Sabremech Cowling Mod Testing (Ongoing)

[Sabremech]

46 minutes ago, cctsurf said:

That's obviously not how you're doing the carbureted models...

You are correct, but I think I’m going to look at something similar to connect to my new carb air box and make it a bit easier to mod. 

[Dream to fly]

That snorkel that is attached to the air inlet is open to the high pressure zone behind the prop?  Do you know if it will apply "boost" to the engine?  If that could increase M.P. by 2in  that would be awesome.  I'll start drilling holes tonight.    I have been thinking of a ram air system that works unlike what we have now.  After seeing the streaking on the side of the cowl I was wondering if putting a scoop that protruded maybe a inch to the side for induction if that would produce worthy gains.

[cctsurf]

1 hour ago, Dream to fly said:

Do you know if it will apply "boost" to the engine?

From what I've seen across the history of watching this site, etc. is that it works similar to a ram air for boost by getting rid of the corners, etc. that are involved in the original induction system.  From what I've read in this thread is that they hope to have ~.25inhg lower manifold pressure than the ram air as it was originally working, yet not have the problems associated with the ram air system.

[Dream to fly]

From what I've seen across the history of watching this site, etc. is that it works similar to a ram air for boost by getting rid of the corners, etc. that are involved in the original induction system.  From what I've read in this thread is that they hope to have ~.25inhg lower manifold pressure than the ram air as it was originally working, yet not have the problems associated with the ram air system.

You are bursting my dreams.......

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[cctsurf]

1 minute ago, Dream to fly said:

You are bursting my dreams.......

Sorry...  This is why I'd prefer to go experimental...  If I don't like something, I could just change it, or try something new just for the sake of it.  But no time at the moment.

I've got to say, I love that intake, I looked at the Van's website and they don't have one for my 'c model, but hopefully sabremech will rectify that situation...

'course I've got the older 'c model, so that's another step of extending the mod...

[Captnmack]

Sabremech, just so you know, my F is undergoing a Major renovation and hopefully I’ll be able to incorporate yours...Here’s where it sits now:

[Sabremech]

2 minutes ago, Captnmack said:

Sabremech, just so you know, my F is undergoing a Major renovation and hopefully I’ll be able to incorporate yours...Here’s where it sits now:

That’s going to look very nice when done!

David

[Captnmack]

4 hours ago, Sabremech said:

That’s going to look very nice when done!

David

Especially with your Cowl?

[Mcstealth]

Any new updates?

[DXB]

57 minutes ago, Mcstealth said:

Any new updates?

Ears perk up every time I see a post on this thread 

[jetdriven]

On 1/24/2018 at 10:06 AM, Dream to fly said:

That snorkel that is attached to the air inlet is open to the high pressure zone behind the prop?  Do you know if it will apply "boost" to the engine?  If that could increase M.P. by 2in  that would be awesome.  I'll start drilling holes tonight.    I have been thinking of a ram air system that works unlike what we have now.  After seeing the streaking on the side of the cowl I was wondering if putting a scoop that protruded maybe a inch to the side for induction if that would produce worthy gains.

There was a LoPresti Comanche 250 cowl that had a prop wirh a special paddle extension on the trailing edge that passed about 1/4” in front of an extended hole that led right to the fuel injector. Ram air if there ever was such a thing and it only added IIRC around  1” over ambient. 

The lopresri J cowl adds around 1/2-1” of MP over ambient.  It’s trickier to do that then you think. The lopresti Mooney cowl seals off the air box. The stock J air box didn’t do that. So when you select ram air the extra pressure over ambient simply pressurized rhe airbox and went backwards through the air filter. 

[Bennett]

There was a LoPresti Comanche 250 cowl that had a prop wirh a special paddle extension on the trailing edge that passed about 1/4” in front of an extended hole that led right to the fuel injector. Ram air if there ever was such a thing and it only added IIRC around  1” over ambient. 
The lopresri J cowl adds around 1/2-1” of MP over ambient.  It’s trickier to do that then you think. The lopresti Mooney cowl seals off the air box. The stock J air box didn’t do that. So when you select ram air the extra pressure over ambient simply pressurized rhe airbox and went backwards through the air filter. 

