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Search took 0.00 seconds. Search: Posts Made By: Fitz
Forum: Traditional Aircraft Engines 10-13-2006, 12:12 PM
Replies: 13
Views: 3,576
Posted By Fitz
I'm not sure if this was mentioned in the...

I'm not sure if this was mentioned in the original thread, but Lycoming has the white paper available as a pdf here:

http://www.lycoming.textron.com/support/engineOperationTips/SSP700A.pdf

It is...
Forum: RV General Discussion/News 09-22-2006, 03:26 PM
Replies: 12
Views: 1,738
Posted By Fitz
Where the IFR ticket will help is with things...

Where the IFR ticket will help is with things like the June gloom and marine layers. It is not going to get you through icing or convective activity. No airplane is truly 'all weather' - and this...
Forum: Traditional Aircraft Engines 09-18-2006, 11:56 AM
Replies: 191
Views: 23,530
Posted By Fitz
We still see premature failures for things like...

We still see premature failures for things like valve guides off center, heads out of round, that sort of thing. That is manufacturing 101 these days. It is probably economics of scale, you can...
Forum: Traditional Aircraft Engines 09-15-2006, 12:55 PM
Replies: 191
Views: 23,530
Posted By Fitz
Technology needs to serve a purpose. In a GA...

Technology needs to serve a purpose. In a GA aircraft that needs to either mean more efficiency or more reliability.

So far, when you consider the operating conditions - basically pedal to the...
Forum: RV General Discussion/News 09-14-2006, 10:20 AM
Replies: 16
Views: 1,745
Posted By Fitz
I'm not sure how this would connect to user fees....

I'm not sure how this would connect to user fees. VFR Flight Following is provided on a workload permitting basis. The controller is there for IFR traffic, if he/she is busy, they'll tell you. If...
Forum: Traditional Aircraft Engines 09-13-2006, 11:04 AM
Replies: 142
Views: 15,640
Posted By Fitz
Vote 4...

Above even 5000' it is very hard to generate the heat and pressure nec. to get detonation. It sounds like carb ice to me.

-jjf
Forum: RV General Discussion/News 09-12-2006, 07:23 PM
Replies: 18
Views: 1,975
Posted By Fitz
One thing to keep in mind is that most existing...

One thing to keep in mind is that most existing aviation engines are largely thermally limited. That is why we have to run so much richer than Best Power (say .85-.86 lambda) WOT.

Also, in a...
Forum: RV General Discussion/News 09-11-2006, 03:19 PM
Replies: 18
Views: 1,975
Posted By Fitz
Something to keep in mind is that even though...

Something to keep in mind is that even though ethanol has less latent energy a significant loss in range may not occur. The flame front is cooler and has somewhat different characteristics, so...
Forum: Traditional Aircraft Engines 09-01-2006, 11:21 AM
Replies: 7
Views: 2,110
Posted By Fitz
On www.advancedpilot.com they are selling some...

On www.advancedpilot.com they are selling some reprints on some introductory texts. Don't let the age of the books fool you, they are very good.

-jjf
Forum: Traditional Aircraft Engines 08-23-2006, 01:22 PM
Replies: 10
Views: 2,015
Posted By Fitz
I read this a few days ago and I am still...

I read this a few days ago and I am still wondering about it myself. The best answer I've gotten so far is that "copper is cheaper, easier to install, and hasn't proven to be a problem".

I haven't...
Forum: RV General Discussion/News 08-17-2006, 04:26 PM
Replies: 61
Views: 9,613
Posted By Fitz
I don't nec. disagree, but comments like this...

I don't nec. disagree, but comments like this remind me of debates about the CAPS system in a Cirrus. Fans go on and on about all the lives saved, but on close inspection most the deployments have...
Forum: RV General Discussion/News 08-17-2006, 10:39 AM
Replies: 4
Views: 951
Posted By Fitz
Oldie but goodies...

I notice that AdvancedPilot is reprinting some classics. Look at the three books at the bottom of the page. Don't let their age fool you, they are great...
Forum: RV General Discussion/News 08-17-2006, 10:37 AM
Replies: 61
Views: 9,613
Posted By Fitz
Remember the limitations

I think that Milt's posts on this subject is one of the best that I have seen in awhile. XM weather in the cockpit is great. It gives you a very clear, 'big picture' view of the weather, complete...
Forum: Traditional Aircraft Engines 08-14-2006, 07:41 AM
Replies: 34
Views: 4,601
Posted By Fitz
Not really a hush/hush secrecy thing, just...

Not really a hush/hush secrecy thing, just technology. When ECUs were simple almost any yahoo with a simple programmer could dump a PROM and decipher tables.

