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Im having issues with the car running hotter than I'd like on highway. I have a th350, 373s, and a 305 with lt4 hot cam. Recently my stock rad was leaking so i installed a 2 1" row northern aluminum rad. I burped the system using a spilless funnel. It runs a lot cooler around town but on the highway it still creeps up to 225-230 on an aftermarket gauge with the sender mounted in the intake manifold. I have a 180 TSTAT and stock single electric fan on a manual switch.
My car does about 4000 when cruising at speed on the highway and when I run it hard I may be between 5000-6000 rpms for bursts at top seed.
What temp should I expect to run at on the highway with my setup? How do i tell if my lower hose is collapsing or if my water pump isn't up to snuff?
I have the air dam installed but only the large center flap.
I have always run a non recirculating catch can. I don't think this is ideal so tonight I connected the hose to the base of the can and added a hose to vent the top. Haven't test drove it yet but doubt this will fix my issue.
Here's a few pics of my air dam and shrouding. It looks like I'm missing quite a few pieces but I'm not sure if they are critical. I took the shroud around the hood latch off for the pics.
Last edited by tommy z-28; 09-15-2015 at 09:45 PM.
How's your chin look? I've noticed with my car that at high speeds it bends down and gets in the way of the air dam. But my car rides 2 -3 inches lower than yours and that could factory into it for me.
It looks like the air is going around or above the radiator, you need to add the pieces at the top to force the air through the rad. You could try making some pieces out of cardboard to see if it helps.
Looks like on both sides of the rad, the pieces that should make the whole area in front of the rad into a box, are both missing. Should be basically just a flat sheet of plastic separating the area in front of the rad from the area where the headlights are, on each side. You can make that up out of almost anything that air can't go through and that you can hold in place with tie-wraps, screws, whatever.
Might want to consider gluing a piece of pipe wrap foam insulation to the underside of the hood, such that it lines up with the core support and seals the hood to the rad.
As ex- said, make sure that ALL the air that comes up in front of the rad, has to go THROUGH the rad to get into the underhood area.
Then there's the matter of hot air under the hood getting back OUT... a common mistake people make is to remove the strip of sealing material from the back of the hood. Ideally you want the underhood volume to be a LOW pressure zone; since air flows from a zone of HIGH pressure (front of the rad hopefully) INTO a zone of LOW pressure (under the hood), you don't want to do ANYTHING that could raise the underhood pressure. But de-insulating the hood back there does EXACTLY that, at speed: when going fast (above 40 or so), the base of the windshield is one of the HIGHEST pressure zones on the whole car. You DO NOT want to connect that zone to the underhood area!!! That does NOT "let out the heat", as you will so often hear in the McDonalds parking lot on Fri night from all the spank-offs; rather, it PREVENTS proper air flow through the rad, by DECREASING the pressure differential across it.
I have heard quite a lot that that air dam and those plastic pieces behind the bumper before the radiator are pretty important for cooling, but I'm running right around 200° sometimes a little hotter and I'm missing all of it. I bought a temp gun from harbor freight to confirm because my aftermarket gauge cluster was doing weird things and it was giving me anywhere from 190-200 depending on temperature and how long it was running. I have replaced everything except the head gaskets. So I'm not quite sure why I'm running so cool if I'm missing those pieces if they are so important, so for me personally, not having those isn't making me run hot. I live in Phoenix too so we have mostly been 100+° until the last 2 weeks. I have read if your AFR is off that can make temps rise up. You said you swapped the cam and I have read on here that a tune is pretty much required if you don't run the stock cam.
09-09-2015, 08:58 PM
