Has anyone experienced O-ring failure since switching to Evans?
 

Like the title says, just wondering if anyone's had any o-ring trouble since they switched to Evans NPG+? I've read in past threads how evans is supposed to prevent the uncontrolled localised boiling of coolant that leads to warping. I'm very interested in switching to Evans only I'm not sure how easy it is to come by in the UK. Could Evans possibly be the solution to what seems to be the major cause of rotary death? What do you guys who are running the stuff think?

wtf is evans npg+???

A substitute for glycol based coolant. Do a search; there's lots of info.

Evans NPG+ is great in my book. Ran the stuff for 2 years in Texas heat...including a few track events...and never had any problems at all. The engine is as strong as ever.

If you can't get it locally, be sure to stock up on it. You can't put water in your system if you happen to lose some. This is the most concern I had with the stuff so I always kept a couple of gallons around.

I just started using NPG+. Reason was I lost 2 motors due to coolant seal failure. The coolant seal is fine for the 2nd gen turbo but not 3rd even though the coolant seal was supposedly better in the 3rd gen. All things being equal, my suspicion is on the coolant and/or coolant system unable to control heat being generated.

A secondary reason was that none of the pressure caps (3 OEM and 10 Stant caps) that I've used were able to keep its rated pressure for more than 3-6 mos. Because the difference b/w 16 psi and 13 psi is about 20 degF in boiling point, the seals could have been damaged w/o me even knowing it due to localized boiling.

Hence my experiment with NPG+.

NPG+ has some strange characteristics though. It has 1/3 less thermal conductivity; more viscous; takes on heat and shed them much faster than EG/water mix. Because of these characteristics, flow rate must not be decreased and radiator should be thicker by 20-30%.

I like it very much for the fact that it doesn't boil at operating temp and is not dependent on the cap to maintain rated boiling point.

I don't like it b/c it's $25/gallon.

I'm not sure if you mistyped or just don't understand Thermal Conductivity.

Evans has 1/3 less thermal conductivity, that means it takes on and sheds heat much SLOWER than standard coolant.

I'm defo gonna give evans a try. I've got my coolant system drained out for winter so as soon as the spring arrives I'm gonna track some down. Gonna fit an up-rated rad and change my coolant hoses over the winter months. Dya recon I'll still need to flush with sierra coolant if my system's been dry for a couple of months? The sierra's probably just as hard to come by as the NPG+.

Sierra is dirt cheap...I would think you could find it somewhere local. Maybe not there.

I think you should flush it with Sierra though. There are many places within the engine and heater core where coolant will be trapped. That old stuff is NOT compatible with the Evans.

It isn't cheap...but you won't need to flush your system next winter. Evans is non-corrosive and can stay in the system a long time as long as you don't have other issues. (coolant seal issues, etc.) Also, be sure to run Evans at a lower pressure. I put a lower pressure rad cap on my alluminum AST (7psi) to take some strain off the coolling system. You can convert to zero pressure if you want...but I had a leaking problem when I did that.

Really? Where was it leaking from? I really like the idea of running a zero pressure cooling system, it must drastically prolong the life of the coolant hoses etc. Still, you wouldn't want to waste any of that stuff, what with it costing $25/gal! (God only knows what it'll cost over here in rip-off britain!).

Evans IS glycol. Just like sierra, with some snake oil stuff supposedly added. You can just run 100% sierra and save a lotta $$$. A bottle of aftermarket cooling system additive every year or so wouldnt hurt.

Well, I attempted to modify my old cap...and ended up leaking from there. It seems that Evans also expands a bit more than water/coolant mixtures. The 7psi cap was my quick and easy fix. It is likely that the problem I was seeing was my own fault.

After I converted to Evans I never saw over 105C on the hardest track days in 100F temperatures. This was the only conditions I saw the leak...tossed the 7psi on and haven't had a problem since.

So why are we to assume this stuff would be better than water/antifreeze?

The main thing that I like about it is the 350F+ boiling point. Zero localized boiling potential which is probably the first major cause of warping within a engine.

But it will increase you oil temperatures, sure it will help with localized boiling and corrosion, but high engine and oil temperatures aren't a good thing.

The point is you can run any antifreeze 100% and have a similar effect.

NPG = propylene glycol = Sierra
NPG+ = propylene glycol + ethylene glycol = Sierra + Prestone

Higher engine temperatures a good in some applications (higher efficiency) but not in rotaries. Localized boiling is a selling point only, localized boiling absorbe the latent heat of vaporization from the immediate surface on which it occurs. One could make a good argument in favor of localized boiling as well as against it. However, when it occurs in the water pump it is cavitation and a bad thing.

How did you come up with these conclusions? Did you do a chemical analysis or a spectrographic analysis?

