Riviting Front Baffle and Spinner profile cutting

December 31, 2008

Today I completed the front baffle by attaching the angles and brackets that hold the baffle I used some button head rivits to attach the brackets as they were just sitting around and was what I had. I see no reason to go to all the work to flush rivits in those brackets as it really isn’t required for aerodynamics and the button is just faster and easier. I also went up to my friends shear and cut baffle wrap arounds and had formed them to the cylinder profile and rivited them on to the baffle using button heads again. Once that was done I marked the location for the intake and used the fly cutter (dangerous freaking thing but awesome good at its job as long as your fingers don’t get into an argument with it.) I cut out a large enough hole to accept the SCAT duct flange. I then make a backing plate to hold it on because I wanted to sandwich the flange to the baffle so that I could also include a metal screen that I could change as required. The screen is basically a course filter to keep birds or other big bug or FOD from going down my intake. I know that dust and dirt can still go down it but filters will take away performance and most experimental hard core acro birds don’t have them every little bit of perf counts! Once I finished that I cut and attached a new SCAT duct between the injector throttle body and the front baffle. All I have left is to attach rubber seal to the baffle and secure the baffle to the engine permanently.

I got my prop bolts in today from Saber Manufacturing www.sabermfg.com

I ordered 7″  long bolts with thin washers since I already have a 3/16″ crush plate.   They look nice and out to work great…they better for $96 which is cheap for prop bolts but still freakin expensive.

On to the spinner since I don’t want to fuss with the oil cooler hood yet.  It is 26 degrees outside I don’t have a cooling issue right now so I could just fly as is with no oil cooler duct and be just fine but I will probably finish it before I fly I don’t want to take a cowling on and off all the time once I start flying it.   Anyway I have been avoiding cutting the prop profiles out of the spinner since you only get one chance or buy a new one so getting it right the first time is best! I messed around with profiles using paper board until I got one that fit. Then I mounted the prop back plate, front plate and marked on the back plate where the trailing edge of the prop intersected the edge of the back plate. I needed these marks so I could get the profile template on exact opposite sides of the spinner.  I then took my prop profile and tested it 10 or so times rehearsing exactly how I was going to transfer it to the spinner cone. I then disassembled it all and took the back plate over the the cone transferred my reference marks of the trailing edge to the spinner cone. I then laid my profile on to the spinner cone and traced it on to the cone. On both sides.  I made sure to come up 1.5″ from the bottom to account for the back plate depth.  Once I got both profiles transferred I set the spinner cone over the prop to check to see if I was in the “ball park” and it looked as though I was.   I took my angle grinder  with a thin cutting blade and started cutting.  Kinda scary I have to admit.  I cut the blank out roughly and then came in with a thicker grinding wheel to trim close to my traced profile. Once I got the two sides cut I tried it.  I couldn’t first get it slide on so I cut the back side of the prop profile out a bit more and it fit. It was a little tight so I marked locations to trim and continued…rinse and repeat.  Eventually it fit real well.  I was relieved and excited.  I was also exhausted/hungry so I cleaned up and went home. We had a New Years party to go to anyway.  All in all a very long but productive day.

Time spent 8 hours total time spent 54 hours


Securing the front baffle

December 30, 2008

I have been away seeing family for 8 days. I came back with a head cold and spent all of Monday and Most of Tuesday on the couch. I finally mustered up enough energy to go to the airport in the afternoon. I had taken the whole week off of work so that I could finish the airplane before TPS starts on the 5th. Anyway I spent all of my time figuring out how to mount the front baffle to the engine. I have some clearance issues on the #1 baffle so I had to figure out how I was going to secure the front baffle to the #1 side baffle. My old baffle was pretty ratty so I desided to make a new one in doing that I extended the front side down and put a slight bend it it so I could pick up a #8 screw into a 3/4″ x 3/4″ angle that I will rivit to the front baffling See picture below. (I forgot my camera today so I took the next day and posted that with the the screw and rivits that I completed on the 31st Back dating posts)

I also devised a mounting solution for the #2 cylinder baffle near the base as well as the where the #2 cylinder baffle attaches. I used some leftover 1/2″ X 1/2″ angle that picked up the front side of the front baffle and also the top of the fold on that baffle. This attaches to the engine just at the base of the cylinder. I used a piece of 3/4″ x 3/4″ angle to attach the side baffle to the top of the front baffle. I will post some pictures tomorrow.

