NUTEC--out'a da closet

[nephron]

Yeehaaw!!! Found Nutec's new website.
:yeehaw:
http://www.nutec-usa.com/

For a while there, I thought it was something I said ... :silly:

edit: I haven't looked it over just yet. See the 0W5 4 stroke 100% ester motor oil? :eek:

 

[nephron]

The GP 2+ looks new, and very SIMILAR to C12, but oxygenated (edit)! RVP around 6-7, 10% point up from PRO MX by about 15 deg. Very similar endpoint. I might try some of that out, although I'm kind of hooked on the PRO MX. ;)

And I've got a NUTEC 'crack dealer' in Kendall, KS (pop 83). :thumb:

 

[NO HAND]

You're about to talk me into trying some of that Pro MX. Did you need to lean out much on the 500? I know I have access to VP. I was reading the other day about the new VP Ultimate 4, they say it has an oxigen content of 6.2%. This can't be right. It's alot. Did you compare it with Pro MX?

 

[nephron]

Yes. I've printed the specs out, but they're at the office, not where I'm typing from. I'll post them when I get back there. As I recall, the 10% point on Ultimate 4 was around the same as C12, while it's distillation endpoint was higher, possibly to keep the crown cooler. Think about this: a 4 stroke has an inherently higher VE, and may not need as low an endpoint, for obvious reasons.

 

[23jayhawk]

a 4 stroke has an inherently higher VE

VE = volumetric efficiency?

  ... and may not need as low an endpoint, for obvious reasons.

for those of us lacking the requisite intellectual horsepower, please elaborate.

Grazi

 

[nephron]

Sure--simply, less efficient motors, no matter cause, with less efficient combustion will tolerate lower endpoints better because even with all the scavenging and intake/exhaust mixing, a motor's got to have efficient combustion of the 70% of originally intended fuel mass there (100% of what's not been scavenged out into the exhaust). If you've got sludge with 450 degree endpoints comprised of 8-9 carbons, you're gonna spooge, foul plugs, and gum up powervalves in addition to making less power---you've just gone from a VE of 70% on a well-tuned 2 stroke to 50 or 60'%.

With 4 strokes and little overlap b/t intake and exhaust cycles, combustion chamber temp reaches dramatic values rapidly, not only allowing for more completion of chemical endpoints (to CO2 & H20), but allowing higher endpoints to keep a molten crown cool.

 

[Rich Rohrich]

While we are on the subject here is a little something else to consider.

While it's true that four-stroke engines tend to fill the cylinder more efficiently per cycle they also tend to have much cooler piston crown running temperatures and in MANY cases will be better served by a low fuel end point temperature .

Consider the following for a minute. Every time a two-cycle piston is at TDC it is subjected to the heat and pressure of combustion, while a four-stroke engine only sees combustion every other time it reaches TDC. This additional cycle in the four-stroke engine allows a lot of the heat the piston crown sees during combustion to be dissipated through the rings to the cool cylinder wall. High rpm four-strokes with late intake valve close timing also have lower trapped cylinder pressures and lower piston crown temperatures as a result.

The point ?
In my experience I've found that except in special cases like high compression air cooled engines with early intake valve close timing or forced induction engines, a high fuel end point temperature is usually unwarranted for the purpose of cooling the piston crown on a four-stroke engine.

 

[nephron]

Wow, I didn't know that. I've got that Ultimate 4 distillation curve somewhere on my desk.....Ahhh, yes, here it is. Let's compare it to C12:

C12:
10% 131(F)
50% 194
90% 228
E.P. 233.3

Ultimate 4:
10% 122.2
50% 149.7
90% 219
E.P. 266.7

Same lead, same spec. gravity.

I like that 10% point on the Ultimate 4, and my guess would be that it would be THE ultimate fuel for a 125cc 2 stroke. It's funny how the 90% and E.P. are so far apart. It's almost like the distillation curve temps go up exponentially to an endpoint, like maybe they added some complex BIG ASS hydrocarbon ring, or something, that doesn't exactly interfere with the lower point of the distillation curve.

On the 4 stroke thing, I was thinking hotter because of 1) higher compression ratio (& therefore VE), and 2) a hotter than hell exhaust valve glowing up there 24-7.

 

[nephron]

Rich, what could they have done to spread the curve that far? U4 does not appear to have an oxygenate, so the fuel wouldn't 'automatically' benefit, from a 10% point, by the addition of MTBE,ETBE, etc. The RVP is 9.66 vs. C12=7.3. That's one hell of a difference, and goes to show that 2 fuels with virtually the same spec grav's can have entirely different volatilities and distillation curves.

