[dataway]

Originally Posted by Squidward

Yes. And by better, I meant more.

I understand, then, I am preaching to the choir.

You have me by over a decade. I was an instructor in Charleston. I had the chance to run "OMG end of the world" events on the computer sim equipment they installed there. It took a full semi trailer of computer gear to run the physics for that thing. Now they could probably run that simulator with a cell phone. But I digress!

Excellent ... I actually still live within sight of the Kesselring Site ( I can see the D1G containment vessel from my roof). Several years ago I met some engineers up here researching the possibility of a simulator at this site, no idea if it ever happened or not.

I was in the first class they allowed calculators ... so there weren't a lot of computers in use at the time

I look through my notes and cannot imagine how I learned that stuff. 50% of it is Greek to me now. Use it or lose it I guess.

Wish us Nukes had a special thing like "Semper Fi" ... I guess I could say "Beam me up Scotty"

[jamesn]

I worked at the Stant thermostat manufacturing facility for nearly twenty years. That doesn’t make me a thermostat expert, but I’ve been involved with them more than most people. I no longer work for them so this is in no way an endorsement for their products.
Regarding the Stant Super Stat vs the standard line, the Super Stat is generally better. The return spring is bigger, the heat motor is bigger, the sheet metal is bigger and it has stricter performance and manufacturing requirements.
As usual, bigger is better.

[455'73inElCamino]

I run a 180 thermostat but planning on going to 195. Reason, it takes a fair amount of time for my engine to heat up, and if I am going downhill my engine will cool down to 160 degrees or lower! That is too cold. Engines are design to run hotter.

Carnot engines by design run more efficiently hot (as long as your oil/lubricants to break down) with cold air into the engine. Will get most efficiency and power that way.

[dataway]

If you have a 180 stat and your temps go below 180, then you need a new thermostat ... it's broke.
It's whole function is to keep temps at 180, no matter how cool the engine is capable of running.

[Formulajones]

Correct, a thermostats purpose is to not let the engine run cooler than the rated temp. It can run hotter, but won't run cooler.

Sounds like your stat may be slightly stuck open, which would also explain why it takes your engine a fair amount of time to warm up. Because it already has coolant circulating even when cold.

[skullbucket]

Originally Posted by Formulajones

Correct, a thermostats purpose is to not let the engine run cooler than the rated temp. It can run hotter, but won't run cooler.

So true, a thermostat say a 180 means the minimum temp goes,
people do believe it means 180 is the hottest the temp should get so when the gauge says 190 they think they have a problem.

[Don 79 TA]

keep in mind the balanced sleeved high flow stats open at sooner, meaning a quicker rate, but as mentioned it's 160 would be the start (for a 160)
I personally prefer those types over the regular stats
i also use 160, but when i was in NY i would put 195 or 205 in for the winter
i prefer to use the cooler stats in performance cars
they do make a 140 high flow stat, look for it at marine places
I haven't had a need for that

[AdamIsAdam]

I'm also running a 160 hi flow. It runs about 165 in most weather. In hot summer days, it's usually 175-185. On highway with high RPMs, it'll creep up a bit to 195, but comes right back down as RPM's drop.

In winter, it stays 160-165*.

[Jim Moshier]

I use a 195° on daily driver and 180° on my older Pontiacs, as I too have read " the higher the Delta between coolant and air temp,.... the more efficient the heat transfer thru the radiator. My guess is the OEM radiator is designed around an average temp differential that includes 195 degree coolant. I think the manufactures have already done all the research on why, and why for.

[HWYSTR455]

Originally Posted by AdamIsAdam

I'm also running a 160 hi flow. It runs about 165 in most weather. In hot summer days, it's usually 175-185. On highway with high RPMs, it'll creep up a bit to 195, but comes right back down as RPM's drop.

In winter, it stays 160-165*.

How much vacuum advance do you have adding? As the throttle blades open, vacuum drops, like at highway speeds with a little gear. = less advance at highway speeds. This is a perfect example of how a programmable timing curve can help.

