Future of 100LL AvGas - Page 6

frankh · #51 10-25-2007, 04:24 PM

Quote:

Originally Posted by jonbakerok

I recently completed what was probably the fourth top-end overhaul on a 1974 Harley Sportster that I bought last year. With 9.5:1 compression and hemi heads, it was designed to run on 97 Octane leaded premium, but it's obviously been run on unlead for at least 30 years. The stock valve seats on this engine are merely ground out of the raw cast-iron heads -- they aren't even steel inserts. Although you can buy "no-lead" hardened valves and seat inserts for it, most people don't bother.

So what did I find when I pulled the heads? The factory original valve seats were still perfectly servicable after normal grinding for a new set of valves. The valves I replaced were NOT hardened "no-lead" valves, and I didn't waste my money on hardened replacements.

So much for "Valve Recession" theory.

there are so many old wives tales in aviation...Is there one shred of evidence anywhere that lead really does lubrictae valve seats...and even if it does, does it really make any difference to the longevity of the top end of the motor?

Assuming the answer is "NO" I'll continue to use unleaded Mogas for as long as I can find it.

Lets hope we can prove the ETOH will also work as well as 92 Octane mogas...Even if we are getting ripped off.

Frank

frankh · #52 10-25-2007, 04:49 PM

Seems if anyone has the skinny on this he should from what I read.

I'll report back what i hear.

Frank

zzapp · #53 10-25-2007, 05:22 PM

In a previous life my 182 had a Texas Airways engine upgrade. In the hanger was a C185 with a 300 hp continental running on straight ethanol. As I recall, it was a while ago, it was a project with The University of N. Dakota. Don't know that ever became of it. Alcohol as a race fuel has been around for quite a while.
This should not be a problem that can overcome with a little effort. Heck we rip our airplanes apart for minor aero mods.

Build9A · #54 10-25-2007, 06:25 PM

Weren't there several green airplanes at Oshkosh that burn E85. I think I remember them being RVs. could just be dreaming that??

jrsites · #55 10-25-2007, 08:57 PM

Quote:

Originally Posted by the_other_dougreeves

I studied phase equilibria of organic materials as a graduate student and taught the subject several times, both to graduate students and later to consultants. I spent a little time looking at the partitioning of organic materials to tobacco smoke particles - Many hours of my youth were spent in bingo halls, collecting tobacco aerosol. You only need to see the extract from the filter once and you will never consider smoking. Ever.

TODR

Wow. We have very similar backgrounds. I studied "Aviation Management" in college. I also spent a little time looking at the partitioning of the various ingredients in cold pizza. I'm sure that if anyone looked at a cross-section of one of my arteries, they'd never consider eating pizza.

So, yeah, I think we're both pretty smart guys.

In all seriousness, the RV community and it's talents never cease to amaze me.

tomcostanza · #56 10-26-2007, 03:37 AM

Quote:

Seems like in our society, anyone who gets an article published is an expert on the subject and we then use that information as gospel for the rest of eternity.

AMEN !!!

And with the Internet, anyone can publish an article.

johnp · #57 10-26-2007, 08:35 AM

Quote:

Originally Posted by frankh

Seems if anyone has the skinny on this he should from what I read.

I'll report back what i hear.

Frank

dr. shauck did a talk at our eaa chapter (187) about 18 months ago. iirc, the high points were: anodize (or otherwise protect -- maybe alodyne is sufficient?) tank interiors, don't use aluminum fuel lines, and avoid certain rubber components (proseal is not a problem.) also, increase the injector size (inside diameter -- or carby jet), 'cuz etoh doesn't have as high an energy density as petrochemicals. do all this, and you can run pure etoh -- he does. in the same plane, he can run avgas if he leans way back (because of the larger injector diameter). i don't recall anything about partial (10%) etoh.

dr. shauck reported flying the plane to an airshow -- he only used one tank for avgas on the way, keeping the other tank "pure" for ethanol. after his aerobatic routine, he was answering questions about ethanol from onlookers, and to convince one skeptic he took a sample from the ethanol side and drank it. he didn't say if he waited 8 hours before flying after that

shiney · #58 10-26-2007, 09:10 AM

Oil just hit $91 a barrel, if it keeps going like this never mind what the future of AvGas is, what the heck is the future of MOGAS?

RVbySDI · #59 10-26-2007, 09:43 AM

Quote:

Originally Posted by Build9A

Weren't there several green airplanes at Oshkosh that burn E85. I think I remember them being RVs. could just be dreaming that??

Here is a short write up in Plane and Pilot about these guys.
http://www.planeandpilotmag.com/cont.../2006/nov.html

airguy · #60 10-26-2007, 08:42 PM

Quote:

Originally Posted by the_other_dougreeves

I studied phase equilibria of organic materials as a graduate student and taught the subject several times, both to graduate students and later to consultants. I spent a little time looking at the partitioning of organic materials to tobacco smoke particles - Many hours of my youth were spent in bingo halls, collecting tobacco aerosol. You only need to see the extract from the filter once and you will never consider smoking. Ever.

TODR

Nice... I spent my time doing R&D development of microelectrodes, depositing gold nanoparticles on glassy carbon substrate for arsenic detection at PPB levels, and characterization of such. Quite fun dealing with nanoampere currents and RFI in a non-shielded building.

It never ceases to amaze me as to the people who frequent these halls...