Category: Exhaust

Engine Prep

July 22, 2021 – I did some things on the engine to get it ready for the first engine run.

Since I was ready to service the engine with oil, I replaced the stock drain plug with a quick drain.

I installed all of the Skybolt fasteners in the cowling. They provide temporary rubber retainers, so I’m using those until the cowl gets painted. If they don’t last long, I may use the permanent metal rings and buy new ones when it comes time.

I’ve also been trying to figure out how I was going to deal with the sniffle valve in the bottom of the cold-air sump. The valve comes down right between the two crossover exhaust pipes. I slightly bent the tube out of the valve, then used an aluminum tube and a piece of fuel line. We’ll see how long it lasts.

Time: 2:50

Installed CHT and EGT probes

September 7, 2018 – Today I installed the CHT and EGT probes. I’ve ordered a lot of small items from Spruce, and I’m kind of on hold with a lot of things. This I could do today.

Pretty straight-forward; I used some anti-seize to install the CHT probes. These probes from Dynon have a quick-disconnect feature.

The EGT probes use a hose clamp setup to hold the probes. I drilled  1/8″ holes in each exhaust pipe 3″ down from the flange on the cylinders. Insert the probe, tighten the clamp, that’s it.

Time: :50

Installed heat muff

September 6, 2018 – I assembled and installed the heat muff.

The heat muff takes air heated by the exhaust and routes it to the cabin for some semblance of heat. I installed it on the only stretch of pipe that was long and straight enough to accept it: on the pipe from #1 cylinder. Wasn’t sure about this spot, but I’ve seen it on other airplanes, so…

I needed 5 1/2 hands to put this together, but I figured it out.

Time: 1:10

Installed exhaust

August 29, 2018 – Well, that was pretty easy. I got the exhaust installed today.

I got the crossover tubes installed and torqued the pipes to 180 in/lb.

The hangers were pretty simple as well. Vetterman gives you clamps and everything you need to support the pipes at the exit.

I installed the lower cowl to check the space at the exit. Have lots of room there.

The pictures look like the pipes turn outwards, but that’s just the camera angle. They both point straight back.

I attached two angles at the aft corner bolts on the sump, then used the supplied hardware and rubber tube to connect to the clamps on the pipes. The clamps are supposed to be as far aft as possible to provide good support.

Once I got the vertical hangers in, I supported the pipes horizontally to each other. I had to cut the provided tubes because of the short distance between the pipes.

Time: 2:20

Started exhaust

August 29, 2018 – It was time to start with all of the engine hookups.

I took the box from Vetterman out of my bedroom into the garage, and did a quick inventory. I had to run out and get some high-temp anti-seize, then I attached the pipes to the cylinders. Their instructions say to start with 3 and 4, then install 1 and 2.

The pipes are in place, but not yet torqued. I still have to install the crossover tailpipes.

Time: 1:00