I have been surprised at the recent flurry
of carb postings. I assumed that everyone was doing EFI. having
experienced total electrical failure in march on a trip to the Bahamas I was
thinking a lot about that Neanderthal carb bolted under my O320 and the
magnetos, all unaware of what was going on in the radio, GPS, and nav
lights departments. the reality is that you don't want a
reserve battery to get you to the ground safely, you want to get to the
Bahamas and back and THEN look into what's wrong.
my questions are "how much power/performance
is lost with a carb, and which carbs can do manual mixture?". is it
stupid to ask if the Lycoming carb could run a 13B? someone mentioned
Harley carbs having a good history of rough service. what
about marvel/schebler? is this question heresy? :-) isn't efi a
bit of overkill for an engine that basically runs at 100% power, 75% power
and idle? scanning thru the archives I see a lot of postings regarding
mixture, mapping, abrupt failures and such. does this complexity buy
us 5%, 20%? the question of turbo-charging seems to beg similar
line of questioning. kevin
Kevin, not heresy at all. There are several factors here.
First Tracy is doing some development work, but offering a very inexpensive
EMS. Once you get everything right it should give great service. Ed Anderson
is a good indicator that the system will run for a long time once dialed in.
Some guys are doing fully redundant alternators AND batteries and not just
because of the engine, rather a fully electrical panel. Go with what you feel
secure with, and fly accordingly. I have posted before that mags can have
trouble with high RPM engines. So unless you have an early front cover and are
willing to run POINTS, you will still need an ignition.
Most of the carb inquiries have been on account of
George and Richard going with single rotors. I believe Richard may have a
modified stocker ignition and a carbed P-port. He has done us all a great
service building, and now testing a hybrid end plate. mostly aluminum, with a
steel insert. (GOOD LUCK RICHARD!) Lynn and I have both grafted old
mopar EI ignitions on to other engines. These require battery power but are
otherwise unkillable. Available for next to nothing from J.C. Whitney but you
must do the set up and wiring yourself.
Tracy's system looks to be a good one, but you must realize
that wiring and plumbing ABSOLUTELY MUST BE DONE PROPERLY. This is equally
true of a Lycoming install, but more of the FWF or FWB (Canard) is available
to you off the shelf. We lost Buly to some mistakes that he made with the
wiring, not a complete failure, but intermittently causing him fail to
start problems out of the blue. Buly is a good builder too and the
troubles drove him and Tracy crazy. Only when he finally pulled his control
box for an update could Tracy find the problem. He is putting in a Lyc.
clone. This is a terrible loss for us. The problem was self generated, (he
re-soldered a connector to gain clearance rather than re-do the panel), and
that connector had the classically difficult to diagnose intermittent problem.
Bully and family made the tough decision to forgo any further pioneering. To
bad too, his plane would have been a great addition to the conversion
"fleet." The point here is, like flying a cross-country, plan the
install and then stick to the plan. If you run into a bind do the needed
rework and don't "make do."
You can go with carbs or EFI, there are several,
Tracy's is aviation redundant, and the cheapest though. You must be able to
understand the needs of digital electronics to install ANY EFI or EMS.
Troubleshooting wiring is always the toughest job!
This is a super long post already but I must tell you
about a failure I had back in the days I did mechanics work to pay for school.
I was doing a tune-up on a Kawasaki 175 single. Mag ignition 2 cycle, came in
running for a regular service. I did points, timing, plug, carb adjustment,
the works... After finishing my labors, THE DAMM BIKE WOULDN'T START! I
checked spark with a test plug on the cylinder head and drained the float bowl
to check fuel it was clean. This is the simplest engine in the world, a 2
stroke single! To cut to the chase the brand new SPARK PLUG was bad. I broke
it apart later to check and found someone on the production line had left out
the copper core connecting the top of the plug to the center electrode. The
point is no matter how simple you think a job is it still requires logic and
perseverance to be SURE everything is correct. And even "simple" stuff can
fail.
Bill Jepson
Bill,
I couldn't find that Mopar EI in the JC Whitney site - can
you give me some direction as to what that is listed under - I had a look at
electrical.
George ( down under)
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