Aerovee Concerns/Clarifications for a Newbee

[gammaxy]

Mike,

Have you already shared your improved intake elbows with the forum? If they aren't too difficult to install, I'd be interested in getting some and trying them out.

[Onex107]

In conclusion, I chose the Aerovee for all the good reasons. The only problems I have had were caused by me, made during assembly. Easily corrected. The Hobbs just turned 151.3 hours and I'm looking forward to hundreds more.

In an earlier post you mention losing a cylinder due to a fouled plug. Do you feel like this was a problem you caused during assembly? What do you think the culprit was? I would expect that the big gaps (compared to other aviation engines) and the redundant ignition would make completely losing a cylinder due to fouling while in flight (at high power settings) to be pretty unlikely.

I didn't go into a lot of detail about "problems caused by me". First of all, I think this Forum needs a technical site similar to Service Bulletins that are not just complaints but problems that can be avoided by future builders. Factual problems and solutions. The problem I had with carbon fouled plugs was caused by a broken oil ring on #1 piston. I was pumping oil in that cylinder and large pieces of carbon, chipping off the piston face, would short out the plugs. This is a fact about oil rings. The rings that came with my engine kit had a small turned up end on each end of the ring intended to prevent overlap and loss of tension on the cylinder wall. I found one of the turned up ends broken off, laying in the groove. The new ring set I purchased had small red and green plastic blocks molded on the ends of the ring so when you slid it into the cylinder you could see red and green and know the ring hadn't overlapped. I included this problem in my "caused by me" file. An obvious improvement from the rings in stock at Aerovee in 2012.

[Onex107]

The Aerovee is a proven engine, but, it must be assembled, adjusted, and maintained by you.
The advantages of the Aerovee are low initial cost, maintenance expenses, and overhaul cost. And, the Sonex line was designed with that engine in mind.

I agree. I have 220 hours on mine, and after the initial break-in of the engine and the AeroInjector, it's been pretty gas-and-go. I adjust the valves at least every 25 hours, get an oil sample report at every oil change (25 hours), and clean the air filter every now an then. In 3 years and 220 hours I haven't even yet had to replace a spark plug; just cleaned and gapped them. They've been in very good shape at each annual condition inspection. We'll see how they look this spring at the next inspection. I highly recommend getting oil analysis no matter what engine you have. If anything is going on in the engine, it will likely begin to show up as a trend in the reports.

When I had a prop strike a year ago I had the engine apart and cleaned in 2 evenings, and installed a new crank and bearings in 2 more evenings (doing that essentially means putting 90% of the engine back together again). If I had not been the builder of the engine the prop strike would have been a MUCH larger event. Incidentally the inside of the engine, including the crank and bearings, looked almost new. I replaced them from an abundance of caution, and because it would have taken too long and cost too much to send out the crank for inspection.

I've flown two trips to Oshkosh, totaling almost 4,000 miles with no mechanical issues. That was running the engine 10 hours a day.

My biggest "issue" with the VW is I can't seem to keep the right pushrod tubes from seeping oil. It amounts to maybe a teaspoon for every couple of hours of flight, so it's not enough to really even register on the dipstick, but it does register as drips on the pavement under my cowl. It's more of a nuisance than anything. I've tried several times to do all the things you're supposed to do to keep them from weeping, but so far I'm still trying. That's really a VW thing and not an AeroVee thing.

Mike I had the same problem, "caused by me" category. The tubes leaked on one side, the other side was tight. I didn't want to pull the head to do it again. I bought tubes from one of the VW supply sites that are two piece aluminum, one end threaded with double nuts and an O-ring. You take out the push rods, cut the old tubes out and install and tension the new ones. If any one still shows a little oil you take another turn on the lock nut. No more mess in the cowling.

[Ercoupechris]

[quote="Onex107"] The advantages of the Aerovee are low initial cost, maintenance expenses, and overhaul cost AND, the Sonex line was designed with that engine in mind.

Not entirely accurate. The Sonex line was designed with the 2200 Jabiru in mind. Thats why they had to introduce the wider universal cowl that effected the aerodynamic contour of the cowl to fuselage because the VW is wider. I will cede that the horsepower range of the Aerovee made it a good fit and COST was the reason Sonex later introduced the Aerovee. Not a knock on the Aerovee, I opted for the Jabiru 3300 but that also has its own challenges, There is no free lunch when it comes to powering a Sonex.

