No engine gnd. that I was aware of on my 83 Shovel.

 

I thought that since the engine was attached to the frame it was grounded. One other question, is it ok that I grounded the starter relay to the frame and not the starter?

 

That I do`t know.
Sounds ok. But......

 

The motor is probably well grounded to the frame through the mounts but it never hurts to have an extra ground strap to make sure.

 

You can meter it to find out, just check for continuity from the frame to the engine. The battery should be grounded to the frame so grounding anything to the frame is the electrical equivalent as long as the connections are solid, not painted or corroded. And watch for the cheap meters, many people use the diode check setting and listen for the beep but you really want to see the actual ohmage, even as much as 5 Ohms can indicated corrosion but you can probably get by with more since it is an older bike.

 

One other thing about frame grounds.
As stated by Ematicic. No paint. Really helps if you run a tap to clean off the threads too.

 

I put a ground to my transmission on my stroker shovel along with frame. Seemed to help.