What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Dynon D-120 questions

J

jimbower

Well Known Member
I just got a Dynon D-120 EMS for my RV-6A project. I also bought the sensor kit for my Aero Sport Power Lycoming O-320, which doesn't include a tach transducer. I am wondering what other people have used to get a tachometer input for their Dynons.

Also, the Dynon installation manual refers me to an engine manual for various things (like the best location for the EGT probes). Can anybody recommend a manual that would tell me all this?

Thanks!

Jim Bower
St. Louis
RV-6A - just starting on the panel
 
You can use just abut anything

What ignition you going to use?...Almost every ignition outouts a signal that the Dynon can interpret...Mine reads directly from the Pmag....But I know a standard mag puts out a signal that can be read by the Dynon as well.

Frank
 
If you have standard mags, the D120 will read them through the P leads. Hook the D120 to the P leads through pins 32 and 33 on the 37-pin connector. Be sure to use the buffering resistors provided in the install package.

--Marc
 
I'm using one mag and one Lightspeed electronic ignition module. I know that I could connect the P-leads to the Dynon, but since I will only have one lead, I don't think that will work by itself.

I can look at the documentation that came with the Lightspeed (or contact them). The thing is, I've had the engine and ignition system for about 5 years and the Dynons are new units. I'm pretty sure Lightspeed assumed I'd be using a normal tach.
 
I'm not familiar enough with Lightspeed to know if there's a tach output. The D120 will work with just one mag input, but the tach will go dead when you do the mag check during runup.
 
Another solution is to put a tach generator from Van's on the tach fitting and use its output. This way you get the actual rpm regardless of what is firing the engine.

Deene Ogden
 
jimbower said:
I'm using one mag and one Lightspeed electronic ignition module. I know that I could connect the P-leads to the Dynon, but since I will only have one lead, I don't think that will work by itself.

I can look at the documentation that came with the Lightspeed (or contact them). The thing is, I've had the engine and ignition system for about 5 years and the Dynons are new units. I'm pretty sure Lightspeed assumed I'd be using a normal tach.
Click to expand...
Jim,

Check the manual, there are two settings in the EMS depending on what is feeding you the tach signal.

As for the location of the other things like EGT's, CHT's, etc. they were called out in the EMS manual, if I remember correctly. If not, call Dynon, they will send you the correct info.

The other option is to return your probes and buy them from Dynon, that way there will be no compatability questions. That is what and why I bought everything from Dynon.

You also might wish to post this question on the Dynon forum.
 
N941WR said:
As for the location of the other things like EGT's, CHT's, etc. they were called out in the EMS manual, if I remember correctly. If not, call Dynon, they will send you the correct info.

The other option is to return your probes and buy them from Dynon, that way there will be no compatability questions. That is what and why I bought everything from Dynon.
Click to expand...


Bill,

Thanks. I did buy everything from Dynon, so I'm in good shape there. As for the locations, the Dynon manual gives an approximate location for the EGT probes but says to refer to the engine manual. Likewise, the CHT probe locations are given (and are obvious by looking at the engine), but again, they refer the installer to the engine manual for specific torque values, etc. This is as it should be. I am a technical writer, and always refer my reader to specific OEM manuals when there is third party hardware being installed. I'm pretty sure Dynon didn't want to accidentally give information that conflicts with the engine manufacturer's specs.
 
Jim,

Sorry about that, I thought you bought the probes from some place else.

The EGT's go below each cyl the same distance, the exact distance isn't all that important. If they aren't the same distance you will get a different reading from each probe.

Other things to watch out for is to make sure they don't block the spark plugs and/or stick out and contact the cowling.

Mine are angled back. Also, with my O-290 being smaller than the other engines, I have a LOT of room on the sides.

This picture show you how I installed one of mine. Search the forum, this topic has come up in the past and there should be one long thread on the subject.
 
Last edited:
I'm using the tach transducer from Van's. I haven't started the engine yet (hopefully next week!) but I can confirm it works by removing the transducer from the engine and spinning it and watching the RPMs on the EMS spin up. As has already been mentioned, the other advantage of using the tach transducer is you don't have to worry about your ignition system. If you want to swap mags out for p-mags, etc, it's one less thing to worry about.
 
Thanks for all the good help, guys. When I started my RV project 7 long years ago, I knew I wouldn't have made it without lots of people who have solved all my problems before I had them!

Jim
 
You must log in or register to reply here.
Back
Top