Header/Muffler for Merlin 40 UL RE Engine

[kevin king]

Does anyone have a Randy Smith header/muffler to fit a Merlin 40 UL RE that they could sell me? I bought this Jaguar that was built around this motor and dont want to start hacking the plane up to fit a different muffler. It would be much appreciated.
Thanks

Kevin.

[kevin king]

No header/mufflers out there? Unreal. Time to find a new hobby.

[Brett Buck]

No header/mufflers out there? Unreal. Time to find a new hobby.

     That seems a little much - this is a very obscure application, almost all engines from this era are run on tuned pipes, not mufflers. Having said that, IC engines are becoming unsuppoortable for the last 10 years, it's very hard to find any new parts at all. We are all running on the massive stockpile we have built up over years.

   The mufflers you show are just pipe headers with a plug in the end, so any pipe headers that fit the airplane. As I mentioned in PM, I never had a PA40UL and I am not sure that regular PA headers would fit. Headers in particular are in short supply.

     Brett

[kevin king]

Lesson learned Brett. As always thank you for your feedback.

[Jim Hoffman]

I have a stunter w/ a PA 40 Lite RE.  My muffler is a simple header to which I added three alum tubes retained w/ JB Weld.  I plugged the rear of the header w/ a steel plug I found at Home Depot, also held in w/ JB Weld.  Very successful.

The header was initially mounted on the motor with no other restraints.  It resonated in that condition which was resolved with the addition of a mechanical restraint towards the aft of the header.

[kevin king]

Thanks for sharing Jim. I like the 3 exhaust pipes. I found a PA 75 header that fits the 40 UL. Maybe that will work. I doubt it because the length of the rise from the engine to the bend in the pipe seems too long in the photo, which is all I have for reference. I will find out when I actually get the header. It would help if I could get the dimensions from someone with the original PA header/muffler so I could have one made.

Kevin

[Steve Helmick]

My recaller (often faulty) says that Randy Aero headers all are the same flange and have the same "drop"...maybe the same tube diameter also, because I think he only stocks one size of silicon coupler tubing??? I know Jetts use 5-40 screws, while PA's use 4-40's, which isn't a huge problem.

I like Jim's triple outlet design, and it's probably lighter than the rubber ducky version shown in your original post. I'd be apprehensive of the steel plug in the end, because of the different coefficient of expansion would tend to make the JB Weld fail. Room temperature vulcanizing cream (silicon seal) and 3 small machine screws might be more trustworthy if you HAVE to use a steel plug? Aluminimum (sic) would be better, IMO.  Steve

[Lauri Malila]

..and brazing would be the best solution!🤗
L