Modifing Thermostat
Thread Starter
Racer
Joined: Jan 2003
Posts: 252
Likes: 0
From: northern nj
Modifying Thermostat
I read a few post that stated you can modify a stock thermostat to become a 170 stat. Also in the LS1/6 performance book it gives detailed instructions how to do it. I took 1 apart and tried the different ways and have come to the conclusion that it is impossible to do. The spring in the stat does not contract untill it reaches the temperature it is rated for, so basically it will not open fully untill that temperture (190-195) Someone tell me if Im wrong but I dont thinks so. :cheers:
[Modified by cbota, 10:00 AM 5/2/2004]
[Modified by cbota, 10:00 AM 5/2/2004]
Instructor
Joined: Sep 2003
Posts: 124
Likes: 0
Re: Modifying Thermostat (cbota)
I will try and walk you through this, I don't know if it will work in an 04 because tha stats diffrent. Once you take the stat completely apart you will see a small hole inside the housing, this is were the round shaft of the stat goes into the housing. A .101 shim installed into the hole will make your stat about 180F, mine runs at 183F, I was a little off. I used the inside of a yellow butt connecter, it's just the rite size in diameter,it cuts easy and taps right in. If you can locate Team ZR1's website they provide excelent instructions.
Thread Starter
Racer
Joined: Jan 2003
Posts: 252
Likes: 0
From: northern nj
Re: Modifying Thermostat (simplyred02)
Basically that will keep the stat from closing all the way, but the spring will not start contracting untill the 190 temp. is reached, so it will not fully open untill then. I did what you stated and did a number of tests in monitored water temp. The only way that it will full open is to change the spring with 1 that contracts at 160 of 170. Let me know
Thread Starter
Racer
Joined: Jan 2003
Posts: 252
Likes: 0
From: northern nj
Re: Modifying Thermostat (Evil-Twin)
I believe they are 40-60 bucks but that is not the point. The point is this mod doesnt work. If you have the fan come on at a lower temp. the 2 are fighting each other, the stat never fully opens untill 19?. Im laid up right now with a injury so I have the time to test this mod. I just would like to know if someone could prove if I am wrong and what I am missing. :seeya
Burning Brakes
Joined: Apr 2003
Posts: 908
Likes: 4
From: TROY MI
Re: Modifying Thermostat (cbota)
I did it and it works.I checked it on the stove in a pan of water.It took me a couple of tries to get the 160* I was looking for but I got it. My car ran 160* in the cold MI. winter. It runs about 175/180 in warmer weather.Just put a shim in and try it.
Le Mans Master
Joined: Nov 2003
Posts: 8,004
Likes: 250
From: Tampa Fl
St. Jude Donor '12-'13-'14
Re: Modifying Thermostat (yankeevetteconvert)
55 bucks will get you a thermostat and house from a couple of vendors. You see on here, some things are just worth the peace of mind money
Instructor
Joined: Sep 2003
Posts: 124
Likes: 0
Re: Modifying Thermostat (cbota)
Since I have shimmed my stat, I can let my car idle all day in the south Texas heat and it doesn't get over 185F, I also have my fans programed to come on at 180F. The shim mod worked great for me and only cost the price of some coolant and a little research.
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Drifting
Joined: Apr 2001
Posts: 1,779
Likes: 6
From: LOS ANGELES CA.
Re: Modifying Thermostat (cbota)
when I had my LS 1 Edit tuning performed,the tuner set the fans to come on at a lower temperature.I have the stock thermostat,and my temperature rarely goes over 190 degrees.I see no reason to change the thermostat. :chevy :chevy :flag :chevy :chevy
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Re: Modifying Thermostat (cbota)
I believe they are 40-60 bucks but that is not the point. The point is this mod doesnt work. If you have the fan come on at a lower temp. the 2 are fighting each other, the stat never fully opens untill 19?. Im laid up right now with a injury so I have the time to test this mod. I just would like to know if someone could prove if I am wrong and what I am missing. :seeya
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Le Mans Master
Joined: Jan 2001
Posts: 5,002
Likes: 506
From: Hilton NY
Re: Modifying Thermostat (Evil-Twin)
If you cut the large spring the temperature will be reduced and the valve will close all the way. If a lower temperature is needed then more of the spring is cut away. The fans should be adjusted too.
Drifting
Joined: Aug 2002
Posts: 1,258
Likes: 0
From: South
Re: Modifying Thermostat (Fast one)
I cut the spring on an extra stock stat. My fans are set to start coming on at 183 or so. I drove it for 15 mins the first day and the temp was around 185*.
The 2nd day for 30-45 mins at a good pace. The temp was about 178*.
5am on the way to work today with the temp outside being 46*f. I drove 7 miles at 55-60 water temp 145*. Then the interstate for 20 miles and the temp was about 151* driving 80mph. About 4 miles and a few stop lights brought her up to 178* when I pulled into work.
Its supposed to be warmer for the rest of the week, and 89*f sunday when I drive at Road Atlanta.
I may reinstall the stock stat after the track event.
The 2nd day for 30-45 mins at a good pace. The temp was about 178*.
5am on the way to work today with the temp outside being 46*f. I drove 7 miles at 55-60 water temp 145*. Then the interstate for 20 miles and the temp was about 151* driving 80mph. About 4 miles and a few stop lights brought her up to 178* when I pulled into work.
Its supposed to be warmer for the rest of the week, and 89*f sunday when I drive at Road Atlanta.
I may reinstall the stock stat after the track event.
Thread Starter
Racer
Joined: Jan 2003
Posts: 252
Likes: 0
From: northern nj
Re: Modifying Thermostat (silverz06vette)
I understand cutting the spring, but the spring length is also what hold the stat in place. So making it shorter does not make the metal spring contract at a lower temp. Cutting it too short and you risk not having enough pressure to hold the stat in place. I believe you can get your temps lower with the fan coming on at lower temps but the stat is still not open all the way, so they are working against one another.
Melting Slicks
Joined: Mar 2001
Posts: 2,370
Likes: 51
From: New Milford CT
Re: Modifying Thermostat (cbota)
It works, I did it. I took 1 full coil off off the spring. The car was LS1 edited for the fans to come on sooner the next day. Now my temp rarely goes over 192. It used to be 210 or more.
Instructor
Joined: Mar 2004
Posts: 235
Likes: 0
From: MI
Re: Modifying Thermostat (silverz06vette)
Are you talking about the stock thermostat with modification? If so, what did you do to the thermostat to get this great low temp? thanks for any help
:banghead:
:banghead:
Pro
Joined: Apr 2002
Posts: 726
Likes: 2
From: Denver CO
Re: Modifying Thermostat (CJS)
It works, I did it. I took 1 full coil off off the spring. The car was LS1 edited for the fans to come on sooner the next day. Now my temp rarely goes over 192. It used to be 210 or more.
I did @ 1-1/4 to 1-1/2 coils and it rarely goes over 192 and is usually 189. Winter was @ 189 and had no problem with the temp. staying lower. However, I'm looking for 172, so I'll be putting my 160F Hypertech in for summer and replace it with my cut t-stat for winter.
Pro
Joined: Apr 2002
Posts: 726
Likes: 2
From: Denver CO
Re: Modifying Thermostat (cbota)
I understand cutting the spring, but the spring length is also what hold the stat in place. So making it shorter does not make the metal spring contract at a lower temp. Cutting it too short and you risk not having enough pressure to hold the stat in place. I believe you can get your temps lower with the fan coming on at lower temps but the stat is still not open all the way, so they are working against one another.
