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Re: SureFly Electronic Ignition

Posted: Mon Jul 20, 2020 3:31 pm
by Davestation
Diamond_Dan wrote: Mon Jul 20, 2020 3:15 pm Does anyone know the proper way to tap into the manifold pressure for timing advance? Nobody was sure, but Will from SureFly said it would either be a 1/8" NPT to 1/8" hose barb into the primer port or TEE into an existing line. Can someone who has had this done comment?

Each cylinder has that 1/8 plug except #4 is already being used for the MAP gauge in the cockpit and I tee off of that for the left mag but if you’re doing the right then just tap into #3

Re: SureFly Electronic Ignition

Posted: Mon Jul 20, 2020 3:46 pm
by Steve
Davestation wrote: Mon Jul 20, 2020 3:31 pm
Diamond_Dan wrote: Mon Jul 20, 2020 3:15 pm Does anyone know the proper way to tap into the manifold pressure for timing advance? Nobody was sure, but Will from SureFly said it would either be a 1/8" NPT to 1/8" hose barb into the primer port or TEE into an existing line. Can someone who has had this done comment?

Each cylinder has that 1/8 plug except #4 is already being used for the MAP gauge in the cockpit and I tee off of that for the left mag but if you’re doing the right then just tap into #3
The fitting for MP on Cyl #4 is not a simple 1/8" NPT to hose barb. It has an orifice (I forget the size) to moderate fluctuations in MP. It is quite an expensive fitting (> $100). If you use a standard NPT fitting (<$10) for the the SureFly MP vs a T off Cyl #4, are there any issues with MP pulses? Rich?

Re: SureFly Electronic Ignition

Posted: Mon Jul 20, 2020 3:54 pm
by Rich
Steve wrote: Mon Jul 20, 2020 3:46 pm
Davestation wrote: Mon Jul 20, 2020 3:31 pm
Diamond_Dan wrote: Mon Jul 20, 2020 3:15 pm Does anyone know the proper way to tap into the manifold pressure for timing advance? Nobody was sure, but Will from SureFly said it would either be a 1/8" NPT to 1/8" hose barb into the primer port or TEE into an existing line. Can someone who has had this done comment?

Each cylinder has that 1/8 plug except #4 is already being used for the MAP gauge in the cockpit and I tee off of that for the left mag but if you’re doing the right then just tap into #3
The fitting for MP on Cyl #4 is not a simple 1/8" NPT to hose barb. It has an orifice (I forget the size) to moderate fluctuations in MP. It is quite an expensive fitting (> $100). If you use a standard NPT fitting (<$10) for the the SureFly MP vs a T off Cyl #4, are there any issues with MP pulses? Rich?
We cut into the line and used a 1/4" to 1/8" brass barb tee. If you're lucky you could find one at Ace or somewhere else local. I wound up ordering mine off the internet.

Re: SureFly Electronic Ignition

Posted: Mon Jul 20, 2020 4:01 pm
by Davestation
Steve wrote: Mon Jul 20, 2020 3:46 pm
Davestation wrote: Mon Jul 20, 2020 3:31 pm
Diamond_Dan wrote: Mon Jul 20, 2020 3:15 pm Does anyone know the proper way to tap into the manifold pressure for timing advance? Nobody was sure, but Will from SureFly said it would either be a 1/8" NPT to 1/8" hose barb into the primer port or TEE into an existing line. Can someone who has had this done comment?

Each cylinder has that 1/8 plug except #4 is already being used for the MAP gauge in the cockpit and I tee off of that for the left mag but if you’re doing the right then just tap into #3
The fitting for MP on Cyl #4 is not a simple 1/8" NPT to hose barb. It has an orifice (I forget the size) to moderate fluctuations in MP. It is quite an expensive fitting (> $100). If you use a standard NPT fitting (<$10) for the the SureFly MP vs a T off Cyl #4, are there any issues with MP pulses? Rich?

Of course not. It’s a1/8npt to -4 IIRC that obviously connects to the MAP sensor via standard AN hose. I used an AN tee and an AN to 1/8 hose adapter for the surefly input

Re: SureFly Electronic Ignition

Posted: Mon Jul 20, 2020 4:07 pm
by Diamond_Dan
Steve wrote: Mon Jul 20, 2020 3:46 pm
Davestation wrote: Mon Jul 20, 2020 3:31 pm
Diamond_Dan wrote: Mon Jul 20, 2020 3:15 pm Does anyone know the proper way to tap into the manifold pressure for timing advance? Nobody was sure, but Will from SureFly said it would either be a 1/8" NPT to 1/8" hose barb into the primer port or TEE into an existing line. Can someone who has had this done comment?

