Type of engine vibration mount?

[ao.frog]

Hi fellow RV-flyers and builders!

I'm getting ready to install the engine and wonder about what type of engine mount to install, either the standard dynafocal or the aerobatic dynafocal.

I'm planning to use the plane for 50/50 aerobatic and X Country.

What do you RV-ators out there think?
I realise that this will most probably be a personal taste question, but for example:

Those of you with the standard mount and flying aerobatic: is it ok?

And those of you with the aerobatic mount: is it alot of vibration in the airframe?

Lastly; if anyone flown has both types, which do you prefer?

Best regards Alf Olav Frog / Norway

[Mel]

Unless you are going to do serious acro, go with the standard mounts. The aerobatic mounts are VERY stiff and transmit a lot of vibration to the airframe. The arerobatic mounts are designed for "competition" style aerobatics witch the RV isn't really suited for.

[gmcjetpilot]

Originally Posted by ao.frog

Hi fellow RV-flyers and builders!

I'm getting ready to install the engine and wonder about what type of engine mount to install, either the standard dynafocal or the aerobatic dynafocal.

I'm planning to use the plane for 50/50 aerobatic and X Country.

What do you RV-ators out there think?
I realise that this will most probably be a personal taste question, but for example:

Those of you with the standard mount and flying aerobatic: is it ok?

And those of you with the aerobatic mount: is it a lot of vibration in the airframe?

Lastly; if anyone flown has both types, which do you prefer?

Best regards Alf Olav Frog / Norway

I agree with Mel, you don't need acro mounts.

I do have a strong opinion on BRAND. Van's aircraft sells a bargain priced brand of mounts. There are three manufactures, Lord, Berry controls and the third brand which I don't recall name, but is what Van sells.

The ones Van sells work and will do, however you get what you pay for. The best brand is Lord Inc., and the part number you need is:

J-9613-40, they come in pairs and you need to buy (4). They cost from $90 to $100 usd each pair. Van's mounts are cheaper at about $55 but you will be happier with the LORD brand. The LORD design is quite a bit different, even if you just held it in your hand. Further I have used different brands and types and this is the best you can get. It is well worth paying the extra money. This is not the place to be cheap.

You will get much better service from Lord mounts. They also incorporate a low deflection feature that comes into play during start and stop. This will play dividends in maintenance since the engine will not shake the accessories and baffles like a wet dog. You will have less chance of cracks and other vibration related damage. To be clear they are NOT aerobatic mounts, but have a special silicone spacer that reduces large motion engine movement during start and stop. LORD basically has been in business before WWII and makes top end vibration isolators for commercial, military and space. The quality is top notch.

Vibration isolators are more than a piece of "vulcanized rubber" with metal washers and a spacer. The quality and specification of the rubber and the design it self is key to minimizing vibration.

[Radomir]

I went with Lord mounts. $91.50 a piece at www.skygeek.com (part # that George listed above). Just as a side note, I called Lord support about difference between -40 and -49 and they said it's essentially same thing and to get whichever one is cheaper of the two We'll see how it works out.

[osxuser]

We've got the cheapy's on our Cardinal right now, observations:

Yes more vibes are transmitted to the airframe, but the engine seems to move around less as well, which is a good thing. Barry's suck all around (short life), and the Lords are awesome but pricey. Also looking at the mounts that a C421 use, they are Lord, but with a higher heat rating. I was impressed when I saw 8 year old mounts in a 421C with absolutely no sag. Combine those with the gel inserts on the C172 Lords, and I think we'd have a mount that'd last 20 years on an RV.