HomeBuilt101
Well-Known Member
I am digging through the new (to me) airplane and conducting a safety inspection.
This airplane has dual Plasma III ignition systems in it and I want to ensure there is adequate redundancy in the design and installation.
Firstly I noticed that there is naturally only one PC board at the crank and this PC board has two leads coming from it and the two wires are ran together the entire way from the crank sensor to the boxes that are mounted inside the airplane cabin.
Both boxes are installed one on top of each other on the cabin side of the firewall.
This is a plastic pusher airplane so I need to ensure that both boxes do not share a single ground and also that that connection has only one path to the engine ground.
I am going to split up the two crank sensor wires and route them in different directions until they get to the firewall side and I will also cover them in fireproof sheaths.
With respect to the coils, there are 6 coils and each has two high tension leads and these run to different spark plugs so naturally there are two independent ignition systems so that is good...HOWEVER...what I see that concerns me is that all 6 of the coils are mounted next to each other on top of the engine inside the fiberglass cooling plenum. The high tension wires to the spark plugs are the regular old hot rod style silicon insulated wires.
So...I guess the questions are...
If there was a fuel pressure leak and fire on top of the engine as a result of the fuel distribution block or lines leaking this would kill both ignition systems so should the coils be mounted in different locations? This would be possible but not very practical.
I can get fireproof sleeves for the wires however the coil packs and low tension wires are still going to be exposed on top of the engine so that would be a wasted effort.
What should I do to mitigate any risks with this system?
Other than the information described in the installation manual with the system, what other best practices should I follow?
THANKS!!!
This airplane has dual Plasma III ignition systems in it and I want to ensure there is adequate redundancy in the design and installation.
Firstly I noticed that there is naturally only one PC board at the crank and this PC board has two leads coming from it and the two wires are ran together the entire way from the crank sensor to the boxes that are mounted inside the airplane cabin.
Both boxes are installed one on top of each other on the cabin side of the firewall.
This is a plastic pusher airplane so I need to ensure that both boxes do not share a single ground and also that that connection has only one path to the engine ground.
I am going to split up the two crank sensor wires and route them in different directions until they get to the firewall side and I will also cover them in fireproof sheaths.
With respect to the coils, there are 6 coils and each has two high tension leads and these run to different spark plugs so naturally there are two independent ignition systems so that is good...HOWEVER...what I see that concerns me is that all 6 of the coils are mounted next to each other on top of the engine inside the fiberglass cooling plenum. The high tension wires to the spark plugs are the regular old hot rod style silicon insulated wires.
So...I guess the questions are...
If there was a fuel pressure leak and fire on top of the engine as a result of the fuel distribution block or lines leaking this would kill both ignition systems so should the coils be mounted in different locations? This would be possible but not very practical.
I can get fireproof sleeves for the wires however the coil packs and low tension wires are still going to be exposed on top of the engine so that would be a wasted effort.
What should I do to mitigate any risks with this system?
Other than the information described in the installation manual with the system, what other best practices should I follow?
THANKS!!!