Time spent 4 hours total time spent 46 hours.

More work on the Front baffle

December 19, 2008

Today I took the day off work exclusively to work on the plane.  I took the front baffle up to my friends break to bend it.  That seemed to work well.  I then spent a long time trimming the profiles of the #1 and #2 cylinders.  I also spent a while trimming around the starter and engine case.  I eventually took the starter off the engine so it would be easier to fit the sheet metal without scratching everything to pieces.  I drilled a hole to pickup one of the bolt holes on the case that is typically used for an alternator.  I don’t have an alternator so I am free to pic this one up to secure the baffling.  I spent a lot time slowly trimming the forward baffle to fit the cowling. This was numbing after awhile of trimming and fitting the cowling and then repeating after more trimming. I have probably taken this cowling off over 100 times this totally sucks. Anyway I finally got it to fit correctly. I also drilled the holes through the firewall for the 3/4″ x 3/4″ angles that I am using to secure the oil cooler.   I finished up the day cutting a mold out of foam in an effort to make a fiberglass hood for a 2.5″ SCAT duct off the #4 cylinder baffle.

Time spent today 5.5 hours total time spent 41 hours

Modified Exhaust Arrives

December 18, 2008

Tonight I spent the whole time out at the airport fitting my new exhaust mod to the engine. I also was interested to see how the cowling fit with exhaust mods. Unfortunately not perfect. Not to say I am disappointed not at all. I am just a perfectionist. The exhaust doesn’t clear the cowling as well as I hoped oh well, I will just cut it out a little so that it will clear. The really good news is that the pipes clear the engine just like my mock up did. Another master piece from www.AircraftExaust.net.  I didn’t have a hole lot of time tonight because it is late but primary goals were completed.

Time spent tonight 30 minutes Total time 35.5 hours

Fabricating the forward baffling

December 11, 2008

Today I spent some time transferring the paper template I made for the forward baffling to the aluminum sheet I had purchased.  I also cut out the holes for the starter and the lower crank case.  I wanted to wait to actually make the bends in a friends break.   After that I spent some more time figuring out were exactly I wanted to mount the oil cooler.  I had a bit of trouble deciding exactly how what angle I wanted it mounted.

Time spent tonight 3 hours total time spent 35 hours

Moving the Oil Cooler and front baffle

December 10, 2008

Tonight I spent some time figuring out where the oil cooler can go other then on front of the #2 cylinder.  I have been wanting to mount it to the firewall since I will be adding the prop extension and the longer bolts which will hopefully be offset by the oil cooler relocation.   I chose the following location for the oil cooler and I will be make either a fiberglass or aluminum hood to channel the air from the baffles down to the oil cooler.  I think I will go with 2-2″ SCAT ducts to channel the flow into the oil cooler.

After I found a location that worked for the oil cooler I went on to work the front baffling. It will be the hardest to make because of the complex shapes that make the engine crank case. Since I have no templates I decided to use some poster board to start making cuts to make it fit the best I can. Any holes where I cut to much I will take and tape some poster board back in. Once I get it close I will make a new poster board template. Once I get a template I like I will then cut it out of aluminum.

Time spent tonight 3 hours total time spent on the mod 32 hours

Exhaust Re-Route 2

December 4, 2008

Tonight I was able to get a ton done. I was able to get the PVC mock up glued screwed and boxed up. I basically marked and made sure everything cleared the cowling again. I then removed each section and glued it together pre-drilled and then screwed 2- 1 inch deck screws into each joint. I took a load of pictures for the guys at Aircraft Exhaust to use to make the two new pipes. Oh yeah that is my wife helping me hold the exhaust so I can take a picture for the Aircraft Exhaust guys because that is the way they are used to seeing them since they build them on a table.

Time spent 2.5 hours total time spent 29 hours