Sorry, I posted this in the general forum, but then found the gas engine forums...

Im getting a Jackal for my main Christmas gift.. I'll need to cover the engine,retracts etc.

Engine wise.. I have had no luck with the Evolution engines... my Alpha 40 TPS engine ran great for he first day and was nothing but a nightmare after that.. dead sticks, surging when running to full power, power lags, bubbles in the lines... basically the same problems everyone else seems to have.. needless to say I am dropping an OS 46 on the Alpha over Christmas...

So Jackal wise... what would be a good non Evolution motor to install... it seems they push it with the 60NX and the tuned muffler .. I was thinking an OS55 with a Jett Stream muffler, or even an OS61 with a Jett muffler, or getting a Jett 56 / muffler for it..

Anyone have any suggestions/comments?

Thanks, and Merry Christmas!

Read more: http://www.rcuniverse.com/forum/m_10...#ixzz18mtUYKtC

The Jett engine would be the way to go. That small case Jett 60 is the ultimate for the Jackal. I think that using the Jett tuned muffler is the way to go over a tuned pipe. One has to use a small case engine as the regular large case 60's are too large to fit. The motor mounts won't fit on the firewall otherwise. Oh yeah some of the Rossi engines are good candidates too, as are some of the MVVS engines. The OS 55AX wouldn't be a bad choice either.

I have entertained putting one of my Fox .50 engines on a Jackal. I happen to have one of the old Fox pne piece tuned pipes with the Flash Gordon styling. I also have considered using one of my old Fox Hawk .60 engines too.With 25% nitromethane fuel and a smaller prop the Hawk 60 is capable of 22,000 Rpms. But it would likely have to be a bigger prop to get the thrust up for takeoffs though. Unless you have a long paved runway. So RPMs on the Hawk would probably be down around 17,000 or so.

Retracts, I would suggest using what they suggest. I am not sure other retracts would fit OK or not. There is a long running thread over on that other forum where the members have been discussing the Jackal at length.

Hi,
I will most likely go with the OS 55 and a Jett Stream muffler system.
I have already enquired about the Jett .56 and have read it is a great engine, the thing turning me away right now is having to cut the firewall etc to squeeze the bubbleless fuel tank into it...
I know the OS will be slower than the Jett, but I also don't want all the other hassles....

On a sidenote, I have heard Jett makes the tuned pipe for Evolution??? Is it the same as there Jett stream, will it fit an OS 55??

http://www.jettengineering.com/

<table border="0" bgcolor="#ff9999" width="620"> <tbody> <tr> <td bgcolor="red" colspan="6"> <p align="CENTER"><span style="font-size: 12pt;"><font color="white" face="Arial, Helvetica">Jett-Stream High Performance Tuned Muffler Specifications</font></span></p> </td> </tr> <tr> <td bgcolor="red" width="100"> <p align="CENTER"><span style="font-size: 10pt;"><font color="white" face="Arial, Helvetica">Model Number</font></span></p> </td> <td bgcolor="red" width="116"> <p align="CENTER"><span style="font-size: 10pt;"><font color="white" face="Arial, Helvetica">Muffler Fits
Engine Size</font></span></p> </td> <td bgcolor="red" width="45"> <p align="CENTER"><span style="font-size: 10pt;"><font color="white" face="Arial, Helvetica">Weight</font></span></p> </td> <td bgcolor="red" width="79"> <p align="CENTER"><span style="font-size: 10pt;"><font color="white" face="Arial, Helvetica">Bolt Spacing</font></span></p> </td> <td bgcolor="red" width="155"> <p align="CENTER"><span style="font-size: 10pt;"><font color="white" face="Arial, Helvetica">Fits Engines</font></span></p> </td> <td bgcolor="red" width="50"> <p align="CENTER"><span style="font-size: 10pt;"><font color="white" face="Arial, Helvetica">Price</font></span></p> </td> </tr> <tr> <td bgcolor="#ff6666" width="100"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">JS-30</font></span></p> </td> <td bgcolor="#ff6666" width="116"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">5cc (.25-.32)</font></span></p> </td> <td bgcolor="#ff6666" width="45"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">118 grams</font></span></p> </td> <td bgcolor="#ff6666" width="79"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">35.0 mm</font></span></p> </td> <td bgcolor="#ff6666" width="155"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">OS.32, Mag, TT, MDS
(others)</font></span></p> </td> <td bgcolor="#ff6666" width="50"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">$55.00</font></span></p> </td> </tr> <tr> <td bgcolor="#ffcccc" width="100"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">JS-40-TT</font></span></p> </td> <td bgcolor="#ffcccc" width="116"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">6.5-9cc (.40-.50)</font></span></p> </td> <td bgcolor="#ffcccc" width="45"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">128 grams</font></span></p> </td> <td bgcolor="#ffcccc" width="79"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">37.0 mm</font></span></p> </td> <td bgcolor="#ffcccc" width="155"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">OS, TT, GMS, MDS
Magnum, (others)</font></span></p> </td> <td bgcolor="#ffcccc" width="50"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">$60.00</font></span></p> </td> </tr> <tr> <td bgcolor="#ff6666" width="100"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">JS-40-ST</font></span></p> </td> <td bgcolor="#ff6666" width="116"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">6.5-9cc (.40-.50)</font></span></p> </td> <td bgcolor="#ff6666" width="45"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">128 grams</font></span></p> </td> <td bgcolor="#ff6666" width="79"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">38.5 mm</font></span></p> </td> <td bgcolor="#ff6666" width="155"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">Super Tigre
Nelson, Webra</font></span></p> </td> <td bgcolor="#ff6666" width="50"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">$60.00</font></span></p> </td> </tr> <tr> <td bgcolor="#ffcccc" width="100"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">JS-90</font></span></p> </td> <td bgcolor="#ffcccc" width="116"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">10-15cc (.61-.91)</font></span></p> </td> <td bgcolor="#ffcccc" width="45"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">178 grams</font></span></p> </td> <td bgcolor="#ffcccc" width="79"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">42.0 mm</font></span></p> </td> <td bgcolor="#ffcccc" width="155"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">OS .61/.90FX, ST.61-.90
MDS .68, MAG, (others)</font></span></p> </td> <td bgcolor="#ffcccc" width="50"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">$85.00</font></span></p> </td> </tr> <tr> <td bgcolor="#ff6666" width="100"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">JS-120</font></span></p> </td> <td bgcolor="#ff6666" width="116"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">20cc (1.20)</font></span></p> </td> <td bgcolor="#ff6666" width="45"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">200 grams</font></span></p> </td> <td bgcolor="#ff6666" width="79"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">42.0 mm</font></span></p> </td> <td bgcolor="#ff6666" width="155"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">email / call</font></span></p> </td> <td bgcolor="#ff6666" width="50"> <p align="CENTER"><span style="font-size: 10pt;"><font face="Arial, Helvetica">$85.00</font></span></p> </td> </tr> </tbody></table>

