Need Cooling Advice

[210 Sport Coupe]

Hi Guys,

Present cooling system-
Desert cooler 4 core copper/brass in V-8 position, 17" low-profile flex fan, VA shroud, 18" elec. pusher fan comes on when A/C is on. Engine is a 327/300hp basically older rebuild, nuthin' fancy.

Project underway-
355 chevy, 400hp/400tq (approx), 4barrel carb, (no blower or anything) want more room infront of engine so putting rad in 6 cyl. position.
-Should I run one big elec. puller fan with built in shroud?- eliminate engine fan and use a trinary switch for a/c?
If I understand, a trinary switch will let the elec. fan run at one speed then when the a/c is on, the elec. fan will run at higher speed?
-Should I run the big mech. 18" flex fan and shroud and keep my elec. pusher for a/c only?

Want to do the Powertour next year, and was wundering what you guys would recommend. Don't really want to go to alum. rad if I don't have to.

Suggestions?
:bowtielb:

[D.S.]

I would ditch the electric and flex fans and run a clutch fan with thermal clutch and a shroud...
The clutches come as thermal or non thermal, I like the thermal operated ones...
That's just my opinion, others may vary...

[acardon]

-Should I run one big elec. puller fan with built in shroud?- eliminate engine fan and use a trinary switch for a/c?
If I understand, a trinary switch will let the elec. fan run at one speed then when the a/c is on, the elec. fan will run at higher speed?
-Should I run the big mech. 18" flex fan and shroud and keep my elec. pusher for a/c only?


Are you having cooling problems now? Most cooling problems are at slow speed, stop and go traffic and your not using that extra 100 HP anyway.
You may not have enough room for the pusher fan in the 6 cyl position.
You have to have more than a trinary switch to change the fan speed. You will need a 2 speed fan, relays and an extra temperature sender. OR a fan controller such as Spal or Dakota Digital to vary the speed and control it with the trinary switch.

[Black 55]

Read this article on cooling systems

http://www.diamondbackengines.com/technical-white-papers/cooling-sysem-problems/

[Jim '57]

I have been told that the puller fan was the more efficient way to go. If you want the trinary switch to control a second speed or a second fan you will need a relay. You can have the first fan speed to come on with the ignition. You will need another relay for that but it will save the expense of a controller, they are not inexpensive. I went with DD so I could use my DD temp sensor. I have dual two speed fans and 4 relays to activate them
Good luck.
Jim

[210 Sport Coupe]

Are you having cooling problems now? Most cooling problems are at slow speed, stop and go traffic and your not using that extra 100 HP anyway.

No, I don't have a cooling problem the old way. I want to be sure I have a better set-up for the newer engine if I'm going to do the powertour.

Black 55

Thanks for the article, I'm going to read that a couple of times. Lots of info there.

Jim '57

That sounds what I think I had in mind. Do you have a wiring diagram or something that I can see what you're talking about?

I just want to rethink the set-up I got to maximize my cooling while everything is apart.

[hddude]

i just read that article [link for it], diamondbackengines. i`ll say it again, as was mentioned in that article, you could move the water to fast thru the radiator, not giving enough time to cool. it happened to me, that`s why i`m trying to sell this Wieand Twisted Snout aluminum pump. ran hot, overheated, heated up faster. stock pump, no problems.

[Rick_L]

The trinary switch on the a/c system does not run the fan(s) at a higher speed or run a second fan unless you wire it that way. There are many fan setups so you need to make the choice as to what to do.

Here is the setup that I'm going to use.

- Dual 11" fans, wired to run both at half speed at a moderately high coolant temperature. They will run at full speed at a higher yet coolant temperature. Fan control by coolant temp is through the pcm for the LT1 engine I'm using. The wiring scheme uses 3 relays as used on a factory Camaro fan setup.
- The trinary switch will turn the fans on full speed when the refrigerant high side pressure reaches the set point. For my setup this requires two more relays. The reason I want to do it this way is that if the head pressure gets high I want the fan to run hard as possible so I can get the best performance from the a/c because it's HOT here in Texas. It also means that usually when this happens the car is in slow speed traffic or idling so the coolant temperature is going to be helped by running the fan full speed too.

If you have one single speed fan, then you don't have any choices about fan speed or multiple fan use.

If you have a dual speed single fan, then you can run with two set points and wire the trinary to run at either speed.

If you have dual fans you could run one fan when the temperature is moderately high and both when it's really hot. You can run the fans any way you want when the trinary switch closes.

If you don't have a factory EFI computer, you can either use two temperature switches to control the fans, or you can buy one of the programmable fan controllers on the market.

[210 Sport Coupe]

i just read that article [link for it], diamondbackengines. i`ll say it again, as was mentioned in that article, you could move the water to fast thru the radiator, not giving enough time to cool. it happened to me, that`s why i`m trying to sell this Wieand Twisted Snout aluminum pump. ran hot, overheated, heated up faster. stock pump, no problems.

I didn't mention anything about moving the coolant faster, just mentioned elec. fans, mech. fans and position of rad.

Rick L-
Thanks for clearing the trinary switch function. I'm thinking that way (your described set-up) would be too overkill for my engine.

What I do know- putting rad in 6 cyl. position.
What should be used- 2 fans, 1 for the rad, and 1 for the a/c. Now thinking 18" Flexalite 7 blade (quieter fan) inside 6 cyl. shroud and my elec. pusher fan for a/c use only.