Jett 90 t with turbo muffler  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Manufacturers Direct Support Forum >> Jett Engineering Support >> Jett 90 t with turbo muffler
Page: [1]

Login
Message << Older Topic   Newer Topic >>
Jett 90 t with turbo muffler - 12/21/2005 1:28:02 PM   
f3d


 

Posts: 68
Joined: 12/29/2002
From: Konz, Germany, GERMANY
Status: offline 		Dear jett profis,

my Jett 90 torque engine with a turbo muffler overhead on my 3d airplane.
I use a 14x6 APC prop an cool power fuel with 10 % nitro and the engine became much hotter compared to the orginal muffler.

What can I do ???

Best regards Michael
       Post #: 1

RE: Jett 90 t with turbo muffler - 12/21/2005 2:14:44 PM   
bob27s



Posts: 4730
Joined: 4/9/2002
From: Cleveland, OH, USA
Status: offline 		Hi Michael,

Thanks for writing.

The engine will run slightly hotter with the turbo-jett, but it should not be significantly hotter.

Ensure you have good air cooling over the engine AND the muffler.

Often the turbo-jett installations are cowled-in. In the case of aerobatic-type cowls (Extra, Edge, etc) where you use the 'scale' air inlets, often enough the cooling air to the muffler is insufficient, and usually the cooling air exit area is limited too.

On the aerobatic cowls, block off the un-used air inlet. This forces all incoming air over the engine. Allow some cooling air for the muffler as well.

See photo attached of a typical installation

Can you show me a photo of your engine installation ? That may help me diagnose any problems.

Bob

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by bob27s -- 12/21/2005 2:16:12 PM >


_____________________________

Bob Brassell
Jett Engineering - Engine Mfg Support Forum Host

(in reply to f3d)
       Post #: 2

RE: Jett 90 t with turbo muffler - 12/23/2005 8:20:42 PM   
f3d


 

Posts: 68
Joined: 12/29/2002
From: Konz, Germany, GERMANY
Status: offline 		Here some photos of my Jett engine installation.

I us a blatter tank same system as in my pylon modells.

I have no explanation for my problems. The green silikone tube on the muffler is new and up to now not used. Its wintertime and to cold in Germany.

I hope for some good advice because I am not satisfied with the performance of the engine.
I thought it will be better than a OS FX 91 but thats not in my case.

Best regards M. Jakob

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by f3d -- 12/23/2005 8:23:30 PM >

(in reply to f3d)
       Post #: 3

RE: Jett 90 t with turbo muffler - 1/5/2006 8:36:48 PM   
bob27s



Posts: 4730
Joined: 4/9/2002
From: Cleveland, OH, USA
Status: offline 		Hi Michael,

Thanks for the update and photos.....

cooling is clearly not an issue... you have pleanty of airflow there.

A few questions....

The engine pictured is at least 4-5 years old. Has a front-needle carb on it.
When was the engine purchased? Did you obtain it from Jett directly or from another source ?
I am not sure exactly which turbo-jett you have installed. Is i the 15cc version or 20cc version?
Are you able to obtain a rich mixture, or is that difficult ? If it can get a bit richer, does it still get hot ?
Does it get hot only running at full throttle, or at mid throttle, or all the time ?

A few things to check in the mean time ....
The exhaust extension may be causing a problem. Tends to change the tuning length, and sometimes increases backpressure. Have you tried without it installed ?

Check the carb setting instructions in www.jettengineering.com in the tech documents section - a low speed needle that has been turned in too far can cause the top end and midrange to run too lean - that will drive you nuts.

Let me know on these ...

Bob








_____________________________

Bob Brassell
Jett Engineering - Engine Mfg Support Forum Host

(in reply to f3d)
       Post #: 4

RE: Jett 90 t with turbo muffler - 1/6/2006 6:07:23 AM   
f3d


 

Posts: 68
Joined: 12/29/2002
From: Konz, Germany, GERMANY
Status: offline 		Hallo Bob,

thank you very much for your help.
Yes the engine is from 1998-or 1999. I bought it direct from Dub jett with the turbo muffler.

It is called the torque version. The engine is old but still very low running time because of the ........

The exhaust extension made no difference on the heating problem and is taken away.
The engine got to hot with the turbo muffler in all rpm ranges and the trottle respond became very bad.
With the red org. muffler it is better but this type will not fit to my modell because the wing is in the way.
I can run the engine rich and with a lot of smoke but still very hot.

Is it possible to modify the turbo muffler ??

Hallo Bob do you think it make sense to send the engine bag to Dub Jett for a check ??

Thank you for your help.

Best regards M. Jakob


(in reply to bob27s)
       Post #: 5

RE: Jett 90 t with turbo muffler - 1/9/2006 2:48:18 PM   
bob27s



Posts: 4730
Joined: 4/9/2002
From: Cleveland, OH, USA
Status: offline 		There is not much you can do to modify the turbojett. The internal geometry and volume is set up for each engine size range.

If the performance is off substantially, you may want to consider sending it to Jett for review and repair.

As for throttle respone, try using an OS-F plug (The 4-cycle plug). Needs a very cold plug. That may help some of the situation.


_____________________________

Bob Brassell
Jett Engineering - Engine Mfg Support Forum Host

(in reply to f3d)
       Post #: 6

Page:   [1]
All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Engine Manufacturers Direct Support Forum >> Jett Engineering Support >> Jett 90 t with turbo muffler
Page: [1]





Jump to:


Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Member Video Posts | RCU Video Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America

Kaango.com Classifieds

0.563RCU1