Surefly electronic ignition question

[Bob_Belville]

15 minutes ago, DXB said:

I’m reviving this thread - lots of good info here.  Any Surefly install / post install PIREPs from folks with carb’d O-360s with the shower of sparks systems?   
 

My Bendix mags are past due for their 500hr service at annual next month, and I am very close to deciding to replace the left one with Surefly.  

I am curious to hear about install details, potential snags, and observed benefits for starting, power, leaning.

I understand that I’ll need a new Slick harness for the left side?  

I'm not an A&P but I have a SureFly in my E and I'd say your C, assuming the battery is practically right below the left mag, should be a very easy install.  

[DXB]

On 8/27/2019 at 5:12 PM, PT20J said:

The SureFly (missing) advance curve has been bugging me, so I spoke with Jason Hutchison at SureFly. He confirmed that they removed it from the website. He said it was an oversimplification and technically incorrect. He also said that they decided for reasons he declined to elaborate on not to publish the corrected curve(s). He was pretty forthright and I didn't get the sense they are trying to hide anything. I suspect that they are tired of "experts" opining on the details of their design. OK, I get that -- I probably wouldn't get too far trying to get Subaru to send me advance curves for my Outback.

Here is what I did learn: The primary design goal of the advance is to adjust timing so that the peak pressure point (PPP) is about 13 degrees ATDC which they found to be close to the Maximum Brake Torque (MBT) angle for most engines in cruise operation. Operating at MBT gives the greatest efficiency. The use of MAP and rpm is analogous to the old auto distributors that had centrifugal and vacuum advances. At 24" MAP and above, the SureFly will be at base timing. Below 21" it will be fully advanced.

Skip

I thought it would be interesting to post the old advance curve (stolen off Beechtalk) just as an interesting reference, acknowledging it's not quite accurate.  It does give a visual feel for the rpm/MP combinations where it can offer some extra timing advance.  

[jamesm]

DXB .... what engine is this for ?

[Andy95W]

O-360 A1D

[MoonFlyer68]

Old topic but time to revisit it. I had a shop install a Surefly to replace the left mag on my 1968 M20F. I realized that they installed it in the "fixed" timing mode. I contacted the shop again and the shop manager spoke to the mechanic that actually did the work. He set up as fixed timing because he didn't see an easy way to tap into the manifold pressure just took the easy route. The shop manager has apologized and I will be bringing the plane back to them later in the month to get it fixed.

Is anyone able to share the way they tapped into the MP and even better would be actual part numbers if you have them.

Thanks

[Ragsf15e]

18 minutes ago, MoonFlyer68 said:

Old topic but time to revisit it. I had a shop install a Surefly to replace the left mag on my 1968 M20F. I realized that they installed it in the "fixed" timing mode. I contacted the shop again and the shop manager spoke to the mechanic that actually did the work. He set up as fixed timing because he didn't see an easy way to tap into the manifold pressure just took the easy route. The shop manager has apologized and I will be bringing the plane back to them later in the month to get it fixed.

Is anyone able to share the way they tapped into the MP and even better would be actual part numbers if you have them.

Thanks

Mine is sort of “non standard” so it won’t help you.  We removed the standby vacuum at the same time which used mp to run, so we used that connection.  The real way is pretty simple to put an elbow off one of the cylinders mp port and connect the supplied hose.  I’m sorry I don’t have the part numbers, but it’s the same elbow used to feed your mp gage.

[MoonFlyer68]

2 hours ago, Ragsf15e said:

Mine is sort of “non standard” so it won’t help you.  We removed the standby vacuum at the same time which used mp to run, so we used that connection.  The real way is pretty simple to put an elbow off one of the cylinders mp port and connect the supplied hose.  I’m sorry I don’t have the part numbers, but it’s the same elbow used to feed your mp gage.

Actually, that may be a somewhat easy answer. Last year I finally ditched my vacuum system, including standby vacuum. I guess I need to check all that old plumbing (once I find it) to see if that would be an easy place to tap into.

[takair]

10 hours ago, MoonFlyer68 said:

Old topic but time to revisit it. I had a shop install a Surefly to replace the left mag on my 1968 M20F. I realized that they installed it in the "fixed" timing mode. I contacted the shop again and the shop manager spoke to the mechanic that actually did the work. He set up as fixed timing because he didn't see an easy way to tap into the manifold pressure just took the easy route. The shop manager has apologized and I will be bringing the plane back to them later in the month to get it fixed.

Is anyone able to share the way they tapped into the MP and even better would be actual part numbers if you have them.

Thanks

There is a thread here somewhere with pictures and part numbers. I know I posted my simple, but not so elegant approach and some others had some pretty spiffy suggestions. Likely need to do a search for Surefly and manifold pressure. 

[MoonFlyer68]

1 hour ago, takair said:

There is a thread here somewhere with pictures and part numbers. I know I posted my simple, but not so elegant approach and some others had some pretty spiffy suggestions. Likely need to do a search for Surefly and manifold pressure. 

In the wee hours of the night I was able to find a couple other threads showing how people set this up.

[PT20J]

Every cylinder on an IO-360 has a port for manifold pressure. Just unscrew the pipe plug from the #4 cylinder and attach the plumbing there.

[Ragsf15e]

10 hours ago, MoonFlyer68 said:

Actually, that may be a somewhat easy answer. Last year I finally ditched my vacuum system, including standby vacuum. I guess I need to check all that old plumbing (once I find it) to see if that would be an easy place to tap into.

My stby vac was pulling mp off one of the intakes.  The intake had a hole drilled in it and a pipe welded? Coming out.  It happened to be the same size as the sf mp tube.  My mechanic was already sketchy on taking out the intake pipe and having it welded, so he just reused the “port”.  Seems fine.  The port off the cylinder is the correct method though.

[FlyingDude]

T'ed into the MAP gauge line.