Auto Gas Specifications?

Abstract: The spec. for using auto gas in a Grob 109B is Roz 98 the octane rating for most premium gas found locally is 92 I am some what befuddled by the numbers! Who is using 92 octane in their 2500E engine? Thanks, Paul

Subject: Auto gas?
From: "Paul Cullman" <antiqair
Date: 8/6/08 8:13 AM
To: G109_Pilots@yahoogroups.com

The spec. for using auto gas in a Grob 109B is Roz 98 the octane rating
for most premium gas found locally is 92 I am some what befuddled by
the numbers! Who is using 92 octane in their 2500E engine? Thanks, Paul

Subject: Re: [G109_Pilots] Auto gas?
From: "Ackerman Capt. Ron" <ronackerman
Date: 8/6/08 9:54 AM
To: G109_Pilots@yahoogroups.com

Paul,

Roz 98 is a European method of measuring the Octane of Gas. Our 92 octane is the same as the Roz 98. I am still unsure of the use of unleaded gas permissibility.

Capt. Ron

Subject: Re: [G109_Pilots] Auto gas?
From: Soaringrob@qATeSVhRX73DEpKGYU5h-njQrjgQwrFdPm4l3FyZhXBljNhFq4UMmPpPqJY7BtRZnKukH3Q-EXmI3eI.yahoo.invalid
Date: 8/6/08 12:46 PM
To: G109_Pilots@yahoogroups.com

Friends:

I used autogas in my 109A about 17 years ago on an island in Florida where I couldn't get avgas. That engine was a little different than the 109B and the gas was probably different then, too. The engine ran great! Better and smoother than avgas.

A question. I have a 109B now. The leather on the shroud around the panel needs to be replaced. How do I get that shroud out to work on it?

Thanks, Rob Wilkinson

Subject: Re: [G109_Pilots] Auto gas?
From:
Date: 8/6/08 3:19 PM
To: <G109_Pilots@yahoogroups.com>

Thanks so much. I thought that was so but I needed some out side input.
By the way I have found my air filters are in poor condition and after much looking there is no after market filter that will match up to the one installed on my aircraft. I have been in touch with Brackett air filters and they are going to cut me new material to replace the worn out foam!
There is always hope when one is supporting an elderly plane. Regards, Paul

Subject: Re: [G109_Pilots] Auto gas?
From: "Ackerman Capt. Ron" <ronackerman@faBwZxSrUKfdeZNFIR836-KgwOb4W4GbkEHziwhFZxNFoJCQLuDPLZWmK2jfFt1hQRzLw0x3Hr0mzX3xxdiJeg.yahoo.invalid>
Date: 8/6/08 3:41 PM
To: G109_Pilots@yahoogroups.com

Paul,

Also, Every gas station that I have been to in the last month has a sticker on the pump warning that there is up to 10% Ethanol in the gas. This may be very important in our use of auto fuel. Can anyone enlighten us on the dangers of using Ethanol laced gasoline in our engines?

Thanks,

Capt. Ron

Subject: Re: [G109_Pilots] Auto gas?
From:
Date: 8/6/08 8:14 PM
To: <G109_Pilots@yahoogroups.com>

I live in Washington state and all the service stations that I have been in have no stickers as regards ethanol! I did stop at a Shell station and queried the operator if in fact there was ethanol in the fuel. He did not know but called the supplier who said yes there was ethanol in the fuel.
Now Peterson in Nevada has the STC for aircraft to use MoGas and the STC is for regular unleaded with no additive. My neighbor works at ConecoPhilips and he says that they do not add ethanol. I fuel up at Costco and they claim no ethanol. I would say investigate. There are suppliers out there that do no adulterate at this time! Cheers, Paul

Subject: Re: Auto gas?
From: Ray
Date: 8/7/08 7:24 AM
To: G109_Pilots@yahoogroups.com

There is a service bulletin for the Limbach using mogas.

The issues were adequate octane to prevent rough running and fuel system components that could stand up to the potential increased alcohol in the fuel.

I have seen deteriorated fuel lines in person and it is the fastest way to cut off your engines fuel supply and cause aggrivating problems in the fuel filter and carb.

If the parts are up to it a bit of alcohol would be OK and the reduction in lead in unleaded mogas will make the valves last longer.

No alcohol is best in mogas for our use. Personally I blend 100LL with 25% mogas to moderate any adverse effects.

Ray

Subject: RE: [G109_Pilots] Auto gas?
From: "Don Johnston" <rvflyer@Zx0YxzRYZgHc_kCTpN-vpVrqpuvaA1ze5FyFYbrTmSBdFFSeU9S_1EVXuT4flYT7lbezgKk1gv24.yahoo.invalid>
Date: 8/8/08 11:25 AM
To: <G109_Pilots@yahoogroups.com>

All California fuel has ethanol and no one I know with a mogas STC will put it their aircraft. This may or may not apply to the Limbach, but I would be cautious. The main problem is that ethanol scavenges aluminum, so fuel lines can be compromised. Other aluminum components in the engine can deteriorate. Some seals and gaskets may be affected by the additive. Also, I have been told that the ethanol burns hotter, so the more of it there is in the gas the greater the potential for higher temps in the cylinders and EGT. This can be harder on the engine. I beilieve that the percent of ethanol is about to be raised in all fuels where it is used.

SInce I mostly fly a Citabria in CA, I use only 110LL - It may not be as critical in the Grob engines, but I would not assume anything... Perhaps you can use some of this information to dig deeper to be certain about the application before experimenting.

Hope this helps,

Don

Subject: Re: [G109_Pilots] Auto gas?
From:
Date: 8/9/08 9:33 AM
To: <G109_Pilots@yahoogroups.com>

Thank goodness we do not have California regs! We have premium gas with NO ethanol. Paul