Poly 313/318 Aluminium Radiator
 

As the revision of my 408‘s Poly 313 is nearing its end I‘m considering whether it‘s a smart idea to change to an Aluminium Radiator. Does anybody have experience with Aluminium rads on these engines?

Your help is much appreciated.

Justin

I considered installing an aluminium radiator when I added air conditioning to my 410 earlier this year but decided to have an uprated core installed in the original radiator. I changed to a pair of off the shelf 11" Spal puller fans in a shroud. One fan is set to come on at about 88 degrees C or when the air conditioning is switched on. The second is set to about 95 degrees. Both fans come on with manual control.

Even during the hot spells this Summer I don't think the second fan has switched on so, for me at least, the original radiator with a new core works well.

Unless you are considering fitting air conditioning you may not need to uprate the fans. This modification isn't without consequence. My new fans draw way more than the existing alternator and wiring could supply. Adding a second fan relay and rewiring the manual switch to operate the relays rather than supplying full current sorted the wiring issue. The higher output alternator needed a new, larger, cable run directly to the battery and rendered the ammeter pointless. Change to a voltmeter per 411 is the obvious fix.

Other points to ponder:

If the block is silted up you may need better cooling to compensate.

Higher output water pumps are readily available for these engines. I bought one expecting to need it but found the existing perfectly adequate, but I'm not certain what is currently fitted.

If you decide to go for aluminium you will have the choice of vertical flow per the original or cross flow, which many seem to advocate. I'm no expert so you will need to research.

You have a choice of built in transmission cooler or fitting an external unit. I prefer internal as it gets the transmission oil up to temperature quicker.