Oil Lines

Time: 1 Hour

In between the cowl work I started doing the planning behind the engine. This area is pretty tight and you really have to think through things as you go. I decided to start with the large items that don’t have a lot of flexibility. The inverted oil system falls into that category. I had already thought through that layout and mounted the two items in the firewall, the oil separator and the valve. I decided a long time ago that I wanted to build my own oil lines for the custom look. I spoke with several builders and learned what I needed to do. I also decided that I wanted to use Aeroquip fittings and hose. I’m lucky here in the Chicago area that I have a local source for these items, Winner Circle Speed Shop. After getting a little training from them on the assembly I made my first attempts for a couple of those lines.

I love the look and how easy these are to build. They are rated for up to 1000 PSI. You can see these are big lines, -10’s, and don’t offer a lot of flexibility. I will run all of these lines and secure them so that I can plan out all the little stuff.

Engine Cowl Fitment

Time: 20 Hours

Now that the engine is hung I could start on the engine cowl. The cowl comes it two parts, a top half and a bottom half, both come with extra length so you can get a proper fit to your firewall and spinner. First up in this process is to get the spinner bulkhead set in its proper position. Since I’m not in a position to but my propellor I’m going with the spacer method which simulates the propellor. I made a few calls to Hartzell and Jon Thocker from RedLine Airshows to ask questions and get measurements for the composite blended propellor that I will be using. The all metal prop uses a 2 1/4″ spacer which Jon used for his original prop. After discussions we decided that 2 1/2″ would be better to accommodate the different prop. The composite prop has a wider blade that requires the “G” hub which pushes the blades forward by one inch by a built in extension. That in turn moves the spinner bulkhead forward one inch as well. The difference is the aft lip of the Vans bulked is around 7/16″ deep and the Hartzell bulkhead is 1 1/8″ deep. So with the extra 1/4″ on my spacers and the added depth of the spinner bulkhead will get me to a 1/4″ spacer between the forward edge of the cowl and the aft edge of the spinner. I will have a little wiggle room that can be adjusted with washers when the bulkhead is mounted. To simulate the 1/4″ space I cut a disk out of 1/4″ plywood and bolted it to the bulkhead. I also cut out holes to clear the spacers. This way when I mount the bulkhead and spacers to the engine I can slide the cowl tight to the wood spacer. This will give me a consistent 1/4″ space when I remove the wood.

To support the forward end of the upper cowl I created a couple of threaded rod pushers that I could adjust to get the measurements just right. I used some aluminum angle, threaded rod and nuts. I then screwed them to the engine baffle mounting holes.

Once I had those mounted I bolted the spinner bulkhead/spacers into place.

Before I put the top cowl on I made a 2″ measurement aft of the firewall lip around the perimeter. This will be a reference line to measure the aft edge of the cowl. I will be able to measure forward from this line and mark the cowl to get an accurate cut line. With that marked off I put the cowl in place and got my laser out to line it up with the center of the crankshaft. The horizontal lines will tell me where the sides of the cowl need to be cut.

With the laser lines I was able to run tape along those lines to mark the cut lines. I also marked the aft end with tape as I measured forward 2″.

The only cut I wanted to do now was the aft end. I cut it a little long and sanded with a long sanding block to get a straight edge. To lock the back edge in I started the Skybolt installation. To get the holes drilled I needed to see where they are. I used a flood light to shine up through the flanges and cowling. I then drilled a pilot hole to start up sizing the hole to 15/32″ and keep it centered.

I snapped in one of the grommets to see how it lined up.

With the side lines established I was able to space the next two Skybolt tabs so that the side ones will line up perfectly.

Skybolt gives you temporary rubber grommets to hold the surface mounted grommets in place. I put all of them in place through the holes I just drilled so I could put the cowl back in place to drill the four tabs I just put on. Once the cowl was on I inserted the studs and tightened them to hold it in place.

I’m real happy with how these look and open. I have some filling that’s needed on the under side of the cowl to get it to fit flush with the aluminum. Now that I have the top cowl secured I could remove it and sand the horizontal sidelines down to the blue tape that indicates a level line.

Before I can work on fitting the bottom cowl to the fuselage I needed to meet very forward end of the two Cowls together. This is so I can get the circular portion exactly 13 inches in diameter. You need to slide the two portions together so that the nest well giving you that 13 inch diameter, in order to do this you must cut away the corners slowly as you work to get the 13 inch as well as keep the air inlets equal on both sides. I marked out a small section on both sides to cut away being very conservative.

I continue to work and sand down the corners double checking that I was keeping everything somewhat level. Once I had the diameter at 13 inches and everything nested well I drilled two holes on the inside of the inlets to lock the forward section in place.

Once I got the forward edges lined up and drilled I moved on to riveting the vertical row of SkyBolt tabs onto the firewall.

Now came the time to fit the two cowl half’s together on the fuselage. I used a couple of cinch straps to hold everything in place.

To start with I overlapped the top cowl with the bottom cowl along the sides as it fit better this way. I just needed to get everything lined up around the entire cowl so that I could measure the aft edge for that cut. I used the same process as the top cowl using a 2″ line measured aft from the firewall. Then measuring forward from that line 2″ onto the cowl surface. After the aft edge was cut and sanded I began the process of drilling the SkyBolt holes in the lower cowl. I started with one on each side using their clecko insert that they provided as well as drilling two holes thru the spinner bulkhead/spacer. Once I had the lower cowl locked into position I removed the top cowl to give me better access to drill the remaining holes.

