Team Camaro Tech banner

1 - 8 of 8 Posts

·
Registered
Joined
·
278 Posts
Discussion Starter #1
How much of a temp. diff would there be if i changed over to a 160 degree thermostat? I have a 170 degree unit now along with a 17" flex fan and a short fan spacer and no shroud and a 3 core rad. in front of a 396 in a 68 Camaro. I just changed to a taller spacer and am buying a 19" flex fan. Will the lower temp thermostat make much of a difference?
 

·
Retired
Joined
·
26,595 Posts
I'll just reply about the t-stat, with the other changes there's really know way to tell without actually making them because it's all about air flow....

Different temp ratings on t-stats regulate when the fluid in the system is allowed to flow. A 160 will open sooner than a 195. If the fluid temp stays hotter than the t-stat opening temp it won't close and once the t-stat's are open it's all up to the rest of the system as to how hot the engine runs...

Example: Engine temp runs at 200 deg's and you have a 195 t-stat in the system that you change out for a 160. The 160 will open sooner but ultimatly it will never close as the temp will go back to 200 just like with the 195 t-stat.

------------------
...Dennis
'69 RS Convertible w/SS trim
'96 Z28SS #1679 of 2410
"The Club"
 

·
Registered
Joined
·
1,296 Posts

·
Registered
Joined
·
501 Posts
Not much diff...but I do disagree with those who feel a 160 won't cool better than a 195. I run 160 on my 69 and after warm up, the guage stays pegged between 180-185. If I were running a 195, the coolent temp would run somwhere around 200 or a little more, Yes, a wide open 160 flows as much coolent as a wide open 195, but a 195 won't open completely until the coolent temp reaches 195. The reason automakers use the 195's is for emmission purposes. A warmer operating engine, leaner air/fuel mix, retarded spark, etc, all combined, meant less polution (more complete burn off of the A/F mix). I'm of the opinion that from a performance point of view, a cooler engine is a happier engine. My opinion...
 

·
Premium Member
Joined
·
7,728 Posts
You're doing more harm than good running at 160; what really matters to your engine is oil temperature - it wants to be around 230-240 to ensure that moisture and moisture-borne contaminants condensed in the crankcase are boiled off and exhausted through the PCV system and burned, and if you run your engine at 160, the oil won't get hot enough to boil this junk off, so it stays in solution and never goes away - it just continues to higher and higher concentrations, contaminating your oil with acids and alkalis and reducing its effectiveness. Additionally, combustion is more efficient (read more power) and fuel economy is better at 180-195. 160 may make YOU feel good, but it doesn't make your engine feel good.

------------------
JohnZ
'69 Z28 Fathom Green
 

·
Retired
Joined
·
26,595 Posts
Sleepy,

You don't have an overheating problem though and the stat thing is a bit elusive. Let's see if I can explain. With the 160 your stat never closes and temps are maintained at around 180-185 as you state. With the 195 your stat dosen't open until the temp is 195 and climbing, when the system recovers and goes below 195 closing the stat the heat builds up again until the stat opens... Your system works properly the stat just makes it run hotter. It's not the stat cooling the car. The stat's job is to heat the car... And as Sleepy proves it can have an effect on the temp. If an engine is gonna overheat (temp climbs uncontroled) the stat temp won't matter!!

Something else to what Sleepy is saying... Modern computerized cars do use the t-stat as a trigger for emissions, spark timing etc. Back in '69 they only put 195's in AC cars and a few performance models though. The reasoning was to allow the engine to warm up faster.

I have read several times that a t-stat starts to open at the temp it's rated at but doesn't fully open until 10-15deg's above it's rating. My experence's with several t-stats a pan of water and the stove show that when heating up the water the t-stat popped open all at once. it didn't slowly open. When it closed it snapped closed... Each one I did, I started with cool water and brought the temp up and the t-stats opened within 5deg's of it's rating...

------------------
...Dennis
'69 RS Convertible w/SS trim
'96 Z28SS #1679 of 2410
"The Club"
 

·
Registered
Joined
·
501 Posts
Good info...Most of what's been said makes sense. I've no knowledge of the impact of operating temp on crankcase contaminates (alkalis and acids...I'm no chemist) but I can't imagine "harm done" because my engine runs at 185 instead of 205. Given the choice, I'll take 185 here in Texas (besides, my heater get's run only by accident..."God!..turn that damn thang off!!!")...so quick warm-up doens't mean much to me). I'm not convinced there's any advantage to a hotter running engine, other than reduced emissions....I've been called a bonehead before, so feel free. Lastly, let's not forget, a warmer colling-system is under more pressure which means more strain on the pump, gaskets, and hoses. Anybody want to discuss radiator cap pressure? Ya'll have a good weekend!
 
1 - 8 of 8 Posts
Top