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Temp. switch for electric fans ?

GNERGY

GNERGY

1/2 ton status
Joined
Jan 11, 2008
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Location
Arizona
I am running a 180 deg. themostat and picked up a temp switch that will turm my fan on at 185 deg. napa # FS300. I have been reading that it seems everybody goes a little hotter on theirs. Will this be OK, I'm here in Arizona and wanted to keep it as cool as possible.
Give me your thoughts, Thanks
Tarey


Oh, by the way, 91 Suburban with a 383 cu.in.
 
Temp switch/thermostat rating really doesn't matter, other than that they compliment each other. Most GM fan switches are 200*+ for turn-on, simply because the thermostats were 195*...the fan on switch needs to be higher or obviously the fan would never shut off. That's probably why you see mention of 195*+ more often.

A 160* or 180* thermostat is a bandaid, if anything. If the engine can't keep cool at 195*, it won't keep cool at 180*. It's really more personal preference than anything, since higher temperature actually increases engine performance.
 
The truck came with a 180* thermostat in it. I just swapped my 383 stroker in for the stock 350sbc. I've always ran a 180* thermostat back in Ohio. So since it is a TBI motor now it is better to run it a little warmer for performance. Then should I go 180* thermostat and 205* temp switch. Either one is an easy change. Thanks
Tarey
 
Does the truck still have TBI on it? If so you really should install the required 195* t-stat. The ECM uses the CTS (coolant temp sensor) to control the open/closed loop operation and if your coolant temp sensor isn't getting hot enough the truck won't go into closed loop operation and performance will suffer.
 
Yes it is TBI, so I should pick up a 190* t stat. then go with a 205* temp switch ? Do you guys have a part # for the temp switch.
Thanks, Tarey
 
Yes, install the proper 195* t-stat. I'm not any help though for your fan switch.
 
Check some of the Camaro applications. Probably a late '80's TBI one, NOT TPI as the primary fan was controlled by the ECM, not a switch.

Napa's "Echlin" catalog lists the fan switch on/off temps, threads, wiring, etc. Use that to find the right switch. They should let you look at it.

As to your TBI...be very careful dumping a 195* stat in it. Did you have a new chip programmed for the 383? The lower temp stat may be masking some timing problems that will become more apparent if engine temp increases, if you didn't have a chip burned for the motor. Not to mention the fueling issues, but that's another topic.
 
dyeager535 said:
since higher temperature actually increases engine performance.
Click to expand...

Sweet, I'm going to bypass the radiator with a hose for ultimate performance.:D

It's all about the tuning, actually. A cooler engine can make more power, to a point. But TBI is a fickle system. It doesn't even measure intake air temp, so it's best to keep all the variables close to where it is expecting them, which is what I assume you are really saying.
 
Iron heads make more power than aluminum, that's not tuning, it's heat.

If you want to talk tuning on a "wet" intake system, then whats the tradeoff between well atomized fuel (which comes with heat) vs. a cool intake charge? I've never seen anything comparing that, but you'd need two identical castings in iron and aluminum to test, which has been done with heads, but they do a bit different of a job than an intake. :)
 
Maybe you should consider replacing the radiator with a new 4 core radiator ( Auto Zone, Advanced Auto) that was uses on 454 engines. When my old radiator started to leak I just replaced it with a 4 core. My thermostat is 195. The temp sensor ( NAPA adjustable ) in the upper radiator hose is set for 210. At that temp the two electric fans turn on and I can see the temp quickly drop on the guage until the fans turn off at 190 - 195. This system has worked perfect for 5 years. It is important that excess heat be removed as quick as possible.
 
I'm not having any cooling issues. I just bought a 91 Suburban to replace my rusting 81 Suburban that lived most of it's life in the snow belt of Ohio. I am swapping my 383 stroker from the 81 to the 91 and changing it to TBI. I bought the Edelbrock TBI manifold and changed the cam before I swapped the motors. I bored the intake to 2 inches to put a 454 throttlebody on it. I put an adjustable fuel pressure regulator on the throttlebody. I have the 350 injectors in it right now to get it running and then will take it locally to get it tuned to run with the 454 injectors. I have a different fuel pump to put in it also. I installed electric fans and want them to work right the first time.
Thanks
Tarey
 
I can tell you right now you'll be lucky if it runs good enough to take it anywhere with a 454 TBI unit with 350 injectors. I've already tried it and it wouldn't even run.

What trans is in the burb? If it's a 700R4 you better make sure you do something about hooking up the TV cable. 454's never had a 700R4 behind then so the TBI unit doesn't have a provision for the cable.
 
I took the arm off of the 350 throttlebody and put it on the 454 one and pre set my fuel pressure to 13.5 lbs I'm new to this, so I'm trying to go by what I have read on this site. I'm open to all sugestions.
I have also installed an Innovate Mororsports wide band o2 sensor from my GN till i get it tuned. I put a heater o2 sensor in the collector with the wide band cause I'm running headers.
Tarey
 
Ok, i just wanted to make sure if you had a 700R4 that you did something about the TV cable. I did the exact same thing. Since you said you searched you might have come upon my post about me doing that.
 
Be real interested to see a followup post on your 383 with the wideband installed, before tuning.
 
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