Anyone have an electric fan between the rad and AC condensor?

[davepl]

I'd like to sandwich a supplemental electric pusher fan in between the radiator and my AC condensor. That'd keep it reasonably well hidden and is the best location for it to move air too... but there's just not a lot of room, only a couple of inches.

I figured if someone already had one in that location, I'd know for sure what fits.

Anyone have one? Doesn't have to be enormous, it's just for hot idle when things start to climb in traffic (cools fine when moving).

[Mike C]

What engine drive fan setup do you have? If the 4 blade direct drive, upgrade to a 5 blade clutch using the HD temperature controlled clutch. And make sure you have the appropriate shroud. The pusher fan would really help in front of the condenser if you have an R134 ac setup.

[davepl]

I have all new stock equipment for the factory 402 from clutch to 5-blade fan to shroud to HD radiator, so it -should- cool properly at idle, but it can use some help.

Not sure why it creeps up at idle, but it does. It has a touch more camshaft than the stock piece but still super-mild (like under 210 degrees @ 0.50). Otherwise it truly is bone stock.

[Stocker]

No clue if it makes a difference, but the 350 in my K20 has a stock OEM 7-blade clutch fan.

[davepl]

Sorry, mine's a 7 as well, I just assumed without counting! Let's just say "lots of blades and it's the stock AC fan for a big block".

[Mike C]

What thermostat is in the truck? And have you corroborated the stock gauge versus a known accurate mechanical gauge?

[davepl]

Originally Posted by Mike C

What thermostat is in the truck? And have you corroborated the stock gauge versus a known accurate mechanical gauge?

Stock 195. I would not be keen on changing it because it can't hold it there anyway. Thermostats only set the lower point, I'm having trouble with the upper.

I've boiled the gauge literally in a bucket of water on the stove with an ohmmeter and the gauge to make sure it's right. So it should be good.

Once the truck is moving the gauge returns to center. And it can take 20 minutes of idling to creep up, so it's not an everyday problem, but I want a "last resort" fan that isn't running the heater!

[dennislbrooks]

After all the threads giving advice, I did change my 402 180 to a 160 a couple weeks ago and it does act near how you want. Running after warmup in drive stopped 90 degree day about 180-185 and same with ac on under 200. I have 5 blade clutch fan and shroud on a copper ac radiator. May not be what you want. I run 10 degree initial advance on ported vaccuum. Near all on cooling is newer stuff.

My temp sender is electric and the sender is on the side of the driver head just above the exhaust manifold which I believe is where the hottest reading comes from --could be wrong.

[davepl]

Weird... once the thermostat has opened and the engine is at 190, does it matter much whether it opened at 160 or 180? That's the thing I can't wrap my head around. I guess the first couple of coolant exchanges might be cooler, giving it a little more capacity...

[Mrturner1]

Originally Posted by davepl

Weird... once the thermostat has opened and the engine is at 190, does it matter much whether it opened at 160 or 180? That's the thing I can't wrap my head around. I guess the first couple of coolant exchanges might be cooler, giving it a little more capacity...

This is just my guess because I'm with ya on the opening temp not mattering, but if it opened at 160 or 180, maybe it would be easier for the coolant system to maintain that lower temp for a longer time? It would still end up at 195-200 after a while if it was hot enough, but maybe opening sooner puts it a step ahead of the heat.

[davepl]

Yep, it might delay the inevitable a while longer, I can see that. But not fix the underlying problem, whatever that might be!

I put a brand new AC Delco expensive clutch in there too to make sure it was right (no Chinese repro for me, I need it to work, but it wasn't the problem).

[Mrturner1]

Originally Posted by davepl

Yep, it might delay the inevitable a while longer, I can see that. But not fix the underlying problem, whatever that might be!

I put a brand new AC Delco expensive clutch in there too to make sure it was right (no Chinese repro for me, I need it to work, but it wasn't the problem).

I have the same creeping idle temp but it's probably just compression ratio and cam/timing.

For your truck I would check out Flexalite Slim S-blade fans. They are the thinnest ones out there as far as I know

[racerop]

Have you looked at the actual temperature at the sending unit vs the temperature entering the radiator? Maybe the water pump is not moving the coolant efficiently? Just a thought.

[davepl]

Originally Posted by racerop

Have you looked at the actual temperature at the sending unit vs the temperature entering the radiator? Maybe the water pump is not moving the coolant efficiently? Just a thought.

So if that were the case, I'd be able to see that the coolant in the rad (coming in the bottom hose) was cooler but not enough of it being pumped through the engine?

I've tried using a little RPM to move things around, it didn't make a huge difference, but it's a good thought. I'll try that again next time it happens.

[5567Cruiser]

Originally Posted by racerop

Have you looked at the actual temperature at the sending unit vs the temperature entering the radiator? Maybe the water pump is not moving the coolant efficiently? Just a thought.

I had the temp creep with my 350 after A/C, big radiator, 7 blade fan, shroud and after installing a Weiand high flow water pump- problem solved. I can drive in parades in granny with the air on and the temp guage never moves beyond normal operating temp, water pump worked for me.

[AnotherWs6]

Originally Posted by davepl

Weird... once the thermostat has opened and the engine is at 190, does it matter much whether it opened at 160 or 180? That's the thing I can't wrap my head around. I guess the first couple of coolant exchanges might be cooler, giving it a little more capacity...

NOOO> Makes no difference what your thermostat is, a lower stat only delays the inevitable.

Ive got a small electric pusher over my condenser on my big block auto. 80 degree temp I saw the gauge move a smidge after 30 minutes of bumper to bumper with the AC on blast. You just need a little airflow beyond the factory blade fan. It's got to pull air THROUGH the condesnor and then THROUGH the rad. Just give it a bit of help and you're fine

[dennislbrooks]

another article on cooling


http://www.crankshaftcoalition.com/w...cooling_system

[davepl]

Read that whole article on cooling, there's still no good reason (other than perhaps water pump) for mine to overheat when idling.

And if it is the water pump, it should be OK if I keep the RPMs up a bit, but that doesn't generally cool it back down, so I don't think its that.

It's a 100% stock setup, except the AC has been converted to R-134. Everything else the factory put there is there, the way it's supposed to be, and so far as I can tell in good working order.

And yet something must be broken or misadjusted... but what? I'm sure I have more timing than stock, though I will double-check that to be sure.

[AnotherWs6]

Are you relying on the stock gauge? I ask because if you are you may not really know what temp the truck is ever at. These things can be all over the map. Onmy newer truck with a numbered gauge 150 is about 180 in reality. 205 is 212 in reality. And 240 is about 225. Again, just all over. You could be at 192 normally, 198 with the AC issue but think the truck is much hotter than it is. Sending units are not all the same and neither are new gauges necessarily. And especially not 50 year old ones.

[Mrturner1]

Ever get this figured out?

[AnotherWs6]

I wouldn't mind a little more info myself. 2 hours of bumper to bumper this morning and I ended up turning the AC off and cranking the heat. My gauge usually sits a 1/4 inch past fully cold. Today it was directly in the middle. I have no idea what temp that is. Could be 200, could be 230. The truck is old, so are the gauges. But it made me nervous. And it was starting to idle rough until I did that. When I got to work the air cleaner was so hot I couldn't touch it. It's too hot under that hood. The whole thing makes me think lack of air flow from factory fan at idle.