Zenith Aircraft Builders and Flyers
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Engine Mount Bolts?
5th gen Cruzer with a UL 350iS.
Tried to install the Engine Mount today. The supplied AN6-7As on the bottom look fine. The upper AN6-7As have barely 2 threads sticking through... if you look at it from the right angle. The top mount AN4 bolts are only about 80% of the way through. All of the nuts at the proper torque.
Anybody have this experience? Obviously the top mount needs longer bolts and the upper bolts need something a little longer as well. What bolts did you ultimately end up using?
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IMG_6551.JPG, 1.6 MB
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Replies to This Discussion
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Permalink Reply by William Carter
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Not sure why my pictures rotated 90 degrees in the first post.
This morning I made some measurements to figure out what bolts I need. Since the assembly instructions for this part of the newer kits does not include any dimensions I used calipers and tried to make the best measurements I could. I made a couple of each part (while installed) and then took averages. Added them up, converted them to fractions and found the nearest 1/16".
The lower Engine Mount Fitting:
Engine Mount Fitting = 0.0905"
Firewall Bottom Stiffener = 0.0420"
Firewall = 0.0250"
Firewall Side Stiffener = 0.0445"
Engine Mount = 0.1290"
Total = 0.3310" or 21/64" which is approximately 5/16" which would call for an AN6-7A.
The upper Engine Mount Fitting:
Engine Mount Fitting = 0.0905"
Firewall Rear Reinforcement = 0.0405"
Firewall = 0.0250"
Firewall Side Stiffener = 0.0445"
Firewall Top Stiffener = 0.0800"
Engine Mount = 0.1290"
Total = 0.4095" or 13/32" which is approximately 7/16" which would call for an AN6-10A.
The Cabin Frame Bolts:
Cabin Frame = 0.1280"
Firewall = 0.0250"
Upper Firewall Channel = 0.0400"
Firewall Top Stiffener = 0.0800"
Engine Mount = 0.1290"
Total = 0.3220" or 41/128" which is approximately 5/16" which would call for an AN4-6A.
If anyone sees any mistake or has any further advice please let me know.
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