Possible Improved Exhaust Spring…

[Piper J3]

I was digging around on Amazon and found what looks like an improved exhaust spring for the 912 exhaust system. These stainless steel springs are made for motorcycle exhaust and have swivel ends. I’m not sure if length is correct, but at $5.49 for two springs, I’m going to buy a set for evaluation. I think assembled length for the 912 exhaust is 66mm, so these springs would need to stretch 10mm which sounds about right.

 

[Eriselle]

Just out of curiosity, what is the problem you are trying to solve with these springs?

Side note, unrelated, referring to your signature- LSRM-A is the maintenance rating and is not specific to one registration- it's good for any ELSA or SLSA. If yours is tied to a registration number, you have LSRI-A, which is the inspection rating, not the maintenance rating.

 

[cactusman]

I was digging around on Amazon and found what looks like an improved exhaust spring for the 912 exhaust system. These stainless steel springs are made for motorcycle exhaust and have swivel ends. I’m not sure if length is correct, but at $5.49 for two springs, I’m going to buy a set for evaluation. I think assembled length for the 912 exhaust is 66mm, so these springs would need to stretch 10mm which sounds about right.

Have you tried these GPL stainless steel springs?

GPL Stainless Steel Exhaust Spring For 912 Series | Aircraft Spruce

GPL Stainless Steel Exhaust Spring For 912 Series Won't Rust. Lasts for years.

www.aircraftspruce.com

 

[cactusman]

Just out of curiosity, what is the problem you are trying to solve with these springs?

Side note, unrelated, referring to your signature- LSRM-A is the maintenance rating and is not specific to one registration- it's good for any ELSA or SLSA. If yours is tied to a registration number, you have LSRI-A, which is the inspection rating, not the maintenance rating.

A lot of earlier builders went to the stainless springs when a bunch of the carbon steel ones broke. Filling them with the high heat sealant as well as a bead on two sides seems to have lowered the reports of cracked exhaust springs.

 

[seagull]

I am using the stainless springs from Spruce. I have personally put 700 hours on the first set without a single broken one. I replaced all 8 because they were wearing at the spring hook end. They were about 1/2 way through when I replaced them. I put 2 stripes of RTV on the outside of the springs, one on each side.

 

[bbaggerman]

A lot of earlier builders went to the stainless springs when a bunch of the carbon steel ones broke. Filling them with the high heat sealant as well as a bead on two sides seems to have lowered the reports of cracked exhaust springs.

The blobs of RTV on the ends of the springs are important also. I was a little dubious about the necessity of this but then saw a couple of springs that were almost worn through from vibrating hooks. Yikes!

 

[Piper J3]

I got a chance today to trial fit the 58mm Stainless Steel Exhaust Pipe Spring listed in post #1 above. Fit looks excellent with sufficent stretch. I think heavy swivel ends will hold up very well and probably reduce wear on the muffler and exhaust stack loops. I’m going to replace Rotax springs during next condition inspection. Price is half of Rotax Stainless Spring…