What are the factors that were not considered in all of these tests?

I believe that the fans don't run above ~25mph regardless of fan temp settings.

 

I was referring to the factors I mentioned in my post, which tests are you meaning? Some of which are inter-related… intake charge temp variations, knock sensitivity and tuning, different type coolant. Here’s some reference on the subject:

 

Read the exact data you just attached with a std cooling system and a mix of water and antifreeze max power is usually between 170 and 180. This most likely assumes you can also keep the intake charge cool. As noted in previous tests the tested engines actually made more power at cooler temps.

 

AZSP33D, If you read all of the test that I posted, you'd see that in one of the Engine Masters' tests, they did measure everything: fuel temp, plenum temp, runner temp, air charge temp. Post #59....

WRT Knock sensitivity, as it relates to all of these test, two things;
1. Engine Masters didn't change the timing for the various tests. IOW, they likely weren't near knock on any test but their highest temp test. Because....
2. None of the engines were likely in any danger of knock at the colder temps tested, regardless of timing...but especially with timing set that was acceptable at the higher temps.

 

Fair enough, now if you actually read all I have posted here (much less than all you have of course) perhaps you would get my point. Changing the coolant demonstrates the ideal temps and limitations. Even at a loss of CFM due to higher intake temps, it gained a little power. It may seem like I’m contradicting your assertion that more power is usually made with engine running at a cooler temp, or saying the tests you’ve posted are not valid, but I’m actually not.

 

Yeah, I read everything that you posted. I come up with: "Whatever". It's seems to be engines that do not pertain to us, with a cooling system that none of use? IDK. If PG is what that article implies, where is the wide-spread usage? Wouldn't the claims above create an incredible opportunity for OEM's for power and especially for reduced emissions?

I guess I don't "get it", and for now, I'll keep going faster by running cooler.

 

I'm all for you going faster. I don't recommend you switch coolants, and I get it on the PG, but I think it's also inter-related. Those tests are on... drum roll... Small Block Chevy So there are strategies for increasing power by staying below a surface temp limit for combustion chamber, and these are also good for better longevity in most cases:

1. Increase pressure of coolant at the areas where they are running through cylinder heads.
a. More efficient water pump impeller
b. Improvements in design of the flow path (it's amazing how much variation there may be at different cylinders)
c. Proper inlet and restriction (don't remove thermostat without other modifications)
d. Do not underdrive water pump, but note that most will cavitate around 7,000 rpm water pump speed
e. Ensure total system pressure is healthy for the coolant used
f. Data: pressure transducers in the cylinder head for coolant pressure (1-100PSI, easy to do), and temp sensors in different areas of the engine. Usually for the SBC the #2 runs way too cool, #1 cool, cylinders #6/8/5/7 too hot (this takes a lot more work but would be appropriate for a development lab or engine dyno)

2. Improve coolant properties:
a. Decreased surface tension
b. Better hot performing coolant properties.

3. All of the above

This is derailing form the original thread, but wanted to address your comments further about using PG.

There are issues with using PG but I understand the issues and solutions, and have used it very successfully on water cooled dirt bikes (no fan and easy to boil over otherwise) F250 Superduty, BMW M5, Ford Fiesta ST with bigger turbo, C4 Corvette, and about a dozen motorcycles some of which are notorious for cooling issues (Ducati 1098R with just single fan, 1098RS with no fans, 1198S with dual fans, Streetfighter with dual fans, 848 Superbike with no fans, FZo9, MT10, R1, GSXR1000, EX300, etc). Jay Leno runs PG in every water cooled car/bike he has. I do also, but I still have a few vehicles I haven't converted. I've researched the subject quite a bit prior to using it for the first time in 2009 on my 2008 F250 that had notorious/numerous cooling issues. I was so impressed with the results, I studied it further and have learned a lot.

The biggest issue with PG is that it's a "summer formula" because it starts to get thick/heavy in sub zero conditions, and it doesn't pump very well. Evans adds EG to the mix as EG maintains lower viscosity, but then it's no longer a lifetime coolant. There was a company Sierra many years ago selling 99.9% PG coolant, but they are no longer around. Food grade PG is about $30 gallon from Amazon last time I checked, and that's about half the cost of Evans Waterless Coolant.

I think Vaping uses a lot of the worlsd's production of PG (I don't vape btw), and it's heated to like 400 degrees and turns into a very fine fog like mist, it doesn't really boil... it's common stuff, not an exotic substance.

You can still overheat the surface temp of the chamber with PG of course, but it happens at a much much higher coolant temperature, providing more margin.

 

In boat applications running cold lake water with hot engine oil they build the engine with larger piston wall clearance to make up for the reduced bore expansion that cold water causes.

The oil temperature must raise around 200*F minimum for wear and flow reasons. Engine should not be run hard until oil is up to temp.

