Gas tank Ullage slosh baffling

Ullage (from the French ouillage) is a winemaking term that has several meanings but most commonly refers to the headspace of air between wine and the top of the container that it is in.

There are a few other Commandos in the works with variations
of Bob Patton's low rear isolastic stabilizer geometry locations.
Both as warning to them and in quest of a solution for me here's the deal.

I've only discovered two limits to Ms Peel's predictable handling neutrality.
One is ground effect lift-drop influenced by fork slider angles eddies,
the other - surprise serious fuel slosh.

Alert only applies to IS 6 gal tanks and then only when 1/3 empty
and then only on insane flings that require hi side leaps up
after coming out a fast turn into a switch back the other way.
[personally think small tanks hinder cornering as nil knee clamping]

If tank over ~4 gal, not enough slosh space to knock front over,
If less than ~4 gal, not enough mass to knock front over.
So creeps up on ya, as forget about it because combo of
2/3 fuel level and places to harshly fling it rarely co-inside
and not at front of mind focused on the inter face of rubber
and surface adhesion.

First event was almost my last, let a leader of pack on Turnip
Triple lead the way d/t its power into opens, but caught
back up in tights with one last mean S into valley open run
all in plain view all clear to see on our decent from above >

> plan was to get the jump on him into the straight, as
he had to slow more [duh] on his fat tyres and ringing chassis,
so I added torque down into sharp dip to let bike almost trip out in
lean enough, rear slid sideways enough to both bleed speed
some but mainly to get fling up in time to line up into new lane, >

>but just as front lifted and aimed to land just so in time >>>
instead got fuel slapped by the up rising slosh from
the hi side which both lofted front too long it also
pushed front sideways a lane - on coming lane at like 60+ mph.
[Peel switches directions faster than fuel in tank can]

So going 60+ now upright in middle of on coming lane
I was aimed ~45' across it to the edge, throttled panic
power, hung way off opposite to resit the re-fling G's -
on my sudden straight steering to veer back at paint line then
over to proper side of road in shock but back on it trying not
to get too far behind in valley run from failed turn attempt.

So I think tank foam of some sort should fill the space
above tank middle hump with a cut out for fill up splash.
I assume it mostly all floats?
But how squishy is it for size of chunks to stuff in?
Is it sensitive to new gas?
Choices? both pro and con I find : (
pros:
http://stores.spencerashley.com/-strse- ... Detail.bok

http://www.eti-fuelcel.com/R6G.html

http://www.arracing.co.uk/ProductDetail ... ineID=3269

http://www.proalloy.co.uk/pages/669.htm

http://www.demon-tweeks.co.uk/Motorspor ... nk_Baffles
/ATL_Fuel_Tank_Baffle_Foam/1545/2558

http://www.iasa.com.au/folders/Safety_I ... oamex.html

http://cgi.ebay.co.uk/ALLOY-FUEL-TANK-B ... 0379898618

Cons:
Can this stuff sag when fuel low to get chewed up by fuel taps in tank
so pieces get into carb or even sag to clog fuel drainage?

Hope never to need this anti-explosion type
http://www.crestfoam.com/intro.html

hobot

What do oil delivery trucks use as they experience the same thing but at a higher degree?

speirmoor said:

What do oil delivery trucks use as they experience the same thing but at a higher degree?

Click to expand...

Baffles.


Tim

Spillage by trucks and trailers in the steep and crooked places
occurs right where cycle tires are loaded the highest whether just
cruising or missile'ing. Fuel, gut truck grease, hay bale clots
and dump truck gravel are ever present and changing unknowns
to risk on each and every blind. Dead deer and skunk grease
slicks are about as common, damn deer too stupid and stinking
skunks too bold to get out the way.

What trucks need more than baffling is sealed fuel caps
applied properly and cargo containment. Animals
would need electrified fences and over head cover
too.

hobot

So your're problem is more enviromental than mechanical?

Speirmoor, I can't tell if you are responding the the handling
upsets by fuel slosh or the slick crap on roads.

This post was in slim hopes that someone might have
experience on various tank foams and install do's and don'ts.
Ms Peels flight envelopes and opportunities In Ozarks exceeds
what I can pull off on my upgraded SV650 on and off road,
so mostly will not apply to anyone with ordinary bikes
and survival instincts not over whelmed by fabulous handling.

I wonder how much gas slosh might be part of the skippings
about on Gravel and pasture larks just going steady as
can with purpose, only one way to find out for fun.

hobot

hobot said:

Speirmoor, I can't tell if you are responding the the handling
upsets by fuel slosh or the slick crap on roads.

Click to expand...

Well, usually I can't tell what you're talking about as it's usually hidden underneath tons of rather unfitting quantum mechanics or oenology yadayada and maybe a bit to much grammatical creativity. So welcome to the club..... 8)

This post was in slim hopes that someone might have
experience on various tank foams and install do's and don'ts....

Click to expand...

I have - but I have no idea what you want to know in detail. If you want to use it you have to cut the tank open to put it in. Pushing it through the filler neck won't work - the foam needs to be uncompressed and evenly distributed. Furthermore its anti-sloshing effect is generally overrated. The idea of the foam is to limit flow to prevent atomization but that still means that fuel flow is still there and actually quite high. Baffles, "trap door" systems and collectors are far more efficient to prevent unwanted sloshing (and starvation).


Tim

OK Tim, your input is exactly what I lacked and didn't know on
actual issues to effectively install foam in a big Commando tank.
Thanks for enduring my ramble to save me more bad shocks.

Its not good news to me. Don't intend to cut fiber IS tank open
so if impractical to stuff in enough foam to null slosh events
I must re-think safety issues or get a sight glass or
gas gauge to warn me.

Ms Peel with - Patton's robust rear iso link - plus 2 helper links with
some compliance-flex, has a side effect of tempting one into turns
so fast and leaned she falls down to rebound up on rear tire only
- in glee. Every-Thing else in Peel project is only meaningful
to me in relation to that single feature's function beyond
two tire traction limits on and off tarmac.

Yet to see if street tires are a tarmac advantage or not.

hobot