3000 CFM are some of the higher flowing aftermarket fans. That fan should cool fine with a good radiator. Or use a super fan to cool a smaller radiator, up to you. I'd make sure you got all the air out of the system first since that's free. Have you verified the temps with another sensor or a heat gun maybe? Where is your sensor located? A taurus fan cut and glassed to fit the radiator core exactly will cool most anything.

Just mocked one up and glassed it in last weekend. Cost around $100 from dorman. Has a high and low speed. High speed will need 2 relays in parallel as it can draw 60a on initial startup. The motors are huge!

 

This is also a relay option. I've got a couple of these on my car. They're very nice heavy duty relays. Just make sure to use the continuous duty models. http://m.ebay.com/itm/TYCO-12V-75AMP-HEAVY-DUTY-RELAY-V23232-D0001-X001-QTY-1-/231977230525?nav=SEARCH

 

I would think his system is purged as he's running ~215 and comes down if he's coasting.

I'm running a factory single-row plastic/alum 3.8/5.0 radiator on my SN95 and factory electric fan. Runs about 190-200* sitting still, will go below 190 moving in the summer. Still a little warm for me and I'd like to get a "better" rad. in there. But I think the fan makes all the difference in most cases.

All these engines should cool at least at idle and cruise with factory radiators b/c they came from the factory w/ac and a condenser out front. If they don't cool, something is up especially with upgraded parts.

 

Problem with a lot of the aftermarket fan is they have inflated cfm figures. OE fans pull a ton more air and pull the amps to show it.

 

Stupid question, but I have seen it a number of times, is the fan blowing the correct way-sometimes people get the +/- rev. and if blows outward.
Do you have an intercooler in front of the rad?
I always fill from the top radiator hose on new installs, but by now yours is prob full

 

thats a good point, and ive seen that before.

Kind of like trying to figure out why your new build wont start and your buddy asks if it has gas and you wanna kill him but then he ends up being right.

 

I have also seen this a few times. Make sure its right.

 

I just went through this on my build . Took forever to purge the air out. Finally used a Lyle no spill funnel and just ran it while squeezing hoses to force air out. Also would run way hotter with heater hoses blocked off . Finally used a 4 way mixer valve . It needs the flow to open thermostat. Also bought a derale 4000cfm dual fan set up and 160 thermostat. Car runs 180-185 with ac on in traffic, might see 195-200 max. My bet is not fully purged/ not enough fan / blocked heater lines. Sometimes it's not one thing, but a few little things that contribute.

 

There is plenty of flow with the heater lines plugged. They should be plugged in order for the system to operate at it's best. There is a hole the size of a silver dollar behind the thermostat that allows the hi/low side to mix until the thermo opens. Mixing the hi/lo sides will cause the car to warm up more quickly. This is why the thermo on the ne LS engines looks so screwy with the second valve on the end. This is also why you can't just remove the thermo for max cooling.

It's the second disc on the bottom of the thermo seen here. As the thermo opens it is pressed into this port separating the hi/lo sides. You do not want to mix the hi/lo pressure zones in the cooling system for it to cool efficiently. Looping the heater lines reduces efficiency.

 

Well what happened to me was I hooked up my heater core to my ly6. It worked fine until I shut the heat off. In my 83 cutlass , when you shut the heat off , it blocks flow to the heater core by pinching off flow to One of the hoses .. Then the car would over heat. I installed a 4 way mixer valve from a suburban, then it was fine. Other people have blocked off heater lines and have been fine. My car , the thermostat didn't seem to work properly.

 

I was talking to a guy who had swapped out his thermostat with one from a Co. called Reische, they app. make one that allows more flow, I think it is for a Ford, Ford 4D, said it cured his Camaro from running hot-they seem to be pricy, so who knows if they help other appls.

 

No thermostat at all will cool best if you plug the hi/lo side port in the water pump with a freeze plug. I do it on my race car, made a big difference. Slow to warm up though and not the best for a daily driven deal that doesn't have the oil changed super often.

 

My 5.3 runs at 173-180* at all times. Stock 5.3 with 150k on it. cheap procomp high volume LS1 pump, tapped and plugged heater outputs in waterpump, mr gasket 160*F Tstat, 30/70 coolant mix, HOWE cheap universal chevy 28x19 dual core rad, Mark VII dual speed fan. I run the steam lines to the waterpump spacers/waterpump.

Alot of people do not understand the purpose of a dual pass or triple pass radiator. Single pass radiators will out cool a dual pass rad for the most part. Dual or triple pass rads effective cut the rad core in half or thirds, then you have to increase water pressure and volume to compensate for the reduced core size while only getting 1/2 the cooling. Dual and triple pass radiators are designed for circle track cars that spend 99% of the time at very high rpms (where pumps put out the most flow) and will be doing considerably more speed (more airflow). Dual and triple pass radiators are not for the street... hence why no OEM company has ever put them in a car. Theirs a formula for coolant flow when comparing a single pass to a dual pass radiator and it goes to something like 16x more coolant on a dual pass over a single pass. Then you have the issue with the inlet and oulets on the same side (hot top part of the rad and a welded seperator and then the "cold" side literally connected in the same tank) which doesnt seem optimal (heat transfer)

Using a Tstat restrictor can be doable but you have to figure out the hole size so you can mimic a restriction that a stock style Tstat provides. Restriction is required in the coolant system to provide ample time for the fluid to have time to absorb heat from the engine. No restriction will cause coolant temp/flow issues so size needs to be figured out. Negative side is that its always flowing so much slower warm up times and overcooling can be an issue if the setup is very efficent/oversized. Ive gotten my systems so efficent that I was running only a 7lb rad cap with no fluid being pushed out on a 521 BBF in a 87 firebird (no airflow through the front) and got it to run 180-190*F with a 180 Tstat.

Oversimplification of cooling system troubles.
1.) over heating below 40mph at any time, cooling fans to small, inadequate coolant system size (rad), Cap issues, miss matched Tstat, air in the system.

2.) over heating above 40mph... same as above but cooling fans are out of the mix. Airflow switches to ambient air flow. So above + outside air flow

First thing I would do is remove the rad and put in a decent 2 core single pass radiator, I personally like HOWE, USA made, full aluminum and cost less than $200 or any size. Drop Tstat to 180 or 160 (whatever works for your application), set fans to come on at 10* above Tstat opening temp. Leave the fans for now, make sure steam line is correct, system is air free and cap is in good condition.

Your problem sounds like a radiator issue, can't shed the heat prob due to dual pass design (half the cooling area) and not enough coolant flow.

 

my advice- (depending on how much space you have between your fmic and your rad) get a electric fan from a 2001ish 3 series BMW with a automatic trans. Put it between the intercooler and rad. These are pusher fans, bypass the control module and wire it to a heavy dutry/jeep/ect relay. Unless your on a megasquirt Im pretty sure there is a way to control the module but I dont have a clue how to do it.

But these BMW pusher fans are really good.