I'll try it...And yes, it was you....Maybe it was a senior moment??? :jester
Thanks again!

 

Every moment I have is a senior moment.,...
And yes I know it was me...

 

I bought a 180 stat from SLP. It seemed the same as the stock unit. I checked it and it opened and closed identical to the stock unit. Got my money back. :mad I decided to set my fans turn-on temp to the "optimum stock" setting with my Hypertech programmer. This works great. At 70mph cruise it normally runs 194, and it never runs hotter than 208 (water temp.).

I don't believe it is good to run cooler then that anyway.

 

Everyone has an opinion about what temp. to run at. I've studied it and I'm sacrificing HP since the oil in the engine will be a little more viscous. A M.E. that works with me and raced modifieds at the dirt track up to a couple of years ago (started a family) told me that they tried to maintain 200F for optimum oil performance. They didn't worry about cooling; concrete in the cooling ports in the block, but I don't know about the heads. Anyhow, if I'm running 194-196 my oil temp eventually runs over 200. Not good.
O.K., lose HP with the oil thing, but I won't have pre-ignition as readily which means the knock sensor will tell the PCM to keep my timing advanced, so I'll gain power there. Probably a wash, but I KNOW detonation / pre-ignition / knock causes damage to head valves, so I'm preventing damage in that manner. Keep your heads cooler = less chance of knock. Also, the engine is cooler, so the air going in is going to be a little cooler which = more power, too.

I've read a lot about this on the Internet in a number of different webs and it appears that the proper temp for combustion performance, not low emissions, is @172 to 175 F. That's what I'm shooting for on the hiways/byways around town.

Evil, thanks for the review on T-stat removal. Will be doing it again in the next day or two. Hypertech has been kind enough to agree to take back the 180 and send me a 160 to replace it. Someone said earlier that it sounded like I got a 190.....I agree, except, Hypertech doesn't sell a 190 :)

I plan on getting a Napa T-stat. They claim it's 186F. I'll check that on the stove and will compare the casting to the GM unit to try and determine if it should have similar flow characteristics. Then I'm going to cut coils, clean it off, and replace my 180 Hypertech with the modded t-stat. Then mop up the floor in my garage :D

Just kidding. Gonna try to get that one bolt in, Evil, and lose only a quart. That Dexcool's more expensive than beer :eek:

 

FYI

If you look inside the hypertec and most other after market (Even stock) stats you will find the "Intended" stat open temp. Just flip the stat toward the coolant side and peer into the middle pocket of the sorta tube looking thing sticking down.There you will find the target range stamped on the brass center. This will help in atleast knowing you have the correct stat int he box.We have goot quite a few stock stats in 180 boxes.

Phil

 

AHA!! That makes perfect sense. I'll keep everyone updated on what I find.

Now I think I'll go take a :chill: b/c I'm tired of being :mad

:cheers:

 

Removed the Hypertech and it was a 180, stamped on the brass piece. Cut 1-1/8 coils off my stock t-stat and reinstalled. It runs around 188 now around town. That's only @ 4 F less than what it did before. I would still like to get down to @ 175, but I don't know if I'll ever be able to. I'd be nervous to cut any more coils off my stock stat. Guess I'll wait for the Hypertech 160 and stick it in, after testing it on the stove of course. There's got to be a better way than cutting coils :sad:

 

I was going through some "stuff" yesterday in the basement, in a feeble attempt to get things "cleaned up". I found the print that I had made a year and a half ago, on how to modify the OE thermostat.

This link was at the bottom of the page. I just tried it, to see if it still works, and I couldn't get to it. However, my employer has changed a lot of their network security devices lately, and maybe that's why I can't access it. Anyway, here it is. Hopefully you can link to it, and see how an OE t'stat can be modified.
http://andrewb.speedware.com/thermo/thermo.htm

Good luck, this process worked for me.

