Returnline rotax 914

Butt

New Member
Joined
Dec 29, 2005
Messages
16
Hi Guys,
been following the thread about the return line issue with interest since i'm interested in the ems. I do own a rotax 914 engine that is going into a europa. Early in my build, i had set my mind on the grandrapids eis as its capable of working on the 914 engine ie it will subtract the return line fuel from the pressurised side with two flow senders. Is the EMS capable of this ? I also gather from dynon that the ems cannot measure fuel pressure either as they haven't got a way of measuring fuel pessure rom the pressure box. Any one outh there with some views?

regards
 

Simn_Smith

New Member
Joined
Sep 15, 2006
Messages
45
Location
Scotland
Hi,

I have the Europa/914 combo with a Dynon 180. If you want the fuelflow on the dynon it seems that you will require the Matronics diferential unit to process the two sensors. There has been no indication yet from Dynon that it is possible to process two sensors on their units. If it was I would expect that we would have seen mention of this for a future software update.

At the moment I think that UMA are the only people who have anything capable of measuring the fuel pressure in relation to the airbox pressure. A call to Europa in Yorkshire will give you more info.
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
Hello,

We only have the hardware (hence, a software update will never allow us to add this capability without extra hardware) to process one fuel flow sender input, and therefore can not do the subtraction for a return line natively. www.matronics.com makes an electronic component that can do the subtraction and provide a single fuel flow signal to the EMS given two fuel flow senders as input.

We are currently not compatible with any of the senders (including the UMA) that measure fuel pressure in relation to the airbox pressure.
 

lucaberta

New Member
Joined
Apr 22, 2006
Messages
30
Location
Milano, Italy
We only have the hardware (hence, a software update will never allow us to add this capability without extra hardware) to process one fuel flow sender input, and therefore can not do the subtraction for a return line natively. www.matronics.com makes an electronic component that can do the subtraction and provide a single fuel flow signal to the EMS given two fuel flow senders as input.
fair enough. But would it be possible to use only one single fuel flow sender attached to one of the carburetors of my 912, and double that fuel flow reading to obtain the total fuel flow?

Would simply tweaking the K-value in the flow sender page work? Are there any hard limits on the value of the K-value? I take that I shall make it double than the starting 30000, am I correct?

Ciao, Luca
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
That might work, but would require experimentation. However, why no install the fuel flow sender upstream of where the fuel line splits to each carb. Then it captures the true fuel flow to both carbs.

I think our K-factor range is currently 10,000 to 99,999. However, you'd want to decrease the K-factor, not increase it, as the K-factor is telling the EMS how many pulses equal a quantity of fuel, and you're looking to fool it by telling it that fewer pulses equal more fuel.
 

Butt

New Member
Joined
Dec 29, 2005
Messages
16
Hi,
guys are there folk out there with rotax 914 engines atually running the d180? Would want to here their experiences please.

regards
 

Simn_Smith

New Member
Joined
Sep 15, 2006
Messages
45
Location
Scotland
Not had more than about 30mins flying yet due to the wx but I do have 914 and D180.

What do you want to know?
 

azscotts

RV-7A N696JS (reserved)
Joined
Dec 21, 2006
Messages
10
Hello,

We only have the hardware (hence, a software update will never allow us to add this capability without extra hardware) to process one fuel flow sender input, and therefore can not do the subtraction for a return line natively. www.matronics.com makes an electronic component that can do the subtraction and provide a single fuel flow signal to the EMS given two fuel flow senders as input.

We are currently not compatible with any of the senders (including the UMA) that measure fuel pressure in relation to the airbox pressure.
If the above setup would work with a Rotax, I am assuming that a similar setup for my Eggenfellner Subaru RV would work as well..

Can you confirm?
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
Are you talking about the differential fuel flow system? If so, yes, the matronics box will work with any system that can use two fuel flow senders, one incoming and one return.
 
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