Stjohn's RV-7

1 hour.
Not actual building, but some research. It’s amazing what the FAA TCDS’s can tell you. For one thing, I might need a new governor. The one on my engine is a McCauley C290D3/T18. This means absolutely squat without some real numbers. For instance, the drive ratio is .895:1 and the torque range is 120-1200 in/lbs. Why is this a concern? Because if that McCauley turns out to be trash, I’ll have to pick up a PCU5000x, which is pretty freakin’ cool, but the application chart doesn’t spec my governor, exactly. Maybe I’ll have to replace it, maybe not, but I like having options. And just for future reference, here’s a link to the TCDS:
TCDS number E-286

After I cleaned up the shop, I had a look at the engine. The airplane that engine spent its previous life in, the Cessna 172 Cutlass RG, is a 28v airplane. So I have a useless 28v alternator and a useless 28v starter. Maybe not useless, but certainly of no use to me; I’m going to run a 14v system. Maybe. What I don’t get is what’s going to be 12v and what’s going to be 14v and whether or not it matters. So another thing to puzzle out. The good news is, i’ll be able to keep my firewall penetrations to a minimum, because the MGL RDAC (the box all the sensor probes connect to) is mounted on the engine side, with one comm wire going back through the firewall to the EFIS. I’ll need to poke holes for the panel bus power and the control cables, but that should be it. I hope.

4 hours.
Well, i went and did it.. I got an engine.. A Lycoming O-360-F1A6 with 951 hours on it. After getting it home, I realized some work will have to be done to make it viable, if I may understate the case a bit. Right now, it’s sitting on an engine stand with about 7 gallons of oil in it, bathing the internals so it doesn’t turn into a hunk of rust. It’s a little frightening, since it’s really big, and really heavy, and I don’t know any A&P’s. The guy I was going to call is… unavailable. It will need a forward-facing sump so I can throw on an AFP FI system and I’ll need to get a governor that matches my prop. I hope this doesn’t turn out to be a nasty, expensive mess. Until now I had no idea how many places one of those damned things could leak from, and part of it’s my fault. I just HAD to pull off a rocker cover and get a peek at the valves, which, as advertised, were wet with oil.
So I whacked together an engine stand based on Mike Snook’s design. It was a logistical nightmare, renting the hoist, taking delivery, and actually mounting the thing on the stand. Until you’ve done it, you have no idea how awkward an ungainly a 200+ pound block of inert metal can be, especially when it must be treated with extreme care and be manipulated a certain way. What I would have given for a Caterpillar PWL. Then there was the whole oil issue. 7 gallons of oil tries to squeeze out every hole and crack. It runs out the hollow crank in front, it runs out of the magneto gaskets, it runs out of the rocker cover I took off, it runs out of the cooler fittings. I really didn’t think about all that when I flipped it over on the rotisserie and started funneling the Texas Tea into the inverted sump. So I had to find and plug every leak. As it is, I’ve still got a funnel under the rocker and a rag under the centerline of the engine on the T-bar of the stand. It’s scary. I took the ring gear off and sealed up the front with a 2″ jim cap from the aviation department at B&B hardware, but it’s not as nice as one of those little red caps on the TMX-360 on the Mattituck site. I searched high and low for one of those to no avail.
Meanwhile, here are some pics of the engine in the days of and after its arrival:

First day I was able to mess with it. Got the thing hoisted up in preparation for mounting on the stand. Simba is very curious about this heavy thing emanating all the strange odors in his backyard. Here it still has all the Cessna 172RG baffles on it, which will be removed later.

Right now, Simba’s had enough of this thing but he trusts it well enough to turn his back on it.

On the stand. I know it looks like it’s sagging, but it’s not.

From the front.

One thing about the prop I didn’t notice until now. It’s got the 7496 blended airfoil blades. What this means is that my horsepower limit is now 180, and I’ll have a couple of rpm restrictions, but nothing major. I still got a good prop here. Besides, I don’t need 200hp. I’m not trying for any time-to-climb records, and a 180hp engine is going to be easier on the wallet.

Took delivery of my prop today! Hartzell constant-speed blended-airfoil prop. With a spinner! Supposedly this prop is good on any Lycoming 180hp engine, given it’s set up for a constant-speed prop. If I do a 200hp engine, it needs to have a counterweighted crankshaft, or I’ll have rpm restrictions. So that’s a C1E6 with a front-mount sump or an A1B6.

Over the last couple of days, I’ve been pondering engine choices. I really like Jan Eggenfellner’s Subaru H6 package. I trust his judgement, and he has several happy customers who have installed it on their airplanes.. I’ve seen one fly. It makes neat sounds. The thing I don’t like about it is the price. I know all about how important it is to stay in business to continue to support the product and develop new things, and I realize he’s probably not making money hand over fist on this. Problem is, by the time you’ve put the Egg H6 on your firewall, plumbed everything, and bought what you need to make it work and work safely, you’re into about 28 kilodollars and that’s WITHOUT a prop.
I’m the worst.. I’ll oversimplify a complex problem, then not understand why it falls apart, which is surprising, given my line of work. However, I do know a complex problem when I see it and I’m well versed in learning from the mistakes of others. But here’s how I see it: Eggenfellner doesn’t open his engines. Gets ’em right out of the crate, new or barely used (5k price difference in the package), strips off the garbage that you need in a car, puts on a bell housing and PSRU, modifies YOUR engine mount, assembles it, along with the necessary cooling plumbed and mounted, then crates it up and sends it to you. Well, hell.
A quick search of car-part.com turns up an EZ30 for about $3500 and below. I can’t find a price on a new crated one, but a JDM EZ30R with the aggro cam, plastic intake, and AVCS goes for $1700. No ECU, but you can get that fairly easily too. Maybe, just maybe, by doing this myself, I can save enough for that electric constant speed prop.
Because the days of finding a mid-time lycoming for 8 grand that’ll be worth a damn are pretty much over.
More later. Sushi now.

Firewall forward progress goes here.