Since I have the engine mounted, I decided to go ahead and mount the exhaust (mostly in an effort to get more boxes off of the floor that are taking up space.  First up, I needed to squeeze the rivets in the bottom center of the firewall where the cowl outlet sits (you can see the cowl at the bottom of the picture).  The outer portions of the bottom edge of the firewall will attach the lower edge of the cowl.

Here’s the cowl in place with all bolts torqued.  As I’ve mentioned before, I went with the Vetterman four pipe exhaust.

Here is what the exhaust looks like where it exits the cowl.  I like the look of this so much better than the crossover exhaust.  The only issue I ran into is that the four pipes stick out of the cowl slightly different amounts (over 1/2″ difference between the shortest and longest pipes).  I’ve emailed Larry Vetterman to see why this might be the case.

I went ahead and installed the oil filler neck and safety wired it to the case.

Checkoway had one of his hose clamps loosen in flight and recommended safety wiring them to prevent that.  Here, I’ve safety wired the intake tube hose clamps.

I also safety wired the hose clamps on the cylinder oil return lines.

My buddy Andre came over today.  We set the goal of hanging the engine by the end of the day.  There were still a bunch of things that needed to be done to the firewall before we could do that though.  First up was to drill the firewall for the ground block.  Here is the back side of the firewall showing the “forest of tabs” for grounding all of the items in the plane at the same point.  This helps to reduce (if not eliminate) sources of electrical noise in the aircraft.

Here is the forward side showing where the mounting bolt is relative to the battery.  I positioned it high enough that I can remove the battery without hitting the bolt.

We primed and riveted the doublers for the shunt and ANL current limited and fabricated the bus bars that connect them to the input side of the starter contactor.

Next up, we drilled and mounted the Dynon manifold pressure sensor to the firewall.  Finally, we riveted on a couple of nutplates and the parking brake doubler.  You can also see that we riveted on the forward ribs and then reinstalled the pressure transducer.  Afterward, I reinstalled the engine mount with landing gear and torqued/cotter pinned the nuts.

After dinner, we got started hanging the engine.  I had been planning on having a few guys from EAA chapter 338 stop by and help, but after reading about the experience of a few builders, I thought we’d give it a try.  We turned the plane around so the engine hoist had some smooth concrete to roll on.  Here, we’ve just lifted the engine pallet up off the ground so that I can undo the bolts holding the engine to the pallet.  I actually set the pallet gently back on the engine hoist legs so that it wouldn’t put any load on the bolts as I took them off.

Here I’m getting the engine roughly in position.  It was definitely a little nerve-wracking to have $30k worth of engine hanging 3 feet off the concrete.  You can tell that the angle of the engine and the mount are still way off.  Since I don’t have a load tilter, it’s probably easiest to change the angle of the plane.  And yes, that is a garter hanging from the engine hoist (don’t ask).

We propped the tail up on my adjustable shop stool.  I put some wood blocks under the tailwheel fork so that the wheel wouldn’t roll around.  The spring is strapped to the stool.  It looks precarious, but it’s actually pretty solid.

We’ve just about got the engine in place, but the tail is still too low.  It’s close enough that I can push it into alignment though.

I used a little hillbilly engineering and rigged a tie-down strap to one of the rafters.  I used this to lift the front of the engine enough that the bolt holes came into alignment.

Here, we’ve got the top two engine mounts in place and are positioning the engine and plane to get the holes in close alignment.

Here I’m installing the top two bolts.  These went in pretty quickly and with only a little persuasion.

The third bolt (lower right) was not too much harder and went in with a little wiggling of the engine.  The fourth bolt (lower left) was a little more of a pain.  I had to tighten the other three bolts fairly tight and still needed to use a bullet to move the rubber mount a little when getting it in.

I still need to torque all the bolts, but the engine is hung!  The tail is still up on the stool in this shot which is why the plane looks fairly level.

Here’s a shot from the bottom for no good reason.

Now the tail is back on the ground, so this is the attitude the plane will normally be in.

Here I am posing with my newly hung engine.

The plane is now back in its spot in the garage.  This has been a long day, and I’m beat, but I’m totally stoked to have hit this milestone.

I needed to install a bunch of things on the firewall before hanging the engine.  Since the engine mount hadn’t been torqued to the firewall yet, I pulled it with the gear still attached to give me better access.

I laid out the ANL current limiter and shunt and drilled mounting holes through the firewall.

Then I laid out for nutplates and some extra rivets to tie the doubler to the firewall.  The nutplate on the right (at an angle) ties the shunt into the firewall reinforcement angle.

I also laid out for the fuel pass through and installed the throttle cable pass through.  As with other firewall penetrations, this is all steel,  It can also swivel up to 50º to accommodate cables that have to penetrate the firewall other than orthogonally.

I then drilled out for the fuel pass through and some rivets for the doubler.

I replaced the AN3C bolts holding the parking brake on with some flush head stainless steel screws.  Where there is nothing attaching on the forward side of the firewall, I’m trying to keep everything flush so the firewall is easier to keep clean.  I still need to install the rivets in the doubler, but it’s too late to make noise tonight.  I also installed the pass-throughs for the mixture and prop cables.

Since the parking brake is in for good now, I installed and torqued rigid lines connecting the parking brake to the firewall pass-throughs.  It looks like the line on the right is touching the right cable pass through, but there’s plenty of clearance.

I drilled the firewall and rib for the pressure transducer.  I installed a couple of nutplates on the rib and put the various fittings and transducers on the manifold.  I then temporarily installed the manifold on the firewall.  This will have to come off one more time to rivet the rib to the firewall.  I also may have to adjust the fittings and possibly swap out the fuel fitting (lower) for a 90º fitting instead of the 45º fitting that I installed.  Just like all of the other fittings forward of the firewall, I’m using steel here.

On the other side, I installed some brass plugs to cap off the extra ports.

I spent the rest of the night planning out the remaining things that need to mount to the firewall and making sure I had all of the hardware on hand.

I got my exhaust from Larry Vetterman today.  On Larry’s recommendation based on my engine and sump, I went with the four pipe system.  This is a little unusual for RV’s as it seems that most people go with the crossover exhaust which ties cylinders 1 and 2 together as well as cylinders 3 and 4 together resulting in two pipes exiting the cowl.  I’m glad I went with this system for a couple of reasons.  First, I just think it looks better with four pipes exiting the cowl.  Second, the cabin heat muff for the four pipe system passes the air over two pipes instead of one, so Larry claims that you get much more heat out of this system.  Here are the pipes as received from Larry.  The upper four pipes have the flanges on them which mount to the cylinders.  The lower four pipes have ball joints which gives the exhaust system some flexibility to prevent cracking.

Here is the cabin heat muff.

I loosely assembled the upper and lower sections for each cylinder.

The instructions call for using sheet metal screws to hole some of the parts together in the cabin heat muff.  The heat muff in our Cardinal is assembled this way and every time we open the cowl, there are a couple of screws missing.  The plans specify that you can optionally install nutplates, so I installed some K1000-06 nutplates and ordered some extra AN526C632-6 screws.

Here is the temporarily assembled heat muff.  The muff will surround the exhaust pipes from cylinders 1 and 3, and the air inlet and outlet are on the top.

Here’s the inside of the muff showing the nutplates on the top and bottom of the end caps and showing the rods that connect the two ends of the muff.  I’ll assemble this permanently once the exhaust is installed on the engine.