E fan mod test for Rodney Red Rad update

[RLDSL]

It's been a little bit since i started this experiment working with Jerry at Rodney Red radiators to come up with an E fan setup to go with these things, but I've run into an interesting snag, that may have accidently shed some light on a few things. Around town and on secondary highways , my home built shroud and e fan setup was working beautifully ( see old thread } but once we finally got out on the interstate on high speeds some odd things started happening, temps were climbing up to around 240 . This happened with teh flaps sealed shut as well. so assuming the shroud was a failure, I attached the fans directly to the rad, and it made no difference. THis bordered on insanity as it was now in the 30's outside and there's no way it should be getting that hot
Well one day i got it as hot as I could and pulled off the road and popped teh hood and stuck my hand in there and oddly there was a completely cold stripe about 12" wide in the middle of the rad with the fans pulling cold air off there but hot air comming off the sides So yesterday, I brought a fast response temp probe with me on a 50 mile run in 28 deg temps and it was running about 245 and I quickly pulled over on a offramp and started running temps . The middle was ice cold, top tank was only about 195 , bottom tank was only 85-120! Now here's where it gets wierd, As the temp in the engine LOWERED toward 195, the stripe in the middle of the rad all the sudden got hot and the fans were now pulling heat off that area.

I scratched my head and my backside and anything else I could find to scratch and then went to study the coolant flow diagram . Then I got on the Phone with Jerry at Rodney Red and we both have come to a rather interesting conclusion. It looks as if the coolant in the lower tank is too cold and where it enters the engine at from the lower hose, there is that one hole at the front of the head that may be allowing surges of cold coolant to flow straight through to the thermostat instead of flowing back through the block first, causing the thermostat to flutter. After all, in these outside temps, there should be no need for a fan at all, I should almost be reaching for a winter front and it's running the exact same temp now as it was when it was near 100 outside

THis all started to make perfect sense, and I think the IH factory was well aware of this problem on the 6.9 engines when installed in the larger mid size trucks as their rads are about 3 times the size of the Ford pickup rads, and we all have been wondering why on earth they decided to block off one of the coolant ports in the head on the 7.3 at the end of teh head to slow down the flow, I may have just stumbled across the reason.

Gary may have inadvertanly already solved the problem without even knowing it when he turned his thermostat into a high flow

I have some more testing to do , now experimenting with different thermostat arrangments.

Does anyone know if the thermostat in these things are the same diameter as a normal thermostat? I put a new one in right when we did the fan install, but I pitched the old one ( and I was getting low upper tank temps with that one as well , but I didn't dig any further). It looks like a standard Robert Shaw design. IF so, I can get a number of good high flow thermostats at different temps.

 

[tractorman86]

hmm, that is pretty interesting. So what you are saying is that the rodney red is cooling too good for a 6.9

 

[FORDF250HDXLT]

where is your temp sending unit located? stock location? what did you get for temps there with your point and shoot tool,and did it match your gauge?
what are you running for a pressure cap?
where is the temp probe located,and at what temp is it set to make the fans come on? do the fans spin together or independently?

edit,oh it's not pressurized at all.hmmm.

 

[RLDSL]

hmm, that is pretty interesting. So what you are saying is that the rodney red is cooling too good for a 6.9

Well, part of the problem lies in the high power E fans and the auto controller.
THe factory fan clutch pulls a bit of air all the time but not much , the fan clutch doesn't start really drawing air till around 215 where it begins to lock up and it doesn't lock all the way up until a whopping 260 deg , which allows the coolant temp to get a bit warmer before pulling hard air through.

With the e fan controller, I've had nightmares trying to set the thing to turn the fans on later, but for some reason related to the flow patterns they always come on earlier at road speed and the things even on low suck like crazy. That's another problem I'm going to have to work around,I think they are going to have to be triggered by a sensor mounted in the upper hose to function properly. so they aren't coming on prematuraly.

 

[Darrin Tosh]

I think they are going to have to be triggered by a sensor mounted in the upper hose to function properly. so they aren't coming on prematuraly.

I had a Notchback 5.0 Mustang that was hopped up, I put an electric fan on it with a thermostatically controlled sender that was designed to be stuck in the radiator. It was supposed to be near the top radiator hose.