If I were to go by the logic of your argument, localized boiling is good because it indicates that the vaporized liquid has absorbed the heat.

Then why in the world do we need a pressure cap and prevent boiling for water/EG?

Don't like Evans? Don't use it! Or at least don't spread misinformation.

A pressure cap is use to allow a higher operating temperature of the entire cooling system. (Higher efficiency, remember ?)

I have nothing against Evans or Sierra. They are just not the cure-all some ppl represent them to be.

There was ZERO misinformation in my post. I wish it were true for everyone else.

No , I read the freakin Evans web site. Several ppl have asked for MDS on the NPG's. To my knowledge no-one has received them, even though their availability is required by law.

Evans notes that 'controlled' localized (nucleate) boiling occurs with NPG+. Nucleate boiling is great until it gets excessive, then u have DNB or departure from nucleate boiling, where a vapor cloud hovers over the hot spot and surface temps jump up there.

NPG+ has poorer heat trans props vs eg+w. The fluid does warm up quicker than egw, but with less net heat transfer (btu/hr), giving a false indication of better heat transfer.

As long as the bulk fluid temp in the block is low enough, the egw will work fine. if it can't be kept low during sustained high loads, then DNB will result in overheating, and NPG+ would work better at those high bulk fluid temps.

I think if your RWD F3D gets to DNB with NPG or EGW you are FUBAR.

But thats a few too many TLA's .

I run :
75% distiled water
25% Dexcool
1 bottle of REDLINE water wetter
M2 all aluminum radiator
1.3ATM Gant cap with out the AST.
PFC fan points of /86/86/88.

No problems here in Houston summer with over 320rwhp.

Sounds like a good setup. My car doesnt like sitting in traffic in the Houston summer.

Your conclusions are unsupported in that NPG is Sierra and NPG+ is Sierra + EG. The website does not state taht NPG is Sierra and et al. NPG is a form of propylene glycol and NPG+ is another modified form of PG.

That's like looking at Prestone website and concluding that Prestone is alcohol and then implying that you could put alcohol into a car as coolant. Not too unscientific and therefore I submit to you that it's tantamount to misinformation.

Like I said, if you have evidence-meanging facts that lead to these conclusions, let us know.

I'm curious too. I know that the $25 per gallon includes marketing but hey why do people buy Mercedes and BMWs when they're so unreliable?

Why Dexcool? Not better heat transfer? Longevity?

There was an article in C/D a year and a half ago about how it's unsuitable for older vehicles not designed for Dexcool. Dave at KDR saw 3 cars running Dexcool that had coolant seals damaged - see lightning in a world of thunder.

>>pomanferrari: Since you are apparently incapable of looking this up for yourself, here it is with links.

From:
http://www.sierraantifreeze.com/
SIERRA Antifreeze/Coolant is a premium quality, propylene glycol (PG) based antifreeze that provides engine protection comparable to that provided by premium conventional ethylene glycol (EG) based antifreezes.

http://www.evanscooling.com/main25.htm
Evans NPG Coolant is pure coolant - no water added. The non-aqueous propylene glycol (NPG). Evans NPG Coolant is 100% inhibited Propylene Glycol

Evans NPG+ waterless coolant, a proprietary blend of glycols (including ethylene glycol)


http://www.prestone.com/framer.cgi?p...roducts/13.htm
The antifreeze/coolant business, as we know it today, began with the marketing of "Prestone" brand ethylene glycol antifreeze in 1927. It was pure ethylene glycol in cans, with published charts showing protection afforded by specific quantities. It would not boilaway or burn, and was comparatively odorless, offering a distinct advantage to some of the substances used previously.
In 1930, Prestone developed and marketed the first inhibitor to further protect the cooling system and retard rust formation.

I hate to say this but you really do need to read more carefully.

Ingredients taken from the Sierra bottle:
Propylene Glygol
Water
Corrosion Inhibitors
Dye

How is that = to 100% inhibited PG?

Exactly my point.

This type of lazy man conclusions and rebuttals are intellectually dishonest.

You haven't explained how you came to the conclusions that you made.

Like I said, that's like concluding that EG is alcohol therefore denatured alcohol or rubbing alcohol can be used as a coolant.

You want another analogy?


Arabs attacked WTC on 9/11. Iraquis are Arabs. Therefore, by transitive reasoning, Iraquis attacked WTC. On the basis of this intellectually dishonest analysis, we need to go to war.

I've looked at evans for over 3 years now and getting as much info before jumping in. I've decided that the best way to determine if it works is to try it instead of attacking it w/o any basis to support the attacks.

May be I'm a fool for paying $25 per gallon? That is why I wanted your basis for concluding that I could get the same coolant for 1/5 the price. If your analysis made sense, I would have applauded you for yelling that the emperor is naked.

