180 thermostat fitted

[maherm]

HI guys...I have installed a 180 degrees 63mm thermostat and the engine is very happy on the highways-reading 185 to 195 degrees- on the EVIC but it goes back to regular temp. in city driving which is 214-217
I will try the 160 stat i am trying to locate and order .
I had 4 stats to play with by making extra holes but with the same results.
installation is very easy...removing two screws from the housing in front of engine and using same gasket....BTW it is the same thermostat of hemi RAMS and DURANGOS big 63mm,,,really big.
Thermostat: SUMMITRACING SUM-360181 $8.95
BE COOL BCI-78008 $19.69
Just wanted to share my experience.
maherm

[BrilliantBlackHemi]

The reason the temp eventually goes back up it the computer must be reprogrammed to turn the fans on at a lower temperature to match the reduction in the thermostat. At highway speeds, the need for the fan is a lot less so it's still benficial there. Also, the lower t-stat is still good for drag racing when you cool down your car between runs.

Thanks for sharing the info. With it on the front right in your face, I guess it's one of the easier installations. Is this correct?

[qictrk]

Originally Posted by maherm

HI guys...I have installed a 180 degrees 63mm thermostat and the engine is very happy on the highways-reading 185 to 195 degrees- on the EVIC but it goes back to regular temp. in city driving which is 214-217
I will try the 160 stat i am trying to locate and order .
I had 4 stats to play with by making extra holes but with the same results.
installation is very easy...removing two screws from the housing in front of engine and using same gasket....BTW it is the same thermostat of hemi RAMS and DURANGOS big 63mm,,,really big.
Thermostat: SUMMITRACING SUM-360181 $8.95
BE COOL BCI-78008 $19.69
Just wanted to share my experience.
maherm

You may want to put the stock thermostat back in. The new engines today are engineered to run at a hotter temp. Your probably thinking precomputer engines. IMO those days don't hold water on modern day engines unless your running a supercharger. You will find that on warm days, especially in stop and go your engine will acually run hotter than stock and may acually overheat easier. It would take a large thread to explain why your engine will run hotter with a 180 and even hotter with a 160 thermostat. In cool weather you'll be ok. In a few words it's because with a cooler thermostat, the water will be continually circulating at a much higher flow. You will not have a reserve of cool water to be released like the stock one is set up to do. I've had many new, old, and supercharged engines. Been there, done that. Well, I've put out my 2 cents worth. Cecil...........

[Dutch]

Do not use a 160 degree thermostat. Your computer will think the engine is never warming up and will eventually trigger a CE light. Also, 160 degrees isn't hot enough, and the engine will wear much faster at that temp. I would use nothing lower than stock, but 180 at least won't hurt anything. As was said before, you need to have your fan come on sooner.

[Dixietwister]

Aluminun heads and cold thermostat=less power. Cold engine means it takes longer time to get the condensation out of the oil. More engine wear. Plus, plus and plus.

[maneval69]

You may want to put the stock thermostat back in. The new engines today are engineered to run at a hotter temp. Your probably thinking precomputer engines. IMO those days don't hold water on modern day engines unless your running a supercharger. You will find that on warm days, especially in stop and go your engine will acually run hotter than stock and may acually overheat easier. It would take a large thread to explain why your engine will run hotter with a 180 and even hotter with a 160 thermostat. In cool weather you'll be ok. In a few words it's because with a cooler thermostat, the water will be continually circulating at a much higher flow. You will not have a reserve of cool water to be released like the stock one is set up to do. I've had many new, old, and supercharged engines. Been there, done that. Well, I've put out my 2 cents worth. Cecil...........

qictrk,
I must respectfully disagree.
Today’s engines are engineered to produce lower emissions. That’s way they run a little hotter. My 1972 cutlass came with a 195 degree thermostat.
The "old" rules are physics and no computer can change that. Computers do allow the engines to operate at higher temps because that can compensate for pre-ignition (spark knock). AND THIS IS WHY COOLER TEMPS= POTENTIAL POWER. Just changing the stat probably will not show any gains but if we could change the fuel maps, the cars could run leaner with out the computer taking timing advance out. More timing advance=more power, leaner mix (to a point) = more power
As far as the engine running hotter, the 180* stat allows the same amount of flow as the 195* stat. It only opens sooner. Even if it did allow more flow that would not equal less cooling. Now with out air being forced through the radiator the engine will run at the same temp no mater what stat you have. This temp is determined by the fan "on" temperature setting.

Dutch is right. You can go too cool. The computer runs a different program untill it reaches a set temp.

Dixietwister

Aluminun heads and cold thermostat=less power. Cold engine means it takes longer time to get the condensation out of the oil. More engine wear. Plus, plus and plus

.

I'm not sure why you think Aluminum heads and cold thermostat =less power.
The whole point of an aluminum head is it dissipates heat better than iron. This helps eliminate hot spots in the combustion chamber which can cause pre-ignition. (Which the knock sensor will see and the computer will take timing out)
As far as the oil, cooler oil is better for engine life. There is something to the condensation but 180* is plenty of heat to evaporate water.

just my 2 cents

[Northern Rider]

We've always brought our performance engines into this temp range.

