looking the head the better... means the owner changed his oil regular.

 

Get a straight edge and place diagonally along the length. If you get a 0.004" feeler gauge under it, it should be resurfaced.