Mooney Knowledge - Prop governor

[mschmuff]

Hoping someone can help me out with this one!!

I saw a M20L PFM that has the IO550 engine but it has an automatic prop governor.  So you only have throttle and mixture.  I have never seen this on a Mooney.  I figure it can't be good if they did away with it.....right???

[carusoam]

Check the weight restrictions on that set-up. Full fuel / MGTOW becomes a one person airplane, I believe.

Early Ovations have a max Rpm of 2500. Many operators set it and forget it at that position. Not exactly an automatic transmission, but a continuous one at least.

There is a fare amount to be aware of with the earliest long bodies. Including the PFM and modifications and who in FL did them and how they survived the hurricane.

There were early attempts of digital engine Gage's done on that mod as well.

Let us know what you find.

Best regards,

-a-

[N201MKTurbo]

It sounds like you saw a Porsche Mooney. They came from the factory with a single lever power control. They have a Porsche Engine not an IO550

[KSMooniac]

I think some of the IO-550 conversions used a modified throttle/prop linkage plus a mixture control, similar to what Cirrus does.  It is a (poor) solution looking for a problem IMO.  I'd much rather have 3 traditional push-pull/vernier controls.

[KSMooniac]

Here is an example:  http://www.controller.com/listingsdetail/aircraft-for-sale/MOONEY-M20L-PFM/1988-MOONEY-M20L-PFM/1268927.htm

 

carusoam correctly pointed out that useful load on the Porsche conversions is very poor, so check that carefully if you are seriously considering such a plane.  I bet you could easily get a field approval for conventional engine controls if you wanted to switch back.

[Alan Fox]

This was a Porsche converted to a Bravo......  When Porsche dropped the program , the engines were orphaned , even though they have car engines you cant use car parts on them legally , So they were all converted over to a 550 , They have a A.D. for valve springs , that essentially grounds them..... I dont know of any that were not converted to the 550....

[KSMooniac]

I think there were ~5 liquid rockets like that, although some were off the K airframe IIRC.  350 HP...wow.  Even with the GW increase, their useful loads are on the small side, though, but I've heard anecdotally that they have no problem flying a lot over gross, which is no surprise considering they have ~175% more HP than the original airframes!  I would love to fly one for giggles, but I get weak in the knees thinking about owning that rare engine on a plane that I would rely on for regular use.

[bd32322]

I think there were ~5 liquid rockets like that, although some were off the K airframe IIRC.  350 HP...wow.  Even with the GW increase, their useful loads are on the small side, though, but I've heard anecdotally that they have no problem flying a lot over gross, which is no surprise considering they have ~175% more HP than the original airframes!  I would love to fly one for giggles, but I get weak in the knees thinking about owning that rare engine on a plane that I would rely on for regular use.

Apart from the liquid cooling system, will the engine be that different from any other big bore lycoming?

[KSMooniac]

I think it is very different... a coworker friend was really, really close to buying one last year and I was following along with his progress.  Maxwell referred him to RAM in Waco for details about the engine because they used it on a few conversions of their own and were about the best resource for supporting it.  I took that to mean it is sufficiently different that not even Don wants to mess with one.

 

It reminds me of a funny quote I heard long ago and I cannot remember the source:  "Liquid cooling an airplane makes as much sense as air cooling a submarine!"  

[bd32322]

 

It reminds me of a funny quote I heard long ago and I cannot remember the source:  "Liquid cooling an airplane makes as much sense as air cooling a submarine!"  

Haha!

But part of me wonders if the heat carried away by the liquid can be used for deicing / anti-icing, since liquid tends to give off a lot of energy per degree loss in temperature. Then does the weight compare favorably to a TKS installation?

We will never know unless the next Mr. Rutan comes up with something like that.

[bd32322]

Basically use the ice protected surfaces as a radiator for the hot coolant ...

[201er]

I think some of the IO-550 conversions used a modified throttle/prop linkage plus a mixture control, similar to what Cirrus does.  It is a (poor) solution looking for a problem IMO.  I'd much rather have 3 traditional push-pull/vernier controls.

Yeah, it's really not that hard. Leave the black one in all the way, pull the blue one back a lil, and then use the red one to control power.

[Mooneytestpilot]

^ KS Mooniac is right.  Cirrus uses a sort of linkage between throttle and prop control that sets prop speed at "optimum" for the the throttle position.

 

Not sure what they planned to do with non-standard temperature/pressure days though.  

[RJBrown]

Apart from the liquid cooling system, will the engine be that different from any other big bore lycoming?

The engine is a Continental.

Yes there are many valid reasons to liquid cool airplane engines. Just ask those silly guys that built the P51 Mustang why they liquid cooled it. Liquid cooling allows you to maintain much closer tolerances in an engine. Air cooled engines are "sloppily" designed.

[bd32322]

The engine is a Continental.

Yes there are many valid reasons to liquid cool airplane engines. Just ask those silly guys that built the P51 Mustang why they liquid cooled it. Liquid cooling allows you to maintain much closer tolerances in an engine. Air cooled engines are "sloppily" designed.

 

 

The Mustang might have had a large cooling requirement from its large engine and small cowl frontal area (single seat fighter).

I wonder how much cooling drag is reduced by using liquid cooling - although you still have to cool the radiator unless you make it part of the airframe .

 

I have a motorcycle called Buell Blast which has oil stored in its frame! Air hitting the frame cools it instead of a separate oil cooler - interesting.