{"id":563,"date":"2011-02-13T06:16:51","date_gmt":"2011-02-13T06:16:51","guid":{"rendered":"http:\/\/stjohn.openbar.com\/airplane\/?p=563"},"modified":"2011-02-13T06:16:51","modified_gmt":"2011-02-13T06:16:51","slug":"fun-with-afp-and-vetterman-exhaust","status":"publish","type":"post","link":"https:\/\/stjohn.openbar.com\/airplane\/?p=563","title":{"rendered":"Fun with AFP and Vetterman exhaust."},"content":{"rendered":"

4 hours.<\/p>\n

I’m convinced an optimist is a pessimist who hasn’t done a firewall-forward installation yet. Let me amend that. With a plug-and-play setup, that optimism might keep going, but with a frankenmotor like mine, the odds are definitely stacked in a bad way. I decided to tackle one thing at a time. First thing is the throttle body arms. I rotated the throttle body so the diaphragm points to 3:00 again, if you’re looking over the nose. I came up with a scenario that should work, but it might require the use of heat shielding on the control cable end, not sure if that’s a no-no or if it’s OK. Take a gander:<\/p>\n

<\/img>
\nHere, we’re looking up at the engine. First thing to check out is the throttle arm. I ground off the outermost hole so it can swing past the exhaust pipe with enough clearance to make me sleep well at night, but it’s still tight in there. The second thing is the mixture arm. If I’m reading it correctly, it’s in the full rich position right now. Push for rich, pull for lean. I have a call into AFP to see if this will work, but I suspect it will. The bracket bolted to the sump is one of the Van’s IO360 brackets. It’s almost perfect, except for the fact that the bolt holes don’t line up for the Superior sump. Another 1\/8 of an inch apart from each other and they would.<\/p>\n

<\/img>
\nClose up. Do you see how tight it is in there? This is like a game of Tetris, but none of the pieces are the same shape.<\/p>\n

<\/img>
\nFrom the left side. If I rotate the TB so the diaphragm is at 12:00, it bangs into that black rod on the starter. No joy there. Plus, it would make cabling suck even worse, and there would be bellcranks and other fun stuff.<\/p>\n

<\/img>
\nThis shot shows the potential path for the mixture cable. A small spacer putting the rod end bearing slightly above the mixture arm should get it easily clear of the other arm and bearing.<\/p>\n

<\/img>
\nThis is the throttle cable lineup. Since I could clock the throttle arm in any direction I wanted, I got it so the arc is the best compromise for non-interference with the mixture arm, but also I need certainty that there won’t be an over-center condition on the arc swing. there’s still plenty of room to bend the bracket upward, which sends the cable out well clear of the exhaust pipe. I’m trying to keep the rod bearing on top of the arm rather than below it, because I want as little radiated heat as possible soaking the cable. I now need to mock up brackets to make this work.<\/p>\n

Oh, and I discovered something disturbing today: a couple of rotation locks that I believe go inside the fuel tanks to stop the fuel pickup tube fittings from backing out. I’m pretty sure though, that those were the old kind, and the new kind are what’s installed in the tanks. I may have to run a scope in there and check it out, but if there’s no rotation lock on there at all, taking that apart to redo it is going to blow, long and hard.<\/p>\n","protected":false},"excerpt":{"rendered":"

4 hours. I’m convinced an optimist is a pessimist who hasn’t done a firewall-forward installation yet. Let me amend that. With a plug-and-play setup, that optimism might keep going, but with a frankenmotor like mine, the odds are definitely stacked in a bad way. I decided to tackle one thing at a time. First thing […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[5],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=\/wp\/v2\/posts\/563"}],"collection":[{"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=563"}],"version-history":[{"count":0,"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=\/wp\/v2\/posts\/563\/revisions"}],"wp:attachment":[{"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=563"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=563"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stjohn.openbar.com\/airplane\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}