Running cold water with OEM /typical clearances may lead to excess wear & tear, cylinder wall galling, and other issues as seen in boat applications where the engine isn't built with cold water in mind.

Highest engine temperature always gives maximum efficiency. All auto manufacturers go through great lengths to insulate the power plant to improve economy. All power plants in the world run higher efficiency with higher temperature. Efficiency = economy, not power.

 

Thirdgen/Kingtal0n in the thread? ****. This could be the end of a good, data packed thread. Let's see how this goes....

That's (one of the) tired, old, unsubstantiated claims that keeps on getting passed on, w/o being given much thought...or any citations of any thing, to back it up. No data...just regurgitated, old skool "claims". "You'll wear out your engine!". Yet, people don't wear out their engine's, running cooler temps. At least not in a meaningful way.


Sure. Sure.....sure. So answer me this:
The '90's LT1's have a 180° thermostat. In the right conditions, we can push temps down as low as mid 170's....but let's just say it'll run consistently at ~185° (on hwy, w/airflow)....because it will. Cool?
The '90's LT1's have a ~230° Fan on point in the ECM. Temps can spike as high as 232...233ish. But let's just say that it'll stay below 230° consistently (stopped/slow/no airlflow)....because it will. Cool?

With that established, we can agree that GM designed the car, with a whopping 45° operating range. That is a big range. That's the same range as Richard Holdner running his pulls at ~130's and LT1's running in the 180's.
Anyway, let's say I'm cruising down the highway, 80 mph, ~183-185ish°. Am I running inefficiently? Am I missing out on mpg's? How many? Am I producing high emissions?
Now, let's say that I'm stuck in city traffic. No air flow, fans are kicking on at ~230°. Am I realizing optimal efficiency? Am I producing ultra-low emissions?

Of course, the answer is NO, to both, but let's pretend that it's yes...or someone just wants to bring the straw-man argument. If we're going to argue "yes", then why didn't GM put in a 210° or 215° stat and close up that massive operating temp range, in order to get that "efficiency", on the highway?? I mean, they spent a LOT of dough, on rev cooling, 360° increment crank positioning (ABITS), and other features to maximize the efficiency of the LT1. And even you sadi yourself (though IDK WTF you're talking about, but...)
...why didn't they spend $0.00 on a different temp stat....to gain all this "efficiency" that you're claiming?


.

 

An insult and mocking tone always precedes intellectual discussion. They say if you argue with an idiot...


Metal at different temperatures is different sizes. We don't need citations or data it is common knowledge. Those various fluids job of lubrication and carrying energy in the form of heat is also common knowledge and so is that it depends on temperature and circulation efforts reflected in the space between metal parts susceptible to friction which change shape due to temperature.

I would also point out that every auto manufacturer of every engine in the world including power plants, jet engines, ships/aviation, etc... all raise operating temperatures as high as possible over time in search of efficiency, economy, longevity. It is common knowledge, nobody is testing because all the engineers already know.

Chevrolet before 2001 is a mess. Sorry, complete garbage engine and electronics. Technology in those years was rapidly changing due to advancement in fuel injection and computers/modelling so we find a hodgepodge of BS and none of it will make much sense as you pointed out.
Do not look at early designs as if they are 'finished products' those are merely testing and evolving products. I would guess some of the engineers themselves had some qualms over the higher than previously ever run before coolant temps and the 'way they felt about it' and 'what they expect the vehicle's owners to do with it (in terms of hot rodding behaviors)' had as much to do with the slow gradual but necessary push for higher than ever used before coolant temps we find today.
Almost all of that mess goes away in 2001+ as Chevrolet engines copied much from Toyota/Nissan and similar with the coil over plug and sequential EFI with modern electronics, pan support and computer designed girdle and modern oil systems. What you should be doing is looking at THOSE late engines (early to mid 90's Toyota/Nissan/Honda?) and comparing the high efficiency designs with Chevrolets poor implementation from 93-99 and shortly thereafter the revitalized electronics of 01+. Just because some car company does something in the past doesn't mean it was the best or most well engineered design, follow a bread trail and look at what other people are doing, other engines, other designs. This debate is difficult to reconcile with if you tunnel vision for Chevrolet. If we examine every auto manufacturer in the world and compare their timelines, output, efficiency, coolant temps, we would easily crush this debate and its not even a thread at that point.
They did. Gradually all engines in the world are using high temperature thermostats. Your argument is 'why didn't Chevrolet know in the 90's what they know now today?" Well I think if you have to ask that question I will give an answer: Because they didn't know any better yet and because they didn't invent time travel to check what they will do in the future? Seriously though its a mistake they made and once they figured it out and started to copy successful designs from other manufacturer's they never went back.