operating temp

jsf515 · 10-08-2005, 08:30 AM

just curious what kinda operating temps most nailheads run at. i've got my 401 installed back in my lesabre and it seems to be running hot; ~225 after 25 or so minutes of idle. the radiator seems to be flowing well, and pretty much even (no cold spots anywhere to indicate blocked flow).

i don't recall what temp thermostat i put in, but i was thinking of taking a look and going with a cooler one. mostly i was curious what was TOO hot. above 200 seems high to me.

thanks for any help. josh

Ed Raner · 10-09-2005, 09:04 PM

My 401 runs right at 190-195 with a 192 degree thermostat. Make sure of a couple of things. If the car is airconditioned, make sure you have a good shroud that's forcing all the air to go through the radiator. A couple of fellow nailheaders have found that some of the factory setups have the fan too far from the radiator. They've spaced their fans about 1" from the radiator and have been happy ever since. If you do move your fan that close, make sure your motor mounts are good and solid.

Ed

jsf515 · 10-10-2005, 05:17 AM

thanls for the suggestion. i'll check the space between the fan and radiator. another fellow nailheader told me he's got an external electric fan also mounted. i guess that would be another option too.

josh

**heidigirl** · 10-10-2005, 06:45 AM

if you have got a shroud installed, be careful of the fan position. the blades should extend outside of the shroud roughly 30-50 percent. if it is set too deep, the fan will just trap the air inside the shroud.

also, i'm not convicnced there is a problem. afterall, you did idle the engine for 25 minutes, so there is no reason not to expect the temperature to climb under that condition. before doing any additional work to the car, why don't you repeat the idle sequence with a portable house fan blowing through the front of the radiator?

**sicksteve** · 10-12-2005, 08:26 PM

I know most people suggest getting a "puller" elelctric fan on the engine side, but would an electric "pusher" fan on the grille-side of the radiator also help? I have a huge flex fan, and I don't know if I have room for the fan shrould (which probably is the most important element.)Is it correct what someone just mentioned that the stock fan blades should be outside (not inside)the fan shroud area?

I've never had any overheating problems in my '63 Riv with a new handmade radiator and full flushing. My '70 Torornado GT W-34 455 overheated all the time in the CA desert depite similar measures (trans. cooler, flex fan, shrould).

Appreciate any help!

Ed Raner · 10-12-2005, 09:06 PM

I read some test results somewhere that said the best fans were the stock thermo-clutch fans. The flex fan will flatten out as designed (reductioin of hp demands) and even though you're traveling fast enough to force air throught the radiator, the fan creates a moving wall and air builds up in front of it and no more air can move through the radiator.

I don't know about the fan outside the shroud business. Until my shroud disenegrated, I thought the fan was pretty much right inside of it, the tips of the blades were at the point where the shroud had it's smallest diameter. I've only read that here that one time. I would think if it were that big of a deal, I would have run across it somewhere else too.

Ed

jsf515 · 10-13-2005, 10:13 AM

came across this informative article thanks to a thread on the HAMB.

http://www.hotrod.com/techarticles/54879/index.html

haven't had a chance to spend too much time on my ride, but i think the fan needs to be spaced a bit closer to the radiator. any suggestions on how to do this??

Ed Raner · 10-13-2005, 02:01 PM

You can buy actual fan spacers. They come in a large assortment of lengths. They're self centering and allow for any bolt circle. If you choose to run a mechanical fan, depending on whether or not it had the thermal clutch might depend on where you want to put the spacer. I think the thermal clutch is designed to be activated my the temperatur of the air coming through the radiator. You would probably want the spacer behind the clutch but that's going to put a large rotating mass at the end of a small spacer. That could create some harmonic balance problems. I'll read the article you attached more closely and see what else I can come up with.

Ed