Well if the intent was to direct the comment to me then let me tell you I am no kid by any means. However, I thought I would change the thermostat (back to 195) to see what if anything would happen as entertainment for everyone else. Like I said before, I think there is a gray area here (huge one), I think from my standpoint that everyone here is probably correct. You have one side that says higher temps increase efficiency and decrease emissions. The other side says no stat or one lower will give you better performance cooler intake etc., and if you run the engine with no stat or 160*, then it will run cooler. I think the first side is saying do not use the no thermostat/160* thermostat on an engine that is overheating cause it is probably something causing this and lowering the temperature of the thermostat or running with none will only insure the cooling system runs constant and doesn't allow the coolant to sit long enough in the radiator to disipate heat. One side says running no stat/160* will keep a healthy engine cool, the other says don't do it your crazy when what they should say is you are correct it will however at that operating temperature damage to the engine occurs that could be prevented by a higher running temperature. I think if everyone looked at what the other were actually saying they could meet in the middle. Make any sense?

Strangeranger the thermostat was 160, it was dropping at 150 why I don't know because the new one drops right at 195 on the gauge. If at this point anyone cares I will drive it and get it warm and see if I have any issues with heat soak or pinging. Anyone would agree if I set timing and fuel to operate on an engine at 160 then raising the temp to 195 could have some effects on timing/pinging.

 

No, your arguments are bad, I just don't have the time to educate you gents. I do have work to do...


-You have got to be kidding...

On the other hand... I also turn wrenches on my own vehicles and I have worked on cars professionally. I am NOT as smart as some of those Engineers and Scientists.

There are Engineers AND Scientists at work formulating the info that gets published thru the SAE, as well as Mechanics and Technicians. It is a collaborative effort.

jw- you may have to re-tune your engine and you may have to fix whatever is wrong with it. Running at the proper temp is no cure-all.

 

I found this while looking through project mpg:

Thermostat page, project mpg
Read it, they make good arguments against 160 degree thermostats.

I don't know where they get their data from, but they say some of the same things Torque1st has been saying. They actually say the complete opposite of what Bronco351 has been saying:

The restrictors that race cars use does slow the water down some allowing greater heat transfer both from the engine, and to the air via the radiator.

For Bronco351, do you have a temp guage to know what temperature the water is running at without a thermostat? If so, what are your water temps?

Another thought I had was if someone was running a 160 degree thermostat because they had overheating problems, their engine is probably not running at 160 degrees. It is most likely running much closer to normal operating temperature than 160, therefore they wouldn't have any issues with the engine running too cold (efi mostly here).

I help a freind of mine with his race car (circle track), and they told me that the engine puts out the most power when water temp is right around 190...this is carbureted. I have to agree with strangeranger that the colder the water temp is, the more heat from combustion goes to the water than if the water were hotter.

My 2 cents...

 

torque1st
I don't have any issues right now with the engine, it is just known that edelbrock carbs sometimes will not start as they should if the engine has been warmed to operating temperatures. I was unsure if that may occur, goind from the lower thermostat to the 195*, since I first had the problem I installed a spacer and heat tape on the fuel lines. I ran it this morning when I replaced the thermostat to check for leaks etc.and I drove it shortly mainly let it set in one spot for a while and it hovered right around 195* as it should and I was able to restart it without any drama, no pinging on moderate acceleration from start or up hills so it appears its fine as is, for now.

 

I have already run stock thermostats, 180 stats, and now running my 160 stat, which allows the truck to perform better then the former two.

The individual saying that you make more power with a higher water temp is simply not telling the truth, and here is exactly why: with a lower water temp, the timing on EFI equipped engines will advance- and that makes more power than what was lost by running cooler. If i am now making less power- then what explains the better performance i am getting, and most of all, the better gas mileage?? The timing advances automatically in most EFI equipped vehicles. Of course folks like Bronco351 simply advances the timing on the distributor. My wifes car is a 94 Geo Tracker and i was surprised to see the timing adjustable on the distributor. After the 160 stat on her car, bigger radiator, water temp gauge installed- and timing advanced 4 degrees over stock- the result is an increase in gas mileage, from 24 to 28 mpg.

As for water temp gauges- yes, i know what my water temp is, since when i buy all of my trucks now i install water meter #2333, which is a mechanical water temp gauge, and my temp now runs 170 (190 is very highest) even in 95 degree weather (the temp today) And that is with the A/C blowing cold, and it blows much colder now then when i run the truck 220 (which only occured the first two weeks or so that i owned it) j.d., KCK

 

Torque1st couldn't be more right here. Running your engine too cold is not good for it. If that were the case people in the southern states and desert would just remove their thermostats all together. What else would they be good for?

 

That's exactly what I'm saying. If you live in a hot state, you should completely remove your thermostat in the summer, and run 160* thermostat the rest of the year!!!

 

It's easy enough to see wear caused by cooler temps. All you have to do is look at any block laying around with the heads off. Check the ridge at the front of the front cylinder ( anyone who says their high miler doesn't have a ridge didn't look there ). The wear at the front of the front cylinder is caused by the cooler temp caused by the coolant hitting there first. Inline sixes are the absolute worst about this because of the huge hole in the front of the block where the water pump mounts. Everyone has a personal preference for thermostat temps, mine is 195. A carbed engine always gets better mileage that way, for ME anyway. I found this out the hard way by having to use a 195 in an emergency ( I had always used 180's ) and was well rewarded by taking the chance.

