Projects '47 Buick Super Sedanette project

I haven't updated this in a while, so...
I actually drove it into town for the local show this fall. Got the 2 miles or so and right in front of the check in, and it started overheating. Left it on the street for the show & drove it home. I took the heads off and sent them to get rebuilt. Didn't see anything wrong with the gaskets, etc., but it had FelPro gaskets, not factory. Hmm... Valve seals definitely needed replacing and might as well do the valves too. Cylinder walls looked great.
Ordered parts to rebuild front suspension & started tearing that apart. A arm bushings, tie rod ends, big block springs, shocks. Might as well make it drive nice for the 2 miles it goes before overheating!

 

Started to clean things up a bit to put my rebuilt heads back on, and found this:

Apparently, it's not the 62K mile creampuff it was touted to be. Or, maybe it is?

 

Still running hot. Apparently, 500 Caddy motors are hard to cool. Rebuilt heads, new gaskets, etc., started up and after a couple minutes running started pissing out the overflow again. Current radiator is brass 28"X19" (overall) 3-row crossflow. Was new, never used before this project. Has an aluminum shroud only about 1" deep, with Spal electric 16" fan. I can't find a "custom fit" radiator for this, and the ones that are close, like same year Chevy, etc., are not really much bigger. They are taller, but narrower. Example: 25"X22" downflow. Would it be worth the investment for the new aluminum radiator? I'm thinking it might not be any different, and I'll just spend time and money for no gain. Suggestions?

 

Big block Cad engines are easy to cool. My 472 in my 49 Super runs at thermostat opening even in 100 degree heat. You need to get the top radiator hose connection above the thermostat housing to get all the air out. Haver you checked for a blown head gasket?

 

Is your water outlet t0 radiator inlet situation still the same, with the engine the higher of the two? Per @rockable 's suggestion earlier, a taller radiator, which would put the inlet above (or at least even with) the water outlet on the engine (and provided the radiator cap is higher than either) would be the first thing I would address. Use that vertical space under the hood to help keep things cool.

Can you raise your existing radiator a few inches, even if the hood cannot close for the time being, to see if that extra few inches of height makes the difference? I think I would also make that long bend the upper radiator hose has much shorter and a smaller radius, too, so there's no high point for air to become trapped.

 

@BJR Fresh gaskets. The old ones looked good too. There was no indication of a bad gasket, and the heads were magnafluxed. The valve seals definitely needed to be replaced, and as long as they were off, got them rebuilt. I have an in-hose filler in the upper hose, at the high point of the system.
@In_The_Pink Yes, the engine is higher than the radiator, but as stated, there's a filler that's higher. The current GM crossflow radiator fits under the fender lip. It wouldn't just slide up. I feel like there's no, or little air in the system. Pretty sure there has been OEM examples of the radiator lower than the engine, but none come to mind.
So, spend the $$ on an aluminum downflow radiator, and re-do all that entails. The upside of that, is I may be able to use a mechanical fan, but I'd have to fab up a shroud.

 

FINALLY, got my new front springs. Didn't think something so common ('70-'81 Camaro Big Block) would take so long to get here. Hoping it lifts the front enough to be able to drive onto my lift without the bumper guards hitting like they were. This thing was LOW. One side back in today. Hoping the other side back together soon. Then, back on the overheating problem. One step at a time.

 

PROGRESS! Outside with the newly rebuilt front suspension. The big block springs raised it enough to make it drivable. Probably needed those for that big Caddy motor anyway. Looked cool on the ground, but the bumper guards would hit my lift when I drove onto it.
And an admission: I'm dumb. After taking all the cooling system apart to try a bigger radiator, I was left feeling like I was missing something. Even with a Spal fan, I didn't think it was moving enough air. I hooked the fan back up & thought it was slow, so I hot-wired it to the battery & it was much faster. So, investigating I found the problem. I didn't use a thermostat for the electric fan, just wired it to an existing dash switch. The one that made the most sense, is labeled "BLOWER". You guessed it. 3 position switch was on low. Buick, in all its 1947 wisdom, has position 1 as high, 3 as low. Common sense says the farther you pull it out, the faster it goes, but its backwards. I put everything back together and it idled for about 45 minutes. I'm happy!

 

Great! Time to go for a drive.
Thanks for the update

 

Congratulations!!!!

 

Great to hear you got that issue figured out. Sometimes it's the simple things that we all miss.