You sir, tmike, I have no respect b/c of your faulty transitive reasoning and spreading misinformation.

KevinK2, however, is a different story. I went to NPG+ based on his disinterested analysis.

I want to also add that you admitted that Evans will not give out MSD.

YET YOU CLAIM TO KNOW THAT IT'S THE SAME MATERIAL AS SIERRA OR SIERRA MIXED WITH EG???

Gosh, we are sensitive. Strike a nerve ?


Well its PG + Inhibitors... Isnt that inhibited PG ?

Apparently it contains some water so its not 'non-aqueous and dye to make it look pretty and environmentall friendly. Was it a 50-50 bottle or the 'pure' stuff ? I dont understand the argumemt ?

NPG Is PG +inhibitors, right ?
Sierra is PG +inhibitors (and maybe some H2O), right ?

NPG+ is PG + EG right ?
Prestone is EG right ?

I read the freakin website, SEE ABOVE !

LMAO!!!
How about this?

Rubbing alcohol is alcohol right?

Alcohol gives me a buzz.

Therefore, I can drink RUBBING alcohol to get a buzz.

(***for you alcoholics out there, don't do it, it could kill you ****).

****GETTING UP OFF THE FLOOR**** WIPING TEARS FROM MY EYES******

Holy sh*t. You are worse than I thought. No point in discussing this with you. Your transitive reasoning is admirable though we'd still be burning witches and draw flat maps if everyone were using this type of shodding reasoning.

The orignal poster wanted some info on real world data, you come in with conclusions based on shoddy analysis.

Not to start a political flame war but I can see why 70% of the public think Iraq was involved in 9-11; that WMD were found (1 vial of bacteria).

So to get back to the original question here.. Before you 2 JACK-ASSES started debating who is smarter and can read websites and ingredient labels better!!!!!! Grow up and stick to the topic. This EVANS is expensive shit!!, therefore people want to know if it's worth the CHANGE over to evans. NOT what it is made of and how accurate the ingredient labels are.!! CHRIST!!!!!!!!!! SOOOOOOO HAS anyone had o-rings go out after they switched? IMO it is just hype... but i would like to here input.

I'm running evans and my coolant seals are still alive at 72K.

I remember someone mentioning certain rotary engine builders will not warranty the engine without NPG.
Regardless, I run NPG 0 psi without AST and have not had any cooling related problems yet, we'll see how long it'll last.

Haha, I was merely pointing out that tmiked was dragging his knuckles ....

BTW you did say Evans NPG+ is expensive right? And if I were to tell you that you can get the same shit for $7 a gallon instead of $25/gallon wouldn't you be interested?
Now if I fooled you with some half assed reasoning wouldn't you set me right for spreading disinformation?

Now that we're clear on why I did what I did, we can return to regular programming:

I just started Evans with a fresh tune up, I mean reman so I'll let you know in time. The last 2 motors running EG/W lasted 50K each with coolant seals going each time.

In the 2-3 years I've been keeping an eye out on this forum and the big list, I have not seen anyone with coolant seal directly attributed to Evans- although you might want to check with banzai toyota- his coolant seals let go with a motor rebuilt by Pineapple.

Thank you for returning to regular programming.:D I'm not sure what you are meaning about me saying it is expensive? I think it is. And yes I would be upset if I was told the wrong thing.;) What coolant/water ratio were you running with the other motors that blew seals? I had an N/A go out at 120k= miles with traditional coolant/water. My 94 single turbo engine cracked an apex seal. Upon disassembly, I found the rear o-ring on it's last hair. (only around 25-30 k on the engine).....Crazysuprakid.......Have you been running EVANS since the first time the engine was run?( for baseline comparison purposes) Again Thanks for getting back on topic Poman!!

First engine had 30K when I bought the car. Used Preston 50/50 religiously changed every year. Failed at 50K.

Second engine. Noted that coolant never filled all the way up to the filler neck on day one on this engine.

Dexcool 50/50 first 20K then I noticed some funny crud floating in the coolant. Got suspicious and stopped once I found out that Dexcool is some type of acid. Went back to EG 80/20. Failed at 42K. Dragged it out another 6K with blockweld. Both engines on stock radiator.

3rd engine. NPG+ on start up. Filler neck always full. Different operating characteristics than EG/W. Fans must be running to control temperature otherwise it will keep rising to 240. Fluidyne radiator. I have the datalogit so it's not a problem to keep engine temp below 200.

My hunch is that the problem with my first two engines were with the pressure cap. They could never maintain their rated pressure so over time leading to non-observable micro boiling and over time, the boiling coolant killed the motor.

We'll see how long this motor lasts- trouble is I don't put more than 5k a year though.

