C2 replacement Radiator vs Repro

[Edward S.]

Re: C2 replacement Radiator vs Repro

I have had a DeWitt on my 65 BB now for 4 years now with never a problem. One added benefit for me is that the car as run about 20 degrees cooler since I got the original out. I think it's the way to go.

[Edward S.]

Re: C2 replacement Radiator vs Repro

I have had a DeWitt on my 65 BB now for 4 years now with never a problem. One added benefit for me is that the car as run about 20 degrees cooler since I got the original out. I think it's the way to go.

[Wayne W.]

Re: C2 replacement Radiator vs Repro

It always interest me when this topic comes up, it is usually stated that aluminum is better than copper. The heat conductivity of copper is ~ 400, the conductivity of aluminum is ~ 250. Copper is not better than brass. The design characteristics and the weight are the most important factors. I have a copper radiator that I bought for $90 in my 66 with a 350 TPI and it cools just fine. Most problems with replacement copper radiators are caused by other problems.

[Wayne W.]

Re: C2 replacement Radiator vs Repro

It always interest me when this topic comes up, it is usually stated that aluminum is better than copper. The heat conductivity of copper is ~ 400, the conductivity of aluminum is ~ 250. Copper is not better than brass. The design characteristics and the weight are the most important factors. I have a copper radiator that I bought for $90 in my 66 with a 350 TPI and it cools just fine. Most problems with replacement copper radiators are caused by other problems.

[Jack H.]

You're missing the point...

It's NOT a matter of raw thermal conductivity, it's a matter of geometry. Yes, brass (radiators are NOT made from copper...it's too soft/ductile) does have much better thermal conductivity than aluminum (electrical conductivity typically co-varies with thermal conductivity and everyone knows about aluminum wiring issues in the home...).

The boogie is given a space constraint (raw cubic inches), how far can you go scaling down brass (cooling tube wall thickness + cooling fin density) before you reach the limit? With brass, you reach a point where trying to go further results in wall thickness that's too thin for the pressure the radiator has to withstand and it'll rupture/leak.

With aluminum, you can go MUCH further and reach the point where, despite the lower thermal conductivity of aluminum, the BTU dissipation profile actually surpasses that of a brass radiator with given the same size constraints. That's why high performance Corvettes (e.g. L78, L88, Etc.) used a big aluminum Harrison radiator but were DENIED heat generating options like A/C or AT.

When similar BB's were allowed to have creature comfort option items in the '66-74 era, the big Harrison aluminum radiator was replaced with a BIG Harrison brass radiator (give the higher raw heat dissipation characteristics needed to handle the job).

So, there's a trade-off between cost, weight, and size. It's only when you're up against a size or weight constraint (like many race cars are) that you can throw $$$ at the problem and get a higher heat dissipation profile by going with aluminum. The DeWitts web site used to have an nice tutorial on this....

[Jack H.]

You're missing the point...

It's NOT a matter of raw thermal conductivity, it's a matter of geometry. Yes, brass (radiators are NOT made from copper...it's too soft/ductile) does have much better thermal conductivity than aluminum (electrical conductivity typically co-varies with thermal conductivity and everyone knows about aluminum wiring issues in the home...).

The boogie is given a space constraint (raw cubic inches), how far can you go scaling down brass (cooling tube wall thickness + cooling fin density) before you reach the limit? With brass, you reach a point where trying to go further results in wall thickness that's too thin for the pressure the radiator has to withstand and it'll rupture/leak.

With aluminum, you can go MUCH further and reach the point where, despite the lower thermal conductivity of aluminum, the BTU dissipation profile actually surpasses that of a brass radiator with given the same size constraints. That's why high performance Corvettes (e.g. L78, L88, Etc.) used a big aluminum Harrison radiator but were DENIED heat generating options like A/C or AT.

When similar BB's were allowed to have creature comfort option items in the '66-74 era, the big Harrison aluminum radiator was replaced with a BIG Harrison brass radiator (give the higher raw heat dissipation characteristics needed to handle the job).

So, there's a trade-off between cost, weight, and size. It's only when you're up against a size or weight constraint (like many race cars are) that you can throw $$$ at the problem and get a higher heat dissipation profile by going with aluminum. The DeWitts web site used to have an nice tutorial on this....

[Paul L.]

Re: C2 replacement Radiator vs Repro

Anyone know where Zerex G-05 might be found in Canada? Or is there another brand equivalent here?

[Paul L.]

Re: C2 replacement Radiator vs Repro

Anyone know where Zerex G-05 might be found in Canada? Or is there another brand equivalent here?

[Mike M.]

Re: C2 replacement Radiator vs Repro

UAP has it. Also Walmart in my area has it and advance auto I think.

[Mike M.]

Re: C2 replacement Radiator vs Repro

UAP has it. Also Walmart in my area has it and advance auto I think.

[Duke W.]

Re: C2 replacement Radiator vs Repro

It's much more than just the thermal conductivity of the material. The design geometry is important as is material strength and other properties that place a limit on geometry like fin and tube spacing.

This is why the Harrison aluminum radiator looks like a typical aircraft cooler. It will transfer more heat per unit area/volume/mass than any other design.

Duke

[Duke W.]

Re: C2 replacement Radiator vs Repro

It's much more than just the thermal conductivity of the material. The design geometry is important as is material strength and other properties that place a limit on geometry like fin and tube spacing.

This is why the Harrison aluminum radiator looks like a typical aircraft cooler. It will transfer more heat per unit area/volume/mass than any other design.

Duke

[Wayne W.]

Re: C2 replacement Radiator vs Repro

I cant figure out whether you both are agreeing or disagreeing with me. Thats exactly what I said, its the design of the unit that is most important. But there is no reason other than cost, that a brass-copper radiator of a similar size couldnt be designed to fit that hole and do an even better job than the old Corvette aluminum design. That formed plate celular design is nothing new. My 33 Cadillac has a radiator of the same basic design that would cool a Mack Truck and the opening is about the same size.

[Wayne W.]

Re: C2 replacement Radiator vs Repro

I cant figure out whether you both are agreeing or disagreeing with me. Thats exactly what I said, its the design of the unit that is most important. But there is no reason other than cost, that a brass-copper radiator of a similar size couldnt be designed to fit that hole and do an even better job than the old Corvette aluminum design. That formed plate celular design is nothing new. My 33 Cadillac has a radiator of the same basic design that would cool a Mack Truck and the opening is about the same size.

[Duke W.]

Re: C2 replacement Radiator vs Repro

There are design constraints with brass than don't allow the same heat transfer per unit area as aluminum.

The DeWitts Web site has some good information.

Duke