Hey gang,

I just finished a weekend of wrenching on the car and I've got a problem that's bugging me. Here's the specs first:

400SB +.030
2.02 76cc 462 400 heads
FLAT top pistons (10.5 static)
CC 292H cam (Lunati coming soon)
91 Camaro serpentine pulleys (yes, I got the correct water pump)
91 Camaro E-Fan with custom shroud
160* t-stat
3500 stall (Installed this weekend)
4.10 gears in a 12 bolt (Installed both this weekend!)
1 5/8 headers into a dual 3" exhaust (Installed this weekend)

As you can see, I've been a busy guy this weekend smile.gif

Now, onto my dilemma. Since installing the pulley arrangement and e-fan, the car runs too warm for my taste. Before with the mech fan, the temps would be around 180-195 (at the water neck). Now, the temps are at 210 and sometimes higher. I can tell she's getting pretty warm as when I shut it down, it ticks and pops for quite sometime - something it's never done before.

The night I installed the pulleys and fan, the temps were A-OK until I realized the e-fan was spinning the wrong direction. Remember kids, check the airflow BEFORE you start the car. My bonehead move of the week. The temps rose while a friend and I were looking under the hood talking about it. Before I realized it, the temps hit 240 (at the neck) and I shut it down, boilover following.

I see no change in idle, no combustion in the radiator and nothing mixing in the oil or water. I'm not completely dismissing a blown head gasket or cracked head/block, but I see no tell tale signs yet.

Any ideas of what could be causing the extra warm temps? Should I throw some Baar's Leak at it and hope it cures it or live with it? Maybe it has air in it? What would be a good way to bleed any air out?

When it's warm, it refuses to crank even with initial timing at 0*.

Here's some pics of the shroud setup. Inefficient design maybe?

http://www.racingpensacola.com/phpBB2/files/p1140654.jpg

http://www.racingpensacola.com/phpBB2/files/p1140659.jpg

BTW: This is in a '71 Monte Carlo

400's typically run hot....I would not run a factory electric fan. Get a GOOD aftermarket fan. The one you are using is not made for this application. Also if you dont have one already, Id upgrade to a four core radiator. Beautiful fan shroud by the way!!

Yeah, I bet that fan was just meant to handle a TPI 350 at the most. That's IF it was designed with the 350 cars in mind. Considering that most 3rd Gen F-bodies were equipped with v6 or 305V8s, maybe the cooling abilities of the fan aren't all that great. Just a thought.

That fan's for an LG4 305. The tpi 350's and 305s got dual fans. However, that fan has no trouble keepin up with my 327. What are you using to turn the fan on and off? The factory switch for that fan doesnt turn on until 235* then off at 200*. I found a replacement that comes on at 200* and off at 190*.. works fine for me.

Yes, it's off of a 305 car. I drove the car to work this morning (45 minute in-town drive) and the highest it got was 210, but it mostly stayed around 200. It's also nice and cool this morning and not hot and humid.

I've got another 16" fan I picked up at Autozone for another project I could try. It was the biggest one they sold. I think it's a Perma-Cool.

Are ~200* temps OK/Normal at the water neck or is it too high? If they are OK, then I fear I have a starter that's giving under the heat.

Starter OR the starter cable is not big enough.

my 400 runs at 170 deg down the road with a 160 stat and will climb to 180-200 if idling and not moving on a hot day. I have a flex fan and a decent shroud and I think a 3 core radiator, maybe 2 (can't remember) Also that shroud is real trick but its possible its restricting ram airflow from the front

Thanks for the replies and comments on the shroud smile.gif

I think what I may do is the following as my biggest complaint is not starting while hot:

Use a Ford solenoid on the fenderwell and eliminate the standard solenoid.

See the flat areas on the sides of the shroud that angle toward the radiator? I think I'm going to add some one way blow through holes for flow during cruising. If I add some decent sized (2"x4") holes down those sides with a medium stiffness rubber or leather flap, the fan will pull the rubber against the shroud to seal it, but at cruising speeds the ram air will push the rubber away and have another spot to go through.

I may also just go back to the stock wind tunnel fan shroud and find a reverse rotation mechanical fan if I can't get these temps where I'd like to see them.

Use a Ford solenoid on the fenderwell and eliminate the standard solenoid.

You can't eliminate the GM solenoid, it is an integral part of the starter. You can provide it with more current by using a Ford relay and improve the hot starting.

I've used the 2-speed Taurus fan in several installations with great results. The latest was a Datsun 240Z with a blown 355 Chevy and he was very pumped about it. I wire them for 2-speed operation, and the low speed seems to cover all but the most extreme situations.

http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=34361&highlight=taurus

Brian, I built a shroud almost identical to yours but I am using a fan from a taurus. Its a 2 speed. I have it hooked up on high right now and it pulls air like crazy.I have absolutely no cooling problems now