OK, just got the Bird running, rebuilt engine, 68, 350 engine. th350 tranny.. I suppose I could do some searching but thought I would ask..
what has worked best for people, still have the stock thin radiator.. thinking I need to get bigger radiator and add a tranny cooler. does that sound about right... what ya all think.. thanks Tracy

I would recommend doing some searching.

It's probably the #1 problem topic for most of us as these cars always seem to run hot.

Besides the normal issues of failed radiator caps, low, bad or no coolant in the mix and air pockets, you will find FGF specific info on water pumps and diverter plates, types of radiators (alum, brass, 3-core, 4 core...) and whether or not a supplimentary tranny cooler is a good idea (Rodney Red told me no).

I had read enough info on here and the PY boards while working on getting my car back on the road to decide this was not an area to skimp. I went with a full Rodney Red aluminum FGF radiator (not cheap) and new cast impeller water pump with the divider plate clearance minimized.

I was just going to say "here we go again"! This must be the all time most mentioned topic on this site hands down. To bad we couldn't pull all the threads together and make one "HOT" topic. Get it, hot topic. Sorry. If you do a search you could probably spend an entire day reading opinions and suggestions etc...

yea, that would be great to through some troubleshooting threads together, and catorize them, (I know I spelled that word wrong)..I use another site for my diesel chevy that has put some threads together pretty good..
anyway, I just rebuilt this engine and did put in new divider plates, and impeller.. but I will probally go with new rad, I I don't understand why R/R said no on the tranny cooler. I do have all new coolant Plus water wetter and new cap on..

I asked R/R about going with the stick shift radiator and a tranny cooler. He said his radiators work well enough that there would really be no need for that and I should just go with the regular radiator for an auto trans car and run the tranny lines like OEM.

OK, driving down the freeway today, outside temp around 75 deg. and driving around 55 to 75 temp about 200 to 210 deg.
I was wondering about putting in a electric fan and putting it on a toggle switch, so when you get up to about 200, turn it on till it cools down, might come in handy when shutting engine off and letting it run till rad. cools down. maybe put on timer..
otherwise I will look into R/R radiator and see if I can swing it..
So Salmon38, with the new rad. how is your car handling the heat now?

I've had a small setback so I have not really driven the car a lot up to this point after getting running again. But it sure runs cool idling for long periods in the garage.

I bought a $600 alum rad a few years back (still in the car) I was completely dissapointed after installing it as it did not drop the temp one degree. After reading the article in last month's HPP come to find out alum DOES NOT dissapate(s) heat any faster or better than copper/brass. According to the article just the opposite is true. I have since rounded up an OEM 4 core w/ Harrison tanks and will be installing that soon as IMO the original type look much better. My alum rad has already been sold as soon as I get out and shipped...

I just went through this. I had an original 3 core radiator. I had temps of 220 after getting the car idle for 15 - 20 minutes. After I shut the car off I it went to temps as high as 230- 250. I changed to an aluminum 1 inch 2 core radiator using 20% coolant, a bottle and a half of Water Wetter and distilled water. I'm getting idle and running temps of 155-160 now. So just because HPP says aluminum is not better than brass doesn’t mean you should not consider an aluminum rad.

Consider price. Times have changed. I bought an aluminum direct fit radiator with 1 inch core from Summit for 160.00. Jegs has them too. It has better flow than a 4 core brass rad and costs less. The brass replacement rad would have cost 300.00 plus over size shipping.

Fit:
Obviously Aluminums are not original, so if that's an issue, then start saving your money. Also, I had to make some changes to the fan shroud to get it to fit the rad.

There are many other things you can do as mentioned by the others, but I would look at your radiator then go to things like the divider plate distance.

BTW, you probably already know this but, you should test your fluid's boiling point and your thermostat operation before you check your radiator.

Check out my recent thread "250 degrees in 15 minutes". There were a lot of suggestions and articles offered to assit with this kind of issue.

Installing a 7 blade clutch fan solved my problem & that's after the water pump mods and installing filler plates.

so had anyone tried electric fan?

Ok, from research of overheating, I should check the top rad. hose to see how high it is, above the rad. cap or not, looks like where it comes off thermostat it could be a little higher then cap. Well looks like I can try cutting a little hose off and see what happens, maybe also change out thermostat from 190 i think to 180 degree. I think also getting rid of the flex fan that is on it and find a oem fan and clutch..

The flex fan is probably a major contributor.

Changed out the heavy duty OEM clutch fan for one of those fancy aftermarket flex fans on my 1st Mustang after the OEM fan threw a blade. The car ran cool before and overheated after. Got a new HD fan from Ford and never looked at those flex fans again.

I went with a stock 19 inch seven blade clutch fan.

I also advanced my timing which helped and had my baffles in. I used a 180 thermostat at first, but then removed it just to eliminate any possibility that it wasn't working right. I never re-installed it.

Cooling issues are almost never just one thing. You have to have most things dialed in for the temp to stay at normal operating temp.

I've read quite a bit on electric fans and in the end, the only advantage is cooling when the engine is off. They won’t help you when used in addition to a stock fan while the engine is running. There's only so much air you can put through a radiator before it becomes in efficient. Stock fans work fine. Also, electric fans use power, which makes the alternator run harder, which takes power away from the engine, so in the end the extra money may not be worth the gain. Here's an article on it. There are others out there.

http://www.aaroncake.net/rx-7/efanmyth.htm

So Ive been thinking about changine the timing, Im running at 9 btdc right now, and I do have a different cam in just a little bigger not much. I will look for a different fan and clutch tomorrow. not sure what to set the timing at..

