Help! Rocketeers and motor guy in general. Exploding radiator!

Interesting thought,exhaust might leak into the coolant, then travel through the top hose to the upper tank. With the cap off, maybe smell test...
However, one head gasket was blown, maybe gone again, your making high compression and may require improved gaskets. Possibly a thousands of an inch burn across the head or block surface.
Seems to me you said this all started after the HP work?

 

Olds engines do not have too many headbolts so check for warped heads. An oldtimer trick was to drain a little coolant, remove the water pump drive belts and thermostat housing from the engine. Top the coolant up to the thermostat hole and start the engine. Rev her up. Bubbles in the coolant usually means leaking head gaskets or a crack in the head or cylinder. On a V-8 you will be able to tell from which side the bubbles are coming from.

New copper or aluminum racing radiators that can handle over 650HP can be found for under $200.00 now a days. Good luck.

 

Consider a sealer pellet with the new radiator. GM puts em in everything these days and might be the difference between taking it out and enjoying it for a couple years.

 

I agree with above with the addition of make sure each cyl to be tested is at bdc vice tdc of a normal leakdown. that way you test all of the wall that the piston sees.

 

Are you sure thats not a sacrificial anode?

 

EVERYTHING gets sealer. It's apparently easier than designing gaskets to seal. Gaskets are designed first & foremost for ease of ***embly with automated jigs, then if they happen to seal, it's a bonus.

Latest V6 design coming out of GM is rumored to be head-gasketless and rely on sealer & specific surface textures instead. I am not kidding.

 

Yes, I am considering this. My only question was if this would lesson the life of my new baby (walker radiator)!!! but i cant wait to see that mustang radiator gone. Now if I can just get rid of the alternator stuck up top I'd be set.

 

Why not heat the motor to 180 degrees and do a leakdown on each cylinder, I would think this would show something, A leakdown tester isn't that much money...Good luck!

 

Hate to say it but I fought the same problem a couple of years ago. Did every thing I could think of to diagnose from looking for bubbles to hooking up to a very high tech "sniffer" at a friends well equipped shop. Turns out it was a head gasket - but it only leaked at higher R.P.M. Took loosing an expensive Saldana aluminum radiator to make me pull it apart. The cap never leaked, so the pressure built in the radiator until the tubes "plumped while ya cook 'em" just like the old Ball Park Franks commercial! ****ed, but when all was said and done a near new Edelbrock head was pretty badly warped. On a slightly cheerier thought, you mentioned replacing a head gasket - did you retorque it after you warmed it up a few times? I've seen that through a few people in the past , and always where I start with similar problems. good luck