So after all the improvements I put in my 68' still runs hot, better than before but still hot. I took it out to the carshow at the front range airport on Saturday (good show!). On the way down to the show at 6:30am (air temp of maybe 65 deg) I could run at about 70-75 before the temp exceeded 220 which is a slight improvement. On the way back in the afternoon I had to keep it under 60 to keep the temp under 220 degrees. Granted the air temp in the afternoon was in the 90s but 60 on the highway! Is this typical of 68 400?
I’d think this car would run cooler after all the tweaks I have done. The only things I can think of to try now are swapping the current nearly new brass/copper 4-core rad for a 4-core aluminum rad and cutting the hood intakes out. Or maybe it is too much to expect to be able to do more than 60 on the highway on a hot day without overheating? The aluminum radiators seem like they should be more efficient. They have something like 18 fins per square inch vs 12 with my current brass rad and I believe they hold more fluid so more thermal mass to transfer heat out of the engine. But they are spendy!! ($400 bucks from Ames). Does anyone have experience with the aluminum rads? Do they help substantially or not so much? Any other tweaks anyone can think of that might help with the temp issue? So far I have done the following:
New 4-core rad. Swapped out the 195 tstat for a 180 tstat Replaced the water pump with a 11-bolt short shaft Replaced the fan with a 19.5” flex fan Flushed the block and rad and replaced the fluid with the correct mixture. Adjusted the fan position. The fan isn’t quite half in/half out but it is close. I need a 3.25” spacer which isn’t stock and kinda tough to find.
