I have an IO-360 and am replacing the existing fuel flow & pressure gauge with the FP-5L from EI, www.buy-ei.com. I was wondering if anyone has installed the FP-5L and has any pics. I am most interested where to mount the Fuel Flow and Fuel Pressure transducers on the engine and the firewall. I am trying to avoid reinventing the wheel. I appreciate any help with this, thanks.
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EI Fuel Flow and Pressure Installation Help
- Thread starter jswareiv
- Start date
andrew phillips
Well Known Member
hope this helps
Trying to satisfy all manufacturers requirements. Orientation of unit, straight pipe on inflow and outflow, rigid mounting location. The stuff under the firesleeve is aluminum tube with a bracket near each end to hold the whole thing rigid. The unit is intentionally on a slope to allow any air bubbles to work their way out. Let me know if this is helpful.
Trying to satisfy all manufacturers requirements. Orientation of unit, straight pipe on inflow and outflow, rigid mounting location. The stuff under the firesleeve is aluminum tube with a bracket near each end to hold the whole thing rigid. The unit is intentionally on a slope to allow any air bubbles to work their way out. Let me know if this is helpful.
Rick6a
Well Known Member
This topic can generate a wide variety of opinions. I followed IE's written instructions then contacted IE support for a follow-up consultation. I recommend you do the same. They told me the vertical placement I planned by locating the fuel flow transducer between the injection servo and flow divider (spider) was ideal. In their view, that orientation reduces the chances of cavitation. IE support also verbally assured me that using aluminum fittings (as called out by part number in the instructions) were acceptable in this application. Other builders may disagree. Again, it is best to contact IE support with technical questions that may produce conflicting opinion.
Mathew Sharp
Active Member
Hello All!
Your friendly neighborhood EI Tech support rep here!
There are really two issues in regards to EI’s specifications on flow transducer placement.
1. Accuracy of the output of the flow transducer.
2. Safety.
Issue one is pretty basic. After manufacturing flow instruments for a good number of years we have seen that flow transducers accuracy is typically better when mounted after the mechanical fuel pumps. They simply seem to prefer to have fuel pushed through them, not pulled through. The truth of it though is that many installation drawings still read as though we were still using the older Floscan 201 and 231 transducers. I have seen installs that mount the transducer between the pumps with claimed success. The Floscan units were much more sensitive in regards to mounting location, angles of fittings in and out, and attitude. Our new design will tolerate a lot more.
The other more serious issue is in regards to safety. We want to make absolutely sure that the fittings on the transducers never are subjected to conflicting vibration planes. The engine will flex in the motor mounts creating conflicting vibration planes between the engine and the airframe. This is why the “flexible line in” and “flexible line out” is called out so often. This is also why we don’t want the transducer rigid mounted, via a fitting, to a carburetor or fuel pump. A contradicting vibration plane will focus the energy directly to the fitting. It is our sincere concern that with the two conflicting vibration planes here could cause the fitting to fatigue and crack. This would be bad…and we have seen it happen….
On the bright side, we don’t care if the thing flows straight up, or if you put 90-degree fittings in and out of the transducer. Just don’t mount it upside down, flowing sharply downhill, or before the pumps.
Please let me know if you have any questions or if we may be of any assistance.
Matt Sharp
Your friendly neighborhood EI Tech support rep here!
There are really two issues in regards to EI’s specifications on flow transducer placement.
1. Accuracy of the output of the flow transducer.
2. Safety.
Issue one is pretty basic. After manufacturing flow instruments for a good number of years we have seen that flow transducers accuracy is typically better when mounted after the mechanical fuel pumps. They simply seem to prefer to have fuel pushed through them, not pulled through. The truth of it though is that many installation drawings still read as though we were still using the older Floscan 201 and 231 transducers. I have seen installs that mount the transducer between the pumps with claimed success. The Floscan units were much more sensitive in regards to mounting location, angles of fittings in and out, and attitude. Our new design will tolerate a lot more.
The other more serious issue is in regards to safety. We want to make absolutely sure that the fittings on the transducers never are subjected to conflicting vibration planes. The engine will flex in the motor mounts creating conflicting vibration planes between the engine and the airframe. This is why the “flexible line in” and “flexible line out” is called out so often. This is also why we don’t want the transducer rigid mounted, via a fitting, to a carburetor or fuel pump. A contradicting vibration plane will focus the energy directly to the fitting. It is our sincere concern that with the two conflicting vibration planes here could cause the fitting to fatigue and crack. This would be bad…and we have seen it happen….
On the bright side, we don’t care if the thing flows straight up, or if you put 90-degree fittings in and out of the transducer. Just don’t mount it upside down, flowing sharply downhill, or before the pumps.
Please let me know if you have any questions or if we may be of any assistance.
Matt Sharp
GrayHawk
Well Known Member
I don't have an injected engine but I do have the FP-5L on my carbureted O320-D1A. I chose to mount the flow sensor after the mechanical fuel pump, before the carburetor, inline, following the manufacturor's recommendations.
I'm very happy with the accuracy that it gives me, but I do check everything carefully every time I have the cowling off.
I'm very happy with the accuracy that it gives me, but I do check everything carefully every time I have the cowling off.
