shroud for aluminum rad?

[panteramatt]

I have a 69 mach1 and it doesnt have a fan shroud. Im planning on putting a aluminum rad in it and was wondering if theres a shroud that will fit the stock rad and an aftermarket rad. Also, would a electric fan be better or should I be fine with the shroud and rad?

[cmayna]

Not all of us will agree with the issue of going electric or mechanical fan.  I'm going mechanical fan with my aluminum radiator. I bought a 25" 69/70 shroud that covers the entire 25" radiator.  I did have to do some slight modifications but I think it pertains to the specifics of your radiator for they're not all built the same.

[miketyler]

I too love electric fans, as are they cleaner, less menacing, and safer than their belt driven counterparts. However, unless your car just naturally runs cool, you probably will be sacrificing some air cooling CFM in the trade off.

I have a 72 Cuda that I wanted to put electrics on. Spent several hours getting it all set up (the Mystique/Contour dual fan and shroud fits the Mopar 26" radiator perfectly BTW) only to have to pull it off to go back to belt driven fan.   

[Midlife]

So if the electric fan fit perfectly on the 'cuda, why did you have to take it off?

[miketyler]

The electrics didn't cool it as well as the belt driven fan. In fact, it still runs hot even with the belt driven fan. The difference in air flow is night and day and runs slightly cooler with OEM fixed fan. I plan to try an aluminum radiator soon and may even remove the high flow condensor. 

[AzPete]

I have always viewed cooling issues as if the factory setup worked when new, it should still function on a rebuilt car. Going to electrics or aluminum radiators should be done when there are major engine modifications, body modifications, clearance issues due to mods and the such.

It seems to me that so many jump to aluminum and electrics when the issues may be elsewhere. One does not want to mask the original problem until it causes major problems. Just my thoughts on the issue.

[johnpro]

I have always viewed cooling issues as if the factory setup worked when new, it should still function on a rebuilt car.

Not so fast, there, Tonto!  Don't you remember the days back in the '70's and '80's where there where cars by the dozens over-heating on the sides of the roads, as they NEVER worked in some climates?

You SoCal guys will have to correct me, if I'm wrong, but don't the signs still exist on I-5 going up the GrapVine saying to turn off your A/C to help avoid overheating?

All modern day cooling systems use electric fans, and most use aluminum radiators.  Why? Because they are FAR more efficient.  

An electric fan will be pulling at it's max CFM at idle, when you need it most, because of lack of air flow across the radiator, and shut off completely at speeds, when the fan is no longer needed, freeing up HP, and increasing fuel efficiency.  A mechanical fan is least efficient at idle, when it is MOST needed, because the engine is turning so slow.  Then unless it's either a flex fan (usually aftermarket) or a clutch fan, it will cause a big drag at freeway speeds, impeding air flow and lowering fuel economy.

The trick to any electric fan is sizing it and the radiator correctly for the application.  Also, it's been my experience, that aluminum radiators always out-cool brass radiators of the same size.

[miketyler]

For my case I hope you are right. I have spent a lot of money on that car and bet I haven't enjoyed 100 worry free miles out of it. I keep one eye on the road and one on the temp gauge.

The car has all stock AC components inside but from the firewall forward has current equipment including Sanden AC, themostatic clutch switch, and serpentine high flow condensor. I pieced this AC system together and it could indeed be the condensor that is restricting flow to the radiator. The thing is, it works great and I hate to pull it apart.

I feel like I could write a book on all the things I have done to improve cooling on her. I've learned a lot but am now ready to take a step or two back in the pursuit of getting temps back where they need to be.

[AzPete]

I remember cars that overheated towing large trailers and such. The grapevine was hard on everything. Been there several times. Not saying every car that overheated was bad maintenance, but many did not run any coolant back then too. I can remember adds to be sure to add antifreeze for the winter months.