[YNOBIL]

Nearing the end of a frame off restoration on a '67 convert. I have another '67 convert that doesn't like hot weather, I don't want the same problem with my new build. I'm adding the taller AC radiator core support with an aluminum radiator. The Cold Case dual fan setup looks great, how much better is it then the factory fan layout ? I want to be able to drive it a lot in the summer so it will also have Vintage Air.

[Lee]

I just installed VIntageAir in a '67 LeMans convertible, which also has a 455 w/6X heads. Along with the VA, I installed an upgraded 12Si alternator (with appropriate wiring upgrades), and the non-A/C ColdCase radiator (did not feel like altering the core support) & dual electric fans. I used a PWM from DC Control to control the fans.

That controller varies the fan speed, in order to try to keep the coolant at a steady temperature (instead of swinging up and down 20+ degrees like on/off controllers). When the controller senses that the AC compressor clutch engages, it increases the fan speed to 50% if the fan(s) are at a speed lower than that.

When I was charging the VA system, I was taking my time and double checking things, so the car was idling for about 20 minutes. The ambient temps were mid-70's. Whenever the clutch would engage, I could hear the fan speed increase dramatically (to 50%). I had a quality infrared heat gun, and was checking temps on the water crossover and thermostat housing periodically. Temps stayed in the 172-180 range the entire time.

[pgp66]

Lee, that sounds really good, I have that same radiator and fan setup, was that controller from here: www.dccontrol.com
And which one if you don't mind, the FK45 model?

[Lee]

Originally Posted by pgp66

Lee, that sounds really good, I have that same radiator and fan setup, was that controller from here: www.dccontrol.com
And which one if you don't mind, the FK45 model?

Yes, that is the correct source. The owner, Brian Baskin, has helped me with several projects. I've tested some "one-off" things for him as well. Great guy with an excellent product.

On his recommendation, I used the FK75 with the 10-gauge wiring. The 45 probably would have been fine, but I like to have reserve capacity. I was going to use the 8-ga, but he assured me the 10 was sufficient.

The only change I made, was to cut off the supplied connectors on the fans, and installed crimped & soldered Weather Pack connections, to connect the FK75 to the fans.

[YNOBIL]

Thanks for the great advice. Going to order the Cold case radiator kit today while it's still $50 off. The FK75 sounds great but I'll order that when I get closer to needing it. Didn't know where the temp sensor would go. I like that it slides into the radiator and doesn't interfere with my factory gauges.

[hgerhardt]

I've had my '66 GTO since 1987. It's an A/C car with the tall core support. I've had a 462 and later a 440 in it, with originally 3.08 and later 3.55 gears with T-400 trans. One thing I found early on is aftermarket fan clutches come in two ways: "street" thermostatic and "truck" versions. With the engine turning 3000+ rpm on the highway, the "street" clutch was always above the speed at which it could engage, which meant it was always disengaged no matter how hot it got. With "truck" clutches, they'd engage when hot and wouldn't disengage AT ALL no matter the rpm, which meant the belts couldn't transfer enough power to drive the fan at high rpm, so the belts would slip/squeal.

During all of my fan clutch experiences, I was using the factory 7-blade clutch fan, which has pretty aggressive fan blades. Maybe a mid-70's 5-blade clutch fan would have worked better with the "street" clutch.

Eventually, I switched to the early Ram Air 5-blade flex fan and that worked adequately. Still, it made a huge amount of noise at high rpm (the fan's overdriven on A/C cars) so a better solution was still needed.

By now, I had a 4th-gen F-body and noticed that its rad core was identically sized to the tall '66-'67 core, so the light went on in my head. That's why I now have a 4th-gen F-body fan assy in my GTO and that works great. Never going back to a mechanical fan!

[Lee]

On the temp probe for the FK75, I drilled a hole at the bottom of the shroud, and used a grommet to keep from damaging the wire. I also used a clamp to secure the wire, with a little slack in it. I thought I had taken a picture of it, but can't find it right now.

On ordering the controller, give yourself a bit of lead time. DC Control is a one-man show, so at certain times (vacation, holidays, etc) he may have a bit more lead-time to get things shipped. This last controller shipped just a few days after I placed the order, but it has taken a few weeks at times in the past.

Jeg's had the best price I could find a few weeks ago, when I ordered the ColdCase mentioned above.

Good luck!

[YNOBIL]

Originally Posted by Lee

Jeg's had the best price I could find a few weeks ago, when I ordered the ColdCase mentioned above.

Good luck!

I had already ordered from Summit before I read your reply. Turns out Summit and Jegs had identical pricing.