Technical Porous casting or corrosion?

I've got a set of Pontiac cylinder heads I plan to get checked out. Prior to doing that I'd like to get a general opinion based upon a couple of pics to see if I'm wasting my time and money. Relatively hard to find casting so I'm hoping what I'm seeing will not affect gasket or casting sealing. The plan is to load up a few other items and have cleaned and pressure tested. 2nd pic really concerned with what looks like a gauge or pry mark but not sure where it falls in line with sealing with the deck. Both pics are of the exhaust port side deck surface. Any input is appreciated,as always.

 

Since both are at the outer edge, I would say, no problem! But that depends on what seals in that area.






Bones

 

Could very well be either.
I'd say porous casting just by your pictures. In the second shot, it looks like someone went in to dig out the roughness. Either to see how deep it went OR to just remove the porousness to preclude any possible cracking.
I had similar indications in a small Chevy block. I eventually had problems as the whole right side rear corner looked like your pictures, not just small locations..! I cit the corner out with a hacksaw and the water jacket side looked horrible.
I bought another block.

Mike

 

It looks like a outside edge should be ok, in the 2nd pic it looks more like someone used a screwdriver and a hammer to remove the head. I would pull some valves and look at the runners, the valves look rusty and pitted. Inquiring mines need to know what casting number heads they are?

 

Thanks for the input so far. The castings are 540306 or I probably wouldn't even be contemplating spending the time or money on them. These were part of a package deal and some newer more common parts were scrapped due to condition. Holding out hope on these.

 

I'm pretty illiterate on these casting number heads what makes them special? Lippy

 

Early 60s high performance head basically. Newer factory and aftermarket probably easier to come by,cheaper to buy and build and probably offer better performance. But for a technically correct restoration or period build they fit the bill.

 

Keep us posted on the results.

 

Is that a crack in the head above the valve in photo 2 ?

 

And that valve looks to be pretty well sunk into the chamber, like the valve seat is practically gone. Especially seems a little unusual to see that on an intake valve.

 

My gut feeling tells me that the head is just an indication of more defects you can't see.

 

Believe it's just crud on the surface. Looking at this one head in person the main concerns were the divet and the porous condition on the edge. Of the 2 machine shops I've talked to one of which looked at the parts in person it was recommended that they be pressure tested and not magnufluxed but cost these heads and other parts I wanted done at the same time was prohibitive. The other agreed pressure test and not magnufluxed but didnt want to take on the job. After that the entire idea got put in the backburner for about a year. As others have noted the sunken valves were noticed but figured seats,guides and studs would be part of the rebuild. That is if the casting itself is deemed good for use. And then the rocker studs pose another problem being pressed and pinned in place. Believe they are hollow too,so at that point do see if possible to convert to screw in studs etc. So figure hit basics 1st,clean bill of health with receipts and then go from there. I had a gentleman interested in these heads and other parts but didn't want to talk numbers until I had a better idea what it would take to make these useable if at all.

 

306 heads are 1961- early 1962 Super Duty heads. There are certainly better performance heads available, but the value is in their rarity and collectibility.

I'd take them to a a machine shop that knows what they're doing and have them examined closely to see if they're worth saving.

 

Flakiness of the rusted surface in the chamber between the valves. Get all that cleaned out well, smooth out the chambers, the rough pitted surface is an invite for hot spots and detonation.

Id take the time to cc'ing and even out the chambers after any blasting, smoothing etc.

Have you pulled any valves, with that level of corrosion, Id say all the seats and guides are questionable. Could be a large machine shop bill.

 

Cost has certainly taken the wind out of my sails. The only solid quote I've gotten so far was just shy of 1k. That was for 3 sets of heads and 2 bare blocks to be blasted and pressure tested. No decking, boring,CC'ing,seats,guides,nothing else. Gotta make a few decisions here and definitely try and get a couple of other quotes. I know if I don't take everything at once I'll never get around to doing any of it at all.