Fixed pitch - IO-360-M1B?

Dbro172 · #1 07-31-2016, 11:03 AM

Can I run a fixed pitch prop on an IO-360-M1B. I really like the looks of the smooth bottom cowl and I think I would like the simplicity of removing the cowl without the lower FAB... So looking for horizontal induction solution for fixed pitch prop.

ctennis · #2 07-31-2016, 01:37 PM

I just took receipt of my Van's supplied Lycoming IO-360M1B for an RV-8. While I intend to use a CS prop, the engine comes with the end plug in it for a fixed pitch operation. You have to pop the plug out in order to use it in a constant speed configuration, for the oil to travel the crankshaft to the prop. It has some instructions on how to replug in the future for fixed pitch operation.

In my studies of this forum it looks like maybe in the past some engines might have needed hollow vs. solid crank changeouts, but from what I can tell in what I received Lycoming supplies the engine to be "easily" interchangeable.

So bottom line: yes, it should work fine with fixed pitch.

flyinga · #3 07-31-2016, 03:02 PM

I may be misunderstanding your post, but as far as I know the bottom cowl is dependent upon induction configuration and not fixed/constant speed prop.

Dbro172 · #4 07-31-2016, 07:41 PM

Quote:

Originally Posted by flyinga

I may be misunderstanding your post, but as far as I know the bottom cowl is dependent upon induction configuration and not fixed/constant speed prop.

Correct. The IO-360-M1B is the 180hp with horizontal induction (Vans sells them). I already have a FP prop and would like a smooth bottom cowl. I would bet most folks buying the M1B are pairing it to a CS... If everything is OK crank wise I would probably order one from Aerosport configured with an oil return line in lieu of a plug in the end. My O-320 came from them like this and it would make for real simple conversion to CS in the future.

scrollF4 · #5 07-31-2016, 08:27 PM

Derek,
Simple answer: Yes, absolutely. I bought the 2012 Van's Sun 'n Fun Lyco engine/Sensi FP prop special. Mine's a YIO-360-M1B with the Sensi fixed pitch cruise prop, model #72FM8S9-1(85). The engine came set up for constant speed, including the servo, the oil return line, and the prop shaft plug. My trusty A&P Randy Richmond (Richmond Aviation) fabricated a cover plate to seal the servo hole when I removed the prop servo, which I stored for later use along with the oil return line. Don't forget to remove the internal plug (mentioned in Lyco's service bulletin).

Why did I do this? Same reason as you: I prefer the cleaner lines of the non-guppy-mouthed lower cowling. The engine/prop combo flies GREAT, although I'm outperformed on takeoff by my CS friends. Still, over the last 9 days, I averaged 168 KTAS at 8500' going and coming from Oshkosh.

penguin · #6 08-01-2016, 04:20 PM

Quote:

Originally Posted by Dbro172

Can I run a fixed pitch prop on an IO-360-M1B. I really like the looks of the smooth bottom cowl and I think I would like the simplicity of removing the cowl without the lower FAB... So looking for horizontal induction solution for fixed pitch prop.

Yes, certainly you can. Induction arrangement has no bearing on fp or cs.

If your engine is set up for cs and you want to convert to fp install the crankshaft bung. Do not remove or puncture the bung 6" down the crankshaft. Do not remove the oil pipe from the prop governor to front of case. Now install a prop governor cover plate that enables the oil to flow back into the case through the governor - I got one from Aerosport Power.

When you realise cs is a better option you will easily be able to convert back.

Pete