SureFly feedback before I pull the trigger

[Walt]

I'd be interested in one of those Surefly's, I asked Jason at Osh last year if I could get a SF with a max advance of 28 for my HC 370 but the answer was basically nope.

[pecanflyboy]

Originally Posted by Scott Hersha

Dan,
I just talked to Bruce about his engine. He said that he spoke with a Lycoming engine rep at Sun N Fun and was told that the max advance on the 390 with variable timing is 28*.
Incidentally, he has installed the SDS dual ignition system in it’s place, not the EFII system as I said earlier.

Attachment 20973

SPK. ADV. 20VAR - bottom row on data plate.

FALSE! The Lycoming EIS is fixed at base timing, configured by Lycoming...PERIOD. It is NOT advanced. If your Lycoming unit (Black) is advancing and not fixed, it has been tampered with. Therefore, there is no difference in unit behavior between a Lycoming EIS and a Surefly SIM in fixed timing.

Install the unit per the installation instructions it will work fine. Before you go off the reservation based on opinions on this thread, call Surefly. If it is a Lycoming EIS, call Lycoming.

Jimmy

[DanH]

Originally Posted by pecanflyboy

FALSE! The Lycoming EIS is fixed at base timing, configured by Lycoming...PERIOD. It is NOT advanced. If your Lycoming unit (Black) is advancing and not fixed, it has been tampered with. Therefore, there is no difference in unit behavior between a Lycoming EIS and a Surefly SIM in fixed timing.

Jimmy, perhaps you might download Lycoming SI-1443R.

This issue is not that a variable timing EIS is available for the 390-D, but rather, how much is advance it allows. Way back when announced, the Lycoming folks refused to disclose the advance values...which is why Scott's posts are interesting. Several of us here, flying ignitions with the capability to switch inflight, determined the 28 ballpark to be the sweet spot for the 390 running LOP.

I'll attempt to confirm independently of course. And yes, the data plate says the subject engine was an -EXP, not D, not that it matters at the practical level.
.

[Scott Hersha]

Walt,
I’ll ask Bruce to contact you. He was going to sell me the impulse SF for $1400. This includes the drive gear and the ignition harness, which sell for $400+ each at Spruce. They have 1 hour of run time on them by Lycoming before shipping the engine. If you want both he has the other non-impulse one too. Be advised, you won’t have a warranty

[sailvi767]

A bit unrelated to where the thread is going but I had issues with the Surefly install. Surefly went above and beyond to assist me!