As ECUs have increasingly switched to...
Forum: Traditional Aircraft Engines 08-13-2006, 09:16 AM
Replies: 34
Views: 4,601
Posted By Fitz
If there are more threads on efforts to use the...

If there are more threads on efforts to use the Subaru engine in aviation, I'd be interested in reading them.

FWIW, closed loop's main goal in life on the stock ECU is to hold a mix that is ideal...
Forum: Traditional Aircraft Engines 08-12-2006, 03:56 PM
Replies: 142
Views: 15,640
Posted By Fitz
Actually, I still think it is a brilliant example...

Actually, I still think it is a brilliant example of applied science (see my later post where I described it as three points, stoich (peak), Best Power, and 'where we don't break the engine' - then...
Forum: Traditional Aircraft Engines 08-12-2006, 11:03 AM
Replies: 142
Views: 15,640
Posted By Fitz
Actually, it isn't. The long molecules in the...

Actually, it isn't. The long molecules in the fuel break down into different compounds under different conditions. New cars don't knock when we step on the gas because idle is too lean. Idle is...
Forum: Traditional Aircraft Engines 08-11-2006, 12:19 PM
Replies: 142
Views: 15,640
Posted By Fitz
Why not spell out exactly what some of those...

Why not spell out exactly what some of those frustrations are? Reading Lycoming's document SSP700A I got the 'sense' that Lycoming thinks the average pilot is probably too slow and clueless to...
Forum: Traditional Aircraft Engines 08-10-2006, 09:04 PM
Replies: 142
Views: 15,640
Posted By Fitz
If I am understanding you, you are saying that...

If I am understanding you, you are saying that there is a direct relationship between absolute EGT and a specific air/fuel ratio.

My understanding has always been different. In fact, I always...
Forum: Traditional Aircraft Engines 08-10-2006, 04:12 PM
Replies: 142
Views: 15,640
Posted By Fitz
Well, in the AdvancedPilot example, they were...

Well, in the AdvancedPilot example, they were starting with a manufacturer's specified fuel flow for specific conditions. I suspect that the racing folks, who have spent some serial experimentation...
Forum: Traditional Aircraft Engines 08-10-2006, 03:56 PM
Replies: 142
Views: 15,640
Posted By Fitz
[M]aking sure the ratio is at least 12:1 for take...

[M]aking sure the ratio is at least 12:1 for take off.

It had to be done or the engine would choke on the rich mixture fuel.
[/QUOTE]

FWIW, with the fuel flow set per the placard on a C206H...
Forum: Traditional Aircraft Engines 08-10-2006, 03:45 PM
Replies: 142
Views: 15,640
Posted By Fitz
I'm sorry, I'm not following you. The issue...

I'm sorry, I'm not following you. The issue isn't rather the sensor itself consumes BTUs, but what it is measuring. Let's assume the EGT measurement is perfect. Now, instead of providing the...
Forum: Traditional Aircraft Engines 08-10-2006, 03:25 PM
Replies: 142
Views: 15,640
Posted By Fitz
Regarding roughness. Rather it is approved our...

Regarding roughness. Rather it is approved our not, engineers always hate it because the engine is running at a relatively unknown point.

Regarding 'hunting for peak at high powers', I'd have to...
Forum: Traditional Aircraft Engines 08-10-2006, 09:46 AM
Replies: 142
Views: 15,640
Posted By Fitz
But if you left it there the mixture became...

But if you left it there the mixture became richer as you climbed. The engine didn't mind running cooler and generating less energy and it is actually pretty hard to foul and engine with 100 LL once...
Forum: Traditional Aircraft Engines 08-10-2006, 09:20 AM
Replies: 142
Views: 15,640
Posted By Fitz
Don't read too much into the analogy. As you...

Don't read too much into the analogy. As you noted, the approach is for normally aspirated, ROP climbs to non-O2 type levels. I've actually tested this with a lambda meter in the exhaust of a 182...
Forum: Traditional Aircraft Engines 08-10-2006, 12:28 AM
Replies: 142
Views: 15,640
Posted By Fitz
OK, in brief

I really should let the right folks take the bow, but I know the feeling, so... To more clearly 'get' it, let's shift our focus.

First, ask yourself, why do we run so rich for full power takeoffs...
Forum: Traditional Aircraft Engines 08-09-2006, 09:36 PM
Replies: 142
Views: 15,640
Posted By Fitz
But that is not what we are measuring. EGT is...

