440 H.P. 383 Flat Top Stroker w/ Speed Demon Carb, Polished Air Gap Manifold & Vortec Heads Ok I have One. Just in stalled my 383, & the problen that I am having is that I can NOT keep a level temp of 180. Only at idle can I reach this. Eveything is new. The radiator, water pump and heater hoses. Bought a run of the mill thermostat & thought is was bad. Next one was a step up & still did it. Now a Robert Shaw 180 degree thermostat in installed & still gets a drop in temp. when driving in town @ only 35 m.p.h. Now that is about 50 degrees out side and rapidly droping. I have 3/4 of the radiator blocked off now and STILLS drops to 120! The hood is off but, this shouldnt be a factor, should it........??
Yes the hood being off can play a major role in that situation. I ran my impala with the hood off after I put the new motor in and it was running at 120-130 when driving and between 170-180 while at idle. But when I put my hood back on it runs at 180 all day long unless I am sitting still for a long time then it jumps up about 10 degrees. But when I was on the hiway today I noticed that I was running at 160 but it is 43 degrees here today and I have yet to put anything in front of the radiator.
84inark You might check to make sure that the block and radiator are completly full. When you are setting at idle the block would be full to where the temp sender is covered with fluid but when you speed the engine up it could pull the fluid level down enough to uncover the sender. The sender has to have fluid covering it to function properly. Oldcoot
With your set up...I wouldn't worry about it. The cooler ambient airflow into the engine gives you a denser charge and slightly increases HP.