I think the OS55 is a 9cc if I recall... so the JS-40-TT is the one I require...
Im almost tempted to throw one of these on my Alpha 40 as well with the OS46...Trainer on steroids

I doubt if changing from the Evolution engine to something else is going to improve your situation.

Bubbles in the fuel line is not caused by a defective engine, although the reasons that bubbles are being formed and the fact that they are being formed can ruin any glow engine made. You have either a fuel tank problem or a fuel line problem. If any part of the fuel tank is touching any solid part of the model airplane, such as poking the fuel tank neck through the firewall or resting the fuel tank's belly on a wooden bulkhead, you have found your problem. I'm assuming that you have already checked/replaced the fuel line in the system and ensured that the fuel pickup clunk is not close enough to the rear of the fuel tank to suck itself up against the rear of the fuel tank and closing off the engine's fuel source.

A brand new engine, any brand, must accumulate a certain amount of running time before one can expect to tune the engine to perfection and end deadsticks. That's just the way glow engines are these days. Fortunately, it doesn't take all that long for the engines to break-in. Usually one half gallon or one gallon of fuel for the really stubborn ones will do the job. The difference in the engine before and after break-in is quite startling. What was a pig-headed, uncooperative engine turns into a silky-smooth piece of a technical marvel once break-in is achieved. The cheaper the engine, usually the longer the required break-in. Buying an OS engine when you are a beginner isn't a bad idea as it will get you flying successfully in the quickest amount of time - UNLESS YOUR MODEL'S FUEL TANK SET UP IS DEFECTIVE. Most are.

What's the fix? Go to the hobbyshop and look for a fuel tank that will fit completely inside of fuel tank compartment with room for about a half inch of uncompressed foam around every side of the fuel tank. DO NOT LET ANY PART OF YOUR FUEL TANK TOUCH ANY SOLID PART OF YOUR MODEL. The fuel tank needs to be completely isolated from the engine's vibration. Otherwise, your engine will be receiving fuel with lots of bubbles in it, which will mess up any attempt to adjust the carburetor properly.

Good luck and let us know how you fare.


Ed Cregger

New tank, new lines all installed... the engine ran absolutely flawlessly on its maiden flight... after that it ran like $$$$

The tank is setup in the Alpha as it comes from the factory.... there is no foam wrapped around it. There is a balsa wood brace holding the tank from the back.

I will add some though and see how that goes.

Unfortuneatly, I am under 2 feet of snow and its minus something cold in Canada, so there won't be any outdoor fun til Mid April...

Ditto what Ed said.

I agree totally with ED's comments.
FYI,
The EVO .60NX will haul the mail just fine if you do a propper set up of the fuel system just like you will have to do with the others too.

I'm not disputing the problems here. I've had a TPS .455 and the .46NT engines set up without much padding as if asking for bubbles. One plane had no padding. I didn't have any problems.

Yes, once in a while you get lucky and the fuel tank doesn't bubble. That makes it super hard to convince newbies that hard fuel tank mounting is wrong. But I don't argue with what works - for the moment.


Ed Cregger

Now when you add a Jett or Evo .60NX (and Yes a Evo .60NX with Jett muffler is quite the performer) to the mix the installation that used to work is sure to cause problems since the RPM levels will cause fuel foaming guaranted with an improper fuel tank setup.