[Harold Lanfear]

I'm just starting to drill holes in my -8 firewall for wire penetrations and would like know the locations aren't needed for something else after I hang the engine. I trust Van's blueprints, but.....

Anybody have any pictures of what goes directly behind the engine in center firewall (engine side)?

Specifically, I'm drilling for my ground connection and firewall ground tabs at the location Van's uses for the ground point on the drawings; essentially the center of the firewall. Do I have room for the ground tabs without interference?

Thanks much.

 

[RV8N]

Harold,

I ran a grounding strap (braided metal strap) from the left rear of the engine along the left upper motor mount tube. I drilled a hole an inch or so below the left upper firewall-motor mount bolt and bolted the grounding strap right to the firewall. I then used adel clamps to support the grounding strap and hold it away from the mount tube.

The advantage to doing it this way was that the bolt would go thru the steel weldment at the upper left corner of the firewall and would be away from everything else on the back of the engine. it also looked like it would be plenty strong and an excellent ground point.

Karl

 

[till3]

-8 Grounding

I'm just starting to drill holes in my -8 firewall for wire penetrations and would like know the locations aren't needed for something else after I hang the engine. I trust Van's blueprints, but.....

Anybody have any pictures of what goes directly behind the engine in center firewall (engine side)?

Specifically, I'm drilling for my ground connection and firewall ground tabs at the location Van's uses for the ground point on the drawings; essentially the center of the firewall. Do I have room for the ground tabs without interference?

Thanks much.

Harold, I have an older kit and was not provided with wiring diagrams from Van's, believe me, it was the dark ages back then, so I don't know what Van's recommends.

Anyway because the area on my firewall directly behind the engine filled quickly with things like an engine oil cooler, air/oil separater, remote oil/fuel pres sensors, etc., I tried to run as much as I could on the outer edges of the firewall, not the middle. In this manner, I felt safe about interfering with any future modifications

As for grounding, I made three connections: I grounded my FWF on the left (looking forward) motor mount attachment bolt located at the firewall. To do this, I made a grounding wire the same guage as my alt/battery cable. I ran the grounding cable along the motor mount and attached it to the rear of the engine case. (I could have gone to the stainless steel firewall by making a grounding stud, but I wanted this attachment to go directly from the engine to the airframe via the longeron.)

For grounding avionics and other airframe items requiring a more direct grounding, I attached two 14 guage wires to the engine (one at a baffle attachment, the other on the assy case), then ran the wires along the engine mount through the firewall's right outboard side (below the upper engine mount attachment), through the baggage area to the area behind the panel and made grounding bars.

I hope this helps.

Jim