Does the wrong fan clutch affect cooling ?

Will using a fan clutch off of a Buick 6 cylinder on a 470 BBB change the cooling capability of the BBB ? Should a heavy duty 455 clutch be used for the proper cooling results ? I have an aluminum radiator 2 rows 1 1/2" width each row 160* thermostat and a 17" 6 blade metal fan with a full radiator shroud and the fan is 1 1/2" from the radiator but used the 6 cyl. clutch that was on the engine I removed from the Regal. I'm not using the radiator cooler for the trans fluid but have a trans
fluid cooler mounted on the front of the radiator with the location in the middle of the radiator. Highway and driving around 30 mph the engine runs 180-195* but slow cruising 15-20 mph for more than 15 min. and the water temp goes up to 210-215. I'd like to run a little cooler when cruising if possible. Thanks Roger

On The Eighth Day God Created Buick

 

Is it direct fan now without a clutch?

 

It has a fan clutch on it now Mike but the clutch is off a V6 Buick. Roger

 

Doubt a HD would solve it. Have you comfirmed it is coming ON ? I have similar issues and run a flex fan and no clutch. Timing makes a big impact as well on temp. I'm going to try acid flushes next. Good luck. Mike

 

I believe the clutch is a standard non-thermostat control because it does pull air immediately after the engine is turned on. I thought maybe mounting the trans cooler in the middle of the radiator may be hindering air flow causing cooling problems. Thanks Mike

On The Eighth Day God Created Buick

 

You might find that the six-popper and the BBB use the same clutch. Or that the main difference is the shaft length, or the pilot hole diameter. The actual clutch part is likely identical. The rest is just fitment.

If it's a non-thermostatic clutch, you can fling it in the scrap bin right now. They're low-priced junk for people who won't spend the money for a proper part. Get a thermostatic fan clutch that places the fan 1/3-to-1/2 in the shroud, and 2/3-to-1/2 out of the shroud. Of course, the mounting bolt circles, the pilot hole diameter, and the direction of rotation all have to be correct, too.

Some folks insist on buying "heavy duty" fan clutches, but that's NOT recommended by the fan clutch manufacturer because few automotive fans have enough blade pitch to get a heavy-duty clutch to disengage.

Lots of talk about cheap aluminum radiators having mis-formed tubes that are practically plugged at the ends because the tubes are damaged during the construction of the radiator. Yet another example of crappy Chinese workmanship, along with lack of QA here in the States.

Beyond that, there's all the usual overheating problems--retarded ignition timing including failed or disabled vacuum advance, lean fuel ratio, missing air dams or hood seals, dragging brakes, restricted exhaust, low coolant level, eroded water pump impellers, incorrect crank-to-water pump pulley ratios, cooling fan intended for opposite rotation...the list is nearly endless.

If a vehicle with a 160 thermostat runs above 180 at idle or cruise, the 'stat has lost control of the engine temp. SOMETHING is wrong.

Are you sure the gauge is accurate? How do you know?

 

So an intial timing distributor of 0* would run hotter than one of 10* BTDC everything else equal?

 

All good points made above and I'll add one more to the list. You mentioned you were using a 17" fan. Original fans were either 20 or 21 inch and came within an inch or so from the end of the fan shroud. You should find a larger fan. Also, as has been mentioned, the best position of the fan is about 1/2 in and 1/2 out of the end of the shroud. With a 160 degree stat, your car should never run more than 100 degrees from ambient temperature or thereabouts.

 

...or a 20" 7-blade fan

 

So is that Fan with the offset/ paddle. Like there's a blade missing . Does that throw a blob of air more so than a tighter blade fan?

 

Title of Thread: "Does the wrong fan clutch affect cooling ?"

Answer: YES!!!

I could go on and on about my situation with so called HD thermostatic fan clutches from a popular auto-parts store, in the end - factory OEM AC Delco Fan clutch solved my problem in 110 degree AZ heat. All other things including fan being stock. Car will run at 200-220 in that heat range.

 

Does that offset fan move more air. That's what I meant?

 

I'm running a 21 inch 7 blade Buick fan on my '71 GS. Clearance is fine all around the shroud.

 

an offset fan moves about the same amount of air but it is more quiet than a fan with equal gaps between the blades.

 

Where did you get that? The biggest I could find in the bone yards was a 19.75" (some call it 20") 7-blade (GM) from a mid 70's Pontiac big car.

 

I got it from Dennis (Wheelz) about two years ago and just installed it several months ago. It's actually about 20 3/4". Don't know what car it came out of, though.