Man accused of pumping aviation fuel into car at California

[Woxof38]

article says alcohol may have been a factor
http://www.cbc.ca/cp/Oddities/080730/K073002AU.html

[Track]

my car has been running on jet-a since i got it!

lucky enough i get it for free through the company and dont have to steal it

[FamilyGuy]

Whatever. Avgas in a car OOOOOOOh NOOOOOO. The engine will blow up - like in the movies.

Done it for years. Not good for the CATS and that's about it.

Jet A in a car - must be a deisel eh?

[Human Factor]

"It's really stupid. Put aviation gas in your car and it's so heavily leaded that eventually your valves warp and you'll end up with some very expensive repairs."

When did lead start warping valves? I ran AVGAS (given to me free by the company I worked for at the time since they'd have to pay someone to come and take it away otherwise) in my car for years (yes, it was a pre-catalyst car... 1975 was the newest model year I could afford on an apprentice's wage! ) with no problems. The dual Webers sucked it up like beer at a frat party!

[Hedley]

Actually, the lead is bad for the expensive O2 sensors,
and the catalytic converters in your car. Won't bother
the valves or plugs any more than they do on an aircraft
engine, which of course doesn't have O2 sensors or catalytic
converters!

[Human Factor]

Actually, the lead is bad for the expensive O2 sensors,
and the catalytic converters in your car. Won't bother
the valves or plugs any more than they do on an aircraft
engine, which of course doesn't have O2 sensors or catalytic
converters!

Of course, but as I mentioned, my 1975 car was pre-catalyst so I didn't have to worry about damaging any big-brother enforced emissions equipment. My lawnmower loved it too.

[North Shore]

Actually, the lead is bad for the expensive O2 sensors,
and the catalytic converters in your car. Won't bother
the valves or plugs any more than they do on an aircraft
engine, which of course doesn't have O2 sensors or catalytic
converters!

Without setting myself up for ridicule here, I'm a little confused. I realise that back in the day, lead (triethyl?) was added to gasoline as a way of lubricating the valve seats etc.. Then we discovered that it was toxic, and so unleaded fuel. Then catalytic converters etc... so the gasoline that we currently use in cars has no lead in it. OTOH, 100LL, while being "low lead" is still, by comparison, fairly heavily leaded, but that's ok, because of the relatively small volumes being used, and the reliability issues in Aero engines.
Surely, though, modern car engines are engineered to perform optimally in the absence of lead? I'm not just talking about the quoted problems with the O2 sensors and catalytic devices, but more the mechanical operation of the engine? Also what about the octane rating? If your engine is engineered for ~90 octane, then 100 can't be that great (over the long term - I realise that 1 tank probably won't do much)

[Hedley]

Forgetting about lead for a moment, and
just focussing on octane:

A higher octane than you need is harmless.
Your engine will run just fine. However, some
people have noticed a very slight power reduction
on the dynamometer with excessively high
octane fuel. Go figure.

A lower octane than you need is bad - it will cause
detonation, pre-ignition, etc resulting in internal
engine damage.

Back to lead. It increases the octane. Yes, it
also helps lubricate the valve seats but it also
creates lead deposits in the valve guides, spark
plugs, etc.

[xsbank]

Tetraethyl lead was used to prevent detonation and to lubricate the valves. Modern cars use computers and knock sensors to prevent detonation and different metallurgy to ensure the valves work. Ergo bingo, no lead needed on the ground.

Aircraft don't have knock sensors (put up your hands those who would like a computer to automatically throttle back your a/c engine when knocking was detected?) but continue to use lead to prevent detonation in their very simple configuration.

Higher 'octane' gasoline had even larger amounts of lead to prevent a much higher chance of detonation - really high-powered engines squirted water-methanol mixtures into the cylinders to cool them so that leaner mixtures were possible (more power) and detonation was even less possible. 115-130 octane had virtual lumps of lead in it!

Wasn't there a 145 octane fuel around for a while?

[hazatude]

High compression engines love 100LL. I had a little Hyundai Pony at around 10:1 that ran like a cat on fire on it. My 305 Chev pick-up, at around 7:1, hated it.

[Hedley]

avgas that I have known (and loved)

80/87 - red. Tiny bit of lead
100/130 - green. Lotsa lead
100LL - blue. Lotsa lead. Substitute for 100/130
115/145 - purple. Unbelieveable amounts of lead.