How's this for a moronic theory: they're using some small olefins (like butene CH3CH=CHCH3, or Isoprene etc...) to both raise octane and lower the 10% point. ...like @ a huge amount, whilst I'm a little confused on the endpoint, but following common sense, it's got to be a large, straight parafin chain not unlike Iso-octane, perhaps just octane???

 

[bclapham]

Originally posted by nephron
Same lead, same spec. gravity.

i have some questions! what are the octanes on these fuels?

i wonder if a 50:50 mix of U4 and C12 might be a good blend for my application?

U4 does not appear to have an oxygenate

are you sure??? i thought that was the whole deallio with the U4 more MTBE than anyone (AMA) would even allow. Nephron, they did a nice review in MXA on this fuel, i can forward it to you if you need briging up to speed! :confused: :)

while we are on this topic, by my calculation, neat MTBE contains 18% oxygen. so, Rich (or anyone else) can i assume that 10% MTBE blended in a fuel gives 1.8% oxygen????

what is the upper limit on MTBE, i remember Rich saying 30% by volume, does this equaqte to 5.4% oxygen????

one last question (off topic), with regards to jetting and oil ratio: if a bike was set up on the main really well with 30:1 premix, how many main sizes richer would one expect to need if the premix was changed to 20:1? (assuming all other things equal)

i found a bottle of isoprene in the fridge the other day, i am tempted....hehehehehe :p

 

[nephron]

by my calculation, neat MTBE contains 18% oxygen. so

By mol or wt? ;)

I may be wrong about the oxygenate thing and U4, but where I got it was the fuel spec page on VPfuels website. I was looking the distillation curve over, and there was mention of RVP, spec grav, etc....but not of Oxygen content. Flipped over to the MR2 spec page, which I knew had O2, and it showed it.

Maybe they forgot it? ;)

Bruce, I was looking up some stuff on Isoprene the other day, and found out that natural production by rainforest in the southern hemisphere, and eastern US trees (Oak, Maple, etc.) quantitatively WAY outnumbers anything made by man. It's apparently a product of, or involved in, chlorophyl restoration during photosynthesis??? Weird.

 

[bclapham]

well, according to augusts MXA :silly: the VPU4 contains 6.2% oxygen from MTBE and if my calculations are anywhere near right, then that is more than 30% bv!:eek:

to be fair, the VP rep does hang out at the REM races at Glen Helen so there is a good chance that this time MXA could be right on the money.

i might ride at GH tomorrow, so i might have a look for that bloke......he is called "Bruce" apparently so he must be OK!:)

 

[NickInOhio]

Hey Nephron.
You mention U4 may be the ultimate 2 stroke 125 fuel. I was using Ultimate 4 in my 03 YZ250F, and the stuff was so potent. I had to keep it in the back shed (with the bike), because the smell overtook my house within 2 hours! I was using it at 100%, but couldn't get my main jetting correct. However, after my recent surgery, I sold the thumper and am rebuilding my 125.

I just had my 99 YZ125 motor rebuilt, and they converted my motor to a flat top piston kit (never had one before). I haven't even started it yet (still rebuilding), but the shop said I had to run race gas due to higher compression. SOOO......here are my questions.

If higher compression engines require higher octane, how would U4 work in my 250F? Doesn't the 250F have higher stock compression than a 125? I think U4 had a "low 90's" octane rating. I need to buy some gas this week, and would like some suggestions.

Thanks,
Nick

 

[nephron]

Nick--to get the 'correct' answer for any of this (all my stuff is pure mental masturbation, and I'm a total neophyte), you'll have to draw Rich out of the honeymoon suite @ hotel lathe.

Achilles heel?: restraining himself from certain 'types' of posts...try something like saying you're planning on taking the U4 and adding about 30% Toluene to raise the octane a bit, and see if that does it.

 

[Rich Rohrich]

Originally posted by NickInOhio
If higher compression engines require higher octane, how would U4 work in my 250F?

Yes, it will work very well IF you get the jetting correct and you're 250F isn't too sensitive to the change in initial pressure rise and the shortening of the ignition delay period that comes with fuels like this. It has the same basic effect as advancing the timing on these engine. In MOST cases this isn't a problem on the 250Fs.

Comparing the compression ratios between two-strokes and four-strokes in an effort to glean an octane requirement is a total waste of time. It's the ultimate comparison of apples and oranges.

