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Old 06-11-2018, 06:49 PM
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WALTSTAR
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Default Fan of a fan

I recently built a 4 bolt main 6.6 liter small block with dual quads. In order to keep it at 180-190 degrees, I installed a four row radiator and a 16" stainless steel flex fan. As a backup, I have a 16" electric fan in front of it as a puller. Looking at the clutch fan on my 84, I wondered if I could keep the engine a little cooler by installing a similar direct drive flex fan. Has anyone done this and if so, who is the vendor of choice?
Old 06-11-2018, 07:25 PM
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V2Rocket
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you should be running the engine at 190-200 for one thing.
some folks here have tried a Ford? heavy duty fan clutch with success.
Old 07-16-2018, 11:31 AM
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I am thinking of a direct drive fan, not clutch fan. My question is has anyone done such a conversion?
Old 07-16-2018, 12:50 PM
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Why does it need to be cooler?
Old 07-16-2018, 01:38 PM
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WALTSTAR
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I drive it hard and its exceptionally hot and humid here in New York.
Old 07-16-2018, 09:13 PM
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j.kenzie@sbcglobal.net
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Originally Posted by WALTSTAR
I drive it hard and its exceptionally hot and humid here in New York.
Is it actually overheating or is it in the normal range on the gauge? Also depends on what thermostat you have.
Good luck,
Dave
Old 07-16-2018, 10:16 PM
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docmirror
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Reverse the flow direction of the front fan so it is not a puller but a pusher(going from front to rear), also so it is not pushing opposite the direction of travel.

I've no experience with the early fan clutch setup.
Old 07-17-2018, 08:03 AM
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WALTSTAR
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Default TEMP RANGE

Originally Posted by j.kenzie@sbcglobal.net
Is it actually overheating or is it in the normal range on the gauge? Also depends on what thermostat you have.
Good luck,
Dave
Its not
overheating as the stat is new and the engine is not exceptionally hot after a ride. The gauge is at the high-middle mark when it previously was just high of middle overall. Could be the sender, but I tend to like my engines running cooler, rather than hotter like modern engines do.
Old 07-17-2018, 08:05 AM
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WALTSTAR
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Originally Posted by docmirror
Reverse the flow direction of the front fan so it is not a puller but a pusher(going from front to rear), also so it is not pushing opposite the direction of travel.

I've no experience with the early fan clutch setup.
Exactly which fan re you talking about and how would you proppse to reverse the flow without reversing the rotation?
Old 07-17-2018, 08:11 AM
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Speedtoys
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Originally Posted by WALTSTAR
I drive it hard and its exceptionally hot and humid here in New York.

That doesnt mean anything for the engine.
Old 07-17-2018, 08:13 AM
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Speedtoys
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Originally Posted by WALTSTAR

Its not
overheating as the stat is new and the engine is not exceptionally hot after a ride. The gauge is at the high-middle mark when it previously was just high of middle overall. Could be the sender, but I tend to like my engines running cooler, rather than hotter like modern engines do.
thats just it.

You believe cooler is better for...what reason?

Temperatures are important to many things. Best left to those that designed them.

Why make it complicated?
Old 07-17-2018, 08:49 AM
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Originally Posted by WALTSTAR
I recently built a 4 bolt main 6.6 liter small block with dual quads. In order to keep it at 180-190 degrees,
Is the 6.6L in a 928 and getting hot?....anyway a 6.6l is most likely a siameased bore 400...if so do the heads have steam holes? Aftermarket heads need them drilled and OE heads need them cleaned out. Also make sure you timing is right. These are the two most common reasons why for hundreds get hot.

BTW...I have a 406 with a stock radiator and two small electric fans in an off-topic vehicle with AFR heads with drilled steam holes and no overheating problems whatsoever with the air condition on sitting in traffic
Old 07-17-2018, 10:43 AM
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WALTSTAR
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Originally Posted by icsamerica
Is the 6.6L in a 928 and getting hot?....anyway a 6.6l is most likely a siameased bore 400...if so do the heads have steam holes? Aftermarket heads need them drilled and OE heads need them cleaned out. Also make sure you timing is right. These are the two most common reasons why for hundreds get hot.

BTW...I have a 406 with a stock radiator and two small electric fans in an off-topic vehicle with AFR heads with drilled steam holes and no overheating problems whatsoever with the air condition on sitting in traffic
I was comparing a build I did in a chevelle, its not in the 928. You are right that the 400 SBC has siamesed bores with steam holes. The 406 is timed to the "T" and idles smooth at 750 all day regardless of temperature.
Originally Posted by Speedtoys
That doesnt mean anything for the engine.
High revs and ambient temps dont mean anything to an engine? Thanks for that pearl. I will keep it in mind.
Originally Posted by Speedtoys
thats just it.

You believe cooler is better for...what reason?

Temperatures are important to many things. Best left to those that designed them.

Why make it complicated?

You believe riding mine is appropriate, what reason?
Second statement sound like something said in Helsinki.....Who designed temperatures, may I ask?
Nothing complicated about anticipating something like getting caught in summer traffic jam (we all dont live on the open plains) and wanting a "thermal safety factor"..
Old 07-17-2018, 10:56 AM
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Originally Posted by WALTSTAR
High revs
Stock US 16V's engine don't go past 6,000rpm (don't make any additional power much past 5,500). These bottom ends are capable of much, much more. Point is, these engines are so over developed and under powered, a bone stock unit is not going to benefit from running a bit cooler, especially on the street.

The idea of running an engine cooler to make more power absolutely has merit, but you are not going to see such gains with a bone stock US 16V car. You also have to remember these are fuel injected, which means there is a temp sensor dictating the fuel usage. If you run the engine cold enough to fall into a richer area of that sensor, your car will never run with proper air / fuels unless you adjust things.

The cooling system on these cars is very, very efficient and oversized. No need to reinvent the wheel unless you are also planning some other big modifications to increase power. The stock belt driven fan is just as capable of keeping temps under control as the later electric fans and the cooling system is the same capacity as later cars making 100+ more HP.

Do what you want, doesn't really matter to us. Most of us respond to such threads for the benefit of others following along at home who see such threads and start to ponder if they too should be trying to increase the cooling efficiency of their cars.

Originally Posted by WALTSTAR
Nothing complicated about anticipating something like getting caught in summer traffic jam (we all dont live on the open plains) and wanting a "thermal safety factor"..
If a slow moving car is overheating, the fan is failing, the radiator is clogged, impeller on the pump loose etc......something is preventing or not moving enough air through the radiator or coolant flow compromised.
Fix the problem and you'll be fine. A stock 16V US 928 sitting in the Sahara Desert will not overheat at idle if all systems are working as the factory intended.
Old 07-17-2018, 11:00 AM
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I agree with the idea of a thermal safety factor, and a better fan may give you that. The thermostat may prevent that from showing up as lower operating temperature. The better fan may just keep temperature in range on hotter days. By the way there is a cooler thermostat available that will lower your temperature but many here have advised against it.
Good luck,
Dave


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