motorglider engine test

On Friday, November 24, 2017 at 10:44:35 AM UTC-8, wrote:
I need to do a short test run on my ventus 2cxm engine. The fuselage is on its cobra dolley in my garage, and I can wheel it into my driveway and tie the tail to a post. I'm nervous about this, in case there is some pitfall I haven't considered. Has anyone done an engine test run like this?

It is possible to do short engine runs in your configuration ( no wings) , but never with the prop installed. Remove the prop and this will work just fine. Coolant will be running through the engine but no air through the radiator so only short runs.

If you absolutely need the prop attached, install your wings!!! Newtons Laws of action and reaction will apply and roll your fuselage.

BG

On Saturday, November 25, 2017 at 9:06:48 AM UTC-8, BG wrote:
On Friday, November 24, 2017 at 10:44:35 AM UTC-8, wrote:
I need to do a short test run on my ventus 2cxm engine. The fuselage is on its cobra dolley in my garage, and I can wheel it into my driveway and tie the tail to a post. I'm nervous about this, in case there is some pitfall I haven't considered. Has anyone done an engine test run like this?

It is possible to do short engine runs in your configuration ( no wings) , but never with the prop installed. Remove the prop and this will work just fine. Coolant will be running through the engine but no air through the radiator so only short runs.

If you absolutely need the prop attached, install your wings!!! Newtons Laws of action and reaction will apply and roll your fuselage.

BG

I would NEVER run the engine w/o the prop - it has no load and will over-rev. Using saw horses and tying down the tail will work safely. I don't bother with the saw horses if I am only going to run it at a fast idle, which I did yesterday. The dolly and glider are on the back of the trailer. I run the engine (ASH26E) once a month to lubricate it. The test stand Rex has requires removing the engine from the glider - rigging the glider would be easier. Don't run it in your garage, however!

Tom

On Saturday, December 2, 2017 at 11:08:41 PM UTC-6, 2G wrote:
On Saturday, November 25, 2017 at 9:06:48 AM UTC-8, BG wrote:
On Friday, November 24, 2017 at 10:44:35 AM UTC-8, wrote:
I need to do a short test run on my ventus 2cxm engine. The fuselage is on its cobra dolley in my garage, and I can wheel it into my driveway and tie the tail to a post. I'm nervous about this, in case there is some pitfall I haven't considered. Has anyone done an engine test run like this?

It is possible to do short engine runs in your configuration ( no wings) , but never with the prop installed. Remove the prop and this will work just fine. Coolant will be running through the engine but no air through the radiator so only short runs.

If you absolutely need the prop attached, install your wings!!! Newtons Laws of action and reaction will apply and roll your fuselage.

BG

I would NEVER run the engine w/o the prop - it has no load and will over-rev. Using saw horses and tying down the tail will work safely. I don't bother with the saw horses if I am only going to run it at a fast idle, which I did yesterday. The dolly and glider are on the back of the trailer. I run the engine (ASH26E) once a month to lubricate it. The test stand Rex has requires removing the engine from the glider - rigging the glider would be easier. Don't run it in your garage, however!

Tom

I'm looking at making a test stand, perhaps with a small dyno, to test a Hirth F10A engine for an ASK-14. I don't want to fine-tune the linkages on the 4 carbs inches away from a spinning prop. But I plan to do something more substantial than this:
https://www.youtube.com/watch?v=L8mwZBY4O1g
which is downright scary.

On Sunday, December 3, 2017 at 7:23:09 PM UTC-8, wrote:


I'm looking at making a test stand, perhaps with a small dyno, to test a Hirth F10A engine for an ASK-14. I don't want to fine-tune the linkages on the 4 carbs inches away from a spinning prop. But I plan to do something more substantial than this:
https://www.youtube.com/watch?v=L8mwZBY4O1g
which is downright scary.

Depending on configuration, might be easier to make a guard to go between you and the prop. Tip proof base with verticals to support wire fence material barrier or similar. You stand on part of the base so your weight adds to base stability. The guard must make it physically impossible to inadvertently fall into or contact the prop.