Prop Governor and FW adjustment

Hi Guys,

I've searched the threads and still don't have an answer I quite understand regarding the need to change an existing FW when converting to a c/s prop. The salvage RV4 I have has a symmetrical firewall step cutouts.. 7", 7 1/2", 7"

The RV4 thread "Firewall recess for governor?" thread has a nice picture of the firewall with non symmetrical steps.

I have a Lycoming E2A 0-320 with dynafocal mount that will be ready to mount as soon as the governor is selected and in house. The crank is set up for C/S.

I understand the the Hartzell PG is large and requires FW work. Is there a prop governor out there(PCU 5000, MT) that will fit without making changes or do I absolutely have to adjust the existing firewall no matter what prop governor I get?

Both the PCU and the MT would fit easily in my 4. I tried both during the build.

Gov. fit

This is a picture of the jihostroj gov. on my 4.
It is a pretty tight fit. I would not want to try an put in a bigger gov.



Good luck!