Mogas on Fuel Injection

Hello all

Maybe someone can help on my questions.

- Is the Silverhawk FI capable to run on Mogas?

- Are there any bad side with using Mogas on FI?

- Is there also a risk of having "vapor lock" on an FI system with Mogas?

- Is a return line on the Silverhawk usefull/neccesarry/possible to prevent "vapor lock"?

- Does I need the Vans Fuel Injection Fuel Pump and Installation Kit also?

I know, a lot of questions, thanks for answering a few of them!

Dominik
Wings (Tank) RV-7A

Dominik,
Is the SilverHawk FI capable to run on Mogas?
All internal parts are mo gas compatible. However Precision Airmotive, the manufacturer says not to use Mogas. My guess is this may be more of a liability issue then an operational one.

Are there any bad side with using Mogas on FI?
As far as I know, vapor issues aside, there are no more problems running mogas with fuel injection then with a carburetor, as long as properly blended fuel with an appropriate octane for the engine that is using it, is being used.

Is there also a risk of having "vapor lock" on an FI system with Mogas?
There is always a risk of vapor when using car gas, especially the higher you go. It is important to use fuel appropriate to the season it is being used in. Also fuels containing alcohol shouldn't be used. The risk of vapor is before the engine driven pump; once the fuel is past the engine pump the pressures in the fuel injection system should be high enough to prevent vapor lock. A well-designed aircraft system is important in helping prevent the formation of vapor before the fuel gets to the engine driven pump.

Is a return line on the SilverHawk usefull/neccesarry/possible to prevent "vapor lock"?
There is no prevision to use a return line on the SilverHawk fuel injection system.

Does I need the Vans Fuel Injection Fuel Pump and Installation Kit also?
In My opinion it would be appropriate and mandatory to have a airframe auxiliary fuel pump in a fuel injected engine supply system. The high pressure one that Van's sells will work fine with the SilverHawk system and id often recommended for it.

Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

Thank you Mahlon, I hoped you will answer.

So it is only a insurance problem when I fill up my tanks with mogas. Do you think they will change this mind in a few years when mogas is easyer to get than avgas?

What does Mattituck tell to the use of mogas on theyr engines, when the customer has a Silverhawk FI?

Whats about mogas and the LASAR ignition? Do they have any restriction?

Dominik

Dominik,

This is a cut and paste from the FAQ's on our engines, and we tell our customers when they ask:

Can the TMX Series of engines be operated on automotive fuel?

Yes, all of the TMX experimental series of engines can be operated on fresh automotive fuel that meets spec ASTM D-4814 and has a minimum 91 octane rating. The use of automotive fuel that is blended with ethanol or alcohol is not permitted. Engines that have been modified to use higher than standard compression ratio pistons or that are using electronic ignition that advances the ignition timing past standard specifications are not recommended to use mogas. Although the use of 91 octane automotive fuel will work in these engines, that practice should be limited and isn't endorsed.

Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

Dominik,

A few years back either AOPA or EAA ran an article on the difference between MOGAS and Avfuel. Unfortunately I can?t remember which magazine had the article.

Assuming you use the proper octane rating for the engine and the components are MOGAS compatible the biggest thing I remember from the article was that the shelf life of MOGAS is one year and the shelf life of aviation fuel is two. This was due to the ?other? chemicals added to MOGAS. Not a real problem if you are flying a lot.

You also want to heed Mahlon?s warning about using gas blended with alcohol as the alcohol will absorb water, thus you won?t be able to drain it from your tanks, and may find out about the water problem in flight.

As for gas storage, in my last we learned that it is against federal HAZMAT law to store more than seven gallons of gas in your house. Dumb law but your insurance agent might have something to say about it, if you had a fire in your garage.

Just so you will know:

I fellow RV builder that I know is the quality control manager at a large refinerly. When I asked him if he used automotive fuel in his RV he said no way.

According to him, the goverment rules allow a certain amount of water in the fuel. After loading the truck the load is tested and water is added up to the exact amount of the allowable amount.

Regards,
Mike Stephenson

P.S. I can not tell you who nor where, so don't ask.

Cutting the fuel

According to him, the goverment rules allow a certain amount of water in the fuel. After loading the truck the load is tested and water is added up to the exact amount of the allowable amount.

Click to expand...

I've heard a similar story about grains. The farmers sell clean grain and the shipper adds the maximum amount allowed dirt, etc by the government to increase their margins

Is it true, who knows... sounds like your source is more believable than mine, but can this kind of crap really be taking place? If so, why isn't anyone making a big deal about it?

Jonathan