After drilling all the lower cowl holes and inserting the SkyBolts I returned the upper cowl but this time I overlapped the upper cowl sides with the lower cowl sides. The upper cowl had the level line marked with blue tape and was sanded smooth right up to that edge. With the sides overlapping I could use that edge to run a pencil line on the lower cowl by tracing that edge. That would give me my cut line for the lower cowl sides.

So off came the lower cowl again to cut the sides. I used the Dremel tool to get it close to the line and then used my long sanding block to finish it up. After cleaning up all the dust I returned the cowls to check the fit…almost perfect!

Next up was the horizontal side SkyBolt tabs. I New I wanted to do 10 tabs per side so I laid the spacing out so they fit evenly.

I marked the cowl for where the center of each tab should line up so I could return them easily. I then marked the start and ending of the entire row to determine the rivet hole layout. I decided on a 1″ spacing pattern and removed all the tabs after marking where the first aft rivet hole should be. Once all the tabs were removed I drilled all the holes along a line 3/8″ below the cowl edge using my hole layout tool. With all the holes drilled through the cowl I could return each tab one at a time and match drill after clamping them in place. I needed to trim a little off each tab to accommodate the spacing I worked out. I also lowered the tabs from a 1/4″ reveal to a 1/8″ reveal so that I had edge distance for the rivet holes. That little change will throw off my alignment with the vertical tabs by 1/8″ but I don’t think you will notice. If I do I can remove one tab and adjust it later.

The next steps were tho countersink all the rivet holes in the cowl, mark each tab for their location and drill 1/4″ holes in the tables between the rice holes for epoxy/flox to help secure them. Then I riveted them in place so I could start drilling the upper cowl to them.

I then returned the upper cowl and started drilling the holes. The first couple were easy to get to but the next few posed problem as I couldn’t get a light behind them since the engine was in the way. I went back to the technique that I used with the canopy. Drawing two intersecting lines over the center of the hole and copying those lines on the upper cowl to pinpoint the center of the hole.

After drilling all the holes I put in all the parts on the cowl and riveted the barrels on the tabs. Here is what the final product looks like.

The inboard sections on the inlets get a couple of nutplates to hold them together.

So that’s the big step for this cowl…getting it to fit and all the attachment hardware installed. Next up will be the fine tuning of the fit and getting all the gaps to be around 1/16″ to account for the paint. I will also start working on the exterior surface as this thing is rough. The forward edges all have a little mismatch that will need work to get a smooth flow. I also have some work to do on the inside of the cowl including the cooling ramps.

Engine is Hung

Time: 2 Hours

My buddy Glenn received his IO-360 from Vans a few days after mine arrived. With both engines now in the shop we asked our good friend and RV-7 builder Pete to come visit and bring his engine hoist. This gives us an extra set of hands to help with each engine install. I gathered all the parts for the mounts and set them out. One other item I decided to install prior to the engine install is the Show Planes engine driven fuel pump cooling shroud. This shroud wraps the pump and allows for a tube to be connected to the baffling to direct ram air over the pump. This will help keep the pump cool and help with any vapor lock. Installing this with the engine in place is a challenge so getting this done now is ideal.

It only took about an hour to get the four engine bolts and mounting hardware installed. Definitely looks like an airplane now! Now on to the fun stuff!

Engine Hanging Prep

Time: 2 Hours

In prep for my eventual engine hanging I’m working on attaching anything I can to the rear accessory section of the engine. The space is pretty tight back there after the engine is installed so doing them now is advisable from what I have read. One item is the propellor governor. This controls the pitch of the propellor blade via a cable control in the cockpit. It’s bolted with four bolts and torqued to 180-220 in/lbs. The governor has small screws around the perimeter that allows you to “clock” or rotate the inner part to allow the arm to move to a position so the cable gets full range of low and high pitch on the prop.

I will safety wire the screws again once the engine is mounted and the cables measured so that it is clocked just right. I also put in the Dynon oil temp sensor in the oil filter adapter.

Like the back of the engine I also wan to put as much on the firewall as I can. I bought the Raven inverted oil system with my engine and installed the oil separator and valve on the firewall. I spent a lot of time and photos looking at RV-8’s in OshKosh over the last two years to determine where I wanted to mount these.

I just have a few items that I want to take care of before the engine is on but needed to order some parts from Vans first. Hopefully they arrive before next weekend otherwise I’ll be working on those with the engine in place.

Engine Arrives!

Time: 0 Hours

The time has come and my AeroSport Power IO-375-M1S Engine has made its great trek from Kamloops BC to Oswego IL. The truck arrived on time and the driver made quick work of carefully unloading it off the truck. After a quick inspection of the condition of the crate I signed off on the paperwork so he could be in his way.

Once I had it in the shop I put it off of the way so I could work on the wings. With the right upper gear leg fairing done I was finished with the wings and we could remove them. With Glenn’s help we made quick work of the six bolts I had holding the wings on and we put the wings back in their cradles. I then moved the plane back into the original position so that we would have good access to both of our engine mounts for the engine hanging party we will eventually have. Next up was to uncrate the engine after I put it into position just below the engine mount.

We are shooting for next weekend to get the engines hung which will give me a week to get items ready for the big day.