Re: Siezed low-time neglected turbocharger
Posted: Sun Feb 04, 2018 8:12 pm
NWade wrote:[However, the Aerovee and the Turbo still appeal over the alternatives in the following ways:
- Cost: The Rotax, Jabiru, and UL Power engines are all 2 - 3 times the cost of a Turbo. The Corvair is the only other engine in its cost bracket.
- Weight: The Turbo is still under 200 lbs, whereas Corvairs are ~225lbs. The Rotax and Jabiru beat both by a handy margin; but then it goes back to the "cost" line.
- Zero-time parts: Corvairs are all "salvage" engines, right? A lot of folks (myself included) are uncomfortable with the idea of an engine block that's got no history and has been sitting out in the elements for an unknown length of time. You can inspect it in-detail and clean it up, but you can never know what it went through before you found it.
--Noel
P.S. The frustrated cynic in me is compelled to point out that I've got experience with zero-time parts that are still wrong or have failed. :-P
I can't speak to other engines but I have owned and flown a NA VW conversion and a 3.0 Corvair on these air frames. I'd like to address answers to the comments above as directed at the Corvair engines.
1) Cost - Currently the Turbovee is 11,000.00 dollars for 100 HP. The 100 HP Corvair will be substantially less if assembled by the builder (both engines are builder assembled). Even if buying the complete "engine in a box" kit the price is near the same for the same HP.
2) Weight - If the Turbovee with all it's additional parts (additional oil pump, lines, pipe wrap, turbo heat shield & cover, etc) is still under 200 lbs ... it ain't by much and the proposed cooling system that adds complexity will also add weight that will certainly violate the 200 lbs FWF rule. As to the Corvair; my 3.0 is 218 lbs and the 3.0 & 3.3 with the newer billet cranks are even lighter as the billet crankshaft is less weight. Add to that the 20-25 more HP from these engines.
3) Zero Time Parts - True the Corvair reuses the case halves, head cores, and oil cover plate from the rear. But consider that every moving part is replaced with high quality, time tested, new parts. One can reuse the factory crank but new cranks are available, stainless steel valves, guides, rocker arms, purpose designed "dual fuel" forged pistons, forged connecting rods, new cam and gear, high volume oil pump, 5th bearing for prop loads, etc.
To your point about new parts being substandard ... there have been many horror stories on this list about builders receiving parts that had to be returned. The factory has used several suppliers of kit parts and there appears to be no symmetry or even a method to the madness. I'm not against a VW conversion on an airplane and even a lightly built, polished tail dragger that will fly lightweight people in the cooler parts of the earth. This is a great approach for the budget builder.
I stated before; "TANNTAAFL" and that is still true. Can a turbo be made to work on a VW and make enough power to fly this airplane in a manner that gives safety & reliability? I think the jury is still out on that question ...
Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
168.7 hours / Status - Flying
Member # 109 - Florida Sonex Association
https://www.youtube.com/watch?v=1VP7UYEqQ-g