Head quality Options

[gman3850]

Found a set of 914 heads that had been rebuilt and rewelded for 12mm spark plugs. Looked great in the photos. Got them today and had a few questions.


In one of the exhaust ports there seems to be a void in it.

Also there seems to be a void on the outside of seats.

Are these good to go or should I be worried

[Mark Henry]

Welding aluminium with any kind of impurities will cause porosity, hard to get an old casting to weld up without a slight amount of porosity. If the void is superficial and it sealed the seat to head it shouldn't hurt anything.
The one inside the head port looks like a casting flaw, I see small flaws, bubbles, dirt and flashing all the time. Again as long as it doesn't hurt the integrity it should be OK.

But disclaimer it's not in my hands, so it's hard to pass judgment with just pics.

I'd do a time test, level the head chamber up fill with a thin liquid like alcohol, time it 5 minutes and see if you have any leakage pass the valves. I'd also remove the valves and see what kind of job they did cleaning out the ports. When you weld up the seat bores and re-cut for new seats a lot of weld is left in the port that has to be cleaned up.