[John Monnett]

It is not true that the AeroVee was added to the Sonex as an afterthought. It is true the first Sonex (SX-1) was originally powered by a Jab but the design was conceived and built around the 80 hp VW conversion I was developing called the "AeroVee" for Sonex designs. It is, by far, the most popular engine choice.

[mike.smith]

Mike I had the same problem, "caused by me" category. The tubes leaked on one side, the other side was tight. I didn't want to pull the head to do it again. I bought tubes from one of the VW supply sites that are two piece aluminum, one end threaded with double nuts and an O-ring. You take out the push rods, cut the old tubes out and install and tension the new ones. If any one still shows a little oil you take another turn on the lock nut. No more mess in the cowling.

I already have those, and after installing them once, and reinstalling them a second time, no improvement (I bought them because I couldn't get the stock tubes to stop weeping). I want to put a little video camera in there someday and video the tubes while I'm flying. I'd love to get a better overall picture of where and how it's coming from.

[Ercoupechris]

It is not true that the AeroVee was added to the Sonex as an afterthought. It is true the first Sonex (SX-1) was originally powered by a Jab but the design was conceived and built around the 80 hp VW conversion I was developing called the "AeroVee" for Sonex designs. It is, by far, the most popular engine choice.

My apologies John,

My facts were derived from the book "From Sonerai to Sonex", "The Sonex Story" DVD 5:02 mark. It also appeared that the revised universal/Aerovee cowling, that does cause an hourglass shape at the firewall/cowling intersection (unlike the Jabs), might have been an afterthought and would feed into those assumptions . I defer to your statements ALWAYS. My apologies for misstating the facts.

I agree with it being the most popular engine choice, primarily due to cost, but you'd have to admit that the airframe benefits from more horsepower as does the resale value. Thank you for the "B" model, I love the refinements!!! and thank you again for setting the record strait. See you at Sun N Fun in a few weeks

[Area 51%]

For those with what may look like a pushrod tube seal leak, don't discount the rocker stud seals. Those little mutts, especially if the wrong size, will weep/leak oil and it drips down to resemble a tube seal leak.

Ask me how I know.

Degreasing the concrete here regularly @Area 51%

[John Monnett]

" but you'd have to admit that the airframe benefits from more horsepower as does the resale value. "

There is, of course, no substitutes for cubes in performance ( unless you have a jet)! But regarding higher resale value, it depends on a lot more than just engine size. Is the initial higher cost of of alternate (bigger) engines offset by the higher resale price? Instruments, workmanship miss. accessories, pressure and circumstances to sell all have a bearing on the resale value. In general some in the past, for the latter of those reasons, have established unfairly, a perception of a low resale market value for "used" Sonex aircraft that affects future sales. Some are just willing to take a beating for a quick sale driving the market down. BTW, This is not just a Sonex problem...

[Ercoupechris]

" but you'd have to admit that the airframe benefits from more horsepower as does the resale value. "

There is, of course, no substitutes for cubes in performance ( unless you have a jet)! But regarding higher resale value, it depends on a lot more than just engine size. Is the initial higher cost of of alternate (bigger) engines offset by the higher resale price? Instruments, workmanship miss. accessories, pressure and circumstances to sell all have a bearing on the resale value. In general some in the past, for the latter of those reasons, have established unfairly, a perception of a low resale market value for "used" Sonex aircraft that affects future sales. Some are just willing to take a beating for a quick sale driving the market down. BTW, This is not just a Sonex problem...

Thanks for the reply John, I agree that there are an awful lot more reasons that effect resale value. as you may know, I am knee deep in the Waiex 0064 that is being built as a "B" model. I was one of the guys a year ago at Sun N fun saying "Take my money". I am quite sure that I will never sell this plane once its completed. Thats why I am sparing no expense (am on budget to have over $50k when done) I am building the plane that I want based on the design that I most believe(d) in. Yes there will be the "Video games" as you describe them in the panel and more complexities than are necessary, but it will be mine. Thanks for the interactions here.

Best to you, Betty and the rest of the Sonex team. See you guys at Sun N Fun.