Interesting!.. I have been wondering about the switch for a while but am just scared to experiment with a new (another) engine. Guess that's why it took you a couple years to switch huh?

This is great info, thanks everyone, keep it coming! Another major benefit that I can see with evans (from the point of corrosion protection) is the fact that it isn't mixed with anything. That means you have the correct concentration of corrosion inhibitor at all times. Now it was a long time ago, but I remember something from my corrosion course about cathodic inhibitors actually accelerating corrosion when they are not at a specified concentration. I'll check my course notes and report back. There's plenty of scope for getting it wrong when you're diluting your antifreeze with water. Obviously it's vital to have sufficient corrosion protection, especially as these rotary engines are essentially electrochemical cells with their layers of steel and aluminium nicely sandwiched together! Without some form of inhibition that aluminium is gonna take a battering!
Anyways, my motor has 55k original miles under its belt so it couldn't possibly hurt to give evans a try, and who knows, it may even prolong its life......and that's gotta be worth $25/gallon.

With 50/50 Prestone and tap water, I measured 0.13-0.15 volts with a positive multimeter probe in the coolant at the filler neck and the neg probe at engine ground.

The longer the EG/W was in the engine, the higher the voltage. For example, after 6 mos., the voltage was 0.25 volt.

With Evans NPG+, same technique, I measured 0.08 volt.

Unlike what others have concluded, there is a cathodic reaction going on in the engine with the coolant as the transfer media. It is very low though. I want to see if this voltage is constant or increasing over time in the next 6 mos.

There will be both anodic and cathodic activity occuring within the engine. The anodic reaction (metal dissolution) will be active on the surface of the aluminium components (more -ve electrode potential)whilst the cathodic reaction (usually reduction of water and oxygen to hydroxide ions) will be taking place on the surface of the iron components (less -ve electrode potential). The electrons from the anodic reaction flow through the engine and are used up in the cathodic reaction. The coolant acts as an electrolyte providing an ionic conduction path and completeing the corrosion 'circuit'. The inhibitors in conventional coolants act to supress the anodic and cathodic activity in an attempt to control corrosion.
Perhaps Evans relies on the fact that since there is no water present in the coolant, the cathodic reaction is supressed thus preventing corrosion? A little off topic I know but any thoughts?

Following my engine failure (Still do not know the exact cause; stay tuned) I am waiting for the test results of my Evans NPG+ to come back. I have also sent an oil sample to be analyzed.

I will be pressure testing the the engine to pinpoint the location of the leak prior to teardown.

As a Side note, My Diesel engines have not had any coolant related problems since adding Evans NPG +.

I run a Ford TC35D Tractor, Kubota G1800 Tractor, and a 92 Dodge D250 Cummins Turbo Diesel.

banzaitoyota, you had a pineapple motor fail yeah? out of interest, how many miles did the motor have on it when it let go? would be very interested to find out what killed it.

Between 4 and 5K, still don't know the cause of the failure. Doing more testing and pulling this weekend. XMAS Party scheedule permitting

Hmmm...so from what I'm reading on this thread, it looks like nobody has yet had an engine failure attributable to Evans. I've been running Evans for about two years now with a handful of track events (but not aftermarket temp gauge! I know I know...I have faith in the Evans product, I guess.) No problems yet. I was running 0psi for a while until I started to lose coolant, so I changed the cap out to a 13 or 14 psi cap, and no more coolant loss. I think the old cap was simply worn out, but I think I'm staying with the 14 psi cap since I'm not having any problems with it so far.

You may want to look at a lower PSI cap like a 7lb or so. That worked fine for me and will put a little less stress on the cooling system.

Then again, sometimes a good idea not to fix what isn't broken.

Evans
 

Been using Evans for years for dealing with the abuse of Track Events on the coolant system (Instructor with Porsche, BMW) I was at Watkins Glen 7/4/02, ambient temps were 98F coolant temps were 260- 265F all day !! Try that with any configuration of water/coolant .........

So pomanferrari....

You never answered my post. You said Evans had 1/3 lower thermal conductivity while also stating INCORRECTLY that it picked up and shed heat quicker than EG.

It does not pick up heat as quickly nor does it shed it as quickly as a fluid with 1/3 more thermal conductivity. What about that?

I was formulating the answer when KevinK2 said:

"NPG+ has poorer heat trans props vs eg+w. The fluid does warm up quicker than egw, but with less net heat transfer (btu/hr), giving a false indication of better heat transfer.

As long as the bulk fluid temp in the block is low enough, the egw will work fine. if it can't be kept low during sustained high loads, then DNB will result in overheating, and NPG+ would work better at those high bulk fluid temps."

Couldn't have done it better myself. That's why I said it had "strange" operating characteristics.