[RivNut]

5 blades is correct. You'll also notice that they're not placed symetrically around the hub of the fan.

One thing you could do that no one has mentioned yet is to get yourself a mechanical temperature gauge and put the sender in place of the OE sender that's in there now. This will give you an actual temperature reading rather than just a "hot" light.

Make sure that the fins on your radiator AND the a/c condenser haven't been flattened out by some guy with a high pressure washer. If they're bent over and there's no place for the air to flow past the cooling fins, there's no cooling. You'll have to pull the radiator to check this, but it would be worth your time to make sure there are sufficient air passages in both the condenser and the radiator.

[Airy Cat]

I have had at least 6 1963 - 1965 Rivieras and they all ran hot because the radiator does not have enough surface area. It's too small. The best radiator I found for it was that Desert Cooler from Phoenix. Also, Rivieras need 100 octane fuel. That crap they call premium fuel is only 91 or 92 octane and that will make your car run hotter. I can't even start my bar-b-cue on that crap. I run 100LL Av gas in my 60s Buicks.

[Jim_Cannon]

Joe-
My '63 has 5 blades. I don't know what a '65 has (but I suspect it is the same).

I forgot to put in my previous post: your new fan clutch MUST have the small coil spring on the front face. If it does not, take it back and exchange it for the more expensive one that does. I can provide part numbers if you need them.

Use torque values in the shop manual to get it right. Use same nuts, bolts, studs, washers as you had on the old fan.

[joeinbcs]

Thanks for all the help on my overheating problem. I replaced the fan clutch (with the small coil on the face), and took it to a car club meeting last night. No problems so far.
I'm thinking that it might not be a bad idea to take it to a radiator shop and get an opinion on whether I need to have the radiator cored...before the hot light comes on again.
I won't be driving the car often, and don't plan on any long trips, but I still want it to be sorted out and capable. Thanks again to all for your interest and advice. Joe

[RivNut]

Joe,

It might be less expensive and just as effective to have the radiator shop sweat the tanks off, ROD out the tubes, straighten the fins, and reattach the tanks. I did that to the radiator that's in my '64 and I've never had a problem with it. It was actually an extra I had done when I did the one for my '63. You should have seen the one it replaced. We took the tanks off and the tubes were only about half the size they should have been. Besides some fins being bent, lots of fins were just plain missing. What a difference a "clean" system makes.

When the guys who owned these cars originally were driving them, they weren't adding 4 core radiators and electric fans. They were new, clean inside, and worked well. I'm sure that the engineers at Buick put a lot of time and study into what it took to keep this engine cool in all weather conditions.

I don't operate as well either as I did in 1965. Lot's of difference between an 18 year old body and a 62 year old body. My doctor and my mechanic both know me on a first name basis and cash my checks regularly.

Ed

[Jim_Cannon]

I know several guys in Texas that have put in new 3-row radiator cores and still had overheat problems in the summer with A/C on.

It is on that basis that I recommend you go to 4 rows if you are putting in a new core.

I think the R-134A puts a higher heat load on the cooling system than R-12 did.

As mentioned by others, it may also be the lower octane gas used today.

[musclecarfan65]

hmmm ... maybe your carburetor/engine runs too "lean"? most of the times the gas which does not burn works as coolant by carrying out high temperatures.
that's why it's better to run more on the "rich" side than on the "lean" side.
as far as i know that is what engine engineers also normally did when developing carburated engines.
this is based also on an experience a friend of mine made. he bought a completely restored 70' HEMI 'cuda. after driving some kilometer´s the engine was broken (valves, pistons, block, etc.) because the cylinder head gasket was burned away. they found out that the engine was running too hot because the 2 carburetors where way too lean ... the dutch restorer did not test the adjustement of the carbs :-( ... very expensive

[TexRiv_63]

I installed a Vintage Air AC system in my 63 to replace the non-working factory air setup. everything on the car was stock with a recently rebuilt 3-row radiator and a retrofitted overflow tank. I was all ready to go to an aluminum radiator, electric fans, 160 stat, etc. When I talked to the shop that sold me the VA system they said not to change a thing, the factory AC setup was more than adequate to handle the heat. They said what has been already stated by others, obviously all the components have to be in good shape, clean, and working correctly. A shroud is very important and you should add insulation around its edges to keep underhood air from being drawn in. The front-to-back fan placement in the shroud is also very important, the blades should be half in and half out of the shroud opening. (This can be screwed up by having the wrong water pump installed.) I took their advice and installed the system that way and NEVER had overheating problems in 3 years of Texas driving with the AC blasting. One thing about the nailheads, they do run hot, my mechanical gauge showed 210 to 230 in the worst of summer but it never boiled. Full disclosure - my car was not a daily driver, usually 2 to 3 times a week, both freeway and local roads. I did always worry about getting stuck in freeway traffic jam, the ultimate cooling sysytem test, but never had it happen.
One other thing - if your fan clutch is working properly you should hear that fan roaring when you take off after sitting at a light in summer traffic. The roar will die out in a few minutes as the engine cools a little and the clutch loosens up. If you don't hear the roar your clutch is not right.

Good luck!