kojak41

[8D]

I have a couple of ST .51s (old, before China) that I love, but the ST stock mufflers are a pain. Too big and bulky and they come apart in the air. Cost 50% of the cost of a new engine to replace. Is there a bolt=on replacement available? I'm not into metal work so I want something I can just screw on and fly. Thank for any ideas.

Mike H.

w8ye

My Feedback: (16)

Macs makes a nice One Piece Muffler that works on the ST 51. It is easier to get it from Tower or Great Planes/Hobbico. It says for the 40-45 ST but it fits the 51 also.

I used a Tower 46 muffler on mine but it doesn't fit every plane and you have to do a little rattail file work on the exhaust stack to get the muffler to fit. The muffler only costs $15. It'll make your '51 hum.

http://www2.towerhobbies.com/cgi-bin...&I=LXZ653&P=ML for the Macs

http://www2.towerhobbies.com/cgi-bin...&I=LXJB16&P=ML for the Tower

Enjoy,

Jim

bob27s

My Feedback: (19)

You can purchase a jett-stream muffler that will bolt right to the ST-51 engine. One piece, will not fall apart, and will make a real animal of the engine. That is available from jettengineering.com

You noted you were looking for a budget solution. That is often difficult... but not impossible....

If I recall, ths ST and COMO 40 and 51 engines had 37mm (or maybe 38 mm) muffler bolt spacing.

This is the same as the Webra 40/50 engines. Also was the same spacing for an older K&B .61 (veco .61) engine. The current Tower .46, Thunder Tiger 40/46, and Tiger Shark .52 are 37mm

You have options. THE ST-51 will run just fine with any of the mufflers listed here.

This info might help in your search.

w8ye

My Feedback: (16)

Whatever the spacing, there's 1mm difference between a Super Tiger 51 and the OS 46/Tower 46 type mufflers.

Supertiger also has an economy muffler that is small and light weight. It's cheap too. I've seen them used on 51's but they were originally intended for the 40.

Enjoy,

Jim

w8ye

My Feedback: (16)

Here's the Super Tiger economy muffler at $25

http://www2.towerhobbies.com/cgi-bin...?&I=LXFV94&P=Z

Enjoy,

Jim

bob27s

My Feedback: (19)

Yeah, that sounds about right. That would make the ST 38mm - 1mm wider.

w8ye

My Feedback: (16)

I have a OS SX50 in front of me here and I measured the C-C distance as close as I could with the Mitutoyo Digital calipers and it was 37mm or 1.46".

I was reading in the Tower stuff on the net and You cain't believe a word they say about C-C dimensions. They have the Macs for the ST and the one for the OS at 36mm. Then they list a OS 46 muffler at 36.5mm and the Tower 46 at 37mm.

Maybe you can measure your 51?

Enjoy,

Jim

w8ye

My Feedback: (16)

I found a Tower 46 muffler here in the house and it measures 37mm C-C

Enjoy,

Jim

w8ye

My Feedback: (16)

I Found a K&B 61 and it measures 38.1mm (1 1/2" ) C-C across the exhaust screws. I thought someone mentioned the engine up above?

Enjoy,

Jim

mrbigg

My Feedback: (21)

bob27s- i'm interested in one of those mufflers that you guys have. the only problem is that the engine is on a profile ultimate. mystock muffler swivels out to clear the wing. what is the length of your muffler from the rear flange bolt to the outlet? what kind of an increase can i expect?

ChuckN

That crazy ST "dustbin" muffler has always been a sore spot on an otherwise excellent engine. I like to search the swapmeets for older teardrop shaped ST mufflers that slide onto the same exhaust stack as the late model muffler. They aren't too hard to find and can usually be had for less than $10. Best I can tell there were only two sizes - .40 size (.40 - .51) and .61 size (.61 - .91).

