What Lycoming O-360 for Patrol

[Pbruce]

Excellent! Do you buy the switch setup as a pre-built unit from the company that sells the Pmags or do you have to engineer and build it yourself?

[Hewko]

Pmag doesn't supply wiring. It's very simple, a SPST toggle switch from aircraft spruce placed on the panel wired between the jumper leads.

[Pbruce]

Thanks. Anything you don’t like about the dual Pmag?

[Hewko]

My plane has one Pmag and one regular mag. It's happened twice now on a start up after sitting for a couple weeks it runs really rough on the Pmag, shut it down for a few minutes and start it up and it's fine. Apparently it's due to condensation and isn't uncommon. I wouldn't fly without a Pmag or some other electronic ignition on one side and like having one standard mag for reliability.

[jaredyates]

I've been running dual p-mags for a few years and haven't had any trouble out of them. I'd install the same if I were building another.

[noema]

Recently got my engine. I collected all the specs because they are surprisingly hard to find. This is the configuration I am going with.

Lycoming YO-360-A1A

• 180 hp @ 2700 rpm
• Compression ratio 8.5:1
• Minimum fuel grade 91/96 avgas
• 95 octane Mogas adaptable
• Mount: Type I Dynafocal
• Crankcase style: Wide deck
• Alternator mount: boss mount
• Constant speed shaft and governor drive
• Governor location: rear mount
• Weight: 258 lbs
• Carburetor: Avstar 61C26047
• Fuel Pump: Aero 62A23701
• Magneto Left: Slick 66GC25SFNN (impulse)
• Magneto Right: Slick 66GP-0SANN (plain)
• Spark Plugs: Champion 1182-E7
• Starter: Hartzell 31A28861-Y (SKyTec XLT?)
• Alternator (not included): B&C L-40
• Propeller governor (not included): Jihostroj P-920-032/A
• Hartzell Trailblazer (not included) HC-C2YR-1NX/NG8301-3X1

The engine is commonly used in RV builds so a lot the RV parts are interchangeable:

• Vetterman Exhausts
• Baffle Kits
• etc.

[jaredyates]

You can probably eliminate the fuel pump, which will save you from also needing an electric boost pump, pressure sensor, and two firesleeved lines.

[PLTemple]

On the topic of O-360 engines for Patrols, I am curious about which Carburetors folks are getting. There are two different Marvel Schebler MA4-5 carbs that are approved for the O-360, the 'smaller one' is the 10-3878, and the 'larger' one is the 10-4164-1. The 4164-1 can deliver quite a bit more fuel I am told by M-S; they say at full throttle you should get 20 gal/hr. They also have a conversion kit they sell for the 10-3878 that was needed for Mooney's, which needed more fuel flow, and it turns the 3878 into a 3878M, converting it essentially to a 4164-1.
The 10-3878 that came on my engine was running way too lean. We drilled out the nozzle after finding it was only at 0.114" ID, instead of the usual 0.118. That helped a lot, but not enough. I suspect it has a problem elsewhere, such as with the economizer. Considering converting to a 10-4164-1.