Extending life of gasoline by storing under argon

[victorforge]

If you read everything that Snowbum has to say about valve recession (which I know is a challenge) the really bad valve seats were BMW's first attempt at a solution in 1981. They made them from a material that a had a poor heat transfer coefficient which effectively made the problem worse not better. Yours are way prior to that date so will still be cast iron.

What Snowbum also points out is the larger capacity 1000 cc engines are worst affected which ties into fact that the problem is temperature related. I have the smallest airhead engine at 473cc and give or take a couple of barrel fins it has the same cooling surface area as the 1000 cc models with the result that it runs relatively cool. No real surprise then that I don't appear to suffer any valve recession at all. At 600cc you have the next smallest engine which should bode well.

On an unrelated topic do you have any problem with pinging ?
The R60/6 had milder cams which means the valves close a little earlier on the compression stroke. Published compression ratios are based on swept volume but in reality dynamic compression doesn't start until the inlet valve is closed. The end result is that engines with the milder cams have a higher dynamic compression ratio at low revs. This has made the R60 slash models a little more prone to pinging. If you should have this problem the usual solution has been to fit a a cylinder base plate to lower the compression.

Snowbaum’s articles are very informative but a LOT to read. I was actually trying to buy an ‘78 R100s. That’s the one that will likely need it then.

 

[Astro14]

Snowbaum’s articles are very informative but a LOT to read. I was actually trying to buy an ‘78 R100s. That’s the one that will likely need it then.

I remember seeing gleaming, new 1978 RS100s in the showroom at Canton Cycles, in Canton, CT (long since closed). I had a Yamaha DT125 at the time, and was always getting chain lube, or Golden Spectro two stroke oil, or something. I bought a 1977 RM125 the next year, a retired motocross competition bike, and of course, made frequent trips to Canton Cycles. I have always had a fondness for the BMW twins of that era - they were just beautiful, and so very different than most of the offerings from other manufacturers.

I wish you good luck in your search for one.

 

[thastinger]

I've thought of doing this too but for diesel fuel in my tractors that I don't use regularity. Don't know if argon, co2 or nitrogen would be best?

Diesel will last 10 years. Add a product called "lubricity" to it if it is an older mechanical injection engine.

 

[barryh]

Snowbaum’s articles are very informative but a LOT to read. I was actually trying to buy an ‘78 R100s. That’s the one that will likely need it then.

There is a reasonable chance on a bike of that age that the valve seats have already been replaced. It's something to ask about and make a financial adjustment for if they haven't.

 

[wag123]

Good to know - all of the OP’s concerns - storage life, valve seat recession, etc. are the same as mine with the Packard.

Given the price of racing fuel (about $80 for a 5 gallon can), 100LL is attractive at a mere $6.00/gallon. Further, the Reid Vapor Pressure of 100LL is likely to be higher than racing fuel, which tends to have a low RVP.

Since the Packard’s Detroit Lubricator Model 51 is an updraft carburetor, atomization is a concern for me in addition to the above.

Atomization may not be as much of a concern for @victorforge - depending on his riding conditions, particularly temperature, and how well those old Bing carburetors are working.

For summer blend pump AUTOGAS the EPA has set the Reid Vapor Pressure (RVP) standard at maximum of 9.0 psi for designated volatility attainment areas and 7.8 psi for certain designated volatility nonattainment areas. For winter blend in northern climates, the RVP can go as high as 14 psi.
The RVP of racing gas falls in the 5-8 PSI range and doesn’t change with the seasons like pump gas does.
The RVP of 100LL is mandated to fall in the 5.5 to 7 psi range, pretty much the same as racing gas. To me, this lends some credibility to the people who claim that race gas is just repackaged and overpriced AVGAS.
Furthermore, AVGAS is refined to a much higher standard than AUTOGAS.
For those of you interested, using 100LL AVGAS in older non-catalyst engines would not be a concern, and IMO it's use would be highly desirable in collector vehicles due to the fact that it does not breakdown/deteriorate like AUTOGAS does. The trick is finding an airport that will sell it to you.