Battery AND oil tank on firewall?

I ordered my RV-8 engine last week (Aero Sport IO 375 High Compression) so I’m starting to thinking about my firewall. I will be installing the battery on the firewall as well as a full Raven inverted oil system. Raven makes the slobber tank in two sizes, a 4” and 5”. Rob Halas at Raven Aircraft says the smaller tank fits tight cowls such as an RV-8 nicely. I would prefer the 5” air/oil separator tank. Has anyone installed a 5” Raven tank AND the battery on the firewall? I imagine it will be a tight fight but I’m hoping there is room. Thank you.
Bob
303 882-7410

Bob, I ran some weight an balance scenarios on the 8 when I helped a friend build his. The aft mounted battery was better for his Mattituck TMX-IO-360 powered tailwheel 8.

I bet your 375 will come in similar as they are both parallel valve engines of similar proportions.

You might want to move your battery location and free up the firewall space to boot?

my two...

CJ

Hi Bob...

What prop have you got? With an IO-375 and Inverted Oil suspect Battery better of aft unless you have a light fixed pitch prop? Hartzell = definitely Aft!

4" tank I am sure is fine unless you are into really complex / competition figures.

5" tank and Battery I am sure can be made to fit, and Inverted stuff other side.

I know from experience RV-8 is a pig to fly aeros in with a forward CG. Get in near the Aeros Aft CG limit and it is a delight

Thanks for the input. Ok, my dilemma is I have a lot of big bubba buddies and want to be able to take them along. I figured I?d carry some weight in the back when solo if necessary (tool kit???). If anyone has a similar aircraft and is willing to share the W&B I?d like to work with some numbers. Hopefully the battery AND my big buddies can go in the back!
Here is my configuration:
RV-8 tailwheel
Todd Canopy
HW aux fuel tanks
Grove Airfoil landing gear
Aerosport IO 375
Raven full inverted system
Whirl Wind RV200 CS Prop
Smoking Airplanes 3 1/2 gal oil tank fwd baggage compartment
Thanks for your help
Bob

I wanted to mount my battery on the firewall and could not use Van's location due to an additional cabin heat box at that location. Mounting the battery on the upper left seems to be working out well and frees up a lot of space on the upper right for my air-oil separator. This is where I have seen Raven systems, though I have no experience with one...

As an alternative, consider mounting your battery on the floor just forward of the right landing gear tower. This would free up firewall forward space and move the CG just slightly aft.

battery location

I have an 8a, simple o-360 WW200 prop with pc-680 aft mounted battery, backup battery mounted on rear wall of front baggage ,painted, Todd's canopy, & empty wt. of 1098 lbs. The items you plan to put on your firewall & engine wt. I can't imagine not putting in the battery in the aft location.Depending on prop & a firewall mounted battery, you will have at least 35 lbs. more nose wt. and that would mess up my wt. & bal. a lot. Ron

Ron,
You're nothing but a trouble maker...... Now I want my firewall to look like yours. How long did that add to the build time?
Bob

Hi Bob
If you're talking about the swirl? polishing, it took me about 2 hours, one to lay it out and one to do the swirls.

I laid out a 1" grid and used 2" blue scotchbrite discs from an autobody supply. The discs and the mandrel come separately and have a quick change feature. The edges of the discs tend to "round up" a bit as you use them, so I stiffened them with some thin cyanoacrylate (Zap, Hot stuff etc).

I did my firewall on the bench before I attached it and got so I could do about one swirl per second once I got the hang of it. When the edges of the "swirls" got a bit ragged I switched to a new disc, probably went through about three for the job.

If you are already committed to the battery up front, you might investigate the LiFePO4 batteries. The are incredibly light weight for their capacity.

I know this is a old thread but are there any conclusions? Where did you mount the battery in the end?

I am planning for a similar setup (IO-375, full raven inverted system) and want to install the battery as well on the firewall. I will install a 3 blade Catto and I have the airfoiled grove gear. But my fear is that there is not enough space on the firewall due to the bigger cooler which is needed for the IO-375. And I do not want to install the battery in the fwd baggage area (due to my girlfriend )

According to Aerosportpower there must be plenty of people flying around with the IO-375 but unfortunately I do not find a lot of information on this topic.

Cheers Yves