George, thanks. I will post more later, but there is some pertinent stuff here. I plan to add more actual data from some of the carb'd planes we've worked on here in the future.

Just a couple quick comments though. The lyc. chart doesn't show units for the specific fuel consumption, so actual testing has to be done. The other important thing to remember when being skeptical of such large differences in fuel burns is that roughness can be caused not just by one or more cylinders running too lean. It can also be caused by differences in power outputs between cylinders. So, the ol' "turn it out until a little rough, then just richen enough to make it smooth" might not even be running any of the cylinders LOP.

Your turn ;)

Electronic Ignition
 

Steve - sorry for the thread hijack earlier - I hope you find a place to post the spreadsheet.

Hi Guys,

I'm just crawling out from a crazy 1/2 week at work. George - I should have been more descriptive in my last post, but Walt A. had my back. [In my opinion] EI, with a longer, fatter spark can ignite leaner mixtures. Dual EI gives you better spark on both the top and bottom, making for more even lean mixture burns. To support this, when I am running lean, if I ground an ignition(I don't do this regularly), it runs REALLY rough.

The EI advance allows slower burning mixtures to develop power at the right time in the cycle.(I'll admit I am in a bit over my head here, so please feel free to challenge)

As far as the futzing to run LOP, I use carb heat and the throttle to get more even mixture distributions and "steer" the mixture to balance EGT peaks. The movie I spoke of has been cut and edited - I have not seen it yet, but if it does not make me look too stupid :confused: at the MN Wing meeting Saturday, I'll find a way to post it. It won't be exciting, but it might be educational.

I'll work with Alex to get him my carb data for comparison. I am also planning a follow up to his great mixture article for the next MN Wing newsletter.

Prikka,
I have flown an Ellison TBI for three years now and have been very happy with mine. It is simpler, lighter and more efficient than a carb plus it can also run LOP and works in any orientation (good for aerobatics). It can be tricky to get adjusted properly because (I think) it can be so precisely adjusted its possible to setup for current conditions and when the weather changes be slightly out of adjustment. Follow the tuning instructions and add a little more rich to avoid that possibility.
Hope this helps.

Glenn

As you haven't received a single answer to this, I'll make a suggestion: Upload your spreadsheet to Google Docs: http://docs.google.com

Once you do that, you can "publish" the spreadsheet so anyone can view it by just posting a link. For instance, I kept all my costs associated with my flight training there:

http://spreadsheets.google.com/pub?k...BQ3SP-fWhYSlWw

I use Google Docs for almost all of my personal spreadsheet and "word processing" now as it is great to have access to the data wherever there is an internet connection. Hope that helps!

--Bill

But do you think it was worth the price? 1600 U$ sound a lot from a carburettor. :eek:

One thing that I also noticed that they don't recommend it with mogas at all. Here in Finland mogas is significantly cheaper (now about 20 %, in the beginning of next year more like 33 %) than 100ll. Most of the brands has also ethanol but I think some brands can be stil get as ethanol free.

Maybe they should reconsider which kind of gaskets they use in their TBI.