Recently added a vintage air AC system, I know the condenser will block some air, but the car is running hot at highway speeds now. Previously, the fan would pull it down from 195+ to 180 in 30 seconds probably, (Taurus e-fan), now it creeps up to 200+ on the highway (70 mph or so) but when I slow down (50 or so) it'll catch up a bit and hold around 190/195.

Only things that have changed recently are the AC system, a new radiator cap, and I swapped to shell rotella 15w40. I have all the OEM AC baffels in (x-panels and the gaurds around the radiator). Car is a 67 coupe, 400, 350 trans, 2.93 gear. Taurus e-fan shroud misses covering the whole radiator by about 1.5 inches on each side.

Any ideas?

Don't forget the AC condenser is radiating heat besides limiting airflow a bit. The electric fan is not really doing anything at highway speeds.
What crank and water pump pulleys and what radiator is in the car?

I agree the Fan is most likely blocking air flow at highway speeds, also do you have external trans cooler? no overdrive cranks those trans temps up and if only the radiator is cooling it, the temps keep climbing.

Im about to run an aux trans cooler.

I've always suspected the aerodynamics of the front end at highway speeds doesn't feed enough air to the radiator. My car has always run hot on the highway.

Condenser shouldn't radiate heat with the system off should it? Crank and water pump pulleys are stock for a 69 motor w/ AC, I checked the impeller gap before I put the water pump on and it was good. Radiator is a stock 4 core with internal trans cooler.

The e-fan shroud makes sense. I haven't driven it much at highway speeds since I rebuilt it so maybe I didn't notice that before. I just didn't think it would be an issue since it pulls almost 3000 CFM and really dropped temps quick beforehand. Looking around on the net it seems that the shallow shroud could be an issue itself, but all e-fans use a shallow shroud that I've seen.

Sucks that I just found this, we had a 6 hour road trip planned next week to a car show.

May have found a solution, I'll try it and see:

http://www.hotrod.com/how-to/engine/hppp-0802-pontiac-cooling-system-upgrade/

http://www.camaros.net/forums/showthread.php?t=208905&page=3

Add flaps to the shroud that can blow open at highway speeds.

Are you over reacting to the heating? A lot of our cars run over 200F.

Instead of running an electric pump and/or fan, why not run a high volume pump, and a 7-blade fan, either flex or clutch type, and a stock type shroud ?

http://www.jegs.com/i/Flex-a-lite/400/1818/10002/-1

http://www.amazon.com/Flex-lite-1818-Stainless-7-Blade/dp/B000CNHFOE

http://www.ebay.com/bhp/7-blade-fan

http://www.summitracing.com/parts/hda-27...givIaAhML8P8HAQ

http://www.summitracing.com/parts/hda-2797/overview/

http://www.amazon.com/dp/B000C3F3D4/?tag...sl_4qd7m89ttb_e

http://www.ebay.com/itm/Hayden-2797-Thermal-Fan-Clutch-/391117643399?hash=item5b106d9e87&vxp=mtr

Car should not run 25+ degrees over thermostat rating. Common problem to keep climbing at highway speeds. I seem to have conquered this issue with a 4 core brass copper radiator, 7 blade clutch fan and the Hayden heavy duty clutch, factory fan shroud and a smaller diameter water pump pulley.
This is driving in 90+ degrees AZ heat does not go over 185 on the highway, mind you I have 3.73 rear and I'm cruising at 3000+ rpm at 65 mph.
Electric pumps don't move the volume of water needed at highway speeds.

How far over 200 Bob? It hit around 205 on me last night before I turned off on a side road. It has never been over 190 on me before with that same setup.

I'd try the original fan/shroud setup if I had it. Wasn't on the car when I bought it though.

Being just up the road from you, I want to +1 on the stock style mech pump with the cast impeller, big radiator, OEM shroud and the OEM 19 inch 7 blade clutch fan. It works for me. And my 400 model issued block off plates, air dam, and side mastics are not installed yet. My car hardly ever exceeds the 185 degree setting of my thermostat.

On the other hand, my radiator IS a pricey aluminum unit from Rodney Red

I find that most of those who come here with cooling issues have electric fan setups.

It would appear that any of your changes caused the overheating, but you might want to consider "coincidence" and check some of the obvious things.
One easy thing to do is change your radiator cap back to the old
Take cap off and run car with heat on, making sure your coolant circulates inside the radiator (take a peek) and ensure you're getting heat
Hook up a vacuum gage on your manifold and observe the vacuum your getting (15+ and steady needle), making sure its not a head gasket (gage will show, - or maybe timing is way off). It all could cause overheating. Are you sure the radiator isn't plugged? Fan clutch working?

Do you have all the "fillers"? as you added AC, the original cars if AC or 400s came with fillers....3 sets ..rubber fillers on ea side at bottom of radiator, lower baffle, the x fillers at top ....on mine the rubber fillers one was missing , it made about 5 degrees by adding the one in....

Bjorn, do you have a pic of those installed? Mine was an original AC car and had the X panels. I made a set of filler panels to go all the way around the bottom and sides of the core support. I've also filled about every hole and crack on the front with insulation, testing to see if ti made a difference, nothing yet.

Only thing that seems to have helped so far was adding in the "trapdoors" to the fan shroud.

I do somewhere, but I lost my register of where all my firebird pictures were/are...only picture you would need is the rubber fillers ,as the X fillers you had...you most likely then also had the metal lower baffle.....I`ll look and see if I can find picture(s)...

stumbled across them fast....not sure they help much as my pictures aren't of the fillers really , only on how they were attached...hope they may help you

in the first picture you can see the plastic Chrysler headliner clip I used to fasten with, the third and fourth show the original clips I still had in the holes of the missing rubber filler (originally called "masticated"

Thanks, looks like I got it pretty close then. I used some leftover ABS plastic and cut it to fit.

ok, good deal

Think I found the root issue last night. After looking around all over OK and north TX for a good HE radiator a local shop was able to get one (Osborn Radiator in South OKC, guy is great). Figured I'd fire it up and see if there were any cold spots on the old one, let it get up to temp with the fan removed and ~190 or so a couple pinholes opened up right behind where the top of the fan would be. Guess since it only did this at temp and right behind the fan it just blew the fluid into vapor. I'd had that fan off at least 3 times and never saw this leak. I'm no expert but I'd never heard of one doing this, only leaking at higher temp then only overheating on the highway.

sounds like that could be it

Hopefully you found your problem, but if not....

I was curious if you had checked your timing recently and if you had the vacuum advanced hooked to the manifold vacuum. Retarded timing could cause some extra heat, but since the only thing you've changed is the AC unit I doubt this would be the cause of your problem. Also, as someone else stated, if you haven't checked the clearance from the water pump impellors to the water pump baffle, that's worth a ton of extra cooling.