I started with 12 and am trying 14. So far no pinging and the temp may have gone down a bit. I haven't had time to drive it extensively, so can't say for sure if it helped with the temp.

It's really different per engine. If you have a cam with a higher lift and duration than standard, you may need more than 9. Call your cam company and ask them where to start given your cam and engine components. Otherwise you can do what Brian said and start with 12 and keep advancing by two or so until it starts to ping under load, then back off a couple.

Did you build the engine? Do you know what Cam is in it? a friend here in town has had 3 yrs of running hot...he bought a rebuilt crate Pontiac 400 8 yrs ago, finally got it in the car 3 yrs ago...since then it always ran hot ,he tried everything, thermostats , fillers , big radiator, rebuilt tranny, etc ,etc...two weeks ago he bought and installed a stock cam...runs perfect now ...190F on our cruise to Corpus in 90F weather...

Yes, I rebuilt the engine, I had emailed Edlebrock for a mild performance package, performer plus cam 2157, performer intake 2156, and edlebrock 650 carb 1806. runs very well soo far.
today I picked up a new oem fan clutch, 19 inch fan from junk yard off 78 monte carlo. installing a 180 thermostat, and cutting down the top rad hose off thermostate housing, looks like it is a little higher than rad cap.. than mess with timeing a little.

I don't know what diameter the OEM Firebird fans are - is the Monte Carlo fan the same size?

If the diameter of the fan did not matter to you, it suggests that you might not have an OEM fan shroud mounted? That is going to help a lot also.

OEM FGF fans are 19" wide from tip to tip. I've had all the usual hot issues as everyone else. I tracked down, bought and installed every filler panel, mastic rubber fillers and the list goes on and on and until I installed an OEM 19" clutch fan that is when ALL of my hot issues went away. And for good measure I added one bottle of Royal Purple Water Wetter and bang, NO more hot issues. Now, I am replacing my $600 alum rad with an OEM w/Harrison tanks and hopefully still be ok. The alum rad I am replacing has already been sold...

ok, installed the new fan clutch and the 19" fan I got off a 78 monte carlo, replaced the thermostat which was a 180 and the new one is a 180 thought I had a 190 in it.. the timing was off, around 6 degrees and so I put it at 12, also had a vacuum gauge hooked up and looked like a good place for timing... also lowered the top rad hose at thermostat housing so it is lower then rad cap. the 19" fan seems to fit in shroud a little better. fan is just barely inside the shroud. at idle in the garage temp was staying around 180 - 185 deg. will have to wait till the rain is gone to take out for a spin........ thanks for the help, will let you know how this works, I also am running water wetter in system..

I went through this recently. Turned out my radiator was just shot. I think I have MOST of the fillers and things that came with the car. It turns out my old 4 core brass radiator was shot. I put in a new aluminum radiator from Superior radiators in Michigan ($200) and my temps dropped from 215-230F while cruising to 185F. How hot do you think is too hot when you shut the car off? Is this basically unavoidable? I drove the car for about 100 miles at 80 mph the whole way (probably running around 3,000 rpm's the whole time...my tach wire came loose so I don't know exactly) and never got above 190...great! Then i shut the car off and it went up to 225 or so. Is this a problem? Of course it started a bit hard then, but will this hurt the motor at all? I am still getting some pinging under certain driving conditions, mostly after the car warms up and under load (1/2 throttle or so). I'm not sure if it has more to do with my timing or the fact that I'm using 6X heads from a 350 on a 455 engine. How concerned should I be with the pinging? I can basically "control" it by throttle position and thus avoid it, but I do want to get it taken care of at some point. What's the best way to go about diagnosing this? Sorry this got a bit off topic for this thread.

The engine will hot soak after you shut it off, it's normal and nothing you can do unless you want to put in an electric fan with a timer...a waste I think. As far as the pinging you either need to run a higher octane gas and if you are already you need to look at the base timing and adjust down, start with 1 or 2 degrees and test drive. In any event, pinging is NOT good for your motor.

OK, got a break in the rain, brove to town on backroads 40mph and temp didnt go over 180 and came home on freeway at 70 mph and temp didnt go over 190.. so maybe got it.. will find out on hotter day.....

just took car for another spin down the freeway, temp stayed around 190, then started getting it on a little, up to around 85mph, and fast starts, and temp went up to 200 to 205, and when I got home and idled in the driveway a little bit, temp went back down to 190 and holding.
still thinking of maybe going to a 3 core rad or try different fan shroud....

sunday driving back from Corpus in the sun mine stayed at 205F, got in clouds...200F and it was close to 90F out...

and mine hasnt over heated in the summer last 8 yrs...sometimes got up to 210 after a 85-90 run and slow down to stop , but after I get going again it goes to 200-205 at 45-50 after that

What are you using for a rad now? I looked back in this thread and didn't see it so sorry. Nonetheless, you should be using a 4 core with a 400...

got the original i believe 1 or 2 core, probally 2 core.. and running a 350 engine..

I have a 350 with a 4 core OEM style rad and tranny cooler. It gets hot but I've never overheated.

Closest I got to overheating was waiting in the drive-through line at the local Tim Hortons on a hot summer day.

MMMMmmm. Canadian doughnuts....

Tim Hortons, sounds funny to hear that. In the Buffalo area that is all you see on every corner! LOL

You mentioned a one or two core rad. That would only be the case if you have an aftermarket rad. If its original on a standard 68 350 two barrel, then it's prabably a 3 core.

I bet if you changed to a 4 core or an aluminum with a 1 inch core you would drop it more.

190 is not too bad though. Your thermostate won't even let the water fully flow until 180, so 10 more degrees means your probably close now, you just need to dial it in a bit more. Maybe the radiator change will do it.