Dub Jett Engines Support Bob Brassel of Dub Jett Engines provides direct support here for Jett Engines.

Bob and his P51 (and my DAGO)

Reply

Old 07-20-2009, 12:56 PM
  #1  
jay1st
Senior Member
Thread Starter
 
Join Date: May 2009
Location: PAU, FRANCE
Posts: 128
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Bob and his P51 (and my DAGO)

Hi Bob,


I ordered last week a couple of different exhaust systems for OS55AX.
In fact we are 3 friends with the same airplanes, aka DAGO RED from VQ warbirds.
It seems that you P51 is the same brand, so just a change in colors more or less.....


So the idea is to have a fast, very fast, DAGO, and was wondering about your P51 hwo it performs. (need a fast engine as the profile is quite thick)
I am going to fit the Turbo-Jett, the others are going with the Thrust system (and maybe a Super Sports), but no idea what will happen and what size prop to fit.


If by any chance ?I still find it slow, I might go with a Jett engine, but which one ????


Tnx & rgds.

Jay.
jay1st is offline  
Reply With Quote
Old 07-20-2009, 01:08 PM
  #2  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Bob and his P51 (and my DAGO)

Thanks for writing...

The VQ P-51 I have was built around 2001. My understanding is that they improved/changed a few things on the warbird and on the Dago versions.

But a big issue I ran into was that the stabilizer (built up stick structure) was WAY underbuilt. If pushed to a high speed, the entire horizontal stabilizer would flutter.

So I can not really tell you how fast it can go. I had to slow mine down, or it was going to self-destruct.

With my plane, I have the SJ-46, turbojett, and I run either an 11x5 or 12x4 prop. The 12x4 prop slows the plane down a bunch, but allows the engine to unload a bit. Plus, with the 3" spinner, the bigger prop worked much better for take off and landing performance. Very scale like flight down around 1/2 to 2/3 throttle. I only take it to full power on vertical uplines or if doing aerobatics and snaps.

I had flown the P-51 with a 10x6 and it really moved along and then buzzed the stab. So again, it probably can be fast, but I never got it that far.

Using the big props on the SJ-46 and turbo was an experiment to push the muffler to its limits. The combination turns just at 14,000 rpm peak, and I fly it set down around 13,200-13,400 for launch. Once in flight, most guys think I have a .61 engine in the nose It unloads just a bit, and it has no trouble with the big prop. But the 12x4 is as big as you would want to go.

With the OS55AX you can run the 11x6 or 12x4 without any problem. An 11x7 and 12x5 are worth trying too. But let the engine unload a bit, look for that 13,000-14,000 rpm range at ground peak. Aircraft will probably perform VERY well.
bob27s is offline  
Reply With Quote
Old 07-22-2009, 11:55 PM
  #3  
jay1st
Senior Member
Thread Starter
 
Join Date: May 2009
Location: PAU, FRANCE
Posts: 128
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Bob and his P51 (and my DAGO)

Tnx for the explanation Bob.

Going to the post office today to pick-up my package.
So, I'll keep you informed about the results.
jay1st is offline  
Reply With Quote
Old 07-23-2009, 05:36 AM
  #4  
jay1st
Senior Member
Thread Starter
 
Join Date: May 2009
Location: PAU, FRANCE
Posts: 128
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Bob and his P51 (and my DAGO)

Just back from the post office !

Nice looking stuff and good quality too !

But, there is a problem:
The tapped holes on the Turbo -Jett are way too small to fit the screws in.

So I have to drill them bigger and tap them to the original size.

And the caps look good too.

For everybody reading this, don't be shy to order stuff from JETT, it's way cheaper than other stuff compared performance-wise.
And I had the package send over the atlantic in 1 week !

Tnx Bob, I'll send d=some pics with the DAGO and it's Turbo-Jett.
jay1st is offline  
Reply With Quote
Old 07-23-2009, 09:58 AM
  #5  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Bob and his P51 (and my DAGO)

Glad to hear everything arrived safely.

The turbo-jett should have been supplied with matching screws. I believe Dub supplies either 4-40 or 6-32 screws - depending on the muffler. If there was a mistake here, my apologies.

Let me know how the project proceeds.

Bob
bob27s is offline  
Reply With Quote
Old 07-23-2009, 10:04 AM
  #6  
jay1st
Senior Member
Thread Starter
 
Join Date: May 2009
Location: PAU, FRANCE
Posts: 128
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Bob and his P51 (and my DAGO)

There was 3 sets of screws, all the same size.
They fit perfect in the Jett-Streams , but too big for the Turbo.

Anyway, I tapped them bigger.


I'll post some pics with the muffler fitted.
jay1st is offline  
Reply With Quote
Old 08-09-2009, 02:00 PM
  #7  
jay1st
Senior Member
Thread Starter
 
Join Date: May 2009
Location: PAU, FRANCE
Posts: 128
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Bob and his P51 (and my DAGO)

Hi BOB !

Finished the DAGO, and theTurbo-Jett is a perfect fit.

I had to make massive cuts in the cowl, as the engine was getting very hot, the front intake is almost completely covered by the muffler.

It has been clocked at 180 km/h with a 11x8 Graupner Sonic.

Picture of the DAGO, still no stickers as I am still tweaking it.





So I am wondering how much rpm does the Turbo-Jett add to the 55AX ?
jay1st is offline  
Reply With Quote
Old 08-10-2009, 10:45 AM
  #8  
bob27s
My Feedback: (19)
 
bob27s's Avatar
 
Join Date: Apr 2002
Location: Cleveland, OH
Posts: 5,576
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Bob and his P51 (and my DAGO)

RPM gain depends on the setup.

Usually it is along the order of 500-600 rpm, but the biggest difference is torque. You can usually go up one prop size from the stock muffler, and keep the same rpm.

On your setup with the 55 you will probably want to run a 10x8 or 11x7 prop.

When you have a chance, let me know what prop you have, and the rpm you are seeing.

Also, be sure to launch the engine set down from peak rpm about 500-700 rpm. It will unload in flight a bit, and will need the fuel.

Bob
bob27s is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service