For the Franklin Engine Owners

senoiaslim · Post by **senoiaslim** » Tue Apr 24, 2007 5:23 am

I am new to the Maule Board and I am looking forward to buying my first Maule. My question to the Franklin Owners is this. With that engine, can there be mods done to improve HP and or speed with the engine? I have heards that the engine is lighter than the 235 so that can help, but what else can be done. The other part is if you have problems with the engine is there ample help and support to get the engine running again?

a64pilot · Post by **a64pilot** » Tue Apr 24, 2007 2:28 pm

Mark,
I wouldn't do anything to a Franklin, they are a hot rod stock. Beautiful, smooth running engine when they are running. Parts are hard to come by and people with Franklin experience even harder.

MauleWacko · Post by **MauleWacko** » Wed Apr 25, 2007 5:31 pm

Rocketman · Post by **Rocketman** » Thu Apr 26, 2007 2:45 pm

I put over 900 hours on my 6A-350 without putting a wrench to it. You run it right and it will serve you well. I changed the oil every three months or 50 hours. Watch out for oil leaks around the accessary case. Let it idol until the oil temp starts to come up. Always run it long enough to get and stay hot for a while. Be sure and know how to lean the mixture correctly.
It's the best horizontal opposed airplane motor ever built.
Do the other guy's have a 6 cylinder engine with over 200hp that can cruse on 8-9 gph. Not sure, but I don't think so.

MauleWacko · Post by **MauleWacko** » Thu Apr 26, 2007 3:00 pm

senoiaslim · Post by **senoiaslim** » Thu Apr 26, 2007 7:00 pm

Rocketman,

Since you are in the SE, where do you go if you did need to have it worked on? Also what kind of aircraft to you have and what performance specs are you seeing cruise, climb,? I also understand that they are lighter engines????

Thanks

MauleWacko · Post by **MauleWacko** » Thu Apr 26, 2007 7:28 pm

MauleWacko · Post by **MauleWacko** » Thu Apr 26, 2007 7:29 pm

maules.com · Post by **maules.com** » Thu Apr 26, 2007 10:46 pm

There's an M4-220 for sale in AZ, An M5-220 in OR and another in WA

Rocketman · Post by **Rocketman** » Fri Apr 27, 2007 4:39 am

MauleWaco wrote:Rocketman
What setting did you use for cruise? Did you go by the do not run below a certain rpm setting like you here for the GO-300 to keep them running?

When I first got my M4-220 I started a relationship with one George Heinley out in Texas. It was told to me that Heinley was the authority on Franklin engines. I'll bet he has past on now, he was in his 80's back then.

George told me these things and I followed them like it were the Bible; change the oil regularly, lean only above 5000, never run over 1000rpm without the oil temp in the green, always run it until it's hot and then for no less than an hour, use the power setting in the franklin manual that call for the highest RPM settings. George said high RPM and low MP provided the least stress on the crankshaft.

In some notes I kept, I wrote down; 23" & 2500 gave me 135mph & 8-9gph. 24" & 2550 gave me 75% power for 145mph & 10-11gph with a very loud cabin.

George also informed me that one of the biggest problems he found was mechanics didn't know how to install the intake tube packings (O-rings, gaskets) correctly. Done wrong, the 6A-350 will leak air and cause hard starting and run lean and hot. When I got mine it wouldn't idol below 1000 and was hard to start. After I re-installed the packing to his instruction it would start and idol with the throttle closed at 700rpm.

Make sure your engine baffeling is the best it can be. Keep the engine clean, especially the cylinder fin's.

KEEP A CLOSE EYE ON THAT OIL LINE THAT RUNS FROM ONE SIDE OF THE ENGINE TO THE OTHER. THERE IS 80PSI OIL PRESSURE IN THAT LINE AND YOUR ENGINE IS GONE "RIGHT NOW" IF IT RUPTURES. If its oil soaked, change it.

Oh, and every other oil change I put in a quart of marvel mistry oil. I also put 6oz of marvel in each fuel tank every other fill up.

George said run it hard, it was designed to run at 100% on whop-whops. Mine was 1475 STOH when I bought it. I sold it with 2420 TTSN & 945 STOH. The new owner took it over 2600 before it gave up from bleeding out on takeoff at 80psi.

MauleWacko · Post by **MauleWacko** » Fri Apr 27, 2007 7:27 am

Rocketman · Post by **Rocketman** » Sun Apr 29, 2007 8:37 am

MauleWaco wrote:Rocketman
Thanks for the info. I also was told to run it hard. Yes it is very loud inside and I never run it under 2400.

If I remember correctly the 6A-350 is balanced on both ends of the crankshaft. Most other engines are balanced at one end. I may be way off on explaining this but this is why the franklin motor runs so smooth. This would explain why running the motor at higher RPM and lower manifold pressures for desired % of power could make the engine last longer. George said let it spin.
I run mine at 55% power when just waisting fuel. I logged a few times where I burned 8 and 8.5 gph below 5000 msl. I tried to run it at 75% power, one in every ten hours just to blow it out.

Another thing to watch out for is to have your engine mounts checked at every annual. I found that my rubber mounts was worn out and the bolts were bent. Once replaced my speed and overall flight characteristics improved.

For the Franklin Engine Owners

For the Franklin Engine Owners

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