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Does it matter if the bolts that attach the engine mount to the fuselage go from inside the fuselage out or from the engine mount through the firewall into the plane?
I have the Viking 130 mount on a 650. I attached the mount temporarily today to help move from the basement to the garage, The Viking mount needs about a 2 1/2 inch bolt.
With the 10 degree angle on the front of the fuselage mount brackets I don't see how I'd be able to get a long bolt to go from inside out. The AN6-7A in the Zenith plans work ok that way but they aren't nearly long enough.
What do you think?
Thanks - Jim
Not sure I understand the issue. I don't recall anything preventing a long bolt going from inside. I will look tomorrow to refresh my memory.
I did mine with the bolts protruding forward from the inside, through the firewall. In other words, with the threads forward of the firewall. If it were the other way around, the nuts would be very difficult to tighten and inspect.
I recall it being a tight fit (on an XL, with a 13 degree rake), but doable.
My 601 came with the bolts attached to the motor mount with the treads facing forward. - no issue there and it passed the DAR inspection.
Come to think of it, I believe mine did too. But now that I am thinking about it, I think those were superceded or perhaps it occurred when I went with 650 canopy, but in any case I got new ones and used bolts but I still do not recall there being an issue with them having heads on inside and threads forward of firewall.
Thanks guys. Viking is sending me some with my updated ECU and flywheel drive plate. I'll try to get them to face out like normal. Patrick - good point about inspection too.
According to the FAA acceptable methods ,techniques and practices it is preferred to torque the nut if possible but torquing the bolt is not prohibited. Page 7-298 for those interested.
Did you use bolts from Viking? If not, what did you use? Are they facing out (threads on the engine side of the firewall)?
Thanks - Jim
No, My bolt heads are FF. I know I'm a disappointment to the Davis name but I could not get the bolts to go thru like you guys did short of beating the hell out of it or elongating the hole .I researched it and put em in back asswards, I can't remember if Viking supplied them or not but I don't think so.
I think I'll be doing the same as you - Davis's Unite :-)
Do you mind sharing what the immovable object was that was in the way? Some times just a slight change in assembly order can make all the difference in the world.
Sure, it's the engine mount brackets themselves. The front edge is canted back about 10 degrees I think. There just isn't room to get a long bolt through from the inside. I'll take a pick later today.
I must have slightly elongated the hole but don't remember for sure. I do for sure remember that first ones that came with kit, bolt was welded in place. For only 10 degrees, the elongation required would not be very much.