C5 gto

[Gojeep]

Originally Posted by Steve Hamilton

Hi Joel

Years ago I had a car that was hard to keep cool.
I was referred to an engineer that work3d for Modine a company that made ceiling hung heating units. He told me that 1/2 of the fan blade should be in the shroud and 1/2 should be outside. The blades are then able to flow air axially as well as radially. There testing had shown that was the most efficient.

Steve

I seen that posted many times too, or at least a 1/3rd of the fan blades exposed.

[Marc Bourget]

Just as important is the closeness of the match of the blade contour to the fan shroud exit.


Got that tip (and a bunch more) in a class given by a GM Military Vehicle Operations engineer who was the cooling specialist that designed the cooling systems for Israel Military - who had the highest/toughest cooling specifications he had come across.


The "rigors" of the discipline were driven home when he discussed cooling a Freightliner intended for use in the Andes at and above 15,000 ft.

[heinke]

Originally Posted by Steve Hamilton

Hi Joel

Years ago I had a car that was hard to keep cool.
I was referred to an engineer that work3d for Modine a company that made ceiling hung heating units. He told me that 1/2 of the fan blade should be in the shroud and 1/2 should be outside. The blades are then able to flow air axially as well as radially. There testing had shown that was the most efficient.

Steve

Originally Posted by Gojeep

I seen that posted many times too, or at least a 1/3rd of the fan blades exposed.

Originally Posted by Marc Bourget

Just as important is the closeness of the match of the blade contour to the fan shroud exit.


Got that tip (and a bunch more) in a class given by a GM Military Vehicle Operations engineer who was the cooling specialist that designed the cooling systems for Israel Military - who had the highest/toughest cooling specifications he had come across.


The "rigors" of the discipline were driven home when he discussed cooling a Freightliner intended for use in the Andes at and above 15,000 ft.

Thanks a lot for this information! I was unaware of this and thus positioned the shroud edge beyond the blade edge. The good news is that it's much easier to remove material than to add it.

I did take the GTO out for a drive yesterday and the outside temperature was in the high 80's at the time. I didn't measure the AC temp but it felt like it was blowing colder than before. The engine coolant temp ran a steady 195 with the AC on. So engine temp up just a bit, AC temp down and AC worked the entire drive. So the main issue of AC not working at all didn't occur but then again that issue has usually been popping up when air temps are over 90.

I'll trim some metal off the fan shroud and see what happens. This community is fantastic for all the knowledge it contains. Thanks again!

[Fargoman]

You can increase "driving" air flow by cutting holes in the shroud away from the fan and putting flexible flaps over them that will close with the effect of the fan drawing air out when stopped.

Google it as it's pretty common to do even on OEM installations.