My thoughts are if you had that setup, you could install it anywhere in the radiator and adjust when the fan kicks on by the location in the rad. Lower would be cooler, higher would be hotter,..

Something to consider...

 

[1Turbo10]

A couple of thoughts,you can gut the thermostat and that will answer that question. Also is it possible that your cooling system is getting air bound somehow at the higher road speeds,that would keep the water Pump from circulating the Coolant.

 

[FORDF250HDXLT]

i don't think that's the issue though Darrin because:

"After all, in these outside temps, there should be no need for a fan at all, I should almost be reaching for a winter front and it's running the exact same temp now as it was when it was near 100 outside "

though i understand why its running at the same temps as when it was 100 outside,it's because there is a t-stat.
but being cold out,without a winter front cover on,his fans shouldn't be needed at all,and the engine shouldn't be getting hotter,but cooler as he drives down the highway.
at 50 degree temps,i can run my winter cover and the fans will come on low and still keep me around 225 all easy.
if i remove the winter cover,i'll drop right back down to 195-200ish quick and the fans won't even dream of coming on going down the road.in fact,id never see over 205 degrees.

im questioning the gauge temp sensor myself.

 

[bobracing]

Well, part of the problem lies in the high power E fans and the auto controller.
THe factory fan clutch pulls a bit of air all the time but not much , the fan clutch doesn't start really drawing air till around 215 where it begins to lock up and it doesn't lock all the way up until a whopping 260 deg , which allows the coolant temp to get a bit warmer before pulling hard air through.

Something like this work?
http://www.spalusa.com/store/Main.aspx?html=pwmv3

 

[RLDSL]

where is your temp sending unit located? stock location? what did you get for temps there with your point and shoot tool,and did it match your gauge?
what are you running for a pressure cap?
where is the temp probe located,and at what temp is it set to make the fans come on? do the fans spin together or independently?

edit,oh it's not pressurized at all.hmmm.

I have gauges and sensors in a few places and my water temps is reading almost exactly the same as t eh temp on my mechaniocal oil temp gauge in the pan within about 3 deg ,aside from checking with the external meter, so yes, I know the temps are accurate.
The fans come on together off a single computerized controller

 

[RLDSL]

Well, part of the problem lies in the high power E fans and the auto controller.
THe factory fan clutch pulls a bit of air all the time but not much , the fan clutch doesn't start really drawing air till around 215 where it begins to lock up and it doesn't lock all the way up until a whopping 260 deg , which allows the coolant temp to get a bit warmer before pulling hard air through.

Something like this work?
http://www.spalusa.com/store/Main.aspx?html=pwmv3

That's the auto controller that I have and actually I need to go a little lower tech and just run a switch out of the upper rad hose to trigger a pair of relays to kick them on. That smart controller was supposed to be compatible with these fans but shortly after I got it , they came out with a thingy saying these fans are too stout for it, so i don't know how long its going to survive..
Right now I have over $800 in this system, it's top shelf all the way.

 

[RLDSL]

A couple of thoughts,you can gut the thermostat and that will answer that question. Also is it possible that your cooling system is getting air bound somehow at the higher road speeds,that would keep the water Pump from circulating the Coolant.

Chances of pump cavitation are REALLY slim since I'm running Evans waterless coolant , so there's no chance of bubbles forming in the coolant.

 

[OLDBULL8]

Coolant flow 7.3 IDI, don't know if you have this Robert. Basically the coolant circulates thru the block and oil cooler until the t'stat starts to open, then partially to the radiator modulated by the t'stat opening. If you look down into the block t'stat opening, there is a small tower like (about 3/4" ID) and about 3/4" high, the copper bulb on the t'stat kind of sets/extends down into it. I'll measure it tomorrow for sure, that is measure the t'stat length to see if it really does what I'm saying. Did it a long time ago, just don't remember exactly how it is. I believe that tower impedes the flow around the t'stat bulb until the max temp reaches for the t'stat to open wide, I believe that's why an OEM t'stat is recommended/necessary. I don't think your zero pressure has anything to do with the temp, only temp rise would enter into it, and that would be where the sensor is located.