 

Do you want to know why, you naysayers, having your coolant less than 180 will wear out your engine?

*The coefficient of friction between aluminum (pistons) and iron (block) is a function of temperature. As the material's temperature increases, the coefficient of friction between the materials decreases. -me, based on Mechanics of Materials, 5th ed. Dr. Jack McCormac, et al

There is a sharp inflection in the curve of this property between 170-180, where the friction will increase rapidly with temperatures below 170.

Running with no thermostat will creat turbulent flow in the water jackets, resulting in less contact time with the heat transfer zone, and creating hot spots that will likely cause warping of iron parts. I am stunned that some of you still reject the idea that faster coolant flow will not proportionally transfer more heat. It's called THERMODYNAMICS, you oughtta read up about it, since it governs or at least contributes towards almost everything that you do.

I'm glad that you're all smarter than those (SAE) who devote their lives to quantifying the phenomina that you misunderstand and create rumors about.

I'll tell you a quick one in the style of low-temp fans:

The old 302 in my truck lost oil pressure after 21,000 from a fresh rebuild. 1/5 mains were scorched, as were 5/8 rod bearings. The oil always looked dirty. It had a 160 t-stat.

new 302 has almost 20,000 miles on it, it never quits from heat soak, even with an Edelbrock carb, the oil stays light brown until I retire it every 3 or 4 thousand miles, and it makes 60 psi oil pressure above idle, 35 at a slow, hot idle. It has a 180 t-stat.

 

Then explain why my 1987 F-150 lasted over 200,000 miles without any engine problems, not using a thermostat. As far as I know it could stil be running. When I sold it, it was running great!!

 

You Go, Bronco351, why dont all of the rest of you explain my 1985 GMC S-15, 2.8 V-6, very well known engine for blowing head gaskets, burning exhaust valves, blowing black smoke from bad rings. Pinging and detonating so badly when i bought it that you couldnt even run 5th gear on the highway- but i checked the compression, and, with only 50,000 miles it was still factory fine.

After the 4.3 radiator, 160 stat, flex a lite electric fan, yada yada yada. I loaded it one time with a covered, double axle U-haul trailer. It was so full the truck frame was on the axle. Went 900 miles across the USA with it, 3rd gear, 4,000 rpm 50 mph on the interstate. Many other instances of hard use with that pickup.

Then i sold it with 130,000 miles and checked the compression with the new owner right there. The truck met or even exceeded the original compression that it had at 50,000 miles! Ask the new owner! So- do i like 160 stats?? I think you all know the answer there- J.D., KCK

 

Can anyone ever really explain a GMC??
I'll give this 1987 F-150 a shot.
It was a calm cool morning that day, the birds were singing, and the bees were humming, and everyone on the assembly line that day had their mouths held just right as this engine was being assembled, on the day after the evening when all the planets were aligned just right. Just kidding guys!! Don’t nobody get mad.
There are always going to be those few engines that are just right, and just keep going and going. When I was younger I had a 289 in a mustang that just wouldn't quit. I overheated it, blew head gaskets and had water in the oil, and all kinds of stuff. My Dad has a Toyota with over 200,000 miles on it. I had it for 6 years and put 80,000 on it and maybe changed the oil in it 4-5 times. My dad has had it for maybe another 6 and changes the oil in it a little more often?? It's a wagon, and pretty much a rolling toolbox. But it is still going.
With a grand of my cash in the engine, I just feel better going with the fellas that built the blueprints on this issue.

 

engine temperature is one of many factors that affect engine wear..
a low temp engine might have a long life due to the many other things that affect wear being where they are supposed to be.
I know that the engineers here where I work become very upset if any of these factors isnt where it is supposed to be. engine temp being one of them.
Some of the test vehicles here have thousands of hours on the same engine...some not.
For the most part I tend to agree with the engineers...many of which spend long hours getting greasy right alongside our assembly guys...
millions of dollars and manhours later...I think they have their facts pretty straight.

 

The whole of my point is that you cannot tell a story that single-handedly proves or disproves anything. If there were 50 stories posted here about how great 160 t-stats are, then it still wouldn't change anything. There are way too many variables in these stories to draw any conclusions from. I'm very glad that your truck had over 200,000 miles on it with a 160, you could only imagine how much better it would have done with the correct one in. If installing a 160 stat in a vehicle makes it stop pinging and overheating, then it obviously had (or still has) something else wrong with it, and lowering the coolant temp is probably not solving the real problem.

 

Not solving the real problem, eh? Well: as i stated the "real problem" was pinging and detonating. And after the mods i did- it never did this again ever in 80,000 miles and folks all around me with 90,000 mile 2.8 V-6s have the same problem. Pinging, blown head gaskets, burned valves, blowing black smoke. Mine did none of those things at all. Compression factory stock. The real problem not solved??

If it still has some problem with it- the new owner aint complaining. In fact he drove it to Arkansas and emailed me and said it made the trip just fine. (from Kansas) No surprise for me to hear that. As for me- i am sticking with 160 stats- you all stick with stock stats. And good luck. J.D., KCK