Low Temp Thermo

BlownMerc

Registered User
Is there anything I should expect when I install my Low-Temp thermostat in my 90 XR7 Auto....both good and bad comments please.
Brad
 
The thermostat will open quicker, but once it has fully opened, you won't see any difference in volume of flow. There may be some benefit from the thermostat remaining fully open for a longer duration (due to the lower temp "trigger"). The greatest benefit comes from using the lower temp thermostat in conjunction with an adjustable cool-fan switch or a manual overide fan switch........
 
runs hot

LJGriggs said:
The thermostat will open quicker, but once it has fully opened, you won't see any difference in volume of flow. There may be some benefit from the thermostat remaining fully open for a longer duration (due to the lower temp "trigger"). The greatest benefit comes from using the lower temp thermostat in conjunction with an adjustable cool-fan switch or a manual overide fan switch........
what I did was cut the 14 wire at the IRCM FAN RUNS LOW SPEED NOW.................STILL RAN HOT SO I TOOK OUT THEMOSTAT REMOVED COOPER PLUG PUT A FLAT WASHER IN WITH 9/16 HOLE ...........................RUNS BETWEEN 130-140 ALL THE TIME...................FAST FREDDIE :: :) :)
 
For the guy who pulled his thermo....bad idea. The EEC does not come out of open loop until you get above a set temp somewhere around 195 so now you are likely contaminating your oil with the unburnt fuel you are washing the cylinders down with.

Also for the guy looking at a lower temp thermostat......don't run your car in cold temps or you will be in the same condition as outlined above. BTDT on my 89. Dropped 4 MPG in the winter and the oil came out like water from the gas in it last spring.
 
Why would you want to run between 130-140 all the time? And how do you know that's the temperature - typical water temp gauges aren't too accurate in that range.

Duffy, I think the EEC goes into closed loop based on when the oxygen sensors are warmed up, not ECT. What I've seen on my A/F gauge is that on a cold start, the O2 sensor output will slowly rise (over maybe 30-60 seconds) from 0V to around 1V, and then after that it starts switching, indicating closed loop operation. This happens before the temp gauge has even moved. But it would still have problems with open loop modes, you'd be running too rich at WOT because the ECT is so low, not good for power.
 
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Rob,

Allow me to quote from my Ford Advanced Engine Performance Training Manual.....

"Closed loop control of the fuel system is only possible when the following conditions are met.

* Engine Temperature is above a calibrated level.

* The TP sensor is at part or closed throttle and not wide open throttle.

* Other factors in the EEC strategy are satisfied. For example, thermactor air must be either downstream, or bypassed and the EGO sensor voltage must be switching regularly between high and low voltage signals."

I rest my case. (Remember the book is written to cover many models not only the SC so the reference to Thermactor is correct and possible.) Copyright on the book is 89.
 
Duffy Floyd said:
For the guy who pulled his thermo....bad idea. The EEC does not come out of open loop until you get above a set temp somewhere around 195 so now you are likely contaminating your oil with the unburnt fuel you are washing the cylinders down with.

Also for the guy looking at a lower temp thermostat......don't run your car in cold temps or you will be in the same condition as outlined above. BTDT on my 89. Dropped 4 MPG in the winter and the oil came out like water from the gas in it last spring.

Thanks ya'll. I live in Florida and cold temps do not exist here...so I think I'm OK. This is why I want to run cooler since its so damn hot here.
 
Nice you live in the sunny south but without a way to control your fans at the new lower temp you hope to achieve....you might as well flush your good money down the toilet for all the good the lower temp thermo will do you.
 
i don't know if anyone listens to me, butif you put a robert shaw 180 t-stat, and have your fan on constantly by cutting wire 14, your stock temp gauge will read "n" all the time , no matter how hard you stomp on it. The robert shaw flows more coolant than any other t-stat. I think even the t-stat that ford has is different from the t-stats that came when the cars were new. I bought thermostats from every shop around here and they all made the car run hot. The hole sizes were different some were an 8th of an inch smaller or larger. When you look at a robert shaw you can see that it easily out flows any other t-stat.
When i say hot i mean that the stock temp gauge sits between the "r and m". I had 3 motors that blew up from running too hot. TO any one who has a temp gauge that sits on the "r" and "m" get a robert shaw and cut your number 14 wire and you will see a huge difference in your temp. Trust me I know and you don't need a chip. This will make your temp gauge sit on the "n", and you will have a lil more power too from cooler engine temps.
good luck
joe
 
RUN COOOLLLLLLLLLL

I COULD CARE LESS ABOUT THE EEECV.................... I KNOW FROM RACING OVER 50.YEARS WORTH ...........................THAT A COOL ENGINE RUN FASTER THAT A HOT ONE..AND WILL LAST LONGER ALSO................STOCK CARS AND DRAG AS WELL AS SOME GOOD OLD STREET RACING.........I,VE SEEN THE HOT ONES " BLOW UP " WHY THE COOL ONES STAY TOGETHER..................... TO EACH HIS OWN ..................................................................... P.S. WHY USE INTER COOLERS ,DRY ICE, COOL AIR INTAKES ..........I REST MY CASE............FAST FREDDIE:cool: :cool: :cool:
 
First of all no SC's have a EEC V...they are all EEC IV. The reason you cool the IC and all is to decrease the temperature of the air charge to the motor. That has the effect of increasing the adiabatic efficiency of the supercharger since the density of the air charge is increased.

