Does anyone have experience with both Slimline and Bisson Pitts mufflers for the OS 46ax? If so, does the bisson have a lower profile than the slimline? I have a Venus 40 with a 46ax and slimline muffler. Ive had to cut away at the front and sides in order to accomodate the muffler more then I wanted. Now, ive seen pics that others have posted on rcuniverse of the same plane and engine along with a "pitts" muffler as per description, yet no cut-out for the pitts muffler. Im wondering if there is something smaller than the slimline, and if the bisson is it?
See pics- and yes Idid a horrible job cutting, but thankfully have another cowl.

Thanks

I can't imagine any Pitts muffler for a side mounted engine that wouldn't require some serious cowl cutting on this airplane. The other planes you saw may have had the engine mounted inverted using an "inverted Pitts" muffler. That would probably result in the least cowl cutting. I believe inverted is the standard engine mounting for this airplane. I had one with a .46-AX inverted using the stock muffler and it worked excellent.

Slimline makes a ultra narrow pitts muffler, but maybe a tatone muffler setup might be better, or a mac's header and a tuned pipe,....hey, if your going to have the exhaust exposed, go for power and sound!

Get a Dremel sanding drum to open up the cowl.  A light touch you can make nice looking openings.  Use a mask and goggles to protect yourself, and do it outside where ever the neighbor's cat does it's business in your yard.

I don't know what muffler you have there, but its unlike any Slimline or Bisson I have ever seen.


And remember, when trimming a cowl. Measure with a micrometer. Mark it with a crayon. And then cut it with a chainsaw.

It is this:

http://www3.towerhobbies.com/cgi-bin...8&I=LXTEB7

Anyone have a slimline pitts #3218 you'd be willing to part with?

That is the newest muffler that Slimline puts out. It is bigger than the older Pitts style muffer they used to put out. I was sent one of those Q series muffers when I did the review of the Great Planes Cherokee but wound up not using it. Since it was a bit bigger it interferred with the nose wheel steering arm. I had to use one of the older style mufflers instead of the Q series. Unfortunately the older style of muffer is no longer manufactured, so the only way to get one is to stumble across one at a Hobby Shop, Ebay, RCU marketplace, swap meet, or some other source.</p>

Ken</p>

Thanks Ken....The review you did is exactly where I saw the older version. I think its exactly what Ill need. i will need to keep my eyes open. The slimline website still lists the older version for sale. I wrote to them to see if they would possibly still have them lying around. Crossing my fingers.

I mounted my engine at 135* and used a muffler extension. The stock muffler exits bottom center of the plane and doesn't look bad at all. I think this is the least amount of cutting out of all the options. However let us know your progress, I would like to know if a Pitts really is a viable option inside that skinny cowl chin.

According to the website...a Tatone piits muffler should work pretty well as per the dimensions.. I ve never heard of them or know anything about them, so will explore the Slimline option first.

Unless your really set on a pitts style muffler, I would use the stock one. The venus looks much better with a small exit hole for the stock muffler. Anything else and your cowl will be hacked up because the cowl is too small. You'll get better performance from a stock too.

the older style pitts from slimline is still availble , I had no problem getting one a few weeks back for an os 55ax from my LH they ordered it for me , came in a few days later

If Ihad known I would run into this problem Iwould have mounted the engine at a better angle to use the stock muffler and kept it simple. At this point I just dont feel like goin through the trouble of redrilling the holes etc. Thats is definitely something ive learned in this hobby - sometimes you just have to use the KISSmethod. Its not really worth all of the trouble.

Thanks for the heads up Zero!

I`m trying to find a 120AX muffler that well fit inside the cowl of a H9 Funtana 125. Any suggestions would be greatly appreciated.

For what its worth, I have a Cherokee with a 46AX and the Bisson Pitts muffler. It fit my cherokee perfectly with no modification required at all. I dont know how it compares to the slimline muffler dimensionally, but if Ken tried the slim line and it didn't fit, and my bisson does with all other variables being the same, maybe the bisson will work for you.

http://www3.towerhobbies.com/cgi-bin...&I=LX8680&P=ML

Ro, check out this Jett muffler. It's quite small. They make adapters for various engines too.

http://www.jettengineering.com/accy/turbo.html

yo bro found a brison i thinks its a 4223 it rap around the 120ax at least my engine is inverted on my .60 top flite p-51d mustange its about 90 dollars check the brison web sight
you cant get it on tower hobbies the broson dude makes mufflers just for 2 stroke but 4 strokes tooo they are in onterio cannada

http://www3.towerhobbies.com/cgi-bin...LXVNG6&amp;P=8
Give this a look and see if it is maybe a bit better.  I am looking to do a cherokee so I am interrested in that clearance issue that Ken mentioned.

I have the Cherokee and the Bisson muffler fits perfectly.

Bruce

The Bisson Pitts is a smaller volume muffler than the Slimline, hence I have one fitted inside the cowl of my BH EXtra 300s.

For the Venus you will not get a Pitts inside it, the cowl is too narrow. Mounting the stock muffler is probably best.

Also look at www.justengines.unseen.org and have a look at their range. You may be able to get away with an Inverted Upright Muffler and they do custom mufflers as well.

2nd that, the Bisson fits perfectly on the Cherokee. See my post above for a link.

Thumbs down
Slimline is still ripping customers off via their webpage by taking orders and not fulfilling them. Then some idiot named Bill answers their phone and makes up excuse after excuse as to why they are unable to deliver product. I finally had to call my bank to reverse their charges after 3mos of waiting. Stay away from these guys!

I have used both and found that the Bisson are a lot quieter.