Note to readers: Working on firewall forward tasks involves an endless series of chicken/egg scenarios. You often can't install item A until you fit item B, but you usually don't know how item B is going to fit until items A, C, Q, and X are all installed. So I'll try to break up the next series of posts into discrete topics, but be advised that the photos will show multiple projects happening at once, because that's how things actually transpired.
First up, final installation of the oil cooler. I was hoping to be able to keep putting this off, since it's big and fragile and in the way, but in order to install the left magneto I need the oil cooler in place so I can check the hose routing. Of course, in order to fit the oil cooler and hoses in the first place it would have been helpful to have the left magneto installed (see preceding paragraph).
I ended up having to re-clock the lower fitting in order to point the return hose slightly away from the magneto. Of course this meant I had to completely remove and re-seal it too. As for the upper fitting, I had to switch it from a 90 to a 45 to end up with a hose routing that wouldn't hit the mag.
You can sort of make out the magneto in there – it's the black thing just below the far end of the upper oil hose.
On the bottom side, it's a contest between the magneto and the engine mount to see which will interfere with the oil return hose the most. Since the cooler, hose, and magneto are all solidly mounted to the engine, they should in theory all move around together and not relative to one another. So, I chose to bias the hose as far away from the non-moving engine mount as possible – about one finger width, shown here – and accept the fact that the hose will come quite close to the mag.
Here you can see how close the hose comes to the magneto. Depending on the rotation of the mag when it's being timed, it could actually touch slightly. Once the mag is bolted down for good, I'll put some RTV in here to keep anything from chafing.
When you have the magneto in place, it becomes very hard to get a wrench on the inboard fitting of the return hose. In fact you can barely see it (middle of picture). I busted some knuckles getting it tight.
I guess in one sense I got lucky with my oil cooler plumbing – it was inconvenient to re-route the hoses, but at least I didn't have to have new ones made. At a hundred bucks a pop that would have been a bit more than an inconvenience.
Oil cooler mounting bolts, washers, and spacers all installed and torqued.
I sealed the gaps at the top and bottom and in the corners with more RTV. No sense letting any of that precious cooling air escape without doing useful work, i.e. flowing through the oil cooler.
