agtw31

im trying to create less work for this 307 by deleting the clutch fan,and adding a electric fan.

will a 12" electric fan do a good job replacing a clutch fan?

i have a 12" flex a lite for the delta,but concerned it will be enough to keep the 307 cool,considerring i run the a/c a lot during the summer..

i run a 165 stat in summer,switch to 180 in october.

should i go to a bigger size electric fan?

csstrux

IIRC I was running a 14" in an S10 that we converted to a SBC it would do the job...just. Nothing fancy, 305 with a truck cam for a 350 and a factory "hi rise" intake off a 69 truck 350. May be quality of the product, but you may want to look int a bigger one.

joe_padavano

Just out of curiosity, where do you think the electricity comes from? The reality is that to move a certain amount of air requires a certain amount of work. The mechanical fan gets that directly from the engine. The electric fan requires you to lose efficiency in converting kinetic energy to electric and back to kinetic.

Of course, this is an oversimplification, since the mechanical fan runs all the time whereas the electric only runs when the temp sensor turns it on, but still...

wmachine

I've never seen an Olds anything close to stock that won't run cool enough with a totally stock cooling system. That means a clear radiator, clutch fan if called for, proper stock water pump, and don't forget the fan shroud. And a 160-190 thermostat.
When one starts messing around with alternate pieces, it throws things out if whack, and you end up chasing your tail. More isn't necessarily better when it comes to cooling. For instance, it is possible to push the water through the radiator too fast (in various ways), and it doesn't have a chance to cool down.
And a flex fan is never part of the solution.

Lady72nRob71

The stock fan is 18" and moves a massive amount of air when needed.
A 12" electric does not have a chance at competing, especially when the A/C is on.

As long as the stock fan clutch is working right and disengages when it should, power savings would be negligable.

AJCDFIN

Hey; As a fellow buckeye I would not recomened running a 160 stat especially if you run a/c, as wmachine stated coolant needs radiator time for proper cooling,180 is ok. Switching fan set-up has minimal gain if oem clutch is working as designed.

agtw31

thanks for the tips.

i did talk to guy that did service work on 307's when they were new.

he said if you put a tstat lower than 180 in a 307,it will affect your carb idle settings,and your check engine light will stay on,said the idle sensor will flip out in the carb.

he was right.

Lady72nRob71

Yep. I think the ECM closes loop at around 160*. Because the car takes so long to warm up to 160 (and may not), the ECM times out after a certain time and does not go into closed loop and sets a code. The fast idle will remain engaged until closed loop is established.

joe_padavano

Actually, it's the O2 sensor that causes the ECM to go into closed loop - when the sensor voltage starts to vary, that's an indication that the O2 sensor is up to temperature. The coolant temp sensor doesn't cause this directly, but if the coolant temp is lower than the expected value when the O2 sensor causes closed loop mode, then an error code and Check Engine light could be set.