Highway cooling issue

[nawlins-tim]

recently finished a small block malibu wagon project. Went through the motor thoroughly with ALL new parts. Now the motor runs strong and cools well in normal street driving and if I leave my electric fan on all the time , even 100* New Orleans weather, the motor will stay at 180. But on the highway I figure I wouldnt need the radiator fan but I do. Without the fan on it will climb to 205* at least. Im thinking i'm loosing air around the sides of the radiator.( Rad is also a new aluminum 2 row)
I'm looking for some pics of the factory core support to radiator seal that was originally on the Malibu's and Elco's and i'm sure others too. Clear pics would me nice and If anyone has a pair of those flaps that are in useable shape maybe I could buy them and remake a set with the dimensions of your originals.

 

[pontiacgp]

205 is nothing to worry about, plus it's a new engine so you can expect it to run a bit hotter than it will once everything is seated and broken in.

 

[Longroof79]

Are you running an air deflector under your core support?

 

[nawlins-tim]

Got the air deflector and the motor has probably at least 300 miles on it. But isn't it odd for the motor to warm up at 60 mph? With the fans ON and going 60mph the motor cools down right away.

 

[pontiacgp]

205 isn't hot, it's a good temp for highway speeds. At highways speeds the fan being on can actually cause a blockage of air and cause the car to run hotter than with the fans off. I have a thermal switch that does not turn the fans on till 210. Corvette computer turns the fans on at 228 and 94 Firebirds turned their fans on at 230

 

[CWPottenger]

I agree 205 is not a bad temp. Especially if it stabilizes.

 

[williamattop]

carbed or fuel injected? Aluminium heads?

 

[-83MONTESS-]

What kind of rpm are you turning at 60mph? My Cummins does something similiar but my issue is caused by 4.10s lol

 

[pontiacgp]

Here is a picture of Bonnewagon's dash with the stock gauges, you'll notice the temperature gauge warning section is close to 260 so why all the concern about a 205 reading

 

[nawlins-tim]

The issue is that if I pull on to the highway with the motor at 180*,, in a matter of 5 mins doing 65 mph at 2200 or so rpm the temps Raise to 205. But cool down if I put the fan on..by the way its a carbed aluminum headed sbc.