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engine sag

K

kcpgm

Active Member
I'm in the process of painting my RV-7 after 100 hours of flying, I noticed that the engine saged a little standard vans mounts, I also noticed that the oversized ALT pully has rubed on the lower cowl Wound it be adviseable to add a washer between the lower mounts to shim it up?


RV-7 in maine hoping to be able to spray soon been raining for two weeks
 
Adding Washers

I added an extra washer at each lower mount, between the compression pad and engine. The 1/8" thick washer brought the nose up about 3/8" or so. The large washers used were similar to what comes with the mount kit.
 
Sag?

Check your engine mount torgue!
My hangar mate bought a -6 with 150 hours, it had a bad sag. maybe 3/4 inch. We had to repair/adjust several things including the cowl at the alt pully.
the last thing we checked/replaced were the engine mounts.
they weren't torgued tight at all. So the last thing we checked WAS the main problem. While we were installing the mounts, we added one big washer to the front of the bottom and it "completely" fixed the sag problem.
Before we fixed it, we got several opinions from knowledgable people and it seems ok to add washers to the back of the lower motor mount/firewall junction as long as it is large washer to spread the load some.
But one washer on the mount does wonders and in our case, getting the engine mounts installed and correctly torgued was the biggest correction.
Good Luck,
Just our experience, and my .02
 
Engine mounts Brands

On a related subject that I do have first hand knowledge of is the engine mount "isolators". First I want to say all engines will sag after a short period of operation. However I feel the best you can get is Lord Corp.. The proper part number for the Dynafocal is: J-9613-40 x (4). They are about twice cost of the ones Van sells but think they are worth it. I can't say they will sag less but think you will have less vibration and start/stop movement, which is a cause of a lot of wear on engine parts. If you ever take a Lord vibration isolator in hand and side by side compare, they are a world apart.

I love Van's, but... he does tend to pinch pennies. I am down with that usually where it makes sense. The ones he sells are fine ($55 each), but..... yes they are cheaper. They are made by Vibration Isolation Products. The other brand is Berry Controls, which is middle of the road and cost about $75.00 retail (van use to sell these). The Lord Corp. isolator are about $90 apiece (you need a total of 4 to mount engine), and I think they are worth every penny. They helped my vibration issues on my old RV-4.

If you use the plan bushing for the conical mount, do yourself a favor and get the Lord isolator for conical mounts. Now that is a MUST! They are way better than plan bushings. They do cost more than bushings. Part number J-1552. They cost about $35 each, but in this case you need 2 per corner or a total of 8. I believe that is what Van sells for the conical (in pairs) for $75.

Here's info one engine mount condition and sag.
http://www.lord.com/Default.aspx?tabid=1535

Cheers George
 
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I love Van's, but... he does tend to pinch pennies. I am down with that usually where it makes sense. The ones he sells are fine ($55 each), but..... yes they are cheaper. They are made by Vibration Isolation Products. The other brand is Berry Controls, which is middle of the road and cost about $75.00 retail (van use to sell these). The Lord Corp. isolator are about $90 apiece (you need a total of 4 to mount engine), and I think they are worth every penny. They helped my vibration issues on my old RV-4.


Give this guy a call on Barry Mounts. I just bought 4 at $35.00 per mount.

Cumberland Aero Service 1-800-524-6319

Dana Overall
Richmond, KY i39
RV-7, "Black Magic"
 
gmcjetpilot said:
On a related subject that I do have first hand knowledge of is the engine mount "isolators". First I want to say all engines will sag after a short period of operation. However I feel the best you can get is Lord Corp.. The proper part number for the Dynafocal is: J-9613-40 x (4). They are about twice cost of the ones Van sells but think they are worth it. I can't say they will sag less but think you will have less vibration and start/stop movement, which is a cause of a lot of wear on engine parts. If you ever take a Lord vibration isolator in hand and side by side compare, they are a world apart.

I love Van's, but... he does tend to pinch pennies. I am down with that usually where it makes sense. The ones he sells are fine ($55 each), but..... yes they are cheaper. They are made by Vibration Isolation Products. The other brand is Berry Controls, which is middle of the road and cost about $75.00 retail (van use to sell these). The Lord Corp. isolator are about $90 apiece (you need a total of 4 to mount engine), and I think they are worth every penny. They helped my vibration issues on my old RV-4.

If you use the plan bushing for the conical mount, do yourself a favor and get the Lord isolator for conical mounts. Now that is a MUST! They are way better than plan bushings. They do cost more than bushings. Part number J-1552. They cost about $35 each, but in this case you need 2 per corner or a total of 8. I believe that is what Van sells for the conical (in pairs) for $75.

Here's info one engine mount condition and sag.
http://www.lord.com/Default.aspx?tabid=1535

Cheers George
Click to expand...

George,
I asked which mounts were best over on the General Discussions forum but didn't get a single reply. What is the correct Lord mount number for an RV with Dynafocal 1 mounts? Any suggestions on where I could save a few dollars buying Lord mounts for my 8A project?
Charlie Kuss
 
BlackRV7 said:
snipped The other brand is Berry Controls, which is middle of the road and cost about $75.00 retail (van use to sell these). The Lord Corp. isolator are about $90 apiece (you need a total of 4 to mount engine), and I think they are worth every penny. They helped my vibration issues on my old RV-4.

Give this guy a call on Barry Mounts. I just bought 4 at $35.00 per mount.

Cumberland Aero Service 1-800-524-6319

Dana Overall
Click to expand...

Dana
Thanks for the tip. Do you know of anyone who discounts the Lord mounts? Why did you buy the Barry mounts if the Lords are better? Simply on price?
Charlie Kuss
 
Lord Corp isolator engine mount part numbers

chaskuss said:
George,
I asked which mounts were best over on the General Discussions forum but didn't get a single reply. What is the correct Lord mount number for an RV with Dynafocal 1 mounts? Any suggestions on where I could save a few dollars buying Lord mounts for my 8A project?
Charlie Kuss
Click to expand...
The Lord part number for

Dynafocal: J-9613-40 x quantity (4) (note 1) (All 4-Cyl RV's except possibly as noted below)

Conical: J-1552 x quantity (8) (note 2) (All RV's with conical mount)


note 1: I believe the Dynafocal O-235 steel engine mount van sells for the RV-9(A) use the smaller 1-3/8" hole (mount rings). The Part # is than J-9402-24 x (4), call Van or measure your mount to determine if you have a 2" hole or 1-3/8" engine mount. I believe ALL of Van's engine mounts are 2" and therefore the proper part # is J-9613-40 .

The J-9613-40 is for a Mooney M20J 1976 with a Lyc IO-360-A3B6D. This mount is good for all Dynafocal 1 Lycs (O320, O360). The only possible exception is the O-235 if Van's mount uses a small er hole as noted. It's more the steel mount than engine that determines the Dynafocal 1 isolator.​


note 2: (Applies to conical only) First note that the J-1552 is sold as singles, i.e., you need two per corner or a total of 8. The J-1552 is symetric, the hole is right in the center of the isolator, so it does not matter how to mount it.

There is an alternative part number J-6230-1. This is the same as the J-1552, but it has a off-set eccentric hole. The idea is the engine mount is clocked tangential to the torque of the engine. When the prop goes clockwise (viewed from cockpit) the engine moves anti-torque, counter clockwise. I assume this gives more clearance between the spacer and engine mount lug. I don't know, nor was Lord 100% sure why this eccentricity was done, but it does gives more clearance between the isolator spacer and engine lug. All this conical designs are over 50 years old.

Remember on a conical mount the isolator sandwiches integral lugs or rings on the engine, not like the aircraft's steel engine mount like a dynafocal, which sandwiches the steel engine mount; this gives an advantage of more room for a larger isolator. Obviously the dyna-FOCAL mount angles or focuses the four corner at one point approx near the CG of the engine/prop; where in a conical mount, all corners are aimed parallel.

Either J-1552 or J-6230-1 will work but I would suggest the J-1552 since it requires no special clocking. The J-1552 symetric hole should work for all applications, and therefore it's not critical how you "clock them" on the mount, nor do you need to assure they don't rotate in the mount. The J-6230-1 will work, but be aware they are sold in pairs, you only need to buy (4) pairs. A little confusion. If you have questions write me or call Lord Corp.​
 
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