Bottom half of cowling fitted and drilled.

Yesterday my friend Andy Grimm came over and helped me fit the lower half of the cowling.  On & off a BUNCH of times, taking small amounts of material each time.  After a few hours we had it "good enough".   Last night I started drilling all the hinges, and finished that today.


Initial fitting of bottom cowl:

Taping between rivet hole locations:

Drilling hinges:

Fitting the front tabs for the two side hinges:

Final fit of side hinges:

Notch for hinge tab:

Fairings, cowling - this thing is close to being an airplane...

Since last post, spent time working on main gear intersection and gear leg fairings.   I had to get some help to get weight off the main wheels to fit the intersection fairings.  Still some work to go, but I was able to get back onto main wheels.  Last 3-6 days I've finished fabricating the sets of hinges for the cowling, and yesterday/today I trimmed / sanded and fit the front part of the two cowling halves, and today I finished fitting/drilling the cowl top to the fuselage/hinges.   I found that I had to go back and do more fluting of the curved outer part of the top hinges to get the cowling to lay flush.  I'm pretty happy with the fit except for slight gaps on the sides near the "angles" of the top cowling.  But since it's fiberglass I'll figure out a way to make it better cosmetically - this may wait until I'm flying and close to paint.

I also figured out today that when I cut out the oil door, I misinterpreted the location of all the scribe lines - they just weren't very clear on the corners, and it turns out I should have left more material in the two corners where the cam locks will go.  But I do have in "stock" some recessed latches that I may use, and if so they may fit just fine as is.  If not it will be easy to fix the corners by laying up some fiberglass from the inside.

I've enjoyed the cowling more than I expected so far.  I hate cutting/sanding fiberglass but fitting the cowling to the fuselage has been more pleasant than expected.

Starting the fitting process:

Using level and plumb bobs to align top of cowling:

Fitting/drilling to fuse (after sanding repeatedly to fit to fuse).  Note centerline "string" (actually wire) to help with overall alignment:

Drilling the hinges at "transferred" rivet locations:

Clecoed in place, ready to fit bottom of the cowling:

Spinner done

Spent the whole work session today finishing up the spinner.  More work than I thought, but happy with the results.  I used the laser to match holes and to locate the center of the spinner plate flange: I find the laser method to be much more reliable than the magnet method - but it's not aways usable depending on location of the part.   I was able to do all the nutplates and riveting without unbolting the spinner plate. 

Quick update: snorkel installed, EGT probes wired, starting on the spinner

Since last post, continuing to work on multiple smallish items.  I finished up wiring the EGT probes.   Also installed the GPS antennas for PFD and G5 on the glareshield.  I just cut the wires, drilled a small hole for the wire, then spliced the wire using OLC-1 for the center conductor and solder splice with a 20 ga wire to splice the shielding.  (I previously discussed options with Stein who says this approach is fine).   I had considered using new BNC connectors on the wires, but didn't have the right size crimper for the much smaller wire.

I started fitting the spinner - cut out the marked areas on spinner, then did initial fit.  I have opaque fiberglass parts and match-drilling has been an adventure.   I've tried the magnet technique but haven't found it to be perfectly accurate.  I have a laser that seems to be more accurate, so I compared today.  The one photo below shows good correlation but as I turned the prop to new positions (each of the 6 holes in the spinner bulkhead) the magnet didn't consistently match position.  So I think I'll try match drilling based on the laser position.   It's not hard to aim it the right angle to direct the drill along the "axis" of the hole.   We'll see....

I sanded and then put a layer of plain epoxy on the parts of the spinner that match up to the bulkhead and backplate.  That needs to cure overnight.


Snorkel fitted in place:

Laser setup for match drilling, with magnet technique for comparison:

Propeller, exhaust system, odds & ends

Since the last post, working on various firewall forward items and miscellaneous stuff.  The biggest news is that this past weekend, my friend Bob Bohn who is an A&P/IA helped install the propeller and exhaust system.  Since then, I've installed the EGT probes, rest of exhaust system (heat muffs, scat tubes etc), and also finished the nose gear leg fairing. 

Some of the items done since last post:

Nose gear leg fairing:

Finishing up snorkel (alt air door now in progress):

Lines to remote oil filter, filter installed:

 Firewall forward wiring:

Propeller is on the airplane (and another huge box is out of the house):

Exhaust:

Flywheel, prop bolts, alternator belt:

 Scat tubes:

Heat muffs:

I installed a direct ground from engine (via the engine grounding strap attached to engine mount) directly to the battery ground on firewall.  This will reduce risk of starter current taking a ground path through cables or other paths that might create excess heat.

Firewall forward work, starter switch wiring, snorkel fitting

Lots going on these days.  Since last post I received some items needed to finish the installation of the Airflow servo - I had to replace the original studs which meant I needed stud removal tool (nice but expensive item from Snap On) and the recommended Loctite primer and high-temp thread locker for the replacement studs.  Got all that done, permanently mounted the servo and the throttle and mixture cables, and started fitting the snorkel. 

Every decision you make that deviates from Vans "standard" build results in consequences.   The FM-150 servo fits differently from the standard servo, so the snorkel has to be modified to work - I followed the method described by "Nova RV" on Vans Air Force - basically I cut slits (actually removed wedges of material) and remodeled the snorkel to fit the air filter frame as it sits, clecoed it up and then used strips of fiberglass cloth to close the gaps and permanently reshape the snorkel.  I'm happy with the result and will spend the next few days permanently mating the snorkel to the air filter frame, and shaping/sanding the inside and outside surfaces to be smooth and accept the alternate air door. 

I spent quite a bit of time installing and wiring up the CHT probes, running wires to spark plugs, making sure they are all properly supported, etc.

Also I installed fuel line from firewall to fuel pump, fabricated and installed the oil breather hose, fabricated the oil cooler support tray, and all the associated hardware to install the oil cooler.  This includes installing seals and sealing up the corners of the cooler inlet assembly.  While I had the red RTV out, I sealed up the baffles along the front of the engine.

Also - final fitting of the nose wheel fairing using flox to seat the brackets:

Sealing up connectors on CHT wires:

Based on recommendations from experts on VAF, I used these "OLC-1" connectors which avoid the problems that tend to happen with these wires: crimp connectors tend to corrode, solder is not acceptable due to the special metallurgy of the thermocouples, and the standard ring terminals that include screws seem to be problematic as well.

Servo permanently mounted - use Permatex gasket sealant on the gaskets (it's blue):

Mixture cable rod end - I wasn't able to use Aiflow's recommended position here (rod end on top of arm) because the rod end and cable extension (hex shaped rod) interfered with the arm and other structure).  I ran this approach by my guru (Vic S) and he gives it a thumbs up.

Snorkel mods with peel ply in place:

 Oil cooler with seals and fittings for hoses.  Because of the PMAG and use of remote oil filter I ran the oil lines differently from Van's standard - so fittings are clocked to work with those routings.  All good.

Routing wires to cylinders:

Oil cooler tray:

I installed a quick drain for oil changes (when I removed the plug lots of preservative oil came out - that stuff is gooey).