{"id":1012,"date":"2012-07-30T09:40:41","date_gmt":"2012-07-30T15:40:41","guid":{"rendered":"http:\/\/www.velocity-xl.com\/blog\/?p=1012"},"modified":"2012-08-03T10:29:46","modified_gmt":"2012-08-03T16:29:46","slug":"12-2-3-cylinder-intake-drain-lines","status":"publish","type":"post","link":"https:\/\/www.velocity-xl.com\/blog\/2012\/07\/30\/12-2-3-cylinder-intake-drain-lines\/","title":{"rendered":"12.2.3 Cylinder Intake Drain Lines"},"content":{"rendered":"
This entry is part 19 of 50 in the series 12 - Engine \/ Propeller<\/a><\/div><\/div><\/div>
This one is a good example of the… challenges of building an airplane. I started working this particular task almost a year ago.<\/p>\n

Technically, the Velocity is a “kit”. Which means that I should get a bunch of parts and then assemble them into an airplane. With a “plans built” plane, all you get is a bunch of paper. From which you build (or acquire) every single component. Even though the Velocity is a kit, that doesn’t mean there aren’t some of the same challenges that “plans built” folks have.<\/p>\n

On the Continental IO-550 engines, each of the six cylinders has a drain. This allows excess (unburned) fuel to drain out of the cylinder at engine shutdown or if the engine is over-primed prior to start. These six drains have to be merged into a single line which then goes through a “sniffle valve” (I kid you not) that allows fuel to exit but does not allow air to enter. After the sniffle valve the line exits the bottom of the fuselage.<\/p>\n

Here’s the section of the manual that describes this part of the build:
\nThe intake manifold on the Continental has 3 separate 1\/4\u201d lines on each side of the engine coming from each cylinder heads to a manifold. From here we need to make two hard lines that join together at the back of the engine at an AN824-4D Tee fitting. After a short run from the AN824 you will switch to Mil-H-6000 line. Before the drain exits the cowling you have to connect to a short run of 1\/4\u201d aluminum line that is<\/em>
\nflared at one end with an AN818-6D and an AN819-6D. Screw in an AN815-4-4D fitting into your 1H19-6 Cylinder drain valve. This is provided by Continental. Attach you line to this and route the drain valve out the bottom of the airplane.<\/em><\/p>\n

Okay, pretty straight forward. First, I need this drain valve. I looked on and off for almost 6 months. I got a number of different part numbers but still couldn’t locate one. Finally, I got a lead at Global Air Parts and was able to pick one up.<\/p>\n

Now I just need to run the two lines from each manifold to the tee. Except that I DON’T HAVE A MANIFOLD<\/strong>. Nor do I have the lines coming out of each cylinder going to this “manifold”. At the bottom of each cylinder I have a fitting. And that’s it.
\n\"\"<\/a><\/p>\n

I asked my A&P to call me the next time he had a Cirrus (or any other plane with an IO-550 engine) in the shop so I could take some pictures. Within a couple of months, I got a call that a Cirrus was in the shop so I headed out with my camera.<\/p>\n

Here’s a picture of the three cylinder drain lines meeting at the manifold with a 1\/4″ flare fitting.
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Well, I can’t make THAT. So now I start looking for a pair of these things. But are they engine parts or airframe parts. Everyone I spoke to said “Airframe Parts”. Which mean they are available from Cessna, Cirrus, Piper, Beech, etc. This typically means insanely expensive. For example, the sniffle valve cost me $265.00 (used).\u00a0 So I check with all the used parts sources and I can’t find anything. When I went to Oshkosh this year, I looked at every single IO-550 that I could find. Most had the drain lines like the Cirrus. But a couple had homebuilt lines.<\/p>\n

So I made the decision to fabricate my own. I went over to the AeroMart where all the vendors sell everything that you can think of and picked up a bunch of AN fittings.<\/p>\n

When I got back home I decided to run the idea past my A&P, Lynn of Motive Services<\/a>, to see what he thought. Lynn is my go to guy when I have a question about acceptable practices, best methods, is it legal, etc. He did some digging and discovered that the “Tube assembly, Cylinder drain” is actually a Continental part (PN 643584). With a price of about $200 each. Since this is a drain line, not under pressure and will only see fuel if the engine is over primed or after it’s shut down, I decided that fabricating it was acceptable.<\/p>\n

So I got the tubing bender, flaring tool, compression fittings and got to work.<\/p>\n

Here’s the tube from the #6 cylinder.
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Here are the odd cylinder drains run into a 4-way AN fitting
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Now I need to run a line to the front of the engine to meet up with the even cylinders drain line. The bending on these lines was a little tricky because there were a number of directional changes. This is the stuff that Malcolm excels at.<\/p>\n

Odd cylinders drain line running forward.
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At the front of the engine, I had to drop the line a bit to clear some components of the engine. So I had to make a standoff for the Adel clamp.
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Then the lines from both sides meet at a “T” fitting.
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From the “T”, I made up a braided steel hose that would go to the firewall. The manual says that unshielded rubber hose is okay, but I like using the braided line. Since it’s not in use during engine operation, I don’t think firesleeve is necessary (I’ll check with Lynn to be sure).<\/p>\n

Looking up from the bottom at the front of the engine.
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I mounted the sniffle valve on the firewall and attached the other end of the braided steel line to it. I’m thinking about putting a 90 degree fitting on this end so the hose has better routing (I’ll put another clamp on the line later once I’ve changed the fitting).
\n\"\"<\/a><\/p>\n

And finally, I ran a short length of 1\/4 aluminum line from the sniffle valve out the bottom of the fuselage.
\n\"\"<\/a>\"\"<\/a><\/p>\n<\/address>\n","protected":false},"excerpt":{"rendered":"

This entry is part 19 of 50 in the series 12 - Engine \/ Propeller<\/a><\/div><\/div><\/div>

This one is a good example of the… challenges of building an airplane. I started working this particular task almost a year ago. Technically, the Velocity is a “kit”. Which means that I should get a bunch of parts and … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[44],"tags":[],"series":[36],"class_list":["post-1012","post","type-post","status-publish","format-standard","hentry","category-44","series-12-engine-propeller"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts\/1012","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/comments?post=1012"}],"version-history":[{"count":2,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts\/1012\/revisions"}],"predecessor-version":[{"id":1026,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/posts\/1012\/revisions\/1026"}],"wp:attachment":[{"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/media?parent=1012"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/categories?post=1012"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/tags?post=1012"},{"taxonomy":"series","embeddable":true,"href":"https:\/\/www.velocity-xl.com\/blog\/wp-json\/wp\/v2\/series?post=1012"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}