Hodges Fuel Volatility Tester

[rgmwa]

Anybody know where to buy a Hodges Fuel Volatility Tester? Supposedly available from Petersen Aviation Inc in the US, but doesn't appear on their website.

 

rgmwa

 

 

[old man emu]

That question is going to lead to some very interesting discussion.

 

My first Google search lead me to this : https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/airworth/awb/28/003.pdf which talks about aircraft fuel. It's off topic, but interesting.

 

You could try this ad: HODGES VOLATILITY TESTER for sale in Bountiful, Utah - Classifieds KSL

 

See the last page of this PDF for a picture

 

OME

 

autogas_vs_avgas.pdf

 

autogas_vs_avgas.pdf

 

autogas_vs_avgas.pdf

[facthunter]

Volatility is a bit hard to quantify. Vapour pressures of the various components might be more use, and better indicate potential problems with vapour lock and also floats sinking due bubbles in the fuel (like when you take the cork out of a Champagne bottle) This causes "flooding of a float type carburetter.

 

. Lead only "works" above a fairly high temperature. The liquid cooled Rotax 912 series runs too cool, generally for optimum lead additive performance in the alleged "lubricating" function, hence the difficulty sometimes experienced when using it with exhaust valve seating deteriorating. The white residue in the exhaust pipes of engines using lead is from the bromide compound used to prevent it building up too much. The lead is only liquid on the exhaust valve seats in optimum conditions and doesn't help anything anywhere else . It works much the same way as a flux when brazing or sand when used in forge welding steel. (That's something most "moderns" have never done. Weld under the hammer) . Nev

 

 

[Scotty 1]

From the Peterson Aviation site this may help.

 

AUSTRALIA

 

To order STCs in Australia, contact:

 

Dr. RJ Hodges

 

PO Box 84

 

CHURCHILL

 

Australia 3842

 

0407-360844

 

0356-292517

 

 

[rgmwa]

Thanks Scotty, I think that's for STC's rather than the Tester, but will follow up.

 

OME, I saw that advert but am not sure if it's current or not.

 

I'm actually asking on behalf of a mate who lives in a remote town in the Pilbara and has trouble getting reliable supplies of mogas.

 

rgmwa

 

 

[old man emu]

It's worth an email. I don't suppose these things sell like hot cakes.

 

OME

 

 

[Guest Hampden]

Anybody know where to buy a Hodges Fuel Volatility Tester? Supposedly available from Petersen Aviation Inc in the US, but doesn't appear on their website.rgmwa

They are no longer in manufacture and with better fuels these days are not so necessary. The main issue is ethanol not declared in fuel. Not sure of the practicability of testing outside of a lab. "Add a known quantity of water to the fuel/mix it. If the water content increases you probability have ethanol. The Hodges Tester was invented in Australia to measure the Reid Vapour Pressure. To meet EPA requirements for escaping fuel vapour, the petrol companies have lowered the RVP.

 

 

[Guest Hampden]

Volatility is a bit hard to quantify. Vapour pressures of the various components might be more use, and better indicate potential problems with vapour lock and also floats sinking due bubbles in the fuel (like when you take the cork out of a Champagne bottle) This causes "flooding of a float type carburetter.. Lead only "works" above a fairly high temperature. The liquid cooled Rotax 912 series runs too cool, generally for optimum lead additive performance in the alleged "lubricating" function, hence the difficulty sometimes experienced when using it with exhaust valve seating deteriorating. The white residue in the exhaust pipes of engines using lead is from the bromide compound used to prevent it building up too much. The lead is only liquid on the exhaust valve seats in optimum conditions and doesn't help anything anywhere else . It works much the same way as a flux when brazing or sand when used in forge welding steel. (That's something most "moderns" have never done. Weld under the hammer) . Nev

While 100LL is an allowed fuel in the Rotax 912/914, the lead gets picked up in the sump oil which in turn is circulated through the gearbox. The extra lead lubrication can cause premature slipping. We run BP Ultimate 98 and Shell/Rotax oil

 

 

[gareth lacey]

We ordered an stc for our 0235 from USA , cheaper than the Oz one from Dr Hodges , also he was very hard to get on phone or email,

 

cheers Gareth

 

 

[facthunter]

Hampden, I don't like running leaded fuel in a 912, but you may find you have little choice, on the odd occasion and Rotax do allow it. Changing the oil at 25 hours is pretty conservative. You can get a compression loss with an uneven build up on a valve seat occasionally. Usually comes good with return to mogas I'm told, but there might be occasions when it doesn't. You pull the motor through to check the oil level so you get an opportunity to check it by feel. Nev

 

 

[rgmwa]

They are no longer in manufacture and with better fuels these days are not so necessary. The main issue is ethanol not declared in fuel. Not sure of the practicability of testing outside of a lab. "Add a known quantity of water to the fuel/mix it. If the water content increases you probability have ethanol. The Hodges Tester was invented in Australia to measure the Reid Vapour Pressure. To meet EPA requirements for escaping fuel vapour, the petrol companies have lowered the RVP.

It seems that Petersen Aviation in the US sent their stock of volatility testers back to Dr Hodges. As you said, the US have adjusted their fuels and apparently no longer had a worthwhile market for the testers.

 

My mate contacted Dr Hodges last week and was able to get one. Thanks for the reply.

 

rgmwa