I know there's controversy regarding manifold vs ported vacuum, and how much advance to run at idle, but there certainly is a direct correlation to temps. Look at factory base/idle timing and how it changed over the years, and ask yourself 'what if' you run more at idle and restrict total to compensate.

Also compare those base/idle timing numbers to when the factory switched from manifold to ported.

Now add how gas has changed and cam profiles. Not to mention many aftermarket distributors only provide a total of 20-24 degrees of advance.

.

[AdamIsAdam]

Oh, I've gone round and round on my tuning and temps. I have it dialed in well now. I was running 210* at 3,000 RPM before. I have at least 2 full, long threads on the subject.

Short story: replaced restrictive electric fan with Extreme Duty Hayden mechanical fan, spring modified, 18.5" blade fan. NEVER runs over 180* at low speeds or idle. No shroud necessary.

Tuning is really dialed in nicely. Starts right up, runs great all over, eliminated highway speed 'trailer hitch surge' thing, no pinging, etc.

16* @ idle, MECHICAL advance
24 @ 1500 RPM
31 @ 2000
32 @ 2500
36 @ 3000 (all in)

Plus 10* vacuum advance using modified unit with .12" travel per Cliff which worked like a charm. (car hated ported vacuum advance). Runs clean, idles smoothly, doesn't smell. If memory services, I went with P/N #1850/AR20 advance can. I'd have to double check my notes on that one. It opens with 4-6" of vacuum.

I'm good.

[HWYSTR455]

So do you think you have 46 degrees at 3000 RPM on the highway?

On the can, what vacuum does it start to open, and what vacuum is it totally open?

That 16 degrees at idle, does that mean you have 6 degrees of initial?

.

[AdamIsAdam]

(I'LL ADD MY COMMENTS IN ALL CAPS)

So do you think you have 46 degrees at 3000 RPM on the highway?

YES


On the can, what vacuum does it start to open, and what vacuum is it totally open?

STARTS AT 4-6" AND IS FULLY OPEN AT 8-11". I HAVE 14" AT IDLE.


That 16 degrees at idle, does that mean you have 6 degrees of initial?

NO, ABOVE CHART IS ALL WITHOUT VACUUM ADVANCE ADDED.

.[/QUOTE]

[geeteeohguy]

160 'stats in all my Pontiacs for the past 39 years. I live in California, so don't need a furnace for a heater in the winter time. No reason to run a 180-195 'stat where I am......my cars run at 180--210 all the time anyway.

[Schurkey]

Originally Posted by AdamIsAdam

Short story: replaced restrictive electric fan with Extreme Duty Hayden mechanical fan, spring modified, 18.5" blade fan. NEVER runs over 180* at low speeds or idle. No shroud necessary.

Plus 10* vacuum advance using modified unit ... ...It opens with 4-6" of vacuum.

I'm good.

Good, not great.

A shroud on the fan would make it far more efficient, which means you wouldn't need the "extreme-duty" fan clutch with a modified spring--or the horsepower to drive it.

The Heavy- and Severe-duty fan clutches are not suitable for use with typical automotive fans, (Less than 2 1/2" of pitch) because they'll never properly disengage. Hayden says as much on their web site.
http://www.haydenauto.com/Featured%2...s/Content.aspx

How much engine vacuum do you have at highway cruising speed?

Originally Posted by geeteeohguy

160 'stats in all my Pontiacs for the past 39 years. I live in California, so don't need a furnace for a heater in the winter time. No reason to run a 180-195 'stat where I am......my cars run at 180--210 all the time anyway.

That's all the evidence I need to know that either your cooling system doesn't have the heat-rejection capacity it should, or there's problems with excess heat generation.

210 is 40 degrees over the nominal 'stat temperature. The 'stat lost control of the temperature at 20 degrees over. The cooling system is running wide-open and has zero capacity for additional load.

[AdamIsAdam]

Originally Posted by Schurkey

Good, not great.

