Octane tester , breather valve

[Geoff]

From time to time members ask the question regarding fuel age & is it still safe to use.

According to the fuel companies , fuel stored in a fully sealed container can still be OK for 9 months or more , conversely in a an open container may only last a few days.

For boats , there are many variables in between , mainly depending on the type & size or the fuel tank breather.

To answer the octane question I thought somewhere in the world there would be an inexpensive tester , ie on with a probe & digital read out , similar to those one can purchase from garden centers to test the amount of moisture in soil.

Searching the web I was unable to find such a device.

Other than expensive Auto Analysers , has any member seen or know of an inexpensive octane tester??

The other thought I had was a valve device inserted into the breather line that opened when the motor was running but closed when the motor was off.

This would prevent or at least reduce evaporation occurring therefore extending the life of the fuel.

This could be as simple as a neoprene rubber flap or a rubber disc mounted on a light spring holding it against a seat.

However , there may be an issue with the fuel expanding on a hot day & the fumes not being able to vent off

Would be interested in members thoughts , perhaps a project that "hiles" may like to look at.

Geoff

[oz_brett]

to avoid water (condensation) in my fuel I keep the tank full at all times.
to avoid fuel coming out the breather and killing the lawn I disconnect the breather hose and run it into a used oil container - I've had it collect up to 2L of fuel.

What you are thinking is something I had going through my mind a few years back,
Using a cylinder type container (bottle) have the breather from the tank going through the top of the cylinder then back to the bottom allowing fuel to travel both ways without sucking air. a second hose would come from the top of the cylinder to where ever you breather finishes (in my case the fuel cap) the cylinder would also require a screw top lid so that you can add some fuel to use as filter.
= air and overflow fuel from your tank will be filtered through the filter fuel once in the cylinder air will go to the top and fuel at the bottom therefore as fuel in tank expands only air is leaving the cylinder as fuel subtracts it will suck back the fuel from the cylinder so what I am thinking it will only be that small quantity of fuel in the cylinder going stale not the tank full.

probably a good call would be to seriously stainless - they would be able to make it for ya.

"not to scale" the cylinder would not be bigger then the fuel tank

Edited August 8, 2013 by oz_brett

[SargeRX8]

It is a pain and I know whay you mean. I try to keep the valve shut all the time but find my self checking the tank quite often to release pressure. What do I propose? A double valve system. Have youe typical screw valve which you open and close when you go on your trips. Then have a one way spring loaded valve with a spring rated to say 1 to 2psi. I dont know if such has been done but effectively the same as my car. A spring in the fuel cap which will vent automatically and only when the pressure in the tank is capable of pushing the valve open.