Firewall Penetrations

Hello,

Installing a CS O-320 in my -9AQB. Do the Van's locations for firewall penetrations end up being right on? I'd like to do make the holes, but I don't have my engine yet.

Any guidance appreciated.

Pete

As the saying goes...

...never drill a hole or smash a rivet until you absolutely have to.

If I had followed this advice, there wouldn't be patches of hair missing from my scalp.

I absolutely agree. I would NOT drill any holes in your firewall until you have bolted your engine to the mount, and then placed the mount against the firewall. Trust me on this one. I remember the desire to get doing SOMETHING on the firewall, but I held off and am I ever glad I did. Leave your engine on the engine hoist, just swing it (and the mount) up to the firewall, mark a hole once you are happy with the clearance, move it out of the way and make the hole. Then do the next one.

There are lots of firewalls out there with "lightening" holes in them because the hole wound up not being in the right spot. Off by 6" is one thing, but if you aren't careful, you wind up being off by 1/8" or less, and THAT is annoying ;-) Besides, there is a lot of heat and noxious fumes in the engine compartment, and you don't want any extra holes around letting it in to the cockpit.

Just my $0.02.

Cheers

Thanks

Thanks guys, good advice.

Pete

While I agree with all the caution already voiced, I installed my 0-320-D2A and all of the hole measurements called out on the plans worked perfectly. I used the FWF kit from Vans also so all the parts matched up with the hole locations. However YMMV.

I installed Van's 0-360 A1A (Van's specifies the configuration for it's Lycomings) and used their FWF kit. All the holes were in the correct place as described on their FWF plans. If you use a Van's engine and FWF kit that they recommend, the hole locations will be correct. If you use something other than their stock components, then you may have some cause for concern on placement of holes.

Some of the holes are very difficult to drill once the mount and engine are hung. Being able to predrill them is very helpful. But, as others advise, be sure of the placement of the holes. Any deviation from what Van's supplies may result in alternative and unwanted holes.

JMHO

Roberta

Pete,

Just to add to all of this, I pre-drilled my holes in the Firewall, and once my O-320-D2J came in, everything lined up as it should. So far, following The instructions has not caused me to drill a hole in an incorrect location. (Now if I could just read the instructions correctly every time!)

Ron
RV-9A 90965
N379RV - Getting ready to move to the airport.