Mailing List flyrotary@lancaironline.net Message #43502
From: Michael Silvius <silvius@gwi.net>
Subject: Re: [FlyRotary] Re: exhaust manifold
Date: Mon, 21 Jul 2008 20:12:21 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Ed:
 
I am with you on that one 110%. Like they say, if you throw it up in the air and it comes back down don't put it on your plane as it is to heavy.
I suspect that manifold just wont work at least for my application. I only have about 3 inches from the side of the engine to the top/fwd most support tube on my engine mount and as far as I can figure from the photos of that manifold it looks to be just over 4 inches broad so likely its a no go anyhow.
 
Let me ask the collective experience here what is acceptable wall thickness for the initial bends from the exhaust ports in 321 SS.? Is  .065 enough or is more advisable?. And what is a good source for those. Looks like I can use some 2 inch 90 deg bends on a 6 inch radius.
 
Michael
 
 
----- Original Message -----
 

Michael, while a good idea, the only down side, I see is weight.

 

 Early on in my build of my RV-6A, I made an “improvement’ here or there – I mean they only added an couple ounces or half a pound, etc.  Well an ounce at a time, I was horrified to find out at the end,  that my plane end up 120 lbs over Van’s recommended target weight.  Now 44 lbs of that were batteries, but even so weight is the “performance Killer!”  .

 

I initially thought my good friend, Tracy Crook, was ….well, somewhat fanatical about weight and some of the “extremes” he went to avoid and ounce of weight – well, no longer. 

 

I have watch the performance of my aircraft improve as I took off pound after pound.  But, trust me it’s a lot harder to take off (Hummm, applies to weight on all objects  apparently – thinking of my own body {:>) than it is to avoid in the first place.

 

Sometimes, there are certainly other considerations (safety for one) that override weight consideration – but, in my book, that is about the only one (well, perhaps cost {:>))

 

Ed

 

 
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster