It shows it on the video, u can see coolant bubbling by the heat cross over

the coolant you see bubbling in the video is just excess water from when i was rinsing the motor down from its first explosion of water from the radiator neck.

@EchoSixMike, no they didn't pressure test them, just a magnaflux twice

@GTXMatt no tstat, just finished the break in process and was still having this coolant issue, the radiator is a 18" high by 24" wide HD 2 core from a ramcharger, and no i didn't have the cap on when it first puked, wp/alt belt on, tried it again the first time before pulling the heads with cap on and it pissed out the over flow tube hook up, gonna go try another new rad cap and see if the china/mexico junk motorad one was just a turd,

-Mike

Have you tried putting air pressure into one cylinder at a time and look for bubbling in the radiator? It would be good to try to narrow down where the leak is. If you end up with the heads off again, use a straight edge on the block around all sides of each cylinder to make sure there isn't anything funny on that surface. Given that you have tried two gaskets, it must be something either in the head or head surface or block surface.

Well, magnaflux is fine if you're looking for cracks in the valve seats and the like, but if you have some problems in the coolant passages etc, pressure testing is the only choice AFAIK. I sorta thought it was fundamental when checking if heads were worth spit, but I see I'm hopelessly optimistic. S/F....Ken M

Pressurize each cylinder as a start and see what happens, if nothing then take the heads back off and get them pressure tested

Yea i know, and i even asked before in sunk in almost $450 in parts and labor to them, should have not been cheap and got source heads, going to pressure check the cylinders and look for bubbles......at this point i hope something either positive or negative happens, getting real sick of tearing apart and putting back together,

-Mike

you could pull one plug out at a time and run it. even wire off plug should make a cylinder pressure difference.

I figured it might even be a good idea to re torque check the heads since i did have issues with them "sealing?" the first time, so i will pull the valve train and plugs and pressurize the cylinders one at a miserable time, what kind of psi should i pressurize them too ??


-Mike

Put the cylinder on top dead center (approximately) and use 70-80 PSI. The piston might move a little but that shouldn't be an issue. Leave the cap off the radiator and look for bubbles.

I dont know if this is going to find anything. IMO you've probably got a crack between a waterjacket and the exhaust crossover passages, you need need to feed pressure with the #3 or #5 exhaust valve open somehow. Not sure how you'd really do that. I think you need to pressurize the coolant system.

I really don't know what to do then, they put in new guides and valve seats, and I am not sure if either of those things had anything to do with it, hell at this point I think i am gonna buy a set of stealth heads off my buddy and call it a day,

-Mike

It's probably still worth a try, the OP said that the bubbling by the heat cross over was some water that splashed onto that area and was boiling off. To get that much pressure into the water jacket I'd guess it's probably in the combustion chamber? Not sure how much pressure is in the exhaust port but it's still worth a try

well earlier in the thread ( and the reason for the valve guides) was because once i got the heads back from the machine shop for being surfaced and cleaned,I noticed one of the guides was cracked on the intake side, so back they went for a set of guides, seals, hardened seats etc between parts and labor about $450 later on a set of iron heads..... yea i know that was stupid to do, but again the goal was to get it running, now hindsight being what it is I plan on tearing the motor out of the car through the bottom rolling it in the garage, check it, and when it fails testing, i have a nice set of aluminium heads I plan on picking up from Chris2342 tomorrow evening.

Now with aluminium heads that are out of the box new, and a set of felpro 8519 pt-1's, do i need to worry about copper spraying them as well ? I figured new gaskets would be cheap insurance, rather then trying to reuse a set that are barely broke in, or could i reuse them ?

its gonna be a long night tonight.......

-Mike

so motor, trans and front k-frame are all out, not fun by yourself btw



pulled the intake, and pulled all the plugs out, hooked up the compression checker hose ( pulled the valve core out) made sure it was a tight seal, pulled the rocker gear so i would have to keep rolling the motor over for tdc, put 110psi to it and i heard ait hiss from all eight cylinders, but no bubbles...........not a single damn bubble, I am thinking about putting a thermostat in it and running it on the "factory motor stand" and run it, other wise i pull the heads take them to the machine shop tomorrow, have them pressure check, hopefully at no cost to me since they have told me with 2 magnafluxs that they are good and then I dumped soo much $$$ into iron.... frustrating, I am open to any ideas and suggestions guys,

-Mike

Its likely that there is nothing wrong. With no water pump running, and no pressure in the system, you are boiling the water in the heads.
Reading through this thread... It seems you never gave the engine a chance to burb out the air without jumping to conclusions.

I have to agree. My 512 did the exact same thing, twice. Then, I purchased a tool from Snap-On that puts the cooling system into a vacuum (dry, empty, of course) and then "sucks" in the coolant thru a separate hose. I pulled almost 3 gallons into my system. I do have a large, Mark 7 radiator. when I filled the system this way, no getting hot at all. We now fill every new engine build this way and never have an air bubble issue. I bet you just had an air pocket somewhere. I would not run it without a stat and for sure not without belts to turn water pump. I just can't see the heads causing this issue. I think Harbour Freight sells this same tool. Hope this helps.

If your radiator had that much brown [censored] in it you need a NEW radiator. 2 cores with a MINIMUM of 1 inch tubes. 1.25 or 1.5 inch tubes would be even better.

No way would I ever put that radiator back on.

well I feel stupid...... really stupid, after all the bullspit about this carb, when i bought it it was "running ready to go" so i swapped the plastic pump cam arms for metal, turned on the aeromotive pump and it leaked checked good..... the freaking base gasket to carb body was the wrong one and caused the super lean condition !!!!!!!!!!!!!!! motor and all is finally back in and running like a champ, it was a bit delayed since we just had our second son on Oct. 7th, but its all back together and running amazing, except for the trans, 1st and 2nd shift great, 3rd and reverse slip alot, now i adjusted the bands per the transgo TF-2 instructions, but something isn't right I have my ATSG 727/904 rebuild book, and from what i gather all i need to do is retighten the front band, and it should be good to go, is this correct ? I mean 72in lbs on the front kickdown band is not tons of pressure,

Mike