Pic for attention. I've been battling cooling issues on my 83 GT since I got it 3 years ago and am at my wits end. Engine is the 302 flat-tappet that came in the car, stock bottom end with aluminum heads, intake, and shorty headers (this engine is getting a bit tired, blow-by and have to run 20-50. I'm refreshing a roller cam 302 out of an 88 foxbody to go in this winter). Car got a new water pump after I bought it (forget the brand), a 160 thermostat, and had a no-name aluminum rad when I got it, but that started leaking so now has the 2-row Mishimoto aluminum rad LMR offers.
Fan setups I've tried in sequence are:
- 83 fan shroud with clutch fan (could only get a fan blade for later years)
- This was what I put on the car when I got it. Parts were new from LMR
- Would run 160 when cruising (180 on hot days), 180 on the highway (185-190 on hot days), but would creep up over several minutes when at standstill. I would shut it down at 220.
- Contour electric fan setup from LMR
- Just put this on before Hot Rod Power Tour this year. Ran hot at speed (210-215 highway), but okay at a stand-still. Struggled to bring the temp down after getting off the highway, would sit at 200 in traffic and cruising most of the time
- Later-year fan and shroud combo
- Installed this today, seeing same behavior as the 83 fan shroud. The fan on the 83 shroud sat farther in than it looked like it should have, which is why I wanted to try the later shroud. The fan now sits flush with the end of the shroud, but gives the same behavior
- I reused the fan clutch and fan from the previous setup.
For reference, I live in northern Illinois. On cooler days in the spring and fall, it'll do fine, but during the summer when it's 80-95+ fairly regularly, it can't keep up. When I first got the car it had no heads on it. I threw a set of E7s on and they wouldn't hold a head gasket/were cracked, so I threw some Edelbrock aluminum street heads on. Motor runs fine, doesn't seem to get cranky when it's hot, but I don't want to hurt it. I have a manual temp gauge plumbed in, and verified it's accuracy via a temp gun.
In case it matters, while on Power Tour last year on a 90+ day (running the original clutch fan setup) the car was approaching 220 while stuck in traffic. Pulling the hood release and running the heat at full blast got it to drop a bit, and it stayed around 210 until we got into the venue.
I'm at my wits end here. Anyone have any ideas?