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  #51  
Old 12-06-2018, 07:29 PM
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Toobuilder Toobuilder is offline
 
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Quote:
Originally Posted by DanH View Post
You're suggesting the ability to program timing retard at WOT as compared to the typical aircraft magneto's fixed compromise timing?

One of many conflations of spark generation with spark timing

con·fla·tion
/kənˈflāSH(ə)n
noun
the merging of two or more sets of information, texts, ideas, etc. into one.
Indeed. I was following (what I perceived as) Ross' lead off the stale "Hotter spark = higher HP" path and onto the real benefit of a "good" EI. "Good" in this context is one that can be configured to optimize the timing event for each engine.

So in my mind, no conflation here. It was a conscious abandonment of the original question.
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  #52  
Old 12-06-2018, 08:19 PM
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rv6ejguy rv6ejguy is offline
 
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I want to add that a truly weak spark may not light off the mixture-especially if that mixture is very lean or very rich, however, on a standard 8 to 1 Lycoming, at 2700 rpm, WOT at SL, a standard mag, in proper operating condition, has no problem doing that job.

Yes, I've had to suggest to some of our automotive drag racing clients running SDS ignitions, to shrink plug gap to be able to run very high boost pressures. In one case I recall, the spark wouldn't jump a .035 plug gap running something like 150 inches of manifold pressure. We shrunk the gap to .025 and all was well again. This engine was producing 391hp/ L on the dyno which would be the same as a 360 Lyc making 2345hp.

Inductive discharge ignitions certainly have their finite limits but you won't be anywhere close to them with a naturally aspirated Lycoming engine, even with 12 to 1 pistons using a mag or most EIs having a coil with suitable inductance, turns ratio on the windings and being properly saturated (correct charge time).
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  #53  
Old 12-06-2018, 08:52 PM
jump4way jump4way is offline
 
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Quote:
Originally Posted by rv6ejguy View Post
This engine was producing 391hp/ L on the dyno which would be the same as a 360 Lyc making 2345hp.
Where do I find this Lycoming?
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  #54  
Old 12-06-2018, 08:55 PM
Kyle Boatright Kyle Boatright is offline
 
Join Date: Aug 2005
Location: Atlanta, GA
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Quote:
Originally Posted by jump4way View Post
Where do I find this Lycoming?
If HP is your primary interest, here's the Lycoming for you:

https://en.wikipedia.org/wiki/Lycoming_XR-7755
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