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RV8 Typical Firewall Layout

ten4teg

Well Known Member
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Can someone provide a picture of the typical firewall layout on a RV8. I don't see any in the plans and would like some ideas. Thanks
 
The plans are a great place to start -- Scott, Tony, Rian, Ken, Phillip, others, went to a lot of trouble to draw them for us ;)

Screenshot 2026-05-16 at 8.36.03 AM.png

OP-34 shows a typical -8 firewall set up for an IO-360-A, IO-390
 
That IS a great place to start. Just keep in mind that there are so many variables that there is no one correct way to do it. Fuel injection or carburetor, updraft or horizontal induction, exhaust routing, and even ignition type are among the factors that may affect where things go. It's hard to tell until you get the engine mounted and start routing things.

I knew one builder who made a mock-up plywood "firewall" using the actual firewall as a pattern. He included marking all the stiffeners and supports on the plywood and actually installed his engine mount and engine to it so he could determine where he wanted all of the penetrations. It was an extra step, but it made the actual cut-outs in the stainless steel firewall easy work. When all of the penetrations were made on the actual firewall, he just unbolted the engine mount from the plywood and bolted it onto the plane.
 
Many options. I suggest you first decide where you will mount the oil cooler. I prefer mounting coolers on the firewall. Here is an in progress photo of what I did in my current ride. For my IO-360-M1B engine a butterfly valve is needed to keep the oil temp ~180 on days other than the hot ones.

Carl
 

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First question is forward or aft battery?
Thomas, think of the RV8 as the hot rod of the fleet. Many different engine and accessory combinations have been used, some per the Vans plans, some by builder choice. Before doing anything, sit back and think about the engine you want, its layout, the accessories you want, and how they would affect each other. Remote cooler, left or right side, firewall or engine mount location, what sump and servo combination, (yep sometimes affects the cowling), PMags, what avionics, etc. The avionics seems to be a crazy thing to consider FWF, but the different MAP sensors 'might' play into something that you didnt think of. ( We see that Dynon is now using a threaded MAP, so that simplifies things some.) OR, if you are thinking about a SDS or EFii electronic ignition/injection package. Gather all the details of the various systems you can. Sketch them out. It will save you alot of headaches later.
 
The plans are a great place to start -- Scott, Tony, Rian, Ken, Phillip, others, went to a lot of trouble to draw them for us ;)

View attachment 117782

OP-34 shows a typical -8 firewall set up for an IO-360-A, IO-390

Thanks for the pic. I guess my plans are old because it did not have this page. I will be using a IO-360 and a rear battery.
 
Have a look at OP-35 too.

You need to register your ownership of the kit with Vans. Then all the plans are available to download from the Store section of the website. Including all the OP drawings that don’t come with the kits.
There’s quite a few that deal with the firewall.
 
I took over an RV8 build where he bought a QB fuse with the firewall configured for an IO engine but he actually bought an 0-360 which I then purchased as part of the deal still in the crate. I did not catch this until long after getting all the pieces to my hanger and started staring at those firewall diagrams. Trying to figure out where to put a gascolator is the problem. Is it really necessary?

Greg Beckner
83436
 
I took over an RV8 build where he bought a QB fuse with the firewall configured for an IO engine but he actually bought an 0-360 which I then purchased as part of the deal still in the crate. I did not catch this until long after getting all the pieces to my hanger and started staring at those firewall diagrams. Trying to figure out where to put a gascolator is the problem. Is it really necessary?

Greg Beckner
83436
No...unless you live in CANADA....
 
I thought it was for a carb engine, but not for an injection?
I've seen them used on injected and carbureted engines -- all they do is provide for another spot (central) to drain water/sediment from the fuel system.

If you are diligent and sump the tanks during pre-flight, you shouldn't need a gascolator.
 
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