BMW Engined Aquilla

[Oddball]

Hey there Air Hog,

This last weekend Ystervark and the aircraft owners came to visit me at Tedderfield where I am working on the trike and on the Tundra that I have also been building. We intended to tune the engine over the weekend, but ended up finding a lot of interesting new problems! Nonetheless, we ran the engine quite a bit, but were puzzled by two things; the first being that there was a 40-50 degree difference between exhaust temps. We tried swapping EGT probes, put new ones in; swapped the air filters; and finally swapped the entire thottle bodies. Seems that that may be where the problem is... but we are not quite sure yet because the gearbox started making ominous sounds and we had to stop the testing late on Sunday afternoon.
The gearbox was damaged because we ran it without oil for a while..... then realised that and stripped it, cleaned it, filled it with oil and continued the testing- we wanted to make the best of the time that we had with Ystervark; he has been great and we made good progress.
We spent most of Saturday and Sunday performing the tests, but the other thing that we were puzzled with was that we could not get high EGT readings; only up to around 500 deg or so. We have now realised that the probes were in the wrong place- obvious of course, but not when your head is wrapped around other problems, sigh...
So now the gearbox will be repaired (new bearings); the EGT probes moved and a couple of other bits and pieces taken care of and we can run it again- in the next 2 weeks I think.
Don't know about the Kroon fly-in, but maybe...

[Air Hog]

Please Oddball, we must have this at the Kroon Fly-in. See what you can do.

[berniehb7448]

I would like some information on your BMW installation. I am looking at using a BMW Boxer, size 1100-1200, to power a French Pouchel. This is a Pou de Ciel (Flying Flea) derivative with a ladder style aluminum tube frame (open cockpit), aluminum tube wing spars, foam ribs, fabric wing covers. The picture is just to show what they look like.

I have three questions:

1 – Where can I get information about the source and use of the Eboxi ECUs? I did internet searches and came up zero.

2 – Information about the throttle body system you are using and its components.

3 – What other stuff should I be aware of?

From all I have been reading, using the BMW Boxer control and electrical systems is a nightmare with a lot of pitfalls and potential disaster when flying (like side stand switches controlling the ECU!). Therefore it appeals to me to have a stand-alone systems setup, with components working by themselves, minding their own business, and not interfering with each other, allowing relatively safe flight operations.

I really admire your neat and careful work and your other innovative ideas!

Thank you so much!

Bernie Blanke
Georgetown, TX
USA

[KFA]

Hi Bernie, welcome to the forum. I have sent you a pm with the contact details. Enjoy

[Oddball]

Hi there Bernie,

Welcome to the forum! Thanks for the compliments and sorry that I have taken some time to get back to you. The E-boxi is manufactured in the Cape area in South Africa by Otto, who goes under the alias ystervark7 on this forum.

The E-boxi is a simple but robust ECU that seems to work well with the 1200cc fuel injected BMW engine.
We used the standard throttle bodies as found on the motorbike itself, together with an extra insert that allows a second injector per cylinder (used in standby mode). The insert is simple to have machined and I think that either ystervark7 or Oupa-G would be able to help youout with a dxf file that will allow you to get the insert waterjet cut. One problem that we had was the air filters; the ones that we had were too small and we suspect that they may have been causing problems (we were unable to complete the tests to date as we are still waiting for gearbox parts). As soon as we get to run the engine again we can figure out what filters are suitable.
With respect to the gearbox, we used a German made one but think that a locally developed belt drive version may be better; we'll be trying it out on the next engine.
Make sure that your EGT probes are between 50-75mm from the exhast ports (or rather the point at which the exhaust attaches to the engine). We first put the EGT probes way down the line, around 50cm from the ports and couldn't understand why we could not get higher EGT readings, until the penny dropped after a days frustrating testing...
Otto (Ystervark 7) has also updated the user manual for the E-boxi which makes it much easier to use now.
Feel free to ask any other questions.

Jay

[Leprachaun]

Hi Jay and all others on this forum , Just received my gearbox from the Take-off guys , I am waiting for the engine mount from Solowings .
I am planning to use my 1100 BMW bike for the instalation. Will probably throw the injection off - will use Bing carbs as per Rattex 912
Will keep you guys posted .
I hope the engine frame doesnt take to long . Alex Rudd

[SOUT (RIP)]

good day oupa G
please contact me with regards to this coversion......please
regards
Sout

[Stephan van Tonder]

Make sure that your EGT probes are between 50-75mm from the exhast ports (or rather the point at which the exhaust attaches to the engine). We first put the EGT probes way down the line, around 50cm from the ports and couldn't understand why we could not get higher EGT readings, until the penny dropped after a days frustrating testing...

Wouldn't air/fuel ratio(lambda) be better for this kind of tuning?. Or assist at least so that you know you are not going overly rich or lean?.

[Oddball]

Hi there Stephan,

That does help in the process; on the Subaru engine that I am performing a similar process on we have EGT's and an air/ fuel ratio sensor, but EGT's by themselves can provide you with enough feedback to tune the engine if you know what you are doing. Hopefully I will ge to that point soon!

Jay

[Stephan van Tonder]

My problem with EGT alone is that timing can have a drastic effect on EGT and actually hide what the fuelling is doing. I do a fair amount of tuning on aftermarket EFI systems and the only thing I bet on for correctness of fuelling is a wide band lambda reading.
I use a small one meant for car dash installation that is mounted in a little box. Runs off the battery and is very accurate from ratios of 10:1 to 16:1 takes all the guesswork out of tuning.
This Item here http://www.stackltd.com/instruments.html#Lambda

[Oddball]

I agree, it would be good to have one of those in a portable manner to be able to tune better. Did you order yours directly from those guys or get it here in SA? How much did you pay for it. We paid around R4.5K for the one on the Subaru engine.

Jay

[Stephan van Tonder]

http://www.ats-motorsport.co.za/
these guys are the local agents. I think they are around R3k. I have a friend that got it for me for work I did so not 100 sure what they cost commercially.

[Oupa-G]

Dear Stephan and Oddball, Above 3000 rpm we keep the timing constant. Above 6000rpm we run slightly rich for cooling. We also do not do extreme to the limit advancing , the engine must be able to run on 95 and 93 oct and also run on Avgas when necessary . The new Lambda sensors are better with the lead contents but they still do not like it. As these engines run at constant revs the EGT's give a quick reliable reading. Ystervark7 has given me a mixture control in the cabin and that helps with the fine tuning. The power requirement is influenced by the prop pitch the forward speed of the aircraft and the resultant prop loading and the posibility of adjustable pitch. The tuning is very interesting and demanding , sometimes I wish we could just put the plane on a dyno. I have also found that a Pprop , Arplast Woodcomp etc all have different power absorbing personalities. I do own a wide band lambda sensor but will leave that to the fine fine tuning.Justin I would love to talk to you some time and compare notes




Cheers Oupa-G

[Oddball]

A bit of progress, we have the gearbox back and I have put it back on and done some more tests and mods; have a look at http://rawhyde.wordpress.com/ for details.

Jay

[Loco]

Blast from the past what happened to this project?

Cheers
Ant