CVR(T) fuel bladder compatibility with alcohol

A friend of mine said he remembered hearing the fuel bladder in the Scorpion/Sabre/Scimitar would fail if alcohol-based fuels were used.

Has anybody seen this or had any reports? If so was this a minor blend or only if it was heavy blend?

In California all pump gasoline contains up to 10% ethanol so I need to get this figured out before I add fuel.

thanks,

The Alvis Fighting Vehicle Society should know the answer:-

http://www.afvsociety.co.uk/vehicleregister.html

Ethanol fuels are evil.

Drain down your orginal tank adn clean it and preserve it. Fashion an alternate supply source and quick disconnect system and secure and never look back.

Civvy owners just dont do the miles to justify that big of a fuel tank.

What is your aytime high to overnight low temperature swing out where you are?

Honestly, junk fuel is the start of 99% of poor running problems for Ferret and CVRT and Land Rover etc owners.

Robin

Never come across this as a problem, although this is in uk so perhaps not so much ethanol content. Have had the sight glass window go 'soft' and start leaking so maybe that is related. As Robin says you could rig an alternate supply if you want to be safe.

Ethanol fuels are evil.

 

Drain down your orginal tank adn clean it and preserve it. Fashion an alternate supply source and quick disconnect system and secure and never look back.

 

Civvy owners just dont do the miles to justify that big of a fuel tank.

 

What is your aytime high to overnight low temperature swing out where you are?

 

Honestly, junk fuel is the start of 99% of poor running problems for Ferret and CVRT and Land Rover etc owners.

 

Robin

Easily done with the large-body CVR(T) but there isn't much room in the turreted models. I suppose if one were to sacrifice the rear ammo racks one could fab a tank...

The annual range runs from just barely freezing to about 90F, a daily range is typically about 20F

The sight window in my sender housing is already bad from whatever was in the tank, is there an easy fix for this? The fuel tanks assembly is one of the last bits I've not stripped out of my hull, I have to finish emptying it first.

I have bought a new gauge assembly to fit - it is only really a problem when the tank is more than half full (rare). You could always just replace the glass with a piece of metal - after all how often do you need to do a visual check on your fuel level? If it stops, just stick a jerry can in! The 'glass' actually seems to be some kind of perspex or acetate, which may explain why it softens up over time.

If you remove the bag (horrible job), then you might be able to rig something in the empty space, but size would be limited by what you can get through the 'porthole'. Reading your post again however, your bag hasn't actually failed yet, so why go to all this trouble for something that might never happen!?

I have bought a new gauge assembly to fit - it is only really a problem when the tank is more than half full (rare). You could always just replace the glass with a piece of metal - after all how often do you need to do a visual check on your fuel level? If it stops, just stick a jerry can in! The 'glass' actually seems to be some kind of perspex or acetate, which may explain why it softens up over time.

 

If you remove the bag (horrible job), then you might be able to rig something in the empty space, but size would be limited by what you can get through the 'porthole'. Reading your post again however, your bag hasn't actually failed yet, so why go to all this trouble for something that might never happen!?

I run whatever comes out the pump and I am using the original bladder. I do regularly add a can or 2 of SeaFoam between fill-ups. I typically add 20 gallons of gas before each parade, my fuel gauge don't work, I have yet to run out in the middle of an event!

I run whatever comes out the pump and I am using the original bladder. I do regularly add a can or 2 of SeaFoam between fill-ups. I typically add 20 gallons of gas before each parade, my fuel gauge don't work, I have yet to run out in the middle of an event!

Martin

Depending how far your parades are if you are adding 20 gallons at a time you may find you have a nearly full tank....this is how I ended up with 300 litres in my tank...!

Tim

Martin

 

Depending how far your parades are if you are adding 20 gallons at a time you may find you have a nearly full tank....this is how I ended up with 300 litres in my tank...!

 

Tim

Tim,

Yes, first time out this year went to add gas and oops its full! Have been driving all over and not filling up in order to draw it down. Most parades are 2 - 4 miles with a bit of city driving to get back to the flatbed depending on the logistics.

My biggest fear is running out in front of the masses!

Cheers,

Martin.

Hi

On the topic of Ethanol containing gasoline, in the US 10% ethanol containing gas became the rule nearly 10 years ago. It was followed almost immediately by failure of fuel pump diaphragms, gaskets, fuel lines almost any part in the fuel system made of "rubber". Then a little slower by corrosion problems in the fuel system, many gas tanks which had been sealed with early gas tank sealers also started to leak as the sealer was dissolved.

All this having being said, if your MV has been using Ethanol containing fuel for any length of time the worst is probably over accept for the corrosion problem.

Now silly stuff like cork floats on gas tank fuel gauges are sinking or vehicles with fuel cells are having the open cell foam which gives them there explosion reduction status are finding that the foam has disappeared.

