[quickcat]

So I have finally figured out why I cannot keep my big block cool. After trying all kinds of fan setups, waterpumps, and even electric drive, I finally figured out why I have so much trouble keeping the 429 in my 68 cool. After replacing the aluminum with a used stock big block radiator I discovered that the aluminum radiator was not passing enough coolant. It is clogged somehow, most likely from sitting in storage years back. All this time I was assuming that there was nothing wrong with it since I bought it new and it was supposed to be great. I started to suspect that it wasn't efficient enough for the job and decided to try the brass radiator to get better heat transfer.

I just had to share this because I have struggled with it for so long. Don't rule out things when you are troubleshooting something just because you think it is good. The signs are there, test the parts before assuming they are good!

Matt

 

[Harvey]

How do you test an old radiator or heater core? I have both as originals and since the car is completely stripped I would like to test them before instalation. Or should I just jump and put new in for both?

 

[C Gauch]

You can have your old radiator serviced (re-cored, make it a 3 or 4 core - whatever you want). Def. get a new heater core.

 

[quickcat]

My test for this radiator was very scientific..... I held the garden hose, sealed with a rag to one side and observed the flow from the other side. I also watched down the tank (the aluminum radiator is a crossflow design) and was actually able to see the rows of the core that were not flowing. It was about half of them or so. It is amazing that it cooled as well as it did.

If you are having cooling troubles, do the basic troubleshooting. Change the thermostat, observe the coolant flow with engine running to check the pump (thermostat must be functioning properly and open) and if that doesn't get her..... have a radiator shop look at the radiator. A shop here in dayton will do a clean and repair for $60. What a deal!

 

[Local Hero]

How do you test an old radiator or heater core? I have both as originals and since the car is completely stripped I would like to test them before instalation. Or should I just jump and put new in for both?

I take a bicycle innertube and cut it. I clamp each end of the tube to whatever I'm testing. If it's the radiator, the tube clamps to both the inlet and outlet. Same for the heater core. Using the air nozzel on the tube I pressurize the tube and then submerge the device in a tub of water and look for bubbles.

 

[Bad69cat]

That is interesting that you bought it new and had trouble with it just because it sat around...? musta been cheap/bad grade of aluminum then. radiator shops do basically the same thing Mark describes, except they use pressure guages and watch for bleed down. If in doubt have it "boiled" out and tested at the same time. Then you know it's clean inside and out....

 

[quickcat]

I am thinking I am going to just have the brass one fixed (it sprung a leak on me just before winter set in) and throw the aluminum one out. The shrowd fits the brass and it fits the car just right.... and it will transfer heat better. I am thinking that I may have not had a good coolant mix when I stored the car and that allowed corrosion in the core. There were no signs of aluminum corrosion in the tank when i looked down in there so I assumed it was good to go.

 

[rutter0907]

I just ahd mt radiator redone earlier this year and the gentlemen did a flow check on it for me for $10 to see what might need to be addressed.