Van's Air Force
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Bendix fuel injection installation issues
- Thread starter BDHAWK
- Start date
NeilMcLeod
Active Member
I did exactly that on my straight 7, it was not too difficult. I made a new top plate for the FAB and had a spacer machined to go between it and the servo body. I think I needed different length cables for mixture and throttle. I can send pix if that would help.
snoop9erdog
Well Known Member
Interested also
Neil,
Would you please add me as well? Any photos or information/details that you have would be extremely helpfull. I'm planning on installing the Bendix FI on my 9 with the IO-360 L2A.
Thanks,
Neil,
Would you please add me as well? Any photos or information/details that you have would be extremely helpfull. I'm planning on installing the Bendix FI on my 9 with the IO-360 L2A.
Thanks,
Cowl interference
I have a vertical induction IO-360 with a Silverhawk FI. The Silverhawk is a direct copy of the Bendix FI.
My Silverhawk FI has the standard rotation mixture setup. This means as you advance the mixture the mixture arms rotates clockwise from ICO to full mixture. I have Van's stock vibration mounts (not the Lord mounts).
With this configuration you need to mount the FAB as far to the right side of the engine as possible. However the problem I encounter is that there isn't adequate "dynamic" clearance between the end of the mixture shaft and the cowl due to engine vibration during start-up or possibly shutdown. I believe most the excessive vibration occurs during poor hot starts. Additionally depending on the mixture arm that is installed there can be additional interference.
I found out the hard when I notice cowl damage after about 40 hours after first flight (Prior to painting the airplane). I posted an explanation of my "saga" on the forum
http://www.vansairforce.com/community/showthread.php?t=81986
http://www.vansairforce.com/community/showthread.php?t=87797
After the paint shop installed a blister it looked great but after another 40 hours there was additional damage evident (blister wasn't large enough). So I installed a larger blister and had the paint shop repaint the lower cowl. With about 3 hours since the last modification I think I have adequate clearance.
If I had to do it over again I would definitely go with the horizontal induction setup. The vertical induction cowl was designed for proper dynamic clearance with a standard carburator. You will save a lot of time and frustration if you stick with the configuration Van designed the cowls for.
You mileage may vary.
I have a vertical induction IO-360 with a Silverhawk FI. The Silverhawk is a direct copy of the Bendix FI.
My Silverhawk FI has the standard rotation mixture setup. This means as you advance the mixture the mixture arms rotates clockwise from ICO to full mixture. I have Van's stock vibration mounts (not the Lord mounts).
With this configuration you need to mount the FAB as far to the right side of the engine as possible. However the problem I encounter is that there isn't adequate "dynamic" clearance between the end of the mixture shaft and the cowl due to engine vibration during start-up or possibly shutdown. I believe most the excessive vibration occurs during poor hot starts. Additionally depending on the mixture arm that is installed there can be additional interference.
I found out the hard when I notice cowl damage after about 40 hours after first flight (Prior to painting the airplane). I posted an explanation of my "saga" on the forum
http://www.vansairforce.com/community/showthread.php?t=81986
http://www.vansairforce.com/community/showthread.php?t=87797
After the paint shop installed a blister it looked great but after another 40 hours there was additional damage evident (blister wasn't large enough). So I installed a larger blister and had the paint shop repaint the lower cowl. With about 3 hours since the last modification I think I have adequate clearance.
If I had to do it over again I would definitely go with the horizontal induction setup. The vertical induction cowl was designed for proper dynamic clearance with a standard carburator. You will save a lot of time and frustration if you stick with the configuration Van designed the cowls for.
You mileage may vary.
I have an Aerosport Superior IO360 with ECI cylinders and Silverhawk FI, vertical induction.
Like many before me, I made a new top plate for the FAB and off-set it back towards centre as much as I could, but it still required canting to the right to line up with the cowling inlet. It all worked fine and max manifold pressure doesn't seem to be affected.
The only cowling clearance problem I have is with the exhaust flange on the left side ball joint on a Vetterman crossover exhaust. With careful orientation of the flange that went away.
I think Bart supplied an FI with the mixture lever reversed to avoid the cowling blister needed on some installations. Check out the different lever configurations available before you buy. Bart at Aerosport is a good guy to call.
Like many before me, I made a new top plate for the FAB and off-set it back towards centre as much as I could, but it still required canting to the right to line up with the cowling inlet. It all worked fine and max manifold pressure doesn't seem to be affected.