Our club experienced a number of MV parade break downs when this fuel was first introduced.

If you are resurrecting a MV that has not been run on Ethanol, minds well replace all the rubber parts in the fuel system.

Cheers Phil

Hello. I know this post is fairly old but I just thought I'd chip in as I'm a Process Tech. at a Biofuel plant. It's entirely possible to run any engine on an alcohol fuel, especially an ethanol blend like E10. We run 2 2.4Mw gas engines on Biogas (bear with me, I'm getting there). Although Biogas and Ethanol are different, the chemistry that goes on is essentially the same.

Shorter chain hydro-carbon's will burn hotter, especially ethanol which has the addition of inherent oxygen to the fuel, therefore, you're better off running it richer. You're unlikely to get too much engine coking because ethanol's inherent oxygen helps to counteract the additional carbon.

You can also run the engine at a higher compression due to the higher octane (RON) of ethanol. You can work out the octane number of E10 by taking the pump gas at 89 (for instance) x9+ 108.6 (RON of ethanol) and dividing by 10 = 90.96 RON for E10. Seems like a good deal? It's not really, ethanol is about 2/3 the energy density of gas, so increases richness will also help prevent lean burn and piston/cylinder damage.

So, back to the question at hand. Any alcohol will eat natural rubber. We used Viton rubber seals in everything, as this is the only thing resistant to the chemistry going on inside your engine. So if your bladder's anything but Viton it'll perish (it's a shame it's not very abrasion resistant but that's a different story).

Ethanol is also a solvent so it'll start to eat any sludgy horrible stuff in your engine, which will quickly be flushed around and cause pump failures. You'll have to change your fuel filter's more regularly and it might be worth fitting a few more inline filter's if you can get them.

As has been said, you might be better off making a stainless tank (316, not 304, the added chromium and molybdenum helps prevent the solvent wearing the sacrificial outer layer) and adding a drain plug in a sump at the bottom. Ethanol does absorb water, so shouldn't be stored for any length of time, especially where oxygen and moisture can get to it. It also produces it's own moisture as it breaks down... more quickly than gas.

All this said, at E10, it really shouldn't be a huge problem as you're not dealing with a huge concentration and it does have a number of benefit's with the decreased likelihood of engine knock, not that you should get any, I think the CVRT engine was designed by Rolls Royce? to run off some extremely poor quality Russian gasoline.

We've run generating engine's off methanol, ethanol, SVO, glycerol, biodiesel, biogas and various mixes of them.. Just be thankful you don't have to deal with hydrogen sulphide (H2S+(2)O2= H2S04.. in otherwords.. Sulphuric Acid)

Hope all this helps, and if it doesn't I hope it's helped to kill 5 minute's of potential boredom

Ahhh, you just beat me to it..................

Very interesting post thankyou, looks like while my engine is out i should try and run an inline filter in to see when moisture starts to become an issue, i volunteers at a collection with a few very vintage vehicles and we're really not looking forward to seeing what E10 will do as some only get a run around every couple of weeks at best. Hopefully E10 is still a while away for most of us in the UK

Steve

Very interesting post thankyou, looks like while my engine is out i should try and run an inline filter in to see when moisture starts to become an issue, i volunteers at a collection with a few very vintage vehicles and we're really not looking forward to seeing what E10 will do as some only get a run around every couple of weeks at best. Hopefully E10 is still a while away for most of us in the UK

 

Steve

E10 isn't terrible. As I said before, most military vehicles, especially post WW2 were designed to run on very poor quality gasoline and should probably cope just fine with the right precautions. I couldn't suggest what might be the best course of action for ethanol vehicles but I wouldn't be concerned because the emphasis for the industry is moving away from gen.1 biofuels, of which most ethanol road fuel is derived (crops grown for the purpose of energy without nutrient recovery).. I.E. Ethanol isn't as environmentally friendly in Europe as it is in South America for instance, where energy recovery rates are much higher). However, most EN spec. gasoline is already around 5% ethanol so you're probably already using it to a limited extent. There is more focus on other alcohol fuels like Bio-Butanol, which is chemically more similar to gasoline, with a much higher energy density. However, if a vehicle is being stored for a length of time, take the fuel out and always check your oil before you start it up again, if not change it altogether.

If you can get hold of AV-gas I'd say use it. It was fairly easy to get hold of a few years ago however it's slightly rarer nowadays with fewer civilian aircraft flying and tighter regulations on use (largely due to the inclusion of tetra-ethyl lead). The leads great for your valve seats, not so good for your general wellbeing, especially if your in a confined space with the engine running for long periods of time.

I personally dislike the alcohol fuels, they don't give the lubrication to cylinder bores and pistons that regular gasoline does, but that said, were still only dealing with low concentrations so don't be too scared of it. Bio-diesel is much much easier to deal with.

Hope all this helps