[boostedglht]

Head has cracks between each set of valves.when I took motor out was getting pressure in radiator, eng cold put rubber glove over filler spout rev motor and glove starts filling with air. figgered it was head gasket then found these cracks. this is most likley where leak is (right) can this be repaired not to costly.
head has been ported some , have heard people speak of G head on here how do you know which type you have.

 

[tryingbe]

Take the head to a machine shop and have them pressure test it.

 

[4Daytonas]

G HEAD ON 84&85 287 LAST 3 OF CASTING NUMBER .Some call 355 castings early G head.

 

[sleeper_1]

I thought they always crack between the valves, but generally not a problem. There must have been several post on this. ??

 

[ATaylorRacing]

Just get those bigger valve sets and gut out the old seats and replace with the siameesed ones.

 

[tryingbe]

I thought they always crack between the valves, but generally not a problem. There must have been several post on this. ??

Generally not, but when you have leaking exhaust gas into the coolant, it's best to have things checked out before assemble back together, unless you like trial and error and don't care much about the cost of head gaskets and head bolts.

 

[Moosejr]

I had the same problem with my head, . .had the machine shop send the head to a specialist, ..welded the cracks, new seats, ceramic sealed,. .added new cam, etc. while I was at it. . .problem solved. This is a common problem because people are not aware that you need to purge the air out of the head when you change coolant. . .

 

[4Daytonas]

I had the same problem with my head, . .had the machine shop send the head to a specialist, ..welded the cracks, new seats, ceramic sealed,. .added new cam, etc. while I was at it. . .problem solved. This is a common problem because people are not aware that you need to purge the air out of the head when you change coolant. . .

Wow --How much did THAT cost?

 

[detobias]

you will be hard pressed to find a turbo head (G pre87 or swirl 87up) which DOESNT have the cracks between the valve seats

there have been oodles of posts, as well as a ChryCo TSB proclaiming these cracks are OK

as long as they dont extend into the valve seat they are OK ; if I was planning to port a head I would try to find an uncracked one (try looking at TBI cars)

watch for cracks in the steam holes (between the cylinders) and by the "arrow" on the oil galley (top of head); these are bad

 

[Moosejr]

Wow --How much did THAT cost?

I don't remember now, .it was several years ago. . .and I had an inside track, . .the owner of the machine shop that did most of the work was a good friend of mine. If I remember correctly, the decision process went like this: pressure test, ..no leaks, new seats and run it; leaks, well, heat treat, ceramic, guaranteed not to leak, .. the specialist's opinion was that it would be hard to find a head without cracks, and even at that, the likelihood of them developing at some point was good, so the weld and ceramic made good sense.

I remember very specifically that not purging the air out of the head when filling with antifreeze was the leading cause of head cracks on these. I got that information from a Chrysler trained mechanic, as well as the machine shop. . ..

 

[detobias]

my local mechanic just ordered a brand new, fully assembled including cam /lifter /followers for like 264$ ; brand new bare castings are even less

when he gets it delivered, I will check it out ...

I am closer to agreeing with Pope that if you plan to invest money and / or time into a head (porting, OS valves, etc) then it may be smart to start with a new casting

especially considering how hard it is getting to find a good 'used' head ...

PS I have a nice swirl FS ; looks great except cracks between valves