Thermsotat Questions, MRR23, Orion, Frost???
This is a discussion on Thermsotat Questions, MRR23, Orion, Frost??? within the Internal Engine forums, part of the LSx Technical Help Section category; Originally Posted by mrr23 not true. i have both fans going without the AC being on. That is correct, you ...
02-02-2008, 07:43 AM #41
There are different temp setting for both fans,,,you can make them both come on at the same time if you prefer,,,which I currently have that way,,,but it still doesn't compensate for the underdrive pulley and slow moving water pump.
As a matter of fact,,,,I have the car out today,,,nice day with sunshine,,but the temps were in the mid 20's this morning....I was letting the car warmup outside for a few minutes,,,and while idling both fans came on,,,which are set at 185 degrees,,,and they are set to turn off at 180,,,,but they never did,,even this cold out.
It will sit there and idle forever no matter how cold out,,,and the fans will hold the temps around the 185 mark (the on temp setting) and won't go back down until I actually give the car some gas,,,about 1,200 rpms,,,,then after about 20-30 seconds the motor temps come back down below 180 and the fans shut off,,,,,,damn underdrive pulley
02-02-2008, 09:01 AM #42
- Join Date
- Feb 2007
- FairField, CA
RED 35TH ANIVERSARY PKG
- 2002 CAMARO SS 35th LE
Yeah i heard something like that when you change the underdrive pulleys. That the Alt has a hard time charging the bat.. I think you need to get a shorter belt or something like that.. I remember someone sayin something about that.. not too sure tho...
02-02-2008, 12:34 PM #43
02-02-2008, 03:58 PM #44
The current stat,,,which is advertised as 160 (ya right) only starts to open at 172,,,and isn't fully open and temp settled in until 175,,,and the car will run at 176 degrees or there abouts as long as it's moving,,,,which is about right for a stat that is opening like this,,,so it's more like a 175 stat to me.
If I actually found a real 160 stat,,,that theoretically should start opening around 158 degrees or so,,,I am confident the car would easily run at or just below 165 degrees,,I believe the cooling system is easily capable of it,,,,,and should hold those temps while sitting still as well,,,just as soon as I take this stupid underdrive pulley off.
I'm currently modifying the original stat much like the aftermarket does,,,and see what I can accomplish on the stove in boiling water. If I like it,,,it will go in the car and see what the laptop reads with it and go from there.
02-02-2008, 07:17 PM #45
Do people still drill a small hole in the stat to let water through prematurely to get it to run cooler?
02-03-2008, 04:48 AM #46
Some higher end thermostats you buy for the old stuff already has these holes or a check valve in it just for these reasons.
As a matter of fact after I get done modifying the original stat for the LS1,,,if I can get a temperature out of it that I am happy with I will be drilling a hole or two in it as well to experiment with.
Last time I filled the system I had issues with air pockets causing the car to run hot within a couple minutes,,,had to keep shutting it down. Hoping a couple small holes in the stat will cure that this time.
We'll see how it goes.
02-15-2008, 10:30 AM #47
Well I have been experimenting with the thermostat on the stove in a pot of hot water along with a turkey probe to monitor the temperature.
Here's what I found: Get ready, this is going to be lengthy as this took alot of trial and error. I will skip some of the spacers I made to shorten this post as small increments made no measurable change anyway.
The stock original thermostat had a crack open temperature of about 192-195 degrees and was fully open by 205 degrees. Sounds about right so I started playing with spacers.
As many LS1 books tell you,,,,about .090" is about as much as you can go, anymore than that and the thermostat hangs open.
I found this completely FALSE with my thermostat. I started with the recommended .090" spacer and it did absolutely nothing at all for a crack open temp or a fully open temperature. It was obvious a larger spacer was in order.
After making small steps with little to no changes. I finally noticed a difference when I had a spacer of .104". With this spacer the crack open temp was just above 180 degrees and was fully open by 195 degrees.
Finally I found a temp change,,but it accured at no where near the .090" spacer that all the books claim give you about a 170-175 degree stat.
I still had much more to go so I decided a bigger change was in order.
I jumped to a spacer of .147" and this changed the crack open temp to about 175 degrees and was fully open around 190 degrees. Now we are getting somewhere.
Another large jump to .193" spacer gave me a crack open temperature of 170 degrees and was fully open at 190 degrees. And guess what,,,,,at this point the thermostat is still "COMPLETELY" closing,,,,and I'm .103" passed the recommended .090" limit BUT,,,,my temperatures are getting better, so I made another jump.
I went to a spacer of .257" (.007" over 1/4"). If you have had one of these thermostats apart, you are familiar with the hole that the thermostat rod fits into. With a spacer this thick it completely fills this hole flush to the top, so now the thermostat rod is riding on top,,,but I haven't noticed any problems as of yet after cycling the thermostat several times.
Now for the temps,,,,with this spacer the crack open point was approximately 158 degrees,,,,(woohoo much like a real 160 stat should be) and it appeared the fully open temp was around 185 degrees or so. At this point the stat has reached a point ("FINALLY") where it is not quite closing all the way. It's ever so small though, and the thick gasket around the stat that seals it may be touching slightly, just to hard to tell, but the crack is so tiny I believe it won't really be enough to affect much of anything, and the car should warm up just fine until it hits the crack open point. It's not like it has a mega water pump trying to blow water past the stat anyway. (EDIT: Now the stat is completely cool to the touch and although it appears the stat is held open very slightly, I have been shinning a light into the housing and I cannot see any visible light through the other side,,,good enough for me.)
If you notice,,,as my spacer got larger,,,the spread from crack open point to fully open was getting larger, but the temps overall were coming down.
This has me wondering if the stat could benefit from changing the pair of springs that force the stat closed. I am now wondering if the modified stats from SLP and a few others even bothered changing to a different rate spring or not???? In any event, the only real test is to now stick it in the car and monitor the temps with the laptop and see how it acts.
I am hoping to get a more realistic 160 degree operating temp, since now this stat seems to be more than 50% open by the time it hits 165 degrees. Only driving and scanning will tell me for sure.
Just for giggles I noticed alot of casting flash inside the housing so I broke out the porting tools and ground the access flash off the roof and widened the short turn radius
Last edited by Firebirdjones; 02-15-2008 at 10:42 AM.
02-16-2008, 07:03 AM #48
i bet you'll drop another 10* with that port job you did!!!
good write up. keep going with it. have you tried cutting the spring?
02-17-2008, 03:54 PM #49
I am still playing with it,,,the thermostat that is and I am going to take the SLP stat out of the car soon and put it on the stove as well and see how it acts, compare the springs etc....maybe I'll find something
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