 

[nephron]

I post this with the utmost respect for those reading this, and this is meant only to stimulate thought, not blow horns or pound chests. Let's see where we can get with this.

The source of the odd odor of NUTEC fuel may not be what we thought. It looks like it contains 2 very odd, and unlikely, characters: Ethylene dichloride/dibromide.

Now, this may be old news to specialists in this area, but here's what I can't quite get by.

1. EDC, and all other halogenated alkanes are hardly considered flammable
2. EDC has a flashpoint of 55 degrees F, but a distillation range of 180-190--I can still live with that
3. EDB, however, has a flashpoint of 258F
4. Furthermore, it is NONFLAMMABLE--I can't live with that
5. Oddly, however, it's vapor pressure @ 77F is 11, so it's RVP must be much higher
6. These both smell sweet, pungeant, chloroform-like--just how PRO-MX smells (except when burned)
   [/list=1]
   
   So, what's going on here? Are these (in large enough amounts to be put on the MSDS sheet of PROMX mind you) meant to be the low molecular weight answer to keeping high temp and endpoints in the 180-230 range, without having to resort to large (I won't say heavy, because Bromine is very heavy) complex VOC's?
   
   I assume these are in other fuels, but I haven't seen them mentioned before on MSDS's.

 

[nephron]

No one's interested in race fuel these days? Or am I being 'obtuse'? PM me if I'm tearing skin. ;)

 

[Rich Rohrich]

Nephron - Sorry, I wasn't ignoring you I just saw the post this morning. ;)
I want to say Ethylene dichloride/dibromide is used as a lead scavenger, but my memory fails me on this. When I get home tonight I'll look through some of my notes.

I'll have to give this some thought, but I think your theory is interesting and pretty logical. If I can't find the details on my own I'll call in the big guns and talk to my buddy Dr. Dave Redszus for a clarification. I'll try and get a hold of him and see what he has to say.

 

[bclapham]

i would think those compounds are in there only as stabilizers, maybe in PPM levels? dibromoethane is nasty stuff, so even at those levels one should be cautious (assuming those levels of course). dichloroethane is really inert so i wonder why it is there also, but given a hard enough whack, it would be possible to use it for some organometallic chemistry.

 

[Rich Rohrich]

Hey I guess my memory is better than I thought :yeehaw: I checked a couple of SAE resources last night and Ethylene dichloride/dibromide is used as a scavenger in leaded fuels.

Here's the SAE resources :

Harold H. Schobert - The Chemistry of Hydrocarbon Fuels - Butterworth-Heinemann Ltd.

Keith Owen, Trevor Coley - Automotive Fuels Reference Book - SAE - R151


Here's a few links with additional details.

http://www.cdc.gov/mmwr/preview/mmwrhtml/00001712.htm
http://www.vdh.state.va.us/HHControl/ethylenedibromo.pdf
http://www.epa.gov/ttn/chief/le/ethyldi.pdf

 

[NickInOhio]

Rich,
Well, I finally started to break in and jet my rebuilt flat top 125. I tried the Ultimate 4 (left over from 250F), but started to hear weird noises (pre-detonation)? So, I decided to go to the local drag strip and buy some higher octane fuel. Here is what I played with all day.

http://www.citgo.com/Products/FuelGasoline/RacingGasoline.jsp

Can you give me your quick opinion of what this data shows? Does it appear to be a decent fuel for my application?

Thanks,
Nick

 

[Rich Rohrich]

It should work OK for your bike, but you can count on the fact that Ultimate 4 will work much better IF YOU TUNE FOR IT. Fuels like Ultimate 4 with a big load of oxygenate in them usually require less ignition advance due to the shorter delay period (0-10% burned) and faster initial pressure rise. If it's knocking, then that's probably a big contributor. I doubt if it's an octane problem.

Plus don't forget, if they are pumping that Citgo fuel from a bulk tank it's probably going to vary from load to load.

 

[nephron]

Thanks for the links, Rich. My search engine or brain, one or the other must have farted, because I couldn't find that information. Makes sense, as halogenated compounds (other than alkanes) are I believe, radical scavengers in inorganic reactions--but I'd have to defer to Bruce on that one.

I guess that's not what stinks in Nutec, eh?

Rich--do you have an HPLC machine next to your lathe. I'll tell you what--you tell me what stinks about Nutec, and I'll tell you why it stinks when a cirrhotic with varices bleeds and has a huge melanotic stool. Agreed? :eek: