[Tbone]

Has anyone sourced prices on the dynofocal 1 engine vibration mounts? I am getting ready to install the engine and was curious on quality and prices.

 

[gmcjetpilot]

Don't go cheap, Lord mounts

Has anyone sourced prices on the dynofocal 1 engine vibration mounts? I am getting ready to install the engine and was curious on quality and prices.

Van sells some low cost ones (VPI), but if you want the best get the Lord Corp J-9613-40's. They have better shutdown/startup movement control and in my opinion better quality overall. They do cost more, but if you Google you can find the normal suppliers: Spruce Aircraft, Sacramento Sky Ranch, Chief, WagAero. There are no discounts and prices vary from $100-$112. Just shop around. The best I found with a quick check was Sky Geek: $99.50

http://www.skygeek.com/engine-mount-mooney.html

Van does not sell *"Lord" dynafocal mounts; he sells a lowest bid third brand, VIP, not even Barry Controls.

Regardless if you get the "equivalent" to Lords J-9613-40 in another brand, like Berry it will not be the same. Lord is the only one with a silicon filled damper around the spacer, which dampens large scale motion (see pic below). However in flight the silicone damper "de-couples" from normal vibration. Not a put down of Berry Controls, but they tried to copy this low motion design by just increasing the stiffness of the rubber. Thus people complain of vibration in flight with Berry mounts. Lord has the patent on this.

The down side Lord's go for about $100, Berry about $77 and what ever Van's cost, like $60 each. So you might pay about $160 more total? No big deal or savings if your fillings are rattling. Also less vibration during start and shut down means less cracked air boxes, baffles, oil coolers and fretting hoses & wires.


None of the other mounts have that silicon spacer/damper.

Typical spacer with out a damping spacer sleeve.

* Van does sell conical mounts for $99 each. I do believe these are "Lord" J-1552's, which are also awesome, for the conical engine. If you have a conical mounted engine, never use plan bushings, it's horrible set-up. Bushings may only cost $7.50 for each corner but you will not like it. It's a big bullet to spend $400 verses $30 in this case but its worth it. I had a RV-4 with conical mounts and it was NIGHT and DAY with the Lord mounts v bushings.

 

[coastalflyer]

How do you know which Lord part#? There are so many! Is the J-9613-40 the right one for all 320/360 Dynafocals?
Thanks for the info.

 

[Radomir]

That's the part # I used for my 360, and it worked out just fine. I got 'em from SkyGeek...

 

[dpansier]

Lord Engine Mounts

I took George?s engine mount recommendation and purchased the Lord J-9613-40 from Sky Geek and they fit perfectly on my Barrett 390.
Don

 

[Caveman]

Proper bolts for the Lord mounts

Anyone know if Van's engine bolt set works with the Lord mounts as well as the mounts Van's sells? I hope so 'cause that's what I've got... Van's bolts and Lord mounts.

 

[Radomir]

Yes.. it works great.

 

[Tbone]

Thanks for the reply. Found the Lords for $96.28 @ Aircraft supply. Ordered them and the bolts from Vans.

 

[gasman]

TIME TO CHANGE THE MOUNTS

Can the mounts be changed one at a time?

If so, in what order... 6A O320 new lord mounts...............Thanks

 

[randylervold]

Retrofitting?

I'm interested in retrofitting a set of Lord mounts to my IO-320 RV-3B. Short background: I built an RV-8 which I finished in 2001 and used whatever mounts Van's was selling at the time, I believe they were Barry. When fitting the cowl I allowed for 3/16" engine sag which never happened, at least not as of 400 hrs. When I built my -3 I also bought the mounts Van's was selling, probably in 2005, which were now VPI. This time I really didn't allow for any sag but of course it sagged about 3/16" after about 30 hrs. Sheesh.

Anyway, I'm thinking about retrofitting Lords. Do they sag, and is there a noticable difference?

 

[gmcjetpilot]

Don't worry

I'm interested in retrofitting a set of Lord mounts to my IO-320 RV-3B. Short background: I built an RV-8 which I finished in 2001 and used whatever mounts Van's was selling at the time, I believe they were Barry. When fitting the cowl I allowed for 3/16" engine sag which never happened, at least not as of 400 hrs. When I built my -3 I also bought the mounts Van's was selling, probably in 2005, which were now VPI. This time I really didn't allow for any sag but of course it sagged about 3/16" after about 30 hrs. Sheesh.

Anyway, I'm thinking about retrofitting Lords. Do they sag, and is there a noticeable difference?

Randy, like any elastomer product there is some compression or set. If you want to talk to someone who knows, Lord has a 800 number** with very helpful tech/engineering help. My comment is don't worry. You can always slide in a thin (.016") shim / light AN washer to make adjustment to match the previous isolation mounts. (ps, no I don't get commission on lord mount sales.) Setting up new, I'm tempted to try to put in a shim or two between the top mounts, to be removed later, as needed if sag is too great. I doubt the Lord's will sag as much as the cheaper units, but still call them. It's free and they are knowable. I suspect they might not have an exact sag or "settling in" value, but they might. The set I had where still like new after 600 hours. It was not on a RV, so I didn't monitor the sag.

Here's a partial wear guide off their web site: Wear & Care Guide - Lord isolation mounts - GA fixed-wing aircraft

**
In the US and Canada 1 877 ASK LORD (275 5673)
Outside the US +1 814 456 8511, ext. 2511

 

[az_gila]

washer -- spacers

Randy, like any elastomer product there is some compression or set. If you want to talk to someone who knows, Lord has a 800 number** with very helpful tech/engineering help. My comment is don't worry. You can always slide in a thin (.016") shim / light AN washer to make adjustment to match the previous isolation mounts. (ps, no I don't get commission on lord mount sales.) Setting up new, I'm tempted to try to put in a shim or two between the top mounts, to be removed later, as needed if sag is too great. I doubt the Lord's will sag as much as the cheaper units, but still call them. It's free and they are knowable. I suspect they might not have an exact sag or "settling in" value, but they might. The set I had where still like new after 600 hours. It was not on a RV, so I didn't monitor the sag.

Here's a partial wear guide off their web site: Wear & Care Guide - Lord isolation mounts - GA fixed-wing aircraft

**
In the US and Canada 1 877 ASK LORD (275 5673)
Outside the US +1 814 456 8511, ext. 2511

I did this last year on my Grumman... there are Grumman part number washers (and C and P ones I would guess), as well as a Lord part number. They are not AN970 washers, they have a slightly larger diameter that is equal to the metal portion of the engine mount pad. My Grumman certified parts manual lists the shim count as "As Required", but does mention that the next long bolt may be needed.

George's 0.016 is a bit light......you can do some elementary geometry, but the "shim factor" works out to around 3x - so to remove a 3/16 offset at the spinner, around a 1/16 thick washer would be needed.

gil A

 

[gmcjetpilot]

To SHIM or not to SHIM, that's the question

I did this last year on my Grumman... there are Grumman part number washers (and C and P ones I would guess), as well as a Lord part number. They are not AN970 washers, they have a slightly larger diameter that is equal to the metal portion of the engine mount pad. My Grumman certified parts manual lists the shim count as "As Required", but does mention that the next long bolt may be needed.

George's 0.016 is a bit light......you can do some elementary geometry, but the "shim factor" works out to around 3x - so to remove a 3/16 offset at the spinner, around a 1/16 thick washer would be needed.

gil A

Gil you always keep me honest. I am not 100% on what you are saying. I think you are teaching me something, but I am too dense to understand.

I think I understand. I did not know that there where special washers with the dynafocal "system". (I know the conical washers are special non-AN.)

I thought Van supplied AN hardware (nut, bolt, washers) with his bolt kit. Are you saying Van supplies custom washers, like your Grumman? If so I didn't know that. It makes sense the two lower washers FIT the engine pad tightly. It's good to know the Grumman manual calls for shims or allows shims.

Still this does not affect what I was trying to say, which may still be wrong.

The SHIM's I'm talking about, are additional AN960 washers/spacers between the lower engine mount and the dynafocal isolator. The dia small washers, sandwiched in between engine and dynafocal mount are not structural. I think AN970's (fender washers) would be overkill, and you are stuck with 0.063 min thickness. No fine tuning.

Gil, so I was thinking of just jamming in some AN960's as needed. My point with the 0.016/0.032 thick washers allow better fine tuning. Thickness is not a structural issue. The washer/shim is not structural. What am I missing Gil. Do you think that is an issue? Heck, how important can it be. It's just one of four bolts holding your engine on the plane.

How does Grumman recommend you shim and with what kind of washer? (custom ones?) If they don't cost much that might be the way to go. A Lyc and dynafocal mount should be the same or close, Grumman or RV. Thanks for the input.


PS
Some might worry about shims on the engine mount bolts. As with any shim, bolt bending increases, but the margin of safety on the engine bolts is already large. The bolt's critical load is shear and tension, not bending. There are limits on total shim thickness, but we're talking about shimming the lower mounts to raise the spinner. The lower mount bolts are not in tension as much as the top bolts, therefore shims are less critical.

Other wise a custom made spacer/shim/washer machined for the job would be a deluxe solution, instead of stacking washers, regardless of diameter. We don't need to use certified washers do we. What does a special Grumman washer cost?

 

[az_gila]

Washers and spacers

Gil you always keep me honest. I am not 100% on what you are saying. I think you are teaching me something, but I am too dense to understand.

I think I understand. I did not know that there where special washers with the dynafocal "system". (I know the conical washers are special non-AN.)

I thought Van supplied AN hardware (nut, bolt, washers) with his bolt kit. Are you saying Van supplies custom washers, like your Grumman? If so I didn't know that. It makes sense the two lower washers FIT the engine pad tightly. It's good to know the Grumman manual calls for shims or allows shims.

Still this does not affect what I was trying to say, which may still be wrong.

The SHIM's I'm talking about, are additional AN960 washers/spacers between the lower engine mount and the dynafocal isolator. The dia small washers, sandwiched in between engine and dynafocal mount are not structural. I think AN970's (fender washers) would be overkill, and you are stuck with 0.063 min thickness. No fine tuning.

Gil, so I was thinking of just jamming in some AN960's as needed. My point with the 0.016/0.032 thick washers allow better fine tuning. Thickness is not a structural issue. The washer/shim is not structural. What am I missing Gil. Do you think that is an issue? Heck, how important can it be. It's just one of four bolts holding your engine on the plane.

How does Grumman recommend you shim and with what kind of washer? (custom ones?) If they don't cost much that might be the way to go. A Lyc and dynafocal mount should be the same or close, Grumman or RV. Thanks for the input.


....

George...

1. Entire discussion is for the common Dynafocal mounts.

I am talking about washers inserted between the engine mounting pad and the Lord mount.

As you say, one is compulsory at the lower mounts, and is usually supplied with the Lord mounts, not not as part of Vans Dynfocal mounting kit.

The Grumman manual allows extra large area washers to be inserted as shims at any of the four mounting locations. Due to the mounting geometry the addition of a 1/16 washer will shift the spinner about 3/16 away from the corner that is shimmed.

There is a lot of vibration and movement present here (that's why the mounts are rubber......) and Lycoming and Lord have determined that the metal part of the mount (over 2.5 inches diam.) is in contact with the large area of relatively soft aluminum of the engine case. If you insert AN 960 washers as spacers here, you will not have this large contact area.

Special washers exist from multiple vendors for this location. I just checked my Barry mounts from Vans, and the washer they supply is about 2.0 inches diameter. An AN970-7 washer is 1.8 inches diameter, and is 1.109 thick. This would shift the spinner about 5/16 inch is used as a spacer. The Barry part number is 98-9074-11. I believe the Lycoming ones come in thick and thin versions, but don't have any part numbers.

The washers are available from the usual sources at a few bucks each.

The Barry drawings also show these thick, large area washers under the head of the mounting bolts. In this location, they may actually be structural, and become parts of the mechanism to stop the outer metal portion of the mount "cupping" under load.

You should use large area washers as spacers and at locations called out by the mount vendor....

Hope this is clearer....

gil A

The Grumman engine is an O-360-A4K, except for a rear mounted carb., is essentially the same as our O-360 RV engines.

 

[Mel]

Use the large washers

I agree with Gil. To use a 960 washer would be concentrating some pretty large loads into a very small area.

 

[gmcjetpilot]

Isn't that special

I just checked my Barry mounts from Vans, and the washer they supply is about 2.0 inches diameter. An AN970-7 washer is 1.8 inches diameter, and is 1.109 thick.

Got it. Not sure 0.20" (2.0"-1.8") difference dia is a big deal but I'll get some special washers. (typo 1.109 thick?) // Agree AN960's would be smaller bearing area. // I get the 3 to 1 spinner rise to shim ratio, matches the approx 30" long/10" high geom. Thanks for the info. G

 

[ptrotter]

I spoke to Lord technical support awhile ago and discussed the washers. He stated that the washers are not really needed and the only reason for them was in case the built in aluminum face melted and the large washer would not pass through the engine mount hole, therefore keeping the engine on the mount (more or less). He thought this was very unlikely, but it was something that someone thought was a good idea at some time and they keep doing it. He said the aluminum face would bear the load of the bolt head just fine without the washer. The mounts comes with one of the large washers but since you need to use one under the lower mounts to fill the slight recess in the engine, Van's supplies an AN washer to use under the bolt head. Of course the AN washer will fit through the hole in the engine mount, so that theory is out the door anyway. The large washers are hard to find and Lord does not seem to sell them seperately. He suggested checking with local A&Ps to see if the have any old ones left over from when mounts were changed. If I were to need to lift my engine sightly, I would take the large washer from the top mount and use it on the bottom and put an AN washer under the bolt on the top. Those washers are pretty thick, but I don't know if a single one would get you a 3/16" lift. Of course you will need to put in longer bolts as well.

 

[az_gila]

0.109 thick

Got it. Not sure 0.20" (2.0"-1.8") difference dia is a big deal but I'll get some special washers. (typo 1.109 thick?) // Agree AN960's would be smaller bearing area. // I get the 3 to 1 spinner rise to shim ratio, matches the approx 30" long/10" high geom. Thanks for the info. G

Yep... a typo... sorry. It's 0.109 thick for the AN970.

I think the Lord one was a bit thicker... just over 1/8... I'd measure it, but I gave 2 away to a deserving RV-9A....

I got them from the Grumman dealer... seemed to be no problem for him to have them in stock.

gil A

 

[gmcjetpilot]

I spoke to Lord technical support awhile ago and discussed the washers. He stated that the washers are not really needed and the only reason for them was in case the built in aluminum face melted and the large washer would not pass through the engine mount hole, therefore keeping the engine on the mount (more or less). He thought this was very unlikely, but it was something that someone thought was a good idea at some time and they keep doing it. He said the aluminum face would bear the load of the bolt head just fine without the washer. The mounts comes with one of the large washers but since you need to use one under the lower mounts to fill the slight recess in the engine, Van's supplies an AN washer to use under the bolt head. Of course the AN washer will fit through the hole in the engine mount, so that theory is out the door anyway. The large washers are hard to find and Lord does not seem to sell them separately. He suggested checking with local A&Ps to see if the have any old ones left over from when mounts were changed. If I were to need to lift my engine sightly, I would take the large washer from the top mount and use it on the bottom and put an AN washer under the bolt on the top. Those washers are pretty thick, but I don't know if a single one would get you a 3/16" lift. Of course you will need to put in longer bolts as well.

Fascinating, I LOVE IT! More cool trivia detail, but it makes sense. Thanks, guys the good info.