Not all forms of motor racing follow your thoughts on coolant temps. NASCAR typically run well in excess of 200 degrees but I do agree you do have a point of diminishing returns above which a hot engine runs worse than a cooler one but it is all relative. I speak of the difference from 235 to 195 not 225 to 140.

But you are correct....to each his own but do not expect your SC motor to last longer....I guarantee if you run at 130 to 140 all the time you will be rebuilding sooner rather than later.

The primary reason being that on a carburated engine typically you got no fuel enrichment on a cold engine that lasted a long period of time. You either had a mechanical choke you controled by hand or with a throttle kickdown or you had an electric choke that used a heater and only stayed on for a period of time. On our SFI SV's though you will never get out of the cold run strategy and will be running around with altered ignition timing curve as well as fuel map that will dump too much fuel into the cylinders. Todays cars are NOT your Father's Oldsmobile if you get my drift.
 
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What wire bundle is this mysterious wire #14 in? Where exactly is it?
Thanks to all for solving my cooling problem in less time than it takes to find a knowledgable mechanic.
 
As of today 6-11-03, I am finding out that Autozone does not carry the Robert shaw 180' therm, just the 195. And it is made for Autozone by Robertshaw. The correct part number is 457-180 but they don't stock them anymore. Even Pep Boy's out here in CA. only carry Stant. So the only place I have seen them listed is at supercoupeperformance.com for $15. Help... I need one today!

I am still hoping someone will tell me where exactly to find wire #14 to the cooling fan so that the low speed will run when the engine is running.
 
Summit carries the Robertshaw thermostats under the Mr. Gasket brand name, $8.95. But then there's the $7.95 summit handling fee, so unless you need to get some other stuff, you might be better off looking locally for the Mr. Gasket part numbers, these are 4365 (195 deg.), 4364 (180), or 4363 (160).
 
The #14 wire can be found on the harness that attaches to the IRCM (Integrated Relay Control Module) which is located between the air box and passenger side headlamp.Unbolt the harness and look for wire numbers on the connection.

And just for the record, cutting the #14 wire and running with a 180 robert shaw t-stat does not solve everyones problem, but I do agree it will help those cars with only moderate mods. I would suggest wiring a switch instead of just clipping the wire.

Mine has both a pusher and puller fan wired with dual cool fan switches to run both fans constantly on high speed. Even with a Robert Shaw 180 t-stat and the AC turned off, mine slowly climbs to the "R" when outside temps reach 80 degrees.

Since it's usually more of a problem on the highway, I'm going to try adding a larger air dam and re-core the radiator with a 3 row high effeciency core. I dropped the radiator off this morning...$265 plus tax for a custom re-core.

Does anyone remember that air dam application that fits an SC really well ? Pontiac Grand AM maybe ?

David
 
David, I saved this from an earlier Vernon post:
The air dam is GM P/N #22635885. It fits the ’92-‘98 Pontiac Grand Am and it costs about $16.50. It's 3 inches high and leaves about 4 inches of ground clearance when installed on my stock height '93 SC.

There are 4 holes in the flange of the air dam; let's call them #1, #2, #3 and #4. Drill a 5/16 hole in the flange midway between #2 hole and #3 hole. Then using a rat-tail file elongate #2 hole about 1/4 inch toward #1 hole and elongate #3 hole about 1/4 inch toward #4 hole. Using 3/4 inch long 1/2-20 screws, washers and Nylock nuts in holes #2, #3 and the new center hole, secure the air dam to the bottom of your front bumper cover using existing holes in the cover. Drill two new holes in the bumper cover coinciding with #1 hole and #4 hole in the air dam. Again using 1/4 inch long 1/2-20 screws, washers and Nylock nuts secure the ends of the air dam to the bumper cover. (Vernon C. originally)
 
RUN,S COOL

I CAN,T SEE HOW IF YOU HAVE GOOD RINGS AND A GOOD IN INJECTION SYSTEM YOU WOULD HAVE ALL THE FUEL RUNNING DOWN THE CYLINDER WALLS................................FAST FREDDIE ...................P.S. CARS RAN GREAT YEARS AGO WITH OUT ALL THE ELC.;,..,..,,JIOFV UY.//..,//5R8L;HGKDJ GARBAGE....:cool: :cool: :cool: :D :D
 
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