Engine Mounting and Cowling time!

We've attached the mount to the engine and are finding the center of the cowling in preparation for mounting the engine. My daughter Katie is giving me some technical help.

When the manual says that some prying may be required to get the mount on the engine, that is an understatement! I ended up using a long metal pry bar on the mount to get the holes to match up.





Well, here goes, the moment of truth. Note drill with 7/16 bit inserted in top hole. I've measured every way I can think of with plumb bobs, metal rods, rulers, lasers, strings....you name it. Sooner or later, you have to take a deep breath and drill.




The engine is hung. A word to the wise here. Keep a lot of ballast in the nose at this point. A little bump on the nose when the wings and canard are off can tip the whole plane right back. I have two 50 pound bags of lead shot in the nose. It looks really nice.




Bad news. The cowling touches the engine. I will need to modify it to fit. Worse news. As you will see from the next picture, the plenum requires a much bigger hole and therefore a much bigger fix.




Here is an aft view of the pilot side cutout with the plenum on.





The pilot side. Ouch, that's a big hole and it sticks up 3/4 of an inch.




I made some aerodynamic "bumps " to accomodate the cylinders and plenum , but just wasn't happy with the way they looked.




I hated those bumps. They worked fine, but I just wasn't happy with them. I cut them both out again (about 10 wasted hours) and called Scott Swing. He described a better method using pour foam that he employed to make the cowling on Turbo Charlie fit over the turbochargers. As you will see, this is the only way to go!




I used 1/8 inch foam strips from Home Depot as spacers and duct taped them over the plenum. I then put the plenum on and duct taped over the hole and spacers to the edge of the cut out so the foam couldn't get through. Next up , I dam up the perimeter.





Here are the dams for the pour foam. High tech tagboard and duct tape.




Here is the pour foam in place. This stuff is wild. You mix equal measures of the two ingredients in a marked cup, stir briskly for 45 seconds and pour it. It sets up and is ready to sand in only 10 minutes. It shapes easily and quickly with a sanding block.





I sanded the pour foam until it blended in seamlessly with the rest of the cowl. Then I duct taped it . All I have to do now is a 4 bid layup on the outside, dremel out the original cowling and dig out the foam to the duct tape and add one more layer on the inside.





After 3 days of sanding glass, pour foam, and filler, I am the Dust King.






Here is the modified cowl all sanded and ready for filler. It turned out great and will be an invisible repair. Love that fiberglass!





Here is an inside view. All it needed now was a single ply of bid on this side. I added that tonight and gave the whole inside a heavy coat of epoxy. I learned with my last Velocity that if you don't seal the weave in the lower cowl, you will never keep it from getting greasy as you can't get all the oil out of the weave even when painted.






And now..... yes, the prop has been mounted at last!. This is the Aerocomposite prop that has been sitting on the floor in my office at home waiting for this moment. It looks great!




Here is the pilot side where that giant hole was. Take my word for it, you can't tell anything was changed at this point. I am very relieved and pleased with the way it turned out. That pour foam is the best! With the engine, cowling, prop and spinner, the plane is almost 6 feet longer, so I turned it sideways and will leave it that way until I put the wings back on as it now goes almost all the way from the front wall to the garage doors.





Here is the copilot side. You can see that the cowling modification will not be visible once it has been painted. The cowling to spinner gap isn't terrible, but varies by 3/16 of an inch, so I am going to fix that up next.






Here is one more shot of the prop. It is truly one of those builder's moments Andy Millin wrote about. I wasted about a half an hour walking around looking at the prop and spinner and cowl all on the plane at the same time. I will still have to take the prop off one more time (at least) to mount the alternator belt and repaint some scratches on my starter ring gear, and I will need to perfect the gap between the cowling and the spinner. Still, those are all things I know how to do. The finish line is in sight on another major sub assembly. Best of all, it really looks like its taking shape now.