Chevy8588

iTrader: (1)

is it normal for a TPI's dash guage to get all the way up to 240 ( the 3rd line) before the fan comes on?

oil pan 4

iTrader: (1)

I converted to electric fans and built it and wired it from the ground up.
To turn the fan on incase I forget I ordered a fan switch to a '92 Z28 camaro. And yes it turns the fan wired to it on at about the 240'F mark.
So its normal.

Chevy8588

iTrader: (1)

oh ok good, cuz my old TBI always ran about 220, and when i converted it to TPI i was wondering why the hell it was getting so damn hot lol

y84pauloflondon

Correct me if I'm wrong! But I've read on many other threads that the ideal running temp on our cars is 180*-200*. So, do you really wont your fan coming on at 240*....seems a little high!

Chevy8588

iTrader: (1)

my thoughts exactly, ill get an auxillary fan controller and hav it power the auxillary fan on at 200 at 180

y84pauloflondon

This is one of my other post from another thread.........

"Well it depends on what you want?....A stock GM fan switch turns on at 220* and turns off at 200* I believe! Last year I revamped my entire cooling system. I used a hypertech fan switch that turns on at 177* and turns off at 166*. Now she runs cooler and faster, L98's love to run cooler. Cooler temps = HP.....I used (Hypertech part#4026), there's also part #4028 which turns on in the 190s and off in the 180s can't remember exact munbers....hope that helps... "

I did the swap because my car seems to have the most power when cool. But I'm planning on changing the switch from 4026 to the 4028. Reason: some of the engine builders on here feel/believe that the engine will last and perform better in the long run with operating temps of 180+*-200*. And since my car is more of a show car, I want HER to last.....

Chevy8588

iTrader: (1)

i knew about the adjustable auxiallary fan controllers, just wanted to make sure my ECM wasnt taking a dump, because the ECM doesnt turn my main fan on until 238* on my scanner, and i was EXPECTING 221 like my old TBI did, ill get an adjustable fan controller for the auxillary fan and run that as my main. dont forget paul, ive converted my 305 TBI to TPI and supped it up a bit as well so im making sure all my TPI crap works.

oil pan 4

iTrader: (1)

Running cold is a crutch for poor tuning.
If you want your car to last stick with a highish temp that you can mantain in all traffic conditions. That way the only time you heat cycle your engine is when you start it up, drive it and turn it off for more than an hour or so. And not every time you stop and go, say you stop at a long stop light and heat up to 220 then cool down to 160 or so when you get moving, that is a heat cycle and that temp swing is bad.
If you were smart what you would do is put in a 195'F thermo so your temp swing is more like 200'F-220'F, 20 degrees isn't much of a heat cycle.

y84pauloflondon

Thankx for the intelligent advice, But since I put the hypertech fan switch my temp stays between 180*-166+*......So, like you said, a 14* temp swing isn't much of a heat cycle. This is including Stop and Go traffic! **I also have a 170* thermo in it.**

The 4026 replaces the stock fan switch, and I have a manual switch for the secondary fan. My gauge never moves past the 1/4 mark.

91interceptorZ

iTrader: (3)

Is your gauge correct??? my gauge is off by 20 deg. Might use a laser temp gun and point it right on the sensor and compare temps.
and yes 240 is WAY too hot, I would call that overheating.....I run my fans on at 176 off at 165. If I hit 220 I pull over.

y84pauloflondon

A stock TPI.....GM set it up so that the fans come on at 238*. Now with that being said, it has been argued many times before, that 238* is too hot for the TPI engines. Some say its fine-others say thats too hot!

91interceptorZ

iTrader: (3)

my information says fans on at 218-220 deg (all-data) for factory. 238 would be in the red on your gauge. 240 is considered overheating for a sbc.

y84pauloflondon

See, thats what I thought too. I read somewhere that my 87 TPI turns on at 225* and off at 200*(fan). 238* has been stated by others. I really don't know what to make of this...........but 225* sounds high for our engines too.

deadbird

The ECM controlled fan is turned on at 220°F (TPI, 3.1v6)

ANY motor that has a fan switch (LG4, TBI, TPI, 2.8v6) is turned on at 238°F

That is the only two temperatures the (electric) fans ran on these cars for the 10 year span.