Engine running hot in traffic

[1983calais]

Hello everyone. I have a 327 in my MCSS. I built it last winter when I did almost everything to the car but paint. The 327 is bored .30 over, roller cam, roller rockers, 492 GM angle plug heads, and Holley sniper EFI. I put a brand new aluminum 3 core radiator in the car when I put it all together also. When I cruise on the highway or open roads it runs nice and cool. I forgot to mention I have a 160 degree thermostat in it. I had a 180 in it but ran to warm when I would drive in town and traffic so I went to 160. When I get in town and stop and go traffic it gets up to 200 or so from the 160 at cruising. Anyone know why this is? I also put the stock fan and clutch on it from the 305. Fan clutch works as it should also. Thanks all.

 

[pontiacgp]

200 is not hot but I think 160 is too cool

 

[1983calais]

Well i thought 160 is to cool also but with the 180 stat in it it would always run around 190 to 200 and in traffic it would get to 210 sometimes. 160 was the only one Oreilly had that day and I thought I would try it.

 

[pontiacgp]

That's good operating temps with the 180. I don't worry until the temp gets over 225 to 230

 

[1983calais]

the factory 305 ran right at 180 all the time. Cruising and in traffic with the stock radiator. I was just trying to keep it around that. Also running around 190 - 200 degrees on a hot summer day in a black car gets a little warm in the captains chair!

 

[olds307 and 403]

I assume a 5 blade fan? Factory fan shroud? I would get a 6 or 7 blade fan and heavy duty clutch or the GM 4 blade fixed fan. I personally like the large 2 core rads over the 3 core.

 

[MrSony]

I got a dinky $115 radiator and the v6 5 blade fan with a new clutch, thermal type. No shroud, runs at 195 dead. 195 'stat too. Something's not right. Coolant not staying in the radiator long enough? Kinda tired, mind not all together yet. Just a guess.

 

[Turbolq4]

I'm betting that the fan clutch doesn't engage until close to 200*. Take that thing off and put a pair of intrepid fans and a relay on it if you want it to run cooler.

 

[olds307 and 403]

What amperage do the Intrepid fans pull? I can tell you my Stratus fans have fried many relays and thermal switches. I think one 40 amp relay isn't enough. The fans are cheap at the junk yard, the controllers are not. I have had 0 luck with the cheap and mid priced controllers.

 

[Longroof79]

From what I've read about using electric fans. You need one relay per fan unit. Dual fans=dual relays.

I'm running a 7-blade fan, Hayden fan clutch, stock shroud, and 3-core rad. Around town, it doesn't go past 190 degrees. This engine never ran hot. I had used a 18" 7-blade flex fan before this and it always ran cool in the hottest days. The noise of the flex fan drove me crazy, but it did it's job well.