[hazatude]

100LL is around 2 grams per gallon of lead.

[Inverted2]

I remember quite a while ago local drag racers would come to the local airport and buy 100LL for their cars, although it was hush hush. Their big high compression V8s loved the stuff! Way cheaper than racing fuel as well.

[iflyforpie]

:

A higher octane than you need is harmless.
Your engine will run just fine. However, some
people have noticed a very slight power reduction
on the dynamometer with excessively high
octane fuel. Go figure.

As for higher octane being lower power there is some truth to that. Octane is simply what makes the fuel burn stable under high pressure instead of detonating. High compression engines can produce more power since they can suck and compress more air, but more pressure increases the risk of detonation. Thus they require high octane fuels.

Diesel (or Jet-A) are effectively zero octane fuels, but as most of us know they contain far more energy per mass than gasoline or AvGas.

[xsbank]

Diesel "octane" is 'cetane.'

[Redneck_pilot86]

A little off topic, but has anyone ever ran Jet in a Diesel? I'm curious how it performed.

[Inverted2]

A little off topic, but has anyone ever ran Jet in a Diesel? I'm curious how it performed.

Pretty good generally but you have to watch out because the jet fuel is "drier" than diesel so you can damage your injection pump. Some guys dump in some oil to lube things up a bit.

[hazatude]

A little off topic, but has anyone ever ran Jet in a Diesel? I'm curious how it performed.

There is an additive that you can buy to soften-up the Jet-A. I've ran the fuel trucks at the airport on Jet-A for years with no related problems.

[ozone]

The higher the octane the less flammable it is at higher temps. Has a higher flash point. This is hard to get around some peoples heads. Detonation is caused by excessive heat which causes the fuel to ignite at a time it is not supposed to ignite. (will start melting things quickly inside an engine.) Hence the higher flash point needed.

I know a guy who ran jet fuel in his dodge truck. wasn't using anything to lube it. It burnt out his fuel pump which cost $3000 to replace. Didn't really save him any money.

[Track]

ive been putting jet-a in my cars for quite some time without any problems to engine, cat or sensors. I simply add a diesel lubricant found in any auto parts store everytime i fill up...funny thing is tell people my car runs on jet fuel and they just laugh

2000 vw beetle tdi with 240 000kms (been running on jet-a since 140 000 kms)
2005 vw jetta tdi (new pd150 engine) been running on jet-a since purchase

for every 50 liters of jet-a, 12 ounce bottle of lubricant is added ($8)

[Track]

forgot to mention the beetle has a few engine modifications

vnt17 turbo upgrade
huge .216 injectors
boost controller
ecu flash (unitronic)
cat-back straight pipe

puts out 160hp and 305 ft-lb torque and still gets amazing mileage without any difficulty starting in -40 weather

[Cat Driver]

115/145 was better than blue ointment for killing the crabs.

[Human Factor]

The lead was mostly used to cushion the cylinder head valve seats back in the day. Once lead was legislated out of automotive fuel back in the mid-1970s, manufacturers began installing hardened valve seats to prevent the valves from beating the cylinder heads to death.

A similar thing is happening now with a zinc-based compound being removed from automotive engine oils. The zinc provides a cushion for the camshaft lobe where the lifter rides on it in flat-tappet OHV engines. Newer engines have gone to a roller tappet set-up for better efficiency (and faster ramp up, ramp down) and don't need the cushion. Many older engines are now eating up camshafts because of the low or zinc-free SL and SM rated motor oils. Diesel oils still contain the required ZDDP (zinc dithiophosphate) but their detergent levels are excessively high for gas-burning engines and can be damaging.

When will big-brother stop messing with the machines??? This is why The Matrix happened!

[wannabatp]

A little off topic, but has anyone ever ran Jet in a Diesel? I'm curious how it performed.

Dont know any more than whats been talked about here. But, I do know a guy who owns a restaurant and runs his RV on 50/50 diesel/used fat friar oil (filtered twice). Never any problems except it needs to be pre-heated in winter. Could easily run it on straight fat friar oil if he wanted to but his reataurant doesnt produce enough. He's got a 6.2L Chevy V8. His engine is from '97, before there were too many electronics to get in the way of the fuel. He says a newer diesel engine would sh1t if he tried the same thing.

Anybody else do this?

Cheers!

[invertedattitude]

1975 car? Chances are a vehicle of that vintage should require lead.