I see between 1/2” and 7/8” increase in MP with ram air open at 7500’ at most temps aloft. The LoPresti cowl ram air is a beautifully built box, as is the rest of this incredibly expensive cowl. I’m glad I have it for my J, and even more glad that the former owner had it installed. I’ve seen the prop blade extensions, but I didn’t know they were developed for the Comanche.


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[Guitarmaster]

Any new updates?

There hasn't been much to update lately. Riley is getting her new intake installed and then some modification to the lower cowling to see if we can solve the temperature issue.

David is hoping to have it done by the end of the week.

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[Guitarmaster]

Just a quick update before I am off to work.

It's getting close.  The alternate air fits very nicely in the new intake.  David and I were collectively holding our breath that it would fit with no problems.  David is finishing up the baffling and I am hoping to get her back after Wednesday (stupid work getting in the way again).  I am excited to see how the new intake performs!

David is louvering the bottom panel as a first step to solve increased temperatures.  I will post the results of the endeavor.  Keeping fingers crossed for a large decrease!

That's it for now.   

[carusoam]

Fancy!

-a-

[Mcstealth]

On 2/10/2018 at 1:52 PM, carusoam said:

Fancy!

-a-

Fancy-schmancy.

good luck guys. 

[Bob_Belville]

Matt, looking great, is that a challenger air filter? David sent me pics of my cowl which look great. (@Guitarmaster)

[Guitarmaster]

Riley and I went flying yesterday with the new induction system and the louvered bottom panel.

The induction system is great!  There is very little restriction now.  I am seeing only 0.6 - 0.7 inHg difference between ambient pressure and WOT on take-off.  Previous, I was seeing a delta around 1.2 inHg on take-off.  I think that is about as perfect as it gets for a NA airplane.  At altitude, the MP seems to be ~ 0.5 inHg different (lower) than my previous flights with RamAir open.  The conclusion is, with the new intake, the RamAir would create a negligible difference; at best, maybe 0.5 inHg difference.  That makes it unnecessary in my book.  With the removal of the RamAir, came a very clean installation under the hood (I will have pictures later) and it cleaned up the front nicely (see attached pic).
 A side-effect of the intake is that my engine idles very smoothly!  Before, it would run like a big-block Chevy at idle when warm.  That problem is long gone!  The fact that the induction boot was ripped probably had something to do with that.  Regardless, the engine loves the smooth intake air.
As those that have followed this thread for a while know, we are seeing increased CHT's with the removal of the third cowl flap.  We really wanted to keep it gone because it makes such a clean installation.  Unfortunately,  the latest test data indicates a simple louvered panel is not going to cut it.  David will be reinstalling the third cowl flap shortly and we will have results after that.
So the tweeking (not twerking) continues......  
 

Edited February 20, 2018 by Guitarmaster

[Guitarmaster]

21 minutes ago, Bob_Belville said:

Matt, looking great, is that a challenger air filter? David sent me pics of my cowl which look great. (@Guitarmaster)

It's actually a K&N filter.  P/N 33-2060.  

[Bob_Belville]

1 minute ago, Guitarmaster said:

It's actually a K&N filter.  P/N 33-2060.  

I think Challenger and K&N are the same?

 

[Guitarmaster]

1 minute ago, Bob_Belville said:

I think Challenger and K&N are the same?

 

I believe so.

[Guest]

Challenger is the STC’d version of a K&N.  Your filter is likely the same one Vans Aircraft supplies for the RV8.

Clarence

[Bob_Belville]

14 minutes ago, M20Doc said:

Challenger is the STC’d version of a K&N.  Your filter is likely the same one Vans Aircraft supplies for the RV8.

Clarence

I bought the Challenger (PC1176) from PowerFlow when I bought their Exhaust. It was a direct swap out for the Brackett I had before that.

[Guest]

1 hour ago, Bob_Belville said:

I bought the Challenger (PC1176) from PowerFlow when I bought their Exhaust. It was a direct swap out for the Brackett I had before that.

The Challenger/K&N for your E model is different than the Challenger/K&N in David’s new nose bowl conversion.

Clarence

[Bob_Belville]

21 minutes ago, M20Doc said:

The Challenger/K&N for your E model is different than the Challenger/K&N in David’s new nose bowl conversion.

Clarence

Well, David has a new filter for mine anyhow. I'll have the Challenger available if someone is interested in buying but I'll wait until we have the cowl back @ MRN.