Flyman

This one is a little different for most

I installed a LS1 engine in my 1998 Jeep wrangler and I sent my computer out to be reprogrammed by Speed Inc.

The only thing In question is that I told them that I have a 180* thermostat and I only run ONE fan and I will need my fan to kick on accordingly..........well after I got it back and ran it the fan did kick on at 180* and off at around 177 or so. I couldn't belive that this is correct so I called them and they said send it right back and they will take care of it free of charge................Sweet...........BUT


So after talking to a few of you veterns here on LS1tech I was instructed to have the FAN turn on at 195* and turn off at 190* with a 180* thermostat. so I wrote up a letter to do just that, sent it out and I got it back this weekend..................and guess what,,,,,it still turns on at 180*, that was worth another call to Speed inc. the person I talked to on saturday (wont name name's) said that the fan is suppose to kick on at the same time the thermostat is opening, That conversation went on for a long time.....................ANYWAYS.


What should I do.


With only one fan and I do alot of slow crawling and dune running should I just leave it alone because my thermostat actually opens at 177* and the fan looks like it kicks on at 182*

OR

have the fan kick on at 195* off at 190* even though it may run around that higher temp in the summer



I need help on this bad, It has gone on tooo long



Thanks

John_D.

iTrader: (2)

My 180 thermostat was holding 202 degrees under all conditions. Fans on, fans off, idle, cruise. In that case, fans on at lower temps just means the fans are on constantly.

If you can find what temp it's holding at steady cruise over 40 mph, that would be a good target. Then if you slow down, the fan can come on and keep the air flowing over the radiator.

I ended up ditching the 180 thermostat and going with a 160 thermostat, and added a 3mm shim. Even at that, steady state operation with plenty of airflow is 172 degrees.

jimmyblue

iTrader: (11)

The factory 'stat is also about a nominal 180 rating
and held my car at 194F. My Hype-tech 160 holds
about 178F. The all-aluminum motor can run more
water jacket temp than an iron head motor. But I
always liked cooler, better myself. 172F is plenty
cool as long as your radiator holds pressure.

Nominal 'stat ratings are like any aftermarket product
rating pretty much.

I'd think about just forgetting the controlled fans,
get a nice big electric pusher fan up in front and
run it full time. I favor having the tank as a "cold
reserve" for surge loads and having the thermostat
in full authority (not having the fans turn on only
after the 'stat has been overrun).

Flyman

I took my stock stat and added a .084" shim and did alot of testing and it opens at 177*, Well let me rephrase that in about 50* outside temp. the stat keeps the motor cool at 177* Just before the fan kicks on, at 180* the fan kicks on.

So going down the road in the summer the fan will be on all the time, that is a problem.

Flyman

Can anyone else help me?

jimmyblue

iTrader: (11)

Why is the fan being on, a problem? Other than noise,
that's how it was up until the '90s when the manufacturers
needed that last 0.1 MPG.

Another_User

You need to run the fan at a higher temp, like the temps that were recommended to you. When it gets hot out your fan would run forever trying to cool your vehicle to a temp that your thermostat would never let it reach because it would be closed. You need your fan temps higher. In fact, when summer comes around you should still make sure your fan is not running all the time, because you may need to bump it a bit higher. You always have to make sure your fan is not trying to work against a thermostat. Also, lower temp thermostats rarely keep your coolant as cool as they are rated for (hence the higher fan temp settings). I hope that clears things up.

jimmyblue

iTrader: (11)

I still favor an airflow surplus.

Start from the water jacket temp you want to
maintain. Pick the thermostat that does it. Give
that thermostat enough fin, tank, water and air
flow to have authority, and you'll be rock solid.