 

Sent my 180F back yesterday and will hopefully have the 160 in hand for a spring install. Tried your link, but I'm thinking it's gone since it wouldn't come up for me, either. Was the mod the "shim" modification or the "cut the coil" modification? Could you give me the highlights? As stated, I've cut my coil and got a little improvement, but I hate to trim off any more, although I won't say that I'm not going to do it. Any help would be great.
:cheers:

 

"TC", I used the "shim" method. I started with a 1/4" stainless steel screw, chucked it in a lathe and trimmed the OD so it would just drop into the round casing inside the t'stat housing. I then cut an .080" slice off the screw, and used it as a shim. So far, so good......

 

So you had to disassemble the t-stat to drop that shim into the opening in the t-stat housing, right? Now I can visualize what the mod is and why people were mentioning BBs. Hmmmm. Just checked my spring-cutting mod. info and I should have cut off 2-1/8 coils, not 1-1/8 :smash:

80 thousandths, eh. You got you some good machinists skills there!

Well, I'll figure out something....maybe chop up my Hypertech a little when it comes in. 186F for winter and 172F for summer should work well. Need the higher temps in the winter to counteract the cold air in the intake, since the fuel tends not to vaporize when it's cold :lol:

 

TC.. I changed my stat yesterday Oct 28..... from my 160 to the 190... like Ive said, Ive done this many times... I lost less than a pint of coolant using my procedure,.,,, you need some anti sieze compound for the two bolts... a ten mm socket... and an in lbs torque wrench,,, and a pair of water pump..aka dykes, aka adjustable pliers, and some silicone grease... prep:

1) lift front of car....slide under drip pan...
2) fender protection...
3) have the new stat sitting at hands reach,,,with greased "O" ring...
4) use pliers to remove hose clamp.. slide it up on the hose.
5) pull the hose off the housing and push it up under the heater hose... no fluid lose here... ( you may see alittle fuid drip from the housing ) its no problem..
6) remove the first bolt from the housing..( the one furthest from you ) take is and put some anit sieze on it,
7) with some pressure on the housing towards the engine,,, remove the other bolt,,, ( with both bolts removed,,, my housing actually stayed on the engine this time) it allowed me to anti sieze the second bolt...
8) pickup the new stat in one hand .. then remove the old one.. ( this switch should take a few seconds... ( apply ppresure to the hosuing to stop any leaking...
9) put the first bolt in...snugg.... then the second... and torque to 89 in lbs.
10) put the radiator hose back and then the clamp...
11) pull out the drip pan... Note your loss will be very small...
12) start motor check for leaks...
13} check coolant temp... and top off coolant..
Your all done
Preperation takes a few minutes.. but the actual stat exchange should take less than 5 minutes.,,,, hose, bolts, housing off...... new housing on, bolts, torque, hose on.. check... top off




[Modified by Evil-Twin, 4:32 PM 10/29/2003]

 

Well Evil, you've definitely got me beat, but I'm getting better. I can't hold the housing against the block hard enough to prevent a certain amount of leakage, but I only lost @ 1-1/2 quarts this last time, compared to 1-1/4 gallons the first time.....so I'm getting better :D

I found leaving the top bolt in last and putting it in first helped me keep pressure. Once it's snug on installation, and before I replace the lower bolt, I can push in AND down to create pressure and keep coolant from leaking out. I need an extra pair of vise grips and I'll be able to clamp off the coolant reservoir completely, which will help the whole process since it won't be creating head pressure against the t-stat housing and will keep it from leaking out of the reservoir, saving some money and mess.

Thanks for the write-up. I'm sure I'll get down to a 1 pint loss after a little more practice following your write-up.

TC

 

TC my only other thought on the pressure issue is... everytime I exchange stats... it's in the morning before I ever start the car... I also remove the radiator cap, actually the tank cap to relieve any pressure.... the water on the engine side can get up to 16 psi... like I said .. this time I took out both bolts and the stat stayed stuck t0o the engine side.,.. thats the first time that has happened.,.. but I dont use much force to hold back the water with one hand.. IM guessing less than ten to 20 pounds of force... its these little things that make a difference


[Modified by Evil-Twin, 9:19 AM 10/30/2003]