Pireps on firewall forward HP + STC

[N201MKTurbo]

3 hours ago, Sandman993 said:

Didn’t think our Siamese twin mags had anything... no shower of sparks or nuttin.

i did lose a left mag the other day in flight... reading on it from Kelly aerospace was enlightening (pun). Turns out, the condenser was either quits or, the mag cap wasn’t grounded properly to the mag. This causes the points to spark crazy, get hot, and can and did, in my case...cause the nylon cam follower to melt, which causes the timing to drift forward and eventually they won’t open at all...kaput. The P lead wasn’t a part of the discussion. The above is kinda scary to this puny earthling.

the moral to the story is... Siamese twin mags suck... and again, I don’t understand why the powers that be don’t fast track an electronic ignition for these models. It’s not like there aren’t a bunch out there! The Cessna 200hp  177rg shares this inferior mag setup as well. 

Aviation drags along about 75 years behind on this and other matters imo. 

The dual mag is retarded by the impulse coupling during starting. The ignition switch only energizes one mag during starting. An easy modification will energize both for start.

[N201MKTurbo]

3 hours ago, Sandman993 said:

Didn’t think our Siamese twin mags had anything... no shower of sparks or nuttin.

i did lose a left mag the other day in flight... reading on it from Kelly aerospace was enlightening (pun). Turns out, the condenser was either quits or, the mag cap wasn’t grounded properly to the mag. This causes the points to spark crazy, get hot, and can and did, in my case...cause the nylon cam follower to melt, which causes the timing to drift forward and eventually they won’t open at all...kaput. The P lead wasn’t a part of the discussion. The above is kinda scary to this puny earthling.

the moral to the story is... Siamese twin mags suck... and again, I don’t understand why the powers that be don’t fast track an electronic ignition for these models. It’s not like there aren’t a bunch out there! The Cessna 200hp  177rg shares this inferior mag setup as well. 

Aviation drags along about 75 years behind on this and other matters imo. 

Although dual mags do suck. The failure you had can happen on any mag.

[Sandman993]

Ok... got it

[Pete M]

I read somewhere on the internet, so I know it's true:), that the port and polish was only $200 a cylinder. Cheap horsepower if true. 

[Sandman993]

Here’s an update for the firewall forward work I hap performed.

[carusoam]

Nice consistent data, Sand!

From the hours on each sample to the numbers in each column...

Except one... where did all the phosphorous go in your last test?  
 

Did you change up any anti-wear additives?

First thing that popped up in my search...

https://www.machinerylubrication.com/Read/29918/turbine-oil-phosphorus

Best regards,

-a-

 

 

[adverseyaw]

It took me a bit longer than I'd like, but I was finally able to gather enough performance data on this STC to put together an assessment. I've got a summary posted at the link below.

The short version is that above about 9k feet, I get lower fuel consumption than what the POH specifies, or better speeds, or both. Below that, I tend to get neutral or slightly worse numbers. (Most of the POH's I've used depict best-case performance achieved by test pilots, and achieving them can be spotty. So I don't necessarily take the neutral/worse numbers as a performance deficit, just a lack of improvement over stock.)

 

 

[carusoam]

See if @Sandman993 is cruising by...  (interesting FWF data above)

Best regards,

-a-

[Sandman993]

Hi guys... I haven’t done anything in terms of composing or dissecting performance spreadsheets ... my stock engine was a little anemic, I’ll admit that. 1600hrs and worn intake lobes. It did however hit full rpms and could pull 800fpm in a takeoff climb in my warm climate near the Texas coast. That said, I guess the only way to put this performance issue to rest is to have a side by side flight. For my part, I think she’s better in every aspect... runs cooler, uses less fuel at any altitude and pulls harder at higher altitudes. 
a couple months ago, I left mesquite Texas vfr, two men, full tanks, wot full rich and I had to push forward on the yoke to stay at assigned altitude under a bravo shelf. I don’t usually fly that way so it was noticeable. In layman’s terms, we were honking! Normally I would have reduced power, but in just a few moments I could relieve the forward pressure anyway and let her go up, establish the climb power and settle in for the next couple hundred miles. Besides, it was a hoot and I was digging the sensation.

Was fanatical about break in. I’m pleased with the outcome and if I had it to do over... I would most emphatically go for the hi compression again. It’s a no brainer in my view.

sorry adverseyaw didn’t have the same results. Maybe someday we’ll bump into each other that we can take a measurement.

 

anyone heard from the autopilot people?

On 3/5/2020 at 4:08 PM, Jay-with-a-J said:

[Tx_Aggie]

Hey sandman, inquiring minds want to know. In years of asking you have displayed no data. What true airspeed and fuel flows did you see? According to flight aware you sold the plane recently, fast but not fast enough?