The only cowling clearance problem I have is with the exhaust flange on the left side ball joint on a Vetterman crossover exhaust. With careful orientation of the flange that went away.
I think Bart supplied an FI with the mixture lever reversed to avoid the cowling blister needed on some installations. Check out the different lever configurations available before you buy. Bart at Aerosport is a good guy to call.
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NeilMcLeod
Active Member
It's too much hassle to post pix but I'll email them to whoever wants them. I had no issues with cowl clearance but had issues with FAB clearance hence the spacer to move it down and then angle it back up at the front. Definitely had to use the new top plate to move it to the side as much as possible and then angle it toward the inlet. Good time to increase the thickness to eliminate possibility of cracking of which there were some reports of. I also had to relieve the flange on the FAB a bit to clear the mixture arm. On the throttle side Van's cable didn't have enough travel so I drilled another hole closer to the shaft. No clearance (or any other) issues with the Vetterman exhaust that came with the kit. It has all worked flawlessly for 300 hours.
You guys rock!!!
I had searched the site on FI and read about several of the problems but with all these responses on this exact setup it gives me a more clear picture. I'd love the pictures I'm sure they will be worth a thousand words.
My email is [email protected] if it's easier than a PM.
Thanks again.
I had searched the site on FI and read about several of the problems but with all these responses on this exact setup it gives me a more clear picture. I'd love the pictures I'm sure they will be worth a thousand words.
My email is [email protected] if it's easier than a PM.
Thanks again.
Some variations
Gents,
It appears that some haven't experienced interferences as I have. A friend with the same engine, prop and FI has marks on the inside of his cowl where the mixture arm/end of shaft is hitting. His cowl is not painted yet and he has about 800 hours on his RV7A. Very soon he will have his plane painted (so he tells me) and I am fairly certain that based on my experience he will see cracks in the paint on the opposite side of these marks.
There is no doubt in my mind that there is minimal clearance with this setup. Maybe it is the slight variation in engine mounts, shock mounts, prop weight etc that some haven't experienced this interference. As I mentioned in my previous posts the damage didn't occur immediately, it occured many hours since first flight.
I know that I have had some nasty shakey hot starts, but one bad hot start can ruin a nicely painted cowl if there is minimum clearance in this area.
My words of advice are if you going to paint your airplane prior to flying, don't paint your cowlings. After the engine is broken in and all the other areas of possible interferences are fixed (baffle clearances etc.) then paint the cowling. It might save you from repairing and repainting later.
Gents,
It appears that some haven't experienced interferences as I have. A friend with the same engine, prop and FI has marks on the inside of his cowl where the mixture arm/end of shaft is hitting. His cowl is not painted yet and he has about 800 hours on his RV7A. Very soon he will have his plane painted (so he tells me) and I am fairly certain that based on my experience he will see cracks in the paint on the opposite side of these marks.
There is no doubt in my mind that there is minimal clearance with this setup. Maybe it is the slight variation in engine mounts, shock mounts, prop weight etc that some haven't experienced this interference. As I mentioned in my previous posts the damage didn't occur immediately, it occured many hours since first flight.
I know that I have had some nasty shakey hot starts, but one bad hot start can ruin a nicely painted cowl if there is minimum clearance in this area.
My words of advice are if you going to paint your airplane prior to flying, don't paint your cowlings. After the engine is broken in and all the other areas of possible interferences are fixed (baffle clearances etc.) then paint the cowling. It might save you from repairing and repainting later.
This is the exact issue I ran into today. My bendix fuel injection mixture arm linkage interferes with the side of the cowling. The FAB already has a "chunk" taken out of the mixture side and it's slightly offset already (from the previous builder). Even still, there's some rubbing and you can't even get the cowling on because of the interference. I have the RV-6 360 upper and lower cowl by the way.
Could someone email me their setup post photos? It would be very much appreciated. PM me for my email
Here's what I'm dealing with:
Mixture linkage:
Throttle linkage (plenty of room)
Here's some threads relevant to this issue, but I can't tell what the final answer was:
http://www.vansairforce.com/community/showthread.php?t=15778
http://www.vansairforce.com/community/showthread.php?t=87797
http://www.vansairforce.com/community/showthread.php?t=91276&highlight=cowl+bendix
Seems at the minimum I need to get a different "straight arm" from precision to move the arm from the bottom to the top.
I wonder if I could just cut out the entire scoop portion and make it 2 inches wider on the mixture side. Then make that a separate piece that is bolted onto the rest of the cowl. Sure would make it easier.
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