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  #1  
Old 12-09-2007, 10:56 AM
RV7AAAAAAA RV7AAAAAAA is offline
 
Join Date: Nov 2005
Location: Farmington NM
Posts: 57
Default Motor mount measurement please!

Hi If there is anyone out there with an RV7 or 7A motor mount that has not been installed yet. Could you please do me a big favor and measure the distance between mounting hole centers on the bottom of the mount and let me know what you got?
Here is my possible problem...
After using the motor mount to match drill 3 ea 3/8" holes to the 5/16" holes in the firewall I noticed the 4th hole is off center. So I stopped and have not drilled the 4th hole yet. The other 3 holes seem to align perfectly, but the 4th (bottom right corner) may not drill out the exsisting 5/16" hole. It is going to be close - there is a little flex in the top mounts, but none what so ever in the bottom. I could be as little as 1/16" off. My bottom hole distance is 1/4" greater than the top. I took my measurements by inserting 3/8" drill bits in the mounts and measuring center bit to center bit.
Thanks Jim
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  #2  
Old 12-09-2007, 03:00 PM
LifeofReiley's Avatar
LifeofReiley LifeofReiley is offline
 
Join Date: Jan 2005
Location: Round Rock, TX
Posts: 3,778
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Jim,

Get someone to help and drill the bottom outer holes to fit stepping up and ream fit to 3/8" first. You may need to move the mount over a little. The two bottom center holes need to be drilled last. On the top holes you can pull the mount in place to final drill (ream). Put long bolts in the top for whatever hole size you're at now while you fit the bottom holes.

The Bottom of the motor mount cannot be pulled at all!
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Retired N622DR - Serial #V7A1467
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Last edited by LifeofReiley : 12-09-2007 at 03:13 PM.
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  #3  
Old 12-10-2007, 08:22 AM
RV7AAAAAAA RV7AAAAAAA is offline
 
Join Date: Nov 2005
Location: Farmington NM
Posts: 57
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Quote:
Originally Posted by LifeofReiley View Post
Jim,

Get someone to help and drill the bottom outer holes to fit stepping up and ream fit to 3/8" first. You may need to move the mount over a little. The two bottom center holes need to be drilled last. On the top holes you can pull the mount in place to final drill (ream). Put long bolts in the top for whatever hole size you're at now while you fit the bottom holes.

The Bottom of the motor mount cannot be pulled at all!
Thanks Darrell But I've already drilled 3 of the holes and they aligned perfectly. I was curious to what other motor mounts measure cause I suspect mine was dropped or something. I'll be calling Van's later.
Jim
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  #4  
Old 12-10-2007, 01:40 PM
rvtach rvtach is offline
 
Join Date: May 2007
Location: Tucson, AZ
Posts: 99
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I get 13 & 7/8" from the outer holes to the center (same both sides) and 9 & 3/4" between the center holes.

O------13 & 7/8-------O------9 & 3/4-------O-------13 & 7/8-------O


Hope this helps.
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-7A Finishing Kit
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  #5  
Old 12-11-2007, 11:43 AM
RV7AAAAAAA RV7AAAAAAA is offline
 
Join Date: Nov 2005
Location: Farmington NM
Posts: 57
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Quote:
Originally Posted by rvtach View Post
I get 13 & 7/8" from the outer holes to the center (same both sides) and 9 & 3/4" between the center holes.

O------13 & 7/8-------O------9 & 3/4-------O-------13 & 7/8-------O


Hope this helps.
Thanks Jim for doing that for me!!! When I add up you numbers it comes to exactly 37.5" My mount is 37.344" or 37-11/32".
Your mount bottom dimensions would have worked much better (almost perfect) than mine! I think 37.5" would have put me close to dead center. But anyway I finally got the nerve to drill that last hole after talking to Joe @ Van's. He seemed to think that even if that hole was not perfectly round it would still be AOK. So I had a friend pul the mount over while I drilled and wha la 'round hole". Done deal! The 3/8" bit left no sign of the smaller predrilled hole in the firewall. But it was close.!!! I hate to think of what would have been involved in the repair if this had been an unacceptable hole.
But for sure I would have had to get a new mount that measured like yours since the new weldments would have had the holes in the same place as mine
Jim
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