But that is not what we are measuring. EGT is very much like our hands, at a fixed distance from the fire (in a chimney over a fireplace would be more accurate). And CHT (at least measurement...
Forum: Traditional Aircraft Engines 08-09-2006, 02:57 PM
Replies: 142
Views: 15,640
Posted By Fitz
No miss-step at all

You're not stepping in it at all. But think about what we are measuring. To use your campfire analogy. Imagine we act as a temperature probe just over the fire (we stick our hands out to warm them...
Forum: Traditional Aircraft Engines 08-09-2006, 02:23 PM
Replies: 34
Views: 4,601
Posted By Fitz
With gasoline, 12.7 would be a lambda of about...

With gasoline, 12.7 would be a lambda of about .86. A value of .85 to .86 is very typical. 13.3 is a lambda over .90. That is very lean. I would believe it on a few Porche engines, but as a...
Forum: GPS 08-09-2006, 12:40 PM
Replies: 7
Views: 1,320
Posted By Fitz
The 480 does understand Victor airways, which can...

The 480 does understand Victor airways, which can be nice for entering a clearance (as opposed to looking at the chart and finding the waypoints at each bend). It is really nice hooked to an MX-20...
Forum: Traditional Aircraft Engines 08-09-2006, 12:11 PM
Replies: 142
Views: 15,640
Posted By Fitz
As stated above, when you go up in DA, the NA...

As stated above, when you go up in DA, the NA engine can no longer generate more than 75% anyway so...

I'm not sure why so many pilots struggle with this. Of course, 'Recommended leans', just rich...
Forum: Traditional Aircraft Engines 08-09-2006, 11:22 AM
Replies: 34
Views: 4,601
Posted By Fitz
That was me, and I think that referring to it as...

That was me, and I think that referring to it as 'best power', easily construed as Best Power is how I felt I put my foot in it.



That is the point were I think wideband sensing has value. It lets...
Forum: GPS 08-08-2006, 06:38 PM
Replies: 7
Views: 1,320
Posted By Fitz
480 fan but...

I've always really liked the 480 (even before it was Garmin :D). It also gives you WAAS right now (though 430/530 WAAS support seems right there).

As for easier vs. harder. I really think it is...
Forum: Traditional Aircraft Engines 08-08-2006, 05:50 PM
Replies: 34
Views: 4,601
Posted By Fitz
No, the resistor has always been in the Bosch...

No, the resistor has always been in the Bosch wiring harnesses. Remember, the sensors were built for a mass production application. The trim resistor essentially places stoich at the proper point. ...
Forum: Traditional Aircraft Engines 08-08-2006, 09:59 AM
Replies: 142
Views: 15,640
Posted By Fitz
I wasn't comparing auto to aircraft, I was...

I wasn't comparing auto to aircraft, I was questioning a point made about auto engines themselves.

My only points related to aviation were A) that trusting CHT and EGT for detonation detection is...
Forum: Traditional Aircraft Engines 08-08-2006, 09:38 AM
Replies: 34
Views: 4,601
Posted By Fitz
FWIW, Best Power is actually around .85-.86...

FWIW, Best Power is actually around .85-.86 Lambda, though as lean a .9 Lambda on some Porche engines. The EGT temperature will depend, among other things, on the fuel. The reason that I said...
Forum: Traditional Aircraft Engines 08-08-2006, 08:52 AM
Replies: 34
Views: 4,601
Posted By Fitz
FWIW, the Bosch chip uses a fixed calibration...

FWIW, the Bosch chip uses a fixed calibration curve - based on a group sampling. So it does become less accurate with altitude and age. On the Megasquirt web page there is a long white paper on...
Forum: Traditional Aircraft Engines 08-07-2006, 07:44 PM
Replies: 34
Views: 4,601
Posted By Fitz
No one is saying LOP. You want to be at best...

No one is saying LOP. You want to be at best power, generally about 125-175 ROP. It is a race. You can't easily do this with an EGT gauge because you would need to 'peak' first to find a...
Forum: Traditional Aircraft Engines 08-07-2006, 07:04 PM
Replies: 142
Views: 15,640
Posted By Fitz
I'm sorry, I have to disagree with that somewhat....

I'm sorry, I have to disagree with that somewhat. The reason that modern cars do not run lean of peak for fuel economy is primarily polution. Cars spend much of their time idling at 'peak' because...
Forum: Traditional Aircraft Engines 08-07-2006, 06:09 PM
Replies: 34
Views: 4,601
Posted By Fitz
Probably the best way to do it is with a wideband...

Probably the best way to do it is with a wideband O2 sensor in the exhaust system. This has become something of the norm in high performance automotive racing.

The sensors use a pump cell and a...
Showing results 1 to 40 of 40

 
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