Over boosting and High cylinder temps

[kortopates]

WRONG!  You are stating that because one device does not work/perform the same way as a different device that it is not an "AUTOMATIC" device.  Sorry, it doesn't work that way. 
Show me the MANUAL CONTROLS on the Merlyn Black Magic and I will then agree it is not an AUTOMATIC device.  
I am not disputing that the Wastegate on the MB is a better device.  But that is not the question here.  There are no smoke and mirrors, I change the power on my LB and the Merlyn, by itself, adjusts.  So that would... say the word with me... make it automatic by definition.   Sure, if I go outside of the operating range of the Merlyn it cannot keep up with the changes I've made (e.g. craming in full throttle at sea level) or an over boost or a fast descent from altitude. 

But I'm perplexed how a few of you belive operating outside of a devices range suddenly makes it a "manual" device.  I delt with various "automaic" audio and video controls for decades that could be pushed passed their limits.  But none of us (engineers or operators) would suddenly start calling it a "manual" device since it wasn't.  Sure, you occasionally would get beyond the operating limitations and someone would "manually" have to bring it back into range, but then it would continue to perform its "automatic" functions as designed.  The Merlyn is no different.  
 

As you say WRONG! - We have had "automatic" wastegate controllers for a lot long time, much longer than the Meryn has been around. There is long term precedent here in the meaning of a "automatic wastegate" and its always been from the perspective of the pilot in managing MAP. "Automatic" refers to setting MAP at a certain # of inches, with the throttle of course, and the automatic wastegate maintains that pressure throughout changing atmospheric conditions such as climbs and descents where its constantly adjusting wastegate like a prop governor in sense to keep MAP at the desired set point. So from a pilot perspective, regardless of what Merlyn says what's automatic about the pilots control of MAP when they need to keep adjusting throttle to get back to the desired MAP after any change in atmospheric conditions - the pilot is manually controlling MAP; and no differently than with the Merlyn removed.
Just because Merlyn marketing material uses the words automatic doesn't make it a "automatic wastegate" just because they alone want to redefine the meaning to sell Merlyn's implying they to do what real automatic wastegates do - entirely maintain the desired MAP for the pilot. 
The only thing the Merlyn does automatically is to adjust the wastegate as throttle is moved to increase the UDP with altitude and throttle. It senses UDP and adjusts the wastegate pneumatically in an effort to maintain a differential in pressure - but not to maintain a target MAP; it’s incapable of doing this. The Pilot still does this manually. This is a wonderful thing in that it greatly increases the Critical Altitude over a fixed bolt alone, but it's still manual from a pilot perspective as it doesn't decrease the pilot workload in managing MAP. In fact, pull that Merlyn off and you won't really see a difference in behavior of the throttle control because the Merlyn doesn't change at all how the throttle body regulates MAP like a turbo controller does to keep MAP constant. The Merlyn marketing material is full of a lot more BS than just the use of the word Automatic. 

[PeteMc]

1 hour ago, kortopates said:

The Merlyn marketing material is full of a lot more BS than just the use of the word Automatic. 

You're not telling anyone anything they don't already know (or should know)...  But then that's still not the point.  But feel free to continue to change definitions because you don't like particular products. 

[Will.iam]

14 hours ago, PeteMc said:

WRONG!  You are stating that because one device does not work/perform the same way as a different device that it is not an "AUTOMATIC" device.  Sorry, it doesn't work that way. 

Show me the MANUAL CONTROLS on the Merlyn Black Magic and I will then agree it is not an AUTOMATIC device.  

I am not disputing that the Wastegate on the MB is a better device.  But that is not the question here.  There are no smoke and mirrors, I change the power on my LB and the Merlyn, by itself, adjusts.  So that would... say the word with me... make it automatic by definition.   Sure, if I go outside of the operating range of the Merlyn it cannot keep up with the changes I've made (e.g. craming in full throttle at sea level) or an over boost or a fast descent from altitude. 

But I'm perplexed how a few of you belive operating outside of a devices range suddenly makes it a "manual" device.  I delt with various "automaic" audio and video controls for decades that could be pushed passed their limits.  But none of us (engineers or operators) would suddenly start calling it a "manual" device since it wasn't.  Sure, you occasionally would get beyond the operating limitations and someone would "manually" have to bring it back into range, but then it would continue to perform its "automatic" functions as designed.  The Merlyn is no different.  

