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

test stand for breaking in 56Jett

Reply

Old 06-06-2011, 05:39 AM
  #1  
richardgerardi
Thread Starter
 
Join Date: Feb 2008
Location: Little Egg Harbor, NJ
Posts: 342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default test stand for breaking in 56Jett

Do I have to break in the 56 Jett on a stand test? Would it harm if broken in on a plane. The engine is leaning side ways. Thanks
richardgerardi is offline  
Reply With Quote
Old 06-06-2011, 01:46 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: test stand for breaking in 56Jett

You can do it. But I do not recommend it.

A solid test stand gives you a baseline as to how the engine runs. Allows you to
learn how it runs.

Too many variables mounted in the airframe to get you that baseline reference.


What aircraft are you powering??

Bob
bob27s is offline  
Reply With Quote
Old 06-07-2011, 05:19 AM
  #3  
richardgerardi
Thread Starter
 
Join Date: Feb 2008
Location: Little Egg Harbor, NJ
Posts: 342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

The Hangar 9 Jackal. I have always like breaking in engines on the plane. I get to see what problems come up and get used to how they run. I have always had success.
richardgerardi is offline  
Reply With Quote
Old 06-07-2011, 03:18 PM
  #4  
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: test stand for breaking in 56Jett

The problem with that approach ... a problem causing a lean run.... will toast the engine.

Use a 9x6 or a cut down 10x6 for breaking prop.
bob27s is offline  
Reply With Quote
Old 06-08-2011, 05:44 AM
  #5  
richardgerardi
Thread Starter
 
Join Date: Feb 2008
Location: Little Egg Harbor, NJ
Posts: 342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

Thanks Bob I thought the instructions say to use 9x7? Which is best? Thanks again
richardgerardi is offline  
Reply With Quote
Old 06-09-2011, 04:16 AM
  #6  
summerwind
Senior Member
 
Join Date: Feb 2007
Location: fresno, CA
Posts: 3,968
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

listen to Bob, and others that have run high performance engines too.
a 9x6 is the prop to use for breakin on the bench.
you want it to run at almost the speed it will be running when in the air, only it'll be set in a rich setting allowing it to run in the piston/sleeve and rod surfaces at speed with the added lubrication it is getting by being rich.
around 10 3 minute runs is sufficient.
also can't stress using a Jett Bubble tank enough. the system just plain works perfect. no lean runs unless of course you try to get greedy with the needle.
i ran my 50 and 56 on these tanks and never lost a plug. as a matter of fact my 50 just got a new plug after breakin time and 10 flights in the air because it just finally got gray hair

seriously, do the bench time as laid out.........you'll be a happy camper later.
summerwind is offline  
Reply With Quote
Old 06-10-2011, 07:00 AM
  #7  
MJD
My Feedback: (1)
 
MJD's Avatar
 
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,629
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

Ditto, my life gained new meaning when I converted to bubble free tanks a few years ago. One less annoying variable to deal with. I've even seen complaints about the price.. my answer is "huh?". $150-$300 engine, $100-$300 airframe, radio, time.. what's $10 or so extra for a premium fuel system?
MJD is offline  
Reply With Quote
Old 06-11-2011, 11:36 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: test stand for breaking in 56Jett

Thanks guys

9x7 is ok too. But I prefer the lighter load for the first few runs. Get it up to rpm around 17500-18000 while slightly rich.
bob27s is offline  
Reply With Quote
Old 06-11-2011, 12:12 PM
  #9  
richardgerardi
Thread Starter
 
Join Date: Feb 2008
Location: Little Egg Harbor, NJ
Posts: 342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

Bobb this is my last dumb question. can I use a 10x6 APC prop for the Jackal? Or do you recommend 9x7-9x8. Thanks Promise to leave you alone after this hopefully.
richardgerardi is offline  
Reply With Quote
Old 06-12-2011, 07:51 AM
  #10  
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: test stand for breaking in 56Jett

Never any dumb questions!

Yes the 10x6 works great. But I would suggest the 9x7 for the first couple of flights.
bob27s is offline  
Reply With Quote
Old 06-12-2011, 12:21 PM
  #11  
richardgerardi
Thread Starter
 
Join Date: Feb 2008
Location: Little Egg Harbor, NJ
Posts: 342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

I broke the engine today what a monster. I ran it rich 14 to 16k. Ran 4 tanks it ran smoother every time but I noticed the stock tank foam like crazy when reached 1/2 half the rpms would ibncrease significantly so I richened it. I pinched the tubing a few times to leaned it out. I don't think any amount of foam will help with a stock tank.. I bought the Jett 12 oz tank but it is too big. Do you think the Tetra is a good match for this engine. Great job Bob everyone at the field was very impresed by this engine.
richardgerardi is offline  
Reply With Quote
Old 06-14-2011, 09:19 AM
  #12  
summerwind
Senior Member
 
