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-   -   Kitplanes May 2017 - The "Effects of Ignition Advance (https://vansairforce.net/community/showthread.php?t=148100)

Chkaharyer99 03-28-2017 09:58 AM

Kitplanes May 2017 - The "Effects of Ignition Advance
 
on Cylinder Head Temperature, Speed, and Efficiency"

The May 2017 article in Kitplanes written by Nigel Speedy is outstanding.

Nigel does an fantastic job of explaining the effects of varying EI timing over a range of conditions. I found the context of the article to be clear, concise and objective. The illustrations are easy to understand, even for me, a novice in this arena.

It would be really interesting to see this same test conducted using other EI systems on this specific aircraft by this writer. Apples to apples.

Once again, the folks at Kitplanes raised the bar. This is experimental aviation at its best.

Thank you Nigel. Great job!

PilotjohnS 03-28-2017 12:18 PM

Darn
 
Well now i just have to subscribe to the mag. Too many good articles i am missing out on. Going broke just reading about building.....

unitink72 03-28-2017 12:42 PM

agree
 
Quote:

Originally Posted by Chkaharyer99 (Post 1161367)
on Cylinder Head Temperature, Speed, and Efficiency"
Nigel does an fantastic job of explaining the effects of varying EI timing over a range of conditions.

Totally agree. I didn't have an understanding of how timing worked in relation to altitude and mixture, this article fixed that! Bravo Nigel

N941WR 03-28-2017 03:00 PM

Quote:

Originally Posted by Chkaharyer99 (Post 1161367)
on Cylinder Head Temperature, Speed, and Efficiency"

....
It would be really interesting to see this same test conducted using other EI systems on this specific aircraft by this writer. Apples to apples.

Once again, the folks at Kitplanes raised the bar. This is experimental aviation at its best.

Thank you Nigel. Great job!

I agree, it was a very well written article.

Different EI's should give the same results. If not, then they are not firing at the same time.

What differs between the different EI's is where they fire the plugs based on MAP and RPM and even this is should be manageable.

Don't take Nigal's results as absolute numbers. Remember, he has high compression pistons. However, focus on the impact each timing change had on CHT, EGT, fuel flow, etc.

Chkaharyer99 03-28-2017 07:23 PM

Thanks Bill. Maybe I should go back a re-read the article, but how did Nigel manage to manipulate/change the timing in flight? or did he?

I thought the Pmag and EI Commander were set it before flight then don't touch it.

N941WR 03-28-2017 07:43 PM

Quote:

Originally Posted by Chkaharyer99 (Post 1161495)
Thanks Bill. Maybe I should go back a re-read the article, but how did Nigel manage to manipulate/change the timing in flight? or did he?

I thought the Pmag and EI Commander were set it before flight then don't touch it.

With the EICommander, you can change the timing in flight, if you want. However, it is best to play with your timing while sitting on the ground.

There are two ways to change the timing in flight with the EIC, one is to send the ignitions a predefined configuration and the other is to bump the timing one 1.4 degree step at a time. It is up to you as to how you do it.

Nigel experienced an occasional issue with one or possibly both of his P-mags getting messed up when he sent them a new configuration. However, all he had to do was send them a different (standard?) configuration in flight and all was well. We are not sure why he had an issue, but feel free to call me to discuss it.

Ironflight 03-28-2017 09:01 PM

Nigel has promised more articles like this one on different flight tests he's performing on his RV-8. Personally, while I like the specific tests he's doing, the real value is in learning how an experienced test pilot goes about planning test missions and then executing them - and then evaluating the data. We are very pleased to be able to bring this kind of experience to our readers.

Rupester 03-29-2017 08:24 AM

More kudos for Kitplanes and Nigel for a very informative article. Great stuff. :)

ppilotmike 03-29-2017 08:28 AM

Yup.
 
I liked it as well. Especially the way he broke it down for the "non-gearheads" like me.

John Tierney 03-29-2017 08:39 AM

And what a great last name for a test pilot.


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