| Author | Message | ||
     Charles M. Robinson New member Username: F15epilot Post Number: 46 Registered: 02-2004 |
I've been researching a replacement exhaust system for my Auriga (Lyc-IO-540-C4B5). I found two suppliers: Custom Aircraft Parts in El Cajon, CA, makes several pre-fabricated systems and has pics of installs on the Express, both -540's, Cont -550's, and 360's. Aircraft Exhaust Tech will make a custom system for you based on your sending back a PVC mock-up (they send you the PVC parts). The guys at Aircraft Exhaust told me that they had tried to get a contract with Express Aircraft to make exhausts for the Express, and were surprised when I told them that Express Aircraft went out of business--he even asked if I knew what the asking price was for the assets. He said he had never made a system for the Express, but would be happy to help. Both companies seemed very helpful, but differed in opinions on using a 3-in-to-1 on each side versus using a manifold system with increasing diameter pipes as each stack merges (see picture on the Custom Aircraft web site). Aircraft Exhaust suggested the 3-1 on each side as being better for performance and smoothness. He mentioned that the Pitts exhaust I had (constant diameter pipes through the exit pipe) were known for being loud and causing the engine to be a bit rough (mine is particularly rough on shutdown). The Custom Aircraft system uses a ball joint to isolate the header from the tailpipe section; the latter is mounted on both the engine mount and firewall. In addition, I’ve been talking to a custom automotive header design firm in Virginia that will model any engine given the flow parameters from the cylinder head, camshaft profile, and firing order. They have a free website model program, but unfortunately, it won't accept a 540 cu in motor with pistons as big as ours. Still, given the right data, they can custom design an exhaust for performance/economy. I've got the camshaft info from the CAFE article on the IO-360; still working finding the flow information, so if anyone has a cylinder head off an IO-540 (or 360, as they're essentially the same), let me know. Taken to completion, the header design guys assure me they can model the engine and come up with the optimum lengths of pipes for performance (climb and/or cruise). Using those lengths, and some creative PVC glue/cut/glue, I believe we can create a performance-tuned system akin to PowerFlow systems. Before I tread where others might have gone, I thought I'd ask the group if this has been pursued before. More specifically, has anyone looked at modeling the motors and optimizing the exhaust systems? Anyone use Custom Aircraft Parts or Aircraft Exhaust Technologies before? And is anyone interested in sharing some of the costs of the design, if I can get the data (the systems from Aircraft Exhaust Tech have a fixed 'setup' fee which would go down if more than one set is ordered). As a ballpark figure, one custom exhaust would cost about $1600 made in 321 stainless. Custom Aircraft Parts sells theirs for about $1100 w/o a head muff; $1300 with. Look forward to hearing from those interested, especially those who've used either of these companies, or others--I'm sure there are many more. Chuck | ||
| Allyn Roe (Unregistered Guest) Unregistered guest |
Chuck, Try finding CB Aviation around some of the Lancair builders. I ran into this guy at Sun N' Fun 04 and he has a very nice exhaust setup he was using for the ES and IV's. It is a tuned setup that could easily be modified for the Express since they are the same engines. He claims it has a gain in HP, decrease in fuel consumption, and lower temps. He will probably only need a firewall template. Steve Furgesi at EAMF also offers exhausts for the Express. http://www.eametalfab.com/ |