Each cylinder has that 1/8 plug except #4 is already being used for the MAP gauge in the cockpit and I tee off of that for the left mag but if you’re doing the right then just tap into #3
The fitting for MP on Cyl #4 is not a simple 1/8" NPT to hose barb. It has an orifice (I forget the size) to moderate fluctuations in MP. It is quite an expensive fitting (> $100). If you use a standard NPT fitting (<$10) for the the SureFly MP vs a T off Cyl #4, are there any issues with MP pulses? Rich?
I called Bill at SureFly and he confirmed that it is OK to tap directly off the primer port. An orifice is not necessary to damp the pressure variations.

Re: SureFly Electronic Ignition

Posted: Mon Jul 20, 2020 4:23 pm
by Rich
When it comes to that manifold pressure line, shorter is better. I posted some weeks back about making sure there isn't anywhere along its length where it could be pinched, as mine was. It's pretty thin-walled.

Re: SureFly Electronic Ignition

Posted: Tue Jul 21, 2020 2:18 pm
by Rick
I see Aircraft Spruce has 15% off on the SureFly modules this week, with promo code EAASF15:

https://www.aircraftspruce.com/menus/st ... refly.html

This drops the price from $1395 to $1186, in case anyone is getting ready to buy one!

I see where SureFly is talking about some future firmware upgrades to the SIM. Does anyone know if your existing SIM firmware can be upgraded in the field, or do you get what you buy and that's it?

Re: SureFly Electronic Ignition

Posted: Tue Jul 21, 2020 2:23 pm
by Rich
Rick wrote: Tue Jul 21, 2020 2:18 pm I see where SureFly is talking about some future firmware upgrades to the SIM. Does anyone know if your existing SIM firmware can be upgraded in the field, or do you get when you buy and that's it?
Well, it doesn't look trivial to do in the field. There's no evidence of an external data port.

Re: SureFly Electronic Ignition

Posted: Fri Jul 24, 2020 3:31 pm
by Rich
I did some poking around to see what I could find about about a possible firmware upgrade. Based on the always 100% reliable information found on the internet, it appears there is some possibility that there might be a change. But I'm pretty confident it means pulling the unit and sending back to the factory. I'm guessing they use something like an EPROM for the firmware rather than non-volatile memory. Some miscellaneous interesting unverified comments I ran across, plus my impression:

- The Lycoming-branded units might have different advance maps for different engine families. This does make sense to me. Has anyone looked into Lycoming units? The giveaway would likely be different part numbers for different engine groups.
- Currently there is a built-in 100 ms delay in the SIM unit becoming functional. I can see that it is necessary to take a bit to boot up the unit as it needs to react to the current environment (like which direction the unit is rotating). Apparently SF is looking to get approval for a 1 ms delay. A 100 ms delay in an inflight reboot situation at 2400 RPM means 4 revolutions (2 combustion cycles per cylinder) running on the non-SIM during this reboot.
- One statement said that when switch between mags - such as in runup when you're on the right mag and need to switch to left just to get back to both - the transition between the 2 momentarily un-grounds both before grounding the right mag. In control-system parlance, it's break-before-make operation. I have to say it doesn't feel like that to me during runup. The delay in SIM activation could be the culprit, though it seems like more than 100 ms and I feel like the speed with which the key is turned influences that delay when neither ignition unit is firing, with more-rapid movement shortening that delay. But my subjective impression could easily be wrong, especially since there isn't that hiccup switching in the other direction.
- One Mooney owner has a lengthy review currently posted on the Aircraft Spruce page for the SIM4N unit. He had a similar weak-spring situation in his installation that I initially had, though his was even worse.

Re: SureFly Electronic Ignition

Posted: Thu Aug 13, 2020 9:46 pm
by Rich
Some things I discovered in the process of putting new spark plugs in the plane:

1. Surefly needs spark plug gaps to be within spec. More precisely that the gaps not be too small. I was independently informed of this by Surefly and Tempest. It's apparently common to run with the gaps up at .030" with SF. This is way more than I'd want to adjust plugs designed for .017-.021, as are Tempest/Unison - too much bending of that side electrode.

2. Running for an extended period on the non-SIM mag might not be the smartest idea. We'll recheck the timing of the Slick (right) mag, though we did so when installing the SF a few months back. But in the process of diagnosing the problems I was having with the new plugs I had occasion to switch to the right mag for a somewhat extended period in flight to confirm the problem wasn't on that side. When doing so I noticed that all 4 EGTs rapidly soared right on up to 1600 deg :shock: even though the engine continued to run smoothly. I've since confirmed that even during a regular ground runup I get a considerable rise in EGTs if I kept running on the right mag for awhile. It seemed to top out to about a 200 deg rise and it takes considerably longer than the customary duration when doing a runup. Investigation will continue, but this has ramifications for the notion of the traditional mag being a suitable backup for loss of power to the Surefly.