<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
         <<  Lancair Builders' Mail List  >>
         <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>

I don't recall where I read it (I checked several references but couldn't locate it) but the reason for steel fittings on oil lines is to prevent cracking of the fittings under vibration.  This would presumably apply to all fittings attached to the vibrating engine, whether the line contains fuel or oil.

Also, use only flexible lines between the moving engine and the non-moving firewall, and this means oil cooler lines, fuel lines, etc.  If both ends of the line are on the engine, or both ends are on the firewall, then a hard line is okay.

Finally, use a restrictor fitting in your oil pressure sense line, since a broken line would otherwise result in pumping all the oil out.

Tony Bingeles' book "Firewall Forward" says to use steel fittings with steel, well, he means both halves (male and female) of the fitting should be of the same material.  I notice we didn't do this with our hydraulic systems, as the kits come with steel fittings for the flex lines and aluminum bulkhead and elbow fittings.  I'm not worried about that.

If someone could find a reference for all this I'd appreciate it.  I looked in the Sacramento Sky Ranch Engineering Manual, Firewall Forward (Bingelis), the Sportplane Builder (Bingelis), AC 43.13, the Standard Aircraft Handbook, and the Aircraft Spruce catalog and couldn't find it.

- Rob Wolf

LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.