A shroud on the fan would make it far more efficient, which means you wouldn't need the "extreme-duty" fan clutch with a modified spring--or the horsepower to drive it.

The Heavy- and Severe-duty fan clutches are not suitable for use with typical automotive fans, (Less than 2 1/2" of pitch) because they'll never properly disengage. Hayden says as much on their web site.
http://www.haydenauto.com/Featured%2...s/Content.aspx

How much engine vacuum do you have at highway cruising speed?

Interesting reading...

As for vacuum at highway speed, I never got out to measure

As for fan shroud, I don't have a stock radiator, so putting a shroud on would be a project. So I figured I'd work in phases and stop when the results were acceptable. Since I never have temp issues at idle or low speeds, I was ok not having a shroud.

AND THEN I was watching an episode of Engine Masters where they tested various fans and shrouds. They found that a clutch fan robbed the least amount of HP over fixed, flex, etc. And then for kicks, they compared the clutch fan setup with and without a shroud and found that removing the shroud increased HP by 8HP. So I was convinced to go without.

https://youtu.be/ZXdLgaFXZzs?t=14m18s

As for the Severe duty issue, well, it works so I'll just leave well enough alone at this point. But good info, thanks!

[Schurkey]

Originally Posted by AdamIsAdam

As for vacuum at highway speed, I never got out to measure

Tape a gauge to the windshield, route a hose to the manifold. Depending on the vacuum generated by the engine UNDER LOAD, you may not have anywhere near the timing advance you think you have. In other words, have you lost all your vacuum advance on the highway? Is the timing now not advanced enough so that it create heat issues?

Originally Posted by AdamIsAdam

I was watching an episode of Engine Masters where they tested various fans and shrouds. They found that a clutch fan robbed the least amount of HP over fixed, flex, etc. And then for kicks, they compared the clutch fan setup with and without a shroud and found that removing the shroud increased HP by 8HP. So I was convinced to go without.

https://youtu.be/ZXdLgaFXZzs?t=14m18s

As for the Severe duty issue, well, it works so I'll just leave well enough alone at this point.

Yup, I'm surprised that removing the shroud makes an 8 HP difference on the fan that dragged the most. I wasn't expecting that. In fact, I think it's outright suspicious. They're claiming that the fan takes as much as 30 horsepower. Again, suspicious. I don't think the belt will transmit that much power. I wonder how much power was upset due to turbulent air flow over the open carb due to fan blast. They never showed so much as an air cleaner on the carb, and I would have expected some sort of dyno-velocity-stack-airflow-measurement-device.

Of course the clutch fan used less horsepower--the radiator was dry (not heated) so the clutch stayed disengaged. Re-run that test with a hot radiator and see what happens!

I'd like to have had noise measurements included in that test. Guess: The loudest fan robbed the most power.



Note that they claim it's an "OE" (original equipment) style fan clutch. You aren't using an OE fan clutch, you're using an "extreme duty" (Hayden calls them "Severe Duty") AND you've modified it so that it drags EVEN MORE. That fan clutch is practically locked-up. 'Course, I can't tell for sure from here. Only you know.

[AdamIsAdam]

Good info. Next summer I may back off the mod on the spring to have it lock up later since it runs well now. I do hear it moving air as I drive down my street!

I'll check vacuum too some day. Taping a gauge to glass is much easier than running along side the car at 65mph

[Formulajones]

Car Craft did some dyno testing of cooling fans probably 15 years ago??? Memory is fuzzy but here's an old article about it.

Interesting read. Fans can suck quite a bit of HP apparently.

http://www.network54.com/Forum/21565...+Fan+Dyno+Test

[HWYSTR455]

That's what I was trying to get at, vacuum at highway speed. You figure 65-70 mph, M-21, 3.42 gears, that's got to be in the 3000+ RPM range, but the kicker is, throttle position.

You're probably at 1/2 throttle, with the blades open that far, I bet you have less than 8, if not less than 6" of vacuum. So no vacuum advance. That's why it runs hot at highway speeds.

.