BillS

Super Tiger is so proud of the current mufflers that they refuse to show them in the advertising.

turbo.gst

My Feedback: (8)

I had a problem with my ST 90 muffler. I decided to use a mac's header and make a tuned can type muffler( aka like a mousse can). I think this would work great on a profile. It's an idea you may want to consider.

Turbo

mrbigg

My Feedback: (21)

any pics turbo?

bob27s

My Feedback: (19)

Big,

Dimensions for the mufflers are on the jettengineering.com web site, in the TECH DOCUMENTS section. Look at the engine dimensions diagram. You would be using the same muffler as for the SJ-46 or SJ-50. That info will give you an idea of how the fit might be. If required, you can also obtain .25" extension pieces, to space the muffler away from the engine a bit... maybe it can clear below the wing in this way.

Performance....
We typically see 800-1000 rpm increase, on a 10x6 prop (example). Some engines do better, some a bit less, but there has always been a boost above stock muffler performance. The ST-51 (based on my own expereinces with the como 51) responds nicely to a tuned exhaust. Some typical performance examples from testing are shown on the ACCESSORIES page. Look at both the Jett-Stream and Turbo-Jett product pages for the RPM tables.

Edit -

Another option....... The Lite-Jett muffler.

Shown here installed on a Jett SJ-65L-H as a size reference.
Its not tuned, but provides outstanding power, good backpressure balance, is super light, and very compact. May be the perfect solution to your situation. Specify the engine on any order.

img attached. The one labled .40 is for the jett .40L engine (.25-.35 size) and the one market .61 is for the jett 61L engine (.40-65L size)...this is the one that would fit the ST51.

turbo.gst

My Feedback: (8)

mrbigg,

I don't have photos. There is a thread started by Gene Chernosky, in this forum, on building your own mousse can pipe that has photos and enough to get you going.

turbo

kojak41

[8D]

Thanks for the info. Still a little unclear if the Tower .46 muffler will work. Price is sure right. My wife says that I use the bird method of selection all the time (cheap, cheap,cheap).

Mike H.

Rudeboy

Prove her wrong, and go for quality... Jettstream mufflers from Jett Engineering are awesome. Just remember to run your engine in the recommended RPM range mentioned in the instructions.

The OLD teardrop ST mufflers are very good. They make good power, and don't strangle the engine too much... but they are loud... The new ones can't compare.

derferic

My Feedback: (32)

Turbo.gst

What size can did you use for the ST90? Where did you find it?

turbo.gst

My Feedback: (8)

derferic,

I used an Axe deoderant can --- 4 oz.

turbo

derferic

My Feedback: (32)

Turbo,

I would have expected that a larger can would be needed, perhaps 6 to 8 oz. I use a 4-oz can on my OS32 and get about 1200 RPM boost on a 10x5 APC.

What RPM boost are you getting?

mrbigg

My Feedback: (21)

thanks bob. going the site to check them out. turbo- i think i'm going with the jett. not enough time to fabricate- too many projects going on.[sm=drowning.gif] another thing that i don't like about the stock muffler is that the disc that is in there sometimes comes loose and rattles around.

turbo.gst

My Feedback: (8)

derferic,

I designed the mcp to give my pressure ( like a pump). I used my DH Models pipe for my 1.40 2 cycle as a guide. I have picked 800 rpm, but I have better throttle response and mid range -- that is what I was after, not peak. The reason I picked up rpm is because I can set it at peak and leave it. I was having to back off that much to hold the needle on extended verticals to prevent leaning.. Now I can go stright up for as long as I want. I am very pleased, and will try for the same success on other engines in my stable.

Mr. Bigg,

I completely understand the time issue. It took me way too long to get the time for this one. I'm just a tinkerer and luv the results I got...

turbo

derferic

My Feedback: (32)

Turbo,

Thanks for the info. I like your approach regarding pressure. I had not considered that aspect.

derferic

My Feedback: (32)

Turbo,

I forgot to ask where you are picking off the pressure? I assume it to be at the header, correct?