TR2/3/3A TR3 Radiator Rehab

[Jprmm15]

I am finishing up rebuilding my engine for my TR3. I was looking at the radiatior today and I was wondering good tips to see if it usable and also, what type of paint can I use to paint it? Regular engine block paint? Any tips would be great!!

 

[Andrew Mace]

Eastwood sells a radiator paint; they state that engine paint is too thick and can flake off. YMMV....

 

[Geo Hahn]

No only flake off -- but it is thought that thick paint can reduce heat transfer. Of course, I would think, the top tank could be painted with regular paint, it's the fins of the core you wouldn't want lots of paint on.

 

[Jprmm15]

I've read I'm supposed to fill it with water to test it to see if it leaks. True?

 

[MGTF1250Dave]

Aloha,

Your radiator needs to do two things, hold coolant without leaking at operating pressure (4 PSI with standard radiator cap or 7 PSI if you use a TR4 radiator cap) and effectively transfer heat.

First check for cracks where the long filler neck attaches to the upper tank. Also inspect any dents in the tanks for possible leaks. Most radiator shops can pressure test your radiator for leaks, but advise them what the normal operating pressure is so they don't over pressurize it.

Thermal performance is often overlooked if the pressure test is satisfactory. Look closely at the small fins in the core to make sure they are not broken and are attached to the tubes. These fins take the heat from the tube and shed it to the air passing through the radiator.

Use the specialty radiator paint. The heavy coating from regular paints will tend to insulator the radiator so it retains heat.

If the core appears to be damaged most reputable radiator shops can re-core the radiator for less than a new replacement.

 

[TR3driver]

My suggestion would be to take it to a radiator shop and have them test it for pressure holding, flow and thermal efficiency. Servicing the radiator on a TR3 is a PITA once the front apron is installed, so it pays to do it right the first time. If it's basically in good shape, they can clean and paint it as well. My shop will do the pressure & flow tests for free, but you may have to pay for the thermal test.

I had a terrible overheating problem that was eventually traced to poor thermal efficiency; apparently the tubes were no longer in good thermal contact with the fins. But because of the unusual original design, where the tubes run through holes in the fins, the problem was not apparent on casual observation. A recore solved the problem permanently.

Last time I checked, a recore wasn't much cheaper than a new offshore reproduction. But I'm inclined to think the recore produces a better quality result, especially if they use a Modine core.

 

[Andrew Mace]

Last time I checked, a recore wasn't much cheaper than a new offshore reproduction. But I'm inclined to think the recore produces a better quality result, especially if they use a Modine core.

The other factor is that the original top and bottom tanks (assuming they're not damaged) are often better quality than those on the reproduction radiators.

 

[Jprmm15]

Andy do you have anyone in the area you prefer for this?

 

[Andrew Mace]

Josh: check for a PM.

Everyone else: I got a chuckle last night when Josh PM'ed me to tell me that the car in question is the one I'd sold to his father-in-law last spring! Small world!

 

[TRDejaVu]

When I had mine recored last year, I watched them pressure test it to 21 PSI.