ST G21/46 Muffler Adapter needed

[Bill Sequira]

Hello all,
I have a ST .46 G21. I do not have a muffler to fit this engine. As shown in attachment it does not have the muffler lugs on the outside of the case. Instead it has a center hole in the exhaust port. That hole is threaded for a 2.5mm screw. I have seen in the past and adapter screwed to that center hole, and a tube muffler screwed to the adapter. I have emailed both Randy Smith and Leonard Neumann and neither had any. I was informed that what I am looking for is an Adamisin product which is no longer available. Randy gave me a great idea on how to attach a tongue muffler without a hose clamp. However my plane would benefit from the added weight of a tube muffler. Do any of you fine people out there have one or two of these adapters you are willing to sell? OR is anyone willing to produce such an item?
Thank you all,
Bill Sequira

[Randy Cuberly]

Hi Bill,
I guess I'm not completely clear on exactly what you are looking for.  Are you looking for an adapter like the one pictured in your post or something different.  I have a ST G21 46 that has an adapter similar to the one in the picture but the engines is in poor condition except for the case etc.

I would be happy to give you this (parts engine) if in fact that is what you want! 

Randy Cuberly

[Bill Sequira]

Hi Randy,

Yes I am looking for an adapter like the one pictured so I can bolt it to my engine and bolt a muffler to the adapter to get some use out of the ST46.

Thanks,
Bill

[GERALD WIMMER]

Hello. Do these actually hold up well? With one 2.5mm bolt it seems it will wrap or strip the case or do you TIG weld or alloy braze the adapter to the case as well?
Yes I have a lug less S.T. 46 and 40 and this has sparked my curiosity.
 Thanks
Regards Gerald 

[Skip Chernoff]

In my experience adapters like those hold up just fine providing that they are machined properly and have a lip that fits well over the exhaust flange.

[Bill Sequira]

Hi Gerald,
It seems to hold up fine. The bolt is just to secure it in place. I am 99.876%  sure the side that sits against the exhaust port is recessed to fit over the port to hold it from dislodging. It's a shame this little jewels are not made anymore. The ST G21 engines are great engines and many people who have to have mufflers to fly, or just like it quite, don't get to enjoy their engines.

Bill

[Bill Sequira]

Randy, I sent you a PM.
Thanks
Bill

[Randy Cuberly]

Actually I believe they work fairly well if the surfaces of the adapter and exhaust are prepped to be very flat and sealed with silicone sealer!

Bill:
I'll go out to the shop and see if I can find that engine! send me a PM with your mailing address.

Randy Cuberly

[EddyR]

I use to get those from Windy and I retapped all my motors 6/32

Note.   You must remove the sleeve to tap the case.  The tap will hit the sleeve if you no not remove it.
 
The length of the bolt is very important so it does not hit the sleeve.
Ed

[Air Ministry .]

Now Thats a Cunning Idea . Why didnt you tell me earlier . 

Be a fix for the OS 80 & the five foot muffler screw . 

There is a ' strap on ' S T muffler , for the 21 - 40 RV , if youre after nose weight , I think 2 1/2 Oz unless you shave an Oz of fins off .



Tho mines got Sym Black straps and small longitudeinal bolt , so tidier .

Just found this cunning kavan contrivance , looking for picture of above .



The Adaptor appears to bolt to the body , thus usefull ' for other purposes ' .

Old ' U ' strap Merco one might fit too , if you could find one .

[Paul Allen]

I think the threaded hole is 2.6mm not 2.5mm.

[YakNine]

Now Thats a Cunning Idea . Why didnt you tell me earlier . 

Be a fix for the OS 80 & the five foot muffler screw . 

There is a ' strap on ' S T muffler , for the 21 - 40 RV , if youre after nose weight , I think 2 1/2 Oz unless you shave an Oz of fins off .



Tho mines got Sym Black straps and small longitudeinal bolt , so tidier .

Just found this cunning kavan contrivance , looking for picture of above .



The Adaptor appears to bolt to the body , thus usefull ' for other purposes ' .

Old ' U ' strap Merco one might fit too , if you could find one .

I have seen that kavan muffler at Mecoa you can buy just the adaptor, I have thought about that for my G-21 .40 for a base mill it off and mount a tongue muffler to it
 I haven't come up with a use for the evil contraption yet though.TJ

[peabody]

Hi Bill
I think I have just the thing
PM me your address and I'll put it into the mail....

[Steve Helmick]

I'd always assumed that Tom Lay got these adapters from Scott Dinger. weldit74 at yahoo dot com - Scott is a member here on SH, as I recall, so you can search for him under "Members"...."S", not "D".  Steve