66 mustang with 86 5.0
 

I have a 66 mustang with an 86 high5.0 output. Any kme know any cooling specs? What's the average temp an 86 gt runs at? I have a 3 core aluminum radiator, stock for a 289 v8 and I have 2 fans, 1 before and 1 after the radiator. All blowing from out to in. I'm running around 210 degrees F. Is that normal for an 86 gt? Any suggestions to keep the temp down? I'm looking to hit an average of 190F.

The point here is, the engine temperature will always reach a higher temp. than the thermostat's rating. Now, we need to know that rating in your case. The prevailing climate where you live will also influence running temp. 210 degrees is commonly acceptable in ANY engine. If the thermostat is rated at 190, it will begin to open when the eng. coolant reaches 190; then some juice will flow to the radiator and back. The temp. to which the eng. climbs after that depends on many things: how much air is flowing through the radiator, how hard the eng is working, the outside air temp., the condition of the eng. coolant passages. The thermostat will remain open until the eng is stopped and cools down. While cooling, the thermostat will slowly close all the way, waiting to start ov er again.

Does that help you?

just get a 170* thermostat if you want to run cooler. I'm assuming you have a 190*. also helps to completely get all the air out of the system and have a proper coolant overflow setup.

Dont run too low of a tstat on an efi engine because ect temp is a big factor in how much fuel the ecu adds.I guess I should ask this question though since its a 66 were talking about.Is it efi or are you still carbed??If efi,I would either keep the tstat youve got now or switch to a 180° piece.When coolant temps get below 180°,in a efi app,the ecu is gonna run a richer fuel mixture and if you get down to the 160° range,it can actually cause the ecu to go into open loop mode and remain there vs switching to closed loop mode.If it hits 210° at its highest and drops back down by 10-15°,I'd say you're ok,but if thats its lowest temp and it climbs up by 10-15+°,then I would try a 180° tstat and that should satisfy things.Some of the aftermarket electric fans arent all that good at cooling the 302HO,but that normally doesnt cause an issue until you start adding heads,intake, etc.Im sure you're already aware to be very careful about what parts you do add,since the 86 came with no valve reliefs in the pistons & a camshaft is a no no if youre running the stock SD efi with no maf sensor?
The 86-93 Foxbodys did seem to mind whether the factory fan shrouding was in place as far as how well they cooled,but that shouldn't be too much of a factor on your setup since its a stock setup and not heavily modified.Of course, as usual,Im assuming here about any mods??

I'll stop for now until I hear back as to which system youre running,efi or carb.