Join Date: Feb 2007
Location: fresno, CA
Posts: 3,968
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett


ORIGINAL: richardgerardi

I broke the engine today what a monster. I ran it rich 14 to 16k. Ran 4 tanks it ran smoother every time but I noticed the stock tank foam like crazy when reached 1/2 half the rpms would ibncrease significantly so I richened it. I pinched the tubing a few times to leaned it out. I don't think any amount of foam will help with a stock tank.. I bought the Jett 12 oz tank but it is too big. Do you think the Tetra is a good match for this engine. Great job Bob everyone at the field was very impresed by this engine.
seriously, get it on the bench and get the RPM's up where it belongs with a 9x6 in rich setting...................running those numbers you've posted will turn this animal into a prom queen.
wish i could help you with stuffing a bubble jet tank (12oz) into the nose of the Jackal, cuz it would solve all your problems and give you at least 4.5 minutes of run time at full on, (yep it's a guzzler)..............
the Tettra bubbless tanks may have a size that will fit also............have you considered one of those?
summerwind is offline  
Reply With Quote
Old 06-14-2011, 10:20 AM
  #13  
MJD
My Feedback: (1)
 
MJD's Avatar
 
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,629
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

The Tettra 10oz, 11.5oz, and 14oz are all 58mm x 54mm in cross section. Brand of tank does not matter, the engine doesn't read labels.
MJD is offline  
Reply With Quote
Old 06-14-2011, 03:24 PM
  #14  
summerwind
Senior Member
 
Join Date: Feb 2007
Location: fresno, CA
Posts: 3,968
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett


ORIGINAL: MJD

The Tettra 10oz, 11.5oz, and 14oz are all 58mm x 54mm in cross section. Brand of tank does not matter, the engine doesn't read labels.
in a perfect world i would certainly agree, but with this Jackal design, the 12 ounce Jett Bubble tank doesn't fit.

Dub used an 8oz bubble jet in his Sundowner because that's all that would fit............or at least til he saw my pictures of my sundowner with the 12 oz bubble jet shoehorned in.
a Tettra tank would not fit though.
Hangar 9 really sets things up for their product only.
summerwind is offline  
Reply With Quote
Old 06-15-2011, 04:50 AM
  #15  
MJD
My Feedback: (1)
 
MJD's Avatar
 
Join Date: May 2003
Location: Orangeville, ON, CANADA
Posts: 8,629
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

? I was referring to this: "Do you think the Tetra is a good match for this engine." The answer is sure, why not - as long as it fits in the airframe. The Jett 12oz is kind of short and squat. I have no idea if those Tettras will fit as I don't have a Jackal, but my point is that series of three tanks I mentioned are about 2-1/8" x 2-1/4" square so might have a better chance of fitting than the 2-5/8" diameter Jett 12 oz.
MJD is offline  
Reply With Quote
Old 06-15-2011, 11:07 AM
  #16  
summerwind
Senior Member
 
Join Date: Feb 2007
Location: fresno, CA
Posts: 3,968
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett


ORIGINAL: MJD

? I was referring to this: ''Do you think the Tetra is a good match for this engine.'' The answer is sure, why not - as long as it fits in the airframe. The Jett 12oz is kind of short and squat. I have no idea if those Tettras will fit as I don't have a Jackal, but my point is that series of three tanks I mentioned are about 2-1/8'' x 2-1/4'' square so might have a better chance of fitting than the 2-5/8'' diameter Jett 12 oz.
ah i see it now......i was replying, and you were replying to my reply which included the quote.....whew, too much reading for me............bottom line though, this engine will never have a fair chance if the operator keeps buggering it up by trying to run it in on an airframe with a tank issue, no matter what tank he uses.
personally i never could understand why anyone would pony up and pay a premium price for a premium engine, and then squander on the price of a fuel system, or try to bypass the designers instructions.
summerwind is offline  
Reply With Quote
Old 06-15-2011, 12:16 PM
  #17  
richardgerardi
Thread Starter
 
Join Date: Feb 2008
Location: Little Egg Harbor, NJ
Posts: 342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett


ORIGINAL: summerwind


ORIGINAL: MJD

? I was referring to this: ''Do you think the Tetra is a good match for this engine.'' The answer is sure, why not - as long as it fits in the airframe. The Jett 12oz is kind of short and squat. I have no idea if those Tettras will fit as I don't have a Jackal, but my point is that series of three tanks I mentioned are about 2-1/8'' x 2-1/4'' square so might have a better chance of fitting than the 2-5/8'' diameter Jett 12 oz.
ah i see it now......i was replying, and you were replying to my reply which included the quote.....whew, too much reading for me............bottom line though, this engine will never have a fair chance if the operator keeps buggering it up by trying to run it in on an airframe with a tank issue, no matter what tank he uses.
personally i never could understand why anyone would pony up and pay a premium price for a premium engine, and then squander on the price of a fuel system, or try to bypass the designers instructions.

