I have read the threads about vibration for gas engines. It seems most recommend rigid mount of the stand offs to the fire wall because the logic is the radio can be protected with padding.

The DLE 30 manual says it needs to be mounted to a shock absorber during a 2 hour (are 2 hours needed?) break in period to keep the vibration from damaging the engine....


Are soft mounts required for break in? Same question when mounted in the plane. If so, what is the best method.

If it matters to the answer the plane will be a 4* 120.

Thanks!

Bolt it solid to the firewall, as tightly as possible...
Shock mounting a gasser to keep from damaging it is just Looney tunes advice...

I think that the manufacturer is concerned that if you bolt the engine to a very solid test mount, then all the vibration would be centered on the mounting ears and possibly break them. Most people I know don't run the engine on the ground very long at all and this shouldn't be an issue. I can't think of any need to run any gas engine on a test mount for 2 hours. My personal test mount is wood and will absorb some vibration similar to the way an airframe will absorb vibration when flying.

The DLE advise stems from the early DL days, when mounting ears were not all that strong. Because a plane is more flexible than a test stand, DL advised using soft mounting on the test stand. In reality the construction just was too weak, and was changed.
Soft mounting a gasser can lead to more problems than it solves. Think of broken ignition wires, loose ignition caps, stuck carb buttterflies, malfunctioning carb regulating diaphragm.
In chainsaws that is solved by the construction, and carbs are often mounted on a rubber sleeve.

Thanks.

So how long do you recommend for break in on the ground?

Also, manual recommends different oils for break in and flying. What do you recommend
?

Run it long enough to make sure it runs OK. Maybe you can get the needles set and get famiiar with the engine.

ANY good two stroke oil will work, there is nothing different in our toy airplane engines from any other two stroke..
Contrary to the beliefs of some of our EXPERTS
Some work better than others over a VERY LONG period of time....
Amsoil in not one of them over a long period...
One of the very best is Sthil Ultra HP chain saw oil....Documented by T O M, (very tired old man), and getting grumpier all the time...

Talk about getting Grumpy.My engine test stand is the old Road Runner airplane that is 31 years old.I run the engine for maybe 10 mint's to adjust the carb then put it in the air.
Did not get to fly the Syssa today was too cold and windy,no snow though.
BC Grumpy no two.

+14F was the high here today