Adapting a cheap GTB aluminium radiator on my early GT4

So, cheap and Ferrari don't mix, and I always consider that saving money on parts is a good recipe to do the same job over again later. But, read on:

Car is a 1976 308 GT4, with some 220K Km on the clock and fully rebuilt engine just 5K Km ago. Over the summer, I could see the water temp creeping past the 90°C mark. I measured the water temp flowing into the radiator to be 104°C and decided that it was time to take care of the front end of the car. My initial plan was to have the radiator cleaned out or re-cored, fix the bent fins on the A/C radiator in front, and replace the two odd fans (one very similar to original, the other a hack job). With this, I figured things would be good to go. The temperatures on the exhaust headers are all around 300°C, so I'm not worried about the engine running unusually hot.

Of course, this was early august, with all the radiator shops closed. So, while looking around, I ran into an add on fleabay for a new aluminium radiator for a 308 GTB/GTS, or late GT4. The price was only 280€, which is much less than having the original radiator re-cored. It said to ship from Czech Republic, but of course it was made in China. Still, I figured "why not?" I didn't find any threads on these radiators, so I thought it might interest some fellow F-chatters to see what they are like. I will try to document how well it holds up (or doesn't) over time.
This is what it looks like after I glued the side mounting brackets for the fan shroud and test fitted the fan switch

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The radiator arrived in less than a week, no import duties. The workmanship is an odd mix: the structural seals appear to be well done (definitively better than my crappy aluminum welding skills), but the rest is not as well put together: the flanges for the fan switch and drain are beefy, but the weld protrude past the lip. Also, the air vent at the top was not drilled through. No problem, but requires drilling and taping the remaining few mm.

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Another thing are the outside dimensions, which were not exactly accurate. Fortunately, they were a bit smaller and the radiator fit just fine. Also good were the connections for the water pipes (size, location, and orientation). On the other hand, the location of the tabs for mounting the A/C condenser were off by 5mm. To fix this, I cut them off with a cutting disk and welded them back on:

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Overall, I would rate the radiator a 6 out of 10, considering the price and decent fit. The ones sold by superformance are for sure a much better fit and correctly finished. Also, they will have the correct mounting brackets for the model year. On the down side, they are about 4 times the price with taxes and import duties.

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To solve the absence of mounting brackets, I welded some up from mild steel and then glued a piece of hard rubber mat to dampen vibrations.

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I also had to make up a C-clamp for the top which holds the radiator to the front valence via a rubber coupler. I decided to glue this with high T° epoxy to avoid risking welding to the top of the radiator.
The radiator is fully insulated from contact with the ground to reduce risk of electrolysis.

For the fans, I decided to make some modifications and convert to two pulling fans. I found the SPAL VA09.AP12/C-54A suction fans (280mm) to be the largest I could fit, and made a flat shroud out of 1.5mm Al. It sits about 22mm from the radiator fins and is riveted to some flat Al bar glued to the sides of the radiator with high T° epoxy.

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The fans are a tight fit, but do not touch anything and seem to be pulling quite well.

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Of course, "while I'm in there", I fixed the lower fiberglass valence which was all chewed up, and also the spare wheel well which was very much missing a large chunk. The culprit also severely bent the front square tubing of the frame, which I cut out and replaced.


All in all, I'm pretty happy with the result. No leaks at start up nor after warming up to purge the system. Now it's time to put the car back on the road and test it while it's still warm outside!

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Will report back in due course, especially if starts falling appart!

 

Looking forward to getting shocked! They say aluminum radiators are 30% moire efficient than steel ones, and that puller fans add another 20%. I'm not sure how this can be generalised, but I am hoping for care-free motoring in summer with the A/C on full blast


As for the fans, they are pretty widely available since spal is a large supplier. I got them here: https://www.motointegrator.fr/produits/1694383-ventilateur-climatiseur-spal-va09-ap12c-54a for less than 60 bucks each. I would guess any good quality low profile fan will do since originality is already out the window.

I should mention that all the modifications are fully reversible if one wants to go back to stock.