Summerwind and MJD I have never had one of this engines and never dealt with so much foam. So I'm very new to this. Like I said the Jett 12oz is way big and just read about Tettra tanks. I don't think an 8oz Jett is big enough for such engine. Thanks
richardgerardi is offline  
Reply With Quote
Old 06-15-2011, 02:08 PM
  #18  
summerwind
Senior Member
 
Join Date: Feb 2007
Location: fresno, CA
Posts: 3,968
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

richard,

do yourself a favor and set the 56 up on the bench first.......even if you just mount it to 1/2 thick plywood of good grade. the Tettra tank will probably be the one that works in the Jackal, so set it all up on the test bench and get things dialed in along with giving the engine some run time.

for reference, my 56 would only turn a 9x8 at 17,800 when new.....it now spins the same prop at 18,400 on CP 15% fuel with 3 ounces of castor added.
you really want to know where you start out and where it is when it comes on. this way you can find out later what is working and what is not.
seems complicated, but it's not.
i was set to do a Jackal too, but the reports of the tank area keep me away.

i've reinvested in the 56 and built a new Patriot with thinner wing and weighing in at 5lbs12oz's i have a good feeling it's gonna be a steamer.
i am running an 8oz BJ tank, so 2.5-3 minute flights is all it gets.
the 56 is a guzzler and is built for what you want to do with your Jackal, question is, for how long though.
i'm pretty much spent after 3 minutes of high speed runs
summerwind is offline  
Reply With Quote
Old 06-17-2011, 07:51 AM
  #19  
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: test stand for breaking in 56Jett

ORIGINAL: summerwind


ORIGINAL: richardgerardi

I broke the engine today what a monster. I ran it rich 14 to 16k. Ran 4 tanks it ran smoother every time but I noticed the stock tank foam like crazy when reached 1/2 half the rpms would ibncrease significantly so I richened it. I pinched the tubing a few times to leaned it out. I don't think any amount of foam will help with a stock tank.. I bought the Jett 12 oz tank but it is too big. Do you think the Tetra is a good match for this engine. Great job Bob everyone at the field was very impresed by this engine.
seriously, get it on the bench and get the RPM's up where it belongs with a 9x6 in rich setting...................running those numbers you've posted will turn this animal into a prom queen.
wish i could help you with stuffing a bubble jet tank (12oz) into the nose of the Jackal, cuz it would solve all your problems and give you at least 4.5 minutes of run time at full on, (yep it's a guzzler)..............
the Tettra bubbless tanks may have a size that will fit also............have you considered one of those?
I poseted in the speed forum... but just so its here

Break in must be done at operating temperature and rpm. Don't attempt to break it in as if it were a ringed 4c engine. That is the reason for the lighter break-in prop, so it easily gets to operating rpm while still being just slightly rich.

RPM for break in should target 17,500-18,000 rpm. Lean the engine until it gets there, then keep it there. No need to be critical about it, but keep it close. At least 20 minutes like this. The engine would turn the 9x6 well over 18,000 if leaned out (I dont trust 9x6 that high an rpm) but don't search for peak rpm until you put the 9x7 on it.

With the flight prop on it, lean the engine slowly to find peak rpm note that rpm then open the needle out and run the engine about 800-1000 rpm down from there. Just let it run a few tanks there with the 9x7. Then it is ready to fly. For flight, same setting- 800-1000 rpm down from peak ground rpm.

Of note on the tanks... has anyone tried a two-tank installation with the Jackle yet? On the patriot we sometimes installed 2 6oz bubble jett tanks. Rigged in parallel. There are photos somewhere in the speed forum from a few years ago. The tetra bubble tanks are good too, if you find one that fits the space better. That would be good info to have.

Bob
bob27s is offline  
Reply With Quote
Old 06-20-2011, 05:57 AM
  #20  
richardgerardi
Thread Starter
 
Join Date: Feb 2008
Location: Little Egg Harbor, NJ
Posts: 342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: test stand for breaking in 56Jett

Hi Bobb
I got the engine to run steady at 17250 for a couple of tanks. Ran great starts right up and it screams like crazy. Blew a plug so I think more than 17000 at this stage is too lean. I fixed the foaming problem using lots of rubber foam and a bubbless clunk. It really worked. Scrapped the muffler on a hard landing but no serious damage. Thanks for the help
richardgerardi 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