Putting CrankFire on twinplug 2.7.
Is it neccessary to fire both plugs?
How many degrees off the first plug do you fire the second plug?

 

I think it really depends on the compression ratio. There are those who believe if your CR is greater than 9.8:1 you need to go twin plug. It also depends on whether you run race fuel or pump gas. I run 108 octane, single plug, 10.3:1 CR with no problems. If you are running high CR and pump gas you definately need twinplug ignition otherwise detonation could occur. High octane race fuel burns at a slower rate than,let's say 92 octane, so therefore you can use more advance and a few degrees of stagger between firing of the 2 plugs per cylinder. With lower octane fuel you must run less advance and fire the plugs simultaneously.

Good luck !

 

[quote]Originally posted by 74RS911:
<strong>Putting CrankFire on twinplug 2.7.
Is it neccessary to fire both plugs?
How many degrees off the first plug do you fire the second plug?</strong><hr></blockquote>

Hi:

1) Absolutely! That is after all, the whole point,.....

2) Both plugs need to fire at the same time in these combustion chambers. Compression ratio has nothing at all to do with timing values. Time the upper and lower plugs to the same values and if you are using Electromotive, this is very easy to confirm by looking at differential voltages with a DVOM.

Each .1 VDC represents one degree of timing and you can watch the delta by connecting the "+" terminals on each HPV-1 to your DVOM.