Automatic Waste Gate

[lvpazik]

I own a 1980 M20K 231 with a Continental TSIO 360 (GB Engine). First turbo of many I've owned that as a "manual" waste gate. Anyone aware of any retrofit that can turn "any" turbo install on this engine into an automatic waste gate? I pay attention closely however a couple of times over the last 35 hours it's pushed just past the max barely into the red range (41 inches ) but only for about 2 seconds before being corrected. I normally push to 38 or 39 inches for takeoff but on those rare occasions the turbo has kind of surged to the 41 inch number but I quickly  caught it.

[Fly Boomer]

2 minutes ago, lvpazik said:

I own a 1980 M20K 231 with a Continental TSIO 360 (GB Engine). First turbo of many I've owned that as a "manual" waste gate. Anyone aware of any retrofit that can turn "any" turbo install on this engine into an automatic waste gate? I pay attention closely however a couple of times over the last 35 hours it's pushed just past the max barely into the red range (41 inches ) but only for about 2 seconds before being corrected. I normally push to 38 or 39 inches for takeoff but on those rare occasions the turbo has kind of surged to the 41 inch number but I quickly  caught it.

I think the answer is yes, but not sure if STC still available.  Others will know for certain.

[LANCECASPER]

3 minutes ago, lvpazik said:

I own a 1980 M20K 231 with a Continental TSIO 360 (GB Engine). First turbo of many I've owned that as a "manual" waste gate. Anyone aware of any retrofit that can turn "any" turbo install on this engine into an automatic waste gate? I pay attention closely however a couple of times over the last 35 hours it's pushed just past the max barely into the red range (41 inches ) but only for about 2 seconds before being corrected. I normally push to 38 or 39 inches for takeoff but on those rare occasions the turbo has kind of surged to the 41 inch number but I quickly  caught it.

This is the only one STC'd for your airplane. https://www.merlynproducts.com/blackmagicm.html

Thirty years ago I flew a 231 for three years and this upgrade plus a TurboPlus intercooler would have been much welcomed http://www.turboplus.com/mooney231-intercooler.asp 

@Jeff Shapiro from TurboPlus stops by once in awhile

[kortopates]

The Merlyn is still entirely manual, but replaces the fixed bolt with a pneumatic wastegate that greatly increases your critical altitude. But you still have to avoid over boosting and manually adjust with changes in altitude.
But very useful if you want to fly in the upper teens.

A few seconds of overboost is not generally an issue though.

The automatic wastegate solution is the 252 or the 262 modified 231 that has the 252 engine.


Sent from my iPhone using Tapatalk

[jlunseth]

The Merlyn is the only one. It is marketed as “automatic” but more aptly termed manual. It does not maintain MP at a set number, the pilot must do that. I have the Merlyn. You will experience a slight MP rise on takeoff as the plane picks up speed, an inch or less. You will need to reduce MP very slightly (or start off a little lower than max). It probably would be helpful toward the end of controlling MP if you only have the fixed wastegate. The Merlyn does two things. First, it controls bootstrapping, which increases MP simply because the engine is putting out more power. That would help with controlling MP on takeoff, although it does not completely contain the problem. Two, it is capable of fully closing, unlike the fixed wastegate that is always partly open. This increases the critical altitude by quite a bit, from about 15k to about 22,5k. However, if you do not also have the intercooler you will likely see the Compressor Discharge Temp reach redline somewhere in the range of 17-19k (depends on day temps) so not much CA gain without the intercooler.

[PeteMc]

13 hours ago, jlunseth said:

You will experience a slight MP rise on takeoff as the plane picks up speed, an inch or less.

I've never experienced this.  Maybe it was because I was taught to advance the throttle slowly and let the turbo kick in and then slowly continue advancing the throttle to TO power.  Granted, you can really only do this on long runways.  On shorter runways it would be more of a Short Field TO procedure where I'd go to TO power before starting the roll. 

But I've never seen the MP continue to rise from a hair below the 40" I set it to (231). 

 

[lvpazik]

My airplane does in fact have the TurboPlus system. AS far as the merlyn, the company is out of business so I didn't pursue anything. I ended up purchasing 3 new cylinders for 2/4/6. I can't diagnose or control metal fatigue and have no clue how this engine was taken care of prior to my purchasing it. I am well aware of slower throttle advance while the Turbo spools up but I often fly out of shorter runways and I rarely over boost this engine. I spoke with the machine shop that rebuilds engines, cylinders etc. They also told me a small over boost for a very short time (couple of seconds) should not do the damage they saw on this cylinder. I will be more focused on takeoff roll and am excited to be adding three new cylinders. 

[jlunseth]

Are you sure Merlyn Products is out of business? I haven’t tried to contact them and we haven’t needed any parts, but they look alive to me - https://www.merlynproducts.com/magicprofiles.html

[PeteMc]

1 minute ago, jlunseth said:

Are you sure Merlyn Products is out of business?

I just sent them an email.  Let's see if I get a reply tomorrow.

And I will note that if you try to go to the Service: Contact page on their Website, you get an error.  Could just be that they have a problem with their Website, or it could mean they shut it down.

 

[jlunseth]

COVID may have gotten the company, I know they were around in 2021.

Edited December 18, 2023 by jlunseth

[kortopates]

My airplane does in fact have the TurboPlus system. AS far as the merlyn, the company is out of business so I didn't pursue anything. I ended up purchasing 3 new cylinders for 2/4/6. I can't diagnose or control metal fatigue and have no clue how this engine was taken care of prior to my purchasing it. I am well aware of slower throttle advance while the Turbo spools up but I often fly out of shorter runways and I rarely over boost this engine. I spoke with the machine shop that rebuilds engines, cylinders etc. They also told me a small over boost for a very short time (couple of seconds) should not do the damage they saw on this cylinder. I will be more focused on takeoff roll and am excited to be adding three new cylinders. 

What makes you say they’re out of business?

http://merlynproducts.com/blackmagic.html


Sent from my iPhone using Tapatalk

[philiplane]

Merlyn is alive and well, I sent a controller to them a few months ago for test & repair.