Auto Fuel Use In O-320 D1a

Does anyone have experience using auto fuel in the 160HP O-320? Another owner who had used autofuel for a while said his oil analysis numbers increased for aluminum. Would appreciate user input. Thanks, Ron Haynes [email protected]

auto fuel D1A

I have a new lycoming 0-320 D1A. Lycoming says never use auto fuel in the 0-320 D1A. There are STCs for auto fuel available for the lyc 150 hp engine, but I'm not sure of the model #s.

This is from Petersen's web site. They have an STC for auto fuel use with a 160 hp engine in a Cherokee 160 which used the O-320-D2A, which is the same engine as what you have, except for prop mounting configuration. Just my opinion, but it would seem to me, that as long as you had proper flow to the carb and you were using 91 octane or higher octane fuel and were observing the other requirements of the STC, you should be OK using 91 octane and above mogas in your RV with an O-320-D1A.
Good Luck,
Mahlon

PA-28-160, -161, -180, -181

Beginning with serial 28-1761, PA-28-160, -161, -180, & -181's are approved for 91 octane mogas. The installation of this STC requires the removal of the Piper installed electric boost pump and the installation of two different electric pumps. This change in pumps was deemed necessary when this airplane failed to pass the minimum flow tests. It's a redundant system, you can run one pump or the other but the two cannot be operated simultaneously.

Other modifications include the replacement of a fuel line fitting in the fuel selector and placarding the airplane for takeoff and landing on the right tank only.

Much of the plumbing on the new pumps is done in our shop to save time when you have the kit installed. Your IA will have to tighten the fittings and mount the completed pump assembly on the firewall, reshape the line from the fuel selector to the firewall fitting, move the gascolator, change the fuel pump switch and install wiring. Placards on the fuel filler openings and on the instrument panel must also be installed. Installation should take approximately four to six hours.

PA-28's of this series with serial numbers below 28-1761 may have the STC installed if the engine installation is revised to that used on number 1761 and up, and if the line from the right tank is at least 3/8 inch diameter. Doing so however, requires a different exhaust, cowling and prop. It's totally impractical unless you need to rebuild the airplane from the firewall forward anyway.

The complete kit for serial 28-1761 and up, including pumps, fittings, placards, installation instructions and Supplemental Type Certificates sells for $1725.00.

Auto Fuel in O-320

I used Auto Fuel in my RV-6A O-320 for over 250 hours flying time. In addition I fly a C-177 O-360 using auto gas and two C-182's O-470 using auto gas. I had no problems whatsoever burning auto gas.

I fly out of Lubbock, Texas, and never had vapor lock either.

I have just hung a second hand D1A on my RV-9A project. It was from a 6A damaged in the recent hurricanes. It has 885 TTSN and (according to the past owner) has never had a drop of avgas run through it. He used 93 octane and Marvel Mystery Oil, as well as AvBlend in his oil.

It had 8 hours on an oil change and the oil was very clean. The plugs are several years old and look like they have a few hours on them. The compressions are great (76-78 range.) It was flown out of Florida and he said he never had vapor lock, although I suspect that was in part due to having cooling vents to the fuel pump as well as everything else that could get hot (mags, alt, vacuum pump.)

I don't see anything to fear from running proper mogas from what I've seen so far. I may do the same, although I expect to do enough x-c to use avgas part of the time.

Bob Kelly, 90854