In my new Summit catalog Jet has a fan switch for the 305 that comes on at 200 and off at 185. It's supposed to be a direct bolt in replacement. Has any one tried it? I'm tired of running 250 degrees idling in traffic in summertime, and that's with a 160 thermostat. By the way yes the radiator and the rest of the cooling system is in perfect condidtion.

 

92..................I'm not running the Jet fan switch but I have the same one off of a C-4 Corvette.......200* on 185* off........I run a 180 stat and it keeps my LO3 305 very cool during the summer and I have enough heat in the winter also..........if your tired of watching your guage creep up while your in traffic like I was then its a good mod to do......and in the winter time you can switch back to a regular stat for heat if you dont feel comfy with a 180....

 

I have the Jet-Fan Switch dual 12" Perma Cool electric fans and a 180* thermostat and my LO3 305 was still running hot in the summer heat. On a 105* day idling in stop and go traffic, the temperature gauge went to 260* and cooled down to 240* once I started to move. I have since switched to a 195* thermostat and the engine operates at a more consistant temperature (around 195* in 70* weather).

 

that's one of the best things you can add to your engine... the stock switches don't kick on til 237/239 degrees - somewhere in that neighborhood...

 

Do you know if they make one for the 350? Probably the same kit right? I hate watching my temp creep up when I'm stopped as well. Is the sensor that thing that's on the block on the passenger side right underneath the head? Thanks for any info! Matt

 

yeah the fan switch is in between the 6 and 8 cyclinders passengers side...

 

First find out what temp fan sw you have. There are 2 different ones. I believe with a single fan setup where the ECM does NOT control the fan there is a sw at 220, and then one at 240. Perhaps you have the wrong one, wouldn't be the first time. Second make sure the guage is accurate. Many times the sender loses it's accuracy falsly indicating actual temp. I would not go as low as 200 with a fan sw, your fan will constantly be running. That takes it's toll on the alt and the fan relay and motor. GKK is correct about stable temp, a large swing is not good. A 180 stat is as low as I would go. Check with NAPA, they have 2 switches for the TG's and they are only $19. Ideally you want one to turn on at the lowest 215 deg otherwise you'll be buying a new alt every couple of years at best. You want some temp swing before the fan kicks on. Some of the later GM 4 cyls use a 180 stat because they know the average temp will be higher in stop and go traffic and it provides a cushion before the electric fan turns on. I run a zz-4 block with all stock equipment and the primary fan keeps it around 215 degrees in everything but the most extreme heat and then the secondary never lets it go above 230 or so.

 

I've been usnig the Jet 200/185 fan switch and a 180 stat for two years now. Works perfect, no problems, no worries. Temp hasn't much been over 200 since even on the hottest days.

 

Thanks for all the help sounds like the right part for the job. I'll let you know the results if it ever warms up around here