Thanks guys! In my previous experience with this unit I ran the REM37BYs with good success but want to use automotive plugs this time. Autolite 386’s got it! There is a hand written note in the box that says NGK BR8EIX but have not idea where that came from or the reliability of it. Maybe the cross-reference plug for the 386’s.
The Autolite 386 is a 18 MM hot plug for a lycoming. It also has a tapered seat unlike an aircraft spark plug. Be careful not to damage the seat in the cylinder head. And, please don't use to much timing. The NGK BR8ES 14 MM series of plugs with adapters will perform well. Set the plug gap at .025 . Also, make sure the vacuum line is secure and unable to detach form the unit. It will go to full advance and detonate if it comes loose.
I would think it would fail to ambient air pressure, which is more than MP, and would give you less advance than if the vacuum line was attached.
Thanks Full Throttle, that is good additional information. No worries about timing running away…I have the panel mount timing display -as I did on my RV-3- and wouldn’t install EI w/o one. That is interesting about MAP line…my unit does have the MAP sensor and I plan on using it. The manual talks about adding a switch to disable the feature if it fails - which may speak to your comment and concern. I’ll test that feature when I do the installation and may very well install a switch. According to the Vacuum Advance Curve Chart in the manual…maximum advance of 18 degrees would be achieved at 17 inches of manifold pressure. This, in addition to the RPM advance which tops out at 30 degrees at 3,000 rpm.
How many pages is the manual? I have that system in an aircraft I bought. But no manual.
I have a switch to disable vacuum advance in my Rocket, and I use the EFIS to display the timing. I also experimented with changing the advance curve by intercepting the MAP sensor output and inserting my own timing advance curve using a microprocessor. This allowed me to optimize performance.
