Astounding read! University test of fiberglass tank liner...

Re: Astounding read! University test of fiberglass tank line

Not necessarily all roto molded tanks, just some using a certain type of nylon. Problem seems to be with the type of nylon used and water absorption. Water being pulled out of the atmosphere and collecting in the bottom of the tank gets pulled into the nylon and swells. I believe that Ducati is aware of the problems as are KTM.
Some of the tanks have deformed and are no longer the proper dimension for mounting points. Paint problems can arise with swelling tanks. Gasket surfaces for fuel pumps have deformed and allowed fuel-tanks to empty.

Probably won't have much moisture/swelling problems on cars as they are closed fuel systems. Pretty much everyone dumps the closed system on a bike. Bikes sometimes sit with the same old gas in them,(not mine at least not without stabilizer). A swollen tank on a car is likely to never be noticed. On your 15 grand Duc or KTM where it's sitting right between your legs in front of you shedding it's paint you might notice. You might notice if you happen to do your own maintenance and have to remove said tank and it no longer fits when you go to put it back on. Moto-Hooligan makes slotted tank brackets for Superdukes to get around the "growing" problem.

Will[/quote]

I was not aware that big manufacturers had started using nylon rather than HDPE for producing tanks, and I suppose this change of material may well be causing the problems described?

HDPE tanks all swell to some extent though, but this is generally the result of heating up on a hot day, rather than being affected by fuel, which is pretty unlikely as HDPE has no known solvents at room temperature............makes you wonder why they changed to nylon?

Re: Astounding read! University test of fiberglass tank line

My "Rotomolded nylon" tank suggestion was a bit tongue-in-cheek. I was inspired by Kenny Dreer's rotomolded plastic tanks, with a classic Norton style cover to make them look good. I don't know what material Kenny used. I mentioned nylon because I recall some rotomolded nylon gas tanks many years ago that were larger capacity tanks for dirt bikes. Kenny's might well have been HDPE.

Another bit of alcohol fueled Norton trivia. When I bought Jim Schmidt's monoshock Norton back in the late '80s, it had his clever home-made flat slide carbs, and ran on a methanol/gasoline mix. Something like 1/3 methanaol to 2/3 gasoline, if I recall correctly (and I might not). Mixture adjustment was by changing the alcohol/gasoline ratio, but it wasn't much of an issue, because methanol runs well in a broader fuel/air ratio band, so it isn't as fussy as straight gasoline. The bike had an aluminum tank, and I never saw any problems from using the alcohol/gasoline fuel mix in it. The problem it did have was swelling of the flat slides from the methanol. Jim tried a couple different plastic slide materials, but none of them lasted long. I only ran it at one big race, the AMA national at Sears Point, before switching to Mikuni flat slides and straight gasoline. It was quite illegal to run alcohol in AMA, but I had just recently bought the bike, and didn't have time to switch to carbs and get it sorted before the race.

Ken

Re: Astounding read! University test of fiberglass tank line

Maybe roto moulded inner tanks, which would fit within an OE GRP tank shell, after the bottom had been removed would present a good solution to current problems with E fuels?

Re: Astounding read! University test of fiberglass tank line

Carbonfibre said:

Maybe roto moulded inner tanks, which would fit within an OE GRP tank shell, after the bottom had been removed would present a good solution to current problems with E fuels?

Click to expand...

Could work and could be cost effective one time deal with the added benefit of being able to change the color/style of bike by swapping the tank cover with all the old FG tanks to use as cheap fodder.

Some more reading from a Duc site http://www.ducatimonsterforum.org/index ... ic=43639.0

Jean,
You should swing by the Saint-Hubert airport and see if you can buy fuel there. I'll checkout Bromont air field sometime and see if they will allow fill-ups there. The problem has only started as of December in Canada as far as I know. Previously only a few companies had the "blend". Now all gas is suppose to have some percentage of alcohol in it.

Will

Re: Astounding read! University test of fiberglass tank line

Up to the early part of this year, none of the super unleaded fuels here in the UK contained ethanol, so unless owners of bikes with GRP tanks were intent on saving a few pennies, there was up to 2011,no reason to have any sort of problem with Efuels!