I'm surely not questioning your knowledge of the coolant system, just so others that don't know, understands what I'm talking about.

You must be registered for see images

 

[itsacrazyasian]

It's been a little bit since i started this experiment working with Jerry at Rodney Red radiators to come up with an E fan setup to go with these things, but I've run into an interesting snag, that may have accidently shed some light on a few things. Around town and on secondary highways , my home built shroud and e fan setup was working beautifully ( see old thread } but once we finally got out on the interstate on high speeds some odd things started happening, temps were climbing up to around 240 . This happened with teh flaps sealed shut as well. so assuming the shroud was a failure, I attached the fans directly to the rad, and it made no difference. THis bordered on insanity as it was now in the 30's outside and there's no way it should be getting that hot
Well one day i got it as hot as I could and pulled off the road and popped teh hood and stuck my hand in there and oddly there was a completely cold stripe about 12" wide in the middle of the rad with the fans pulling cold air off there but hot air comming off the sides So yesterday, I brought a fast response temp probe with me on a 50 mile run in 28 deg temps and it was running about 245 and I quickly pulled over on a offramp and started running temps . The middle was ice cold, top tank was only about 195 , bottom tank was only 85-120! Now here's where it gets wierd, As the temp in the engine LOWERED toward 195, the stripe in the middle of the rad all the sudden got hot and the fans were now pulling heat off that area.

I scratched my head and my backside and anything else I could find to scratch and then went to study the coolant flow diagram . Then I got on the Phone with Jerry at Rodney Red and we both have come to a rather interesting conclusion. It looks as if the coolant in the lower tank is too cold and where it enters the engine at from the lower hose, there is that one hole at the front of the head that may be allowing surges of cold coolant to flow straight through to the thermostat instead of flowing back through the block first, causing the thermostat to flutter. After all, in these outside temps, there should be no need for a fan at all, I should almost be reaching for a winter front and it's running the exact same temp now as it was when it was near 100 outside

THis all started to make perfect sense, and I think the IH factory was well aware of this problem on the 6.9 engines when installed in the larger mid size trucks as their rads are about 3 times the size of the Ford pickup rads, and we all have been wondering why on earth they decided to block off one of the coolant ports in the head on the 7.3 at the end of teh head to slow down the flow, I may have just stumbled across the reason.

Gary may have inadvertanly already solved the problem without even knowing it when he turned his thermostat into a high flow

I have some more testing to do , now experimenting with different thermostat arrangments.

Does anyone know if the thermostat in these things are the same diameter as a normal thermostat? I put a new one in right when we did the fan install, but I pitched the old one ( and I was getting low upper tank temps with that one as well , but I didn't dig any further). It looks like a standard Robert Shaw design. IF so, I can get a number of good high flow thermostats at different temps.

If you were wondering still. I yanked out of my old 6.9 a plain jane thermostat.

It was a stant, stamped 195 on it. Kept the ****** cool too with a gas radiator!

You must be registered for see images attach

Its the same size as the thermostat for my old 351w, the thermostat i took out was fairly new so we shoved it in a 351 i had that was stuck. Still there too.

 

[Black dawg]

OLDBULL...from the measuring I have done the t stat doesnt reach the seat to block bypass flow.

RLDSL...the t stat is just like the robertshaw high flows. So you are thinking that cool coolant is getting through the bypass to the t stat?

 

[RLDSL]

RLDSL...the t stat is just like the robertshaw high flows. So you are thinking that cool coolant is getting through the bypass to the t stat?

Exactly. That's the only thing that explains the behavior , plus the temp readings at the water neck compared to the temp in the rest of the engine. Some of the extreme cold return water from the inlet from the rad has a shortcut to the thermostat. Because the water neck/ upper hose temp is just barely to thermostat opening temp while the main part of the block is at 240. If it was fully mixing the temp at the waterneck should be the same as the rest of the engine.

For testing I'm going to just pull the thermostat to eliminate the variable, but I think the soloutin is going to be a high flow thermostat and a single speed fan switch set at around 215 to let it heat up a little bit so the thermostat can actually open.