 

Wrong by your own statement here i pasted it for you and your quote “”I change the power on my LB and the Merlyn, by itself, adjusts.”

that is the very definition of manual. You know manual meaning hand. in my case the automatic controller set the correct pressure thus 36” at all altitudes and temperatures. You can not do this as you have to via your hand set your throttle for different temperatures, pressures even as you roll down the runway and get more ram air and turbo spool up you have to tweak (another word for manually using your hand you get it) to either set the throttle below take off power setting and let the turbo spool up to redline or reduce the throttle because the pressure you set as start of takeoff at redlline MP is now over pressure after you have accelerated down the runway. The only thing the Merlin is automatic about is automatically following what throttle setting you set. Semantics about automatic aside, the reality is this just boils down to the Merlin is not altitude compensating where is the 252 is.  Any changes to airflow or temperature changes via altitude climbs or descents or mixture changes, you have to adjust the throttle for manually. Even setting up from 25” MP ROP to 25”MP LOP you have to adjust both mixture and throttle to get the same MP between the two where the 252 you do not as the 252 wastegate automatically senses the lower power coming from the LOP side of operation compared to the higher power side of the ROP operation and thus my MP remains the same and i only have to manually adjust the fuel mixture. Same issue on descent from altitude especially from the FL’s i do not have to touch my throttle setting as my wastegate will automatically adjust to keep my MP constant through the descent. You will have to adjust your throttle as you descend into thicker air as your Merlin does not adjust for or compensate for altitude pressure changes. Another way to think of it is your system is an open loop system with no correction feedback loop it will stay set as long as none of the environment changes where as the 252 system will correct to maintain the MP set when environmental changes without manual intervention. 

[Will.iam]

1 hour ago, PeteMc said:

You're not telling anyone anything they don't already know (or should know)...  But then that's still not the point.  But feel free to continue to change definitions because you don't like particular products. 

Your right your merlin is automatic. It automatically follows your manual hand adjustments to your throttle right up to and including overboosting your engine. Too bad the merlin doesn’t follow a set MP setting. But that would be poor marketing if they revealed that. 

[DonMuncy]

This is a lot of ruckus over the definition of manual. When I got my 231, I thought I should have a Merlyn. When I checked it out, I learned that the pilot still had to watch for (and control) over-boosting. I decided that the cost/effort/benefit wasn't worth it to me. 

[PeteMc]

2 hours ago, Will.iam said:

that is the very definition of manual.

Actually, the very definition of automatic.  I do not adjust the Merlyn.  IT adjust to the change. 

By your definition, a home thermostat is a manual device.  Not the setting of it, but the operation once it is set. 

Edited January 25 by PeteMc

[Will.iam]

1 hour ago, PeteMc said:

Actually, the very definition of automatic.  I do not adjust the Merlyn.  IT adjust to the change. 

By your definition, a home thermostat is a manual device.  Not the setting of it, but the operation once it is set. 

 

imagine if there was a merlin controlling my a/c unit i would have to come back to the unit every time the outside temperature went up another degree i would have to lower the thermostat another degree to offset the degree it rose outside as the merlin would only guarantee to hold temperature the a/c put out was the same delta spread between the temp i set and what the a/c temperature put out regardless of the rising temperature outside. 

 

[Will.iam]

1 hour ago, PeteMc said:

Actually, the very definition of automatic.  I do not adjust the Merlyn.  IT adjust to the change. 

By your definition, a home thermostat is a manual device.  Not the setting of it, but the operation once it is set. 

Ah yes you do control the merlin just not directly. Does the merlin change when temperature changes? no does the merlin change when pressure altitudes changes? no does the merlin change when fuel mixture changes? no. In fact the only time the merlin changes is when you change the udp via the throttle so yes you change the merlin every time as the merlin only reacts to udp which you change with the throttle . 
in fact my thermostat is more automatic then your merlin controller. As at least my a/c thermostat responds to rising temperatures outside the house (closed loop system feedback to keep house at constant set temperature. instead of responding to the output of the a/c unit’s air temperature which as the ojtside air temp rises the indoor temp rises even though the thermostat is demanding a lower temp the merlin is dutifully holding the exact temp spread output to the controller but not to the rising temp the controller sees as it is not tied to the outside temperature but to the controller’s set temperature  

 

[Ragsf15e]

This has turned into a dumb internet debate.

[PeteMc]

1 hour ago, Ragsf15e said:

This has turned into a dumb internet debate.

I was actually going to say that earlier.  

[Fix]

The definition of fully automatic or semi automatic is not the  question here.

I would be much more worried about if you did over boost your engine and had detonation in some of the cylinders resulting in damage that could be a real problem.
Both with lots of money and safety.

Have you examined the engine or investigated it more?

 

 

[MattSet]

Update.  Mine has a bad fuel pump. It was showing 5 gph lower then normal, 19 gph at take off power.  Attempted to reset flow and the pump would not increase and had some strange fluctuations.  New one just came in and setting up flows now.