I'm with you on this one, maneval69.

[qictrk]

[quote=maneval69]qictrk,
I must respectfully disagree.
Today’s engines are engineered to produce lower emissions. That’s way they run a little hotter. My 1972 cutlass came with a 195 degree thermostat.
The "old" rules are physics and no computer can change that. Computers do allow the engines to operate at higher temps because that can compensate for pre-ignition (spark knock). AND THIS IS WHY COOLER TEMPS= POTENTIAL POWER. Just changing the stat probably will not show any gains but if we could change the fuel maps, the cars could run leaner with out the computer taking timing advance out. More timing advance=more power, leaner mix (to a point) = more power
As far as the engine running hotter, the 180* stat allows the same amount of flow as the 195* stat. It only opens sooner. Even if it did allow more flow that would not equal less cooling. Now with out air being forced through the radiator the engine will run at the same temp no mater what stat you have. This temp is determined by the fan "on" temperature setting.
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Your probably going to be ok with the 180. But on a hot day, if your stuck in stop and go, you will over heat faster with a 180 than a 195. Like you say, it opens sooner. But because of this your water will continually circulate at a higher flow and will not allow the ambien air to have a chance to cool the water in your radiator. With a 195 you will start with a higher temp but the flow will be slower allowing more time for the air to cool the radiator down. I have a hard time putting my thoughts into writeing so if your not sure of what I'm trying to say, thats ok. Maybe one the engineers can better articulate what I'm trying to get across. It's not big deal and I don't want to make it anymore than it is. Like I said, you probably can get away with a 180. I've used them in the past too. Cecil..........

[goddardzilla]

Most engines today are designed to operate within a "normal" temperature range of about 195 to 220 degrees F. A relatively constant operating temperature is essential for proper emissions control, good fuel economy and overall performance.

The aluminium pistons and the cast iron block have different expansion rates, they achieve their factory engineered clearance within the temperature ranges provided by the factory t’stat.

For street, non-forced induction engines there is little benefit to a lower temp t’stat. Due to differential expansion rates; lower temp gives a piston/bore clearance is too large, resulting in more oil blowby into the combustion chamber.

Lower temp. Also gives a lower combustion temp. which results in less-complete combustion and higher emissions, and an early build up of carbon, and lowered fuel mileage.

Overall the lower engine temp may result in a slightly denser/richer air/fuel mixture producing a little more power, and possibly a perceived improvement in throttle response, but it also exacerbates ring wear due to the oil washdown effect of unburned fuel.

A set of different heat-ranged spark plug may be needed to try to offset the incomplete combustion.

Small potential positive, definite potential negatives

Zilla

[maneval69]

Zilla

Most engines today are designed to operate within a "normal" temperature range of about 195 to 220 degrees F. A relatively constant operating temperature is essential for proper emissions control, good fuel economy and overall performance.

True – but if you tune an engine for 180 it will produce more power than the same engine tuned to 195 degrees.

The aluminium pistons and the cast iron block have different expansion rates, they achieve their factory engineered clearance within the temperature ranges provided by the factory t’stat.

Pistons have all been aluminum since the 60's and 15 degrees will make an insignificant change in the size of the bore or the piston. (If it’s even measurable) Keep in mind these things work from -32 to 210 with no problem.

For street, non-forced induction engines there is little benefit to a lower temp t’stat. Due to differential expansion rates; lower temp gives a piston/bore clearance is too large, resulting in more oil blowby into the combustion chamber.

See above

Lower temp. Also gives a lower combustion temp. which results in less-complete combustion and higher emissions, and an early build up of carbon, and lowered fuel mileage.

There will be higher emissions but if you have carbon build up you are running to rich.

Overall the lower engine temp may result in a slightly denser/richer air/fuel mixture producing a little more power, and possibly a perceived improvement in throttle response, but it also exacerbates ring wear due to the oil washdown effect of unburned fuel.

Cooler temps should not change the air/fuel ratio. (unless you cool the engine to much like say 160 stat) Anyway a richer mixture would reduce power not increase it. As far as washdown, you would have to be running way too rich (by today’s standards) for that to happen.

A set of different heat-ranged spark plug may be needed to try to offset the incomplete combustion

. This may be necessary but easily checked. Run for a while and pull a plug.

qictrk,
Both a 180 and 195 stat flow the same at 210 degrees. How is one going to make any difference over the other? Opening sooner only make the engine heat up slower from 180 to 210 or whenever the fan cuts on. The thermostats job is to heat the engine up not to cool it off. That’s what the fans are for.
I have had the experience (on the old motors) of removing the thermostat completely and having over heating problems. That local mechanics told me it was because the water moved through the radiator to fast to dissipate enough heat. This sounds like it could happen but the real problem was the fan clutch was weak. After fixing that, the engine ran too cool and took forever to produce heat. So, I put the thermostat back in and everything was fine.

Bottom line - a cooler T'stat will probable make no difference in performance unless you wire one of the fans to run all the time and/or re-program the computer to lean the mixture and add more spark advance.