The Stovebolt Site Forums The Shop Area The HiPo Shop New GM Crate Running Hot

I put a new GM crate 350/330HP in my 52 Burb...it has a 16" electric fan (puller)w/ shroud...it has AC(but I haven't run it...yet, but the condenser is mounted in front of a new "Rodney Red" aluminum radiator.The new motor has about 50 miles on it...
The engine runs hot at idle (200+) and cools down as the truck runs at highway speeds (180-190). The electric fan appears to be operating well,it cycles on at 180...appears to run all the time once the engine warms up)).After driving the truck for 10 miles the engine compartment is so hot you can't touch anything...Is this a new motor break-in issue or do I have other problems?

200* is not all that hot for an SBC..............new engines can run warmer than normal, but still...........

• Are you sure you got all the air out of the system?
  Did you do the old Hot-rodder trick and drill a hole in the t-stat so it could bleed air?
  What shape is your radiator in? Was is clear and clean inside?
  Are you using an aftermarket water pump?
  Belt tensions are good on W/P? No slippage?
  If using an old radiator, does it have it's full capacity, or have some of the tubes been pinched off during repairs?

200* is not too high for a triple-digit summer day in traffic.............with the A/C on, I would suspect it will be 15 deg. higher........
Maybe you need a second fan...........one in front of the condenser and one behind the radiator.
Or go back to a mechanical fan on the engine and an electric for when the "air" is on.........
What RPM's do you turn at highway speed?

what degree thermostat is in it? 160 or 180 is what i used to use in my 454 2wd blazer will open sooner do you have 195deg thermostat in it ? some stuff require a pusher and puller fan any room for a bigger fan.

Thanks for the replies...everything is brand new...the aluminum radiator was custom made for the application including the 16" fan and shroud. The truck has a TH400 auto with the original gauges...no tach (can only guess on RPM). Question: It's pretty tight in the engine compartment with the headers, AC, HEI, fan shroud, etc...should I consider venting the excess heat from the engine compartment?

I know where your coming from......I've been playing around with keeping my Blown Small Block cool.

I would first make sure your not running lean. Also check to make sure your mechanical and vacuum advance are giving you your desired total advance. Are you sure your charging system is giving the required voltage to the electric fan? The only reason I ask is because mine wasn't with my headlights and other items on so I had to upgrade to a PowerMaster Alternator. I also upgraded to an Aluminum high flow water pump with high flow thermostat from Stewart Pumps which lowered the temps about 10 degree's. I'm still looking for more cooling and will be yanking my 4-core desert cooler radiator in favor of a Griffin Aluminum unit pretty soon.

I just put a Walker Z-Cool radiator in my truck (350sbc w/350TH) and a 16" electric fan ... 190* thermostat and a temp sensor that turns the fan on at 190* and off at 170*.

The fan comes on at 190*, as expected, and after 20-30 seconds the temp goes down to around 150* and shuts off. I have AC with a large condenser in front of my radiator ... even with the AC on the temp NEVER goes over 190*