----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
From: William R. Bayne
[mailto:[EMAIL PROTECTED]
Sent: Friday, November 18, 2005
9:03 PM
To: roger anderson;
Cc: 'Coupe-Tech'
Subject: Re: WRB Re:
[COUPERS-TECH] Costs involved inconverting 65hp engine to 75hp or 85hp
RLYTECH
Hi Roger,
Al said he was currently coupeless and shopping for an aircraft, so my response
did presume his primary interest to be coupes.
Accordingly, the A-75 is not listed in the Ercoupe Aircraft Type Certificate
No. 718 as an optional powerplant, nor was this engine ever installed in a
later model coupe by any manufacturer. I concluded that such a conversion was
probably not a financially viable one on a 65hp engine in a prewar coupe if 75+
horsepower was ultimately desired. I stand by that.
There are prewar coupes that have been retrofitted with the C-75 fitted to
postwar airframes, but each was by engine replacement (as opposed to
conversion). Such is a whole different proposition, generally, in terms of
related expense.
The high probability that Al had no serious intention to underwrite the first
approved A-65 to A-75 conversion in a coupe does not excuse my having made a
statement unintentionally too broad in scope when taken out of context. It was
certainly not my intention to mislead anyone, and I apologize to such extent as
this may have resulted.
Best Regards,
WRB
--
On Nov 18, 2005, at 6:33 PM, roger
Actually, and not that it probably
has been done in a Coupe, but an A65 can be easily converted to an A75.
It isn't much more than changing the prop to gain additional
rpm/hp. Some Aeroncas do this as an easy performance (maybe)
increase. Still no electrical though. roger
-----
Original Message -----
From:
To:
'Coupe-Tech'
Sent:
Friday, November 18, 2005 6:09 PM
Subject:
FW: WRB Re: [COUPERS-TECH] Costs involved inconverting 65hp engine to 75hp or
85hp
From:
William R. Bayne [mailto:[EMAIL PROTECTED]
Sent:
Friday, November 18, 2005 6:07 PM
To:
Subject:
WRB Re: [COUPERS-TECH] Costs involved inconverting 65hp engine to 75hp or 85hp
RLYTECH
Al,
The 65hp Ercoupes (prewar) have the A-65 Continental. This engine has no
provision for a generator or starter, and most did not originally have the
necessary electricals (wiring, battery) for night flight. They also had only
one wing tank! The A-65 engine cannot be "upgraded" to anything else.
The postwar Ercoupes up through the CD Model were fitted with the C-75 engine,
starter, generator, battery, etc. The E and G Models had the C-85. There is
very little difference between the C-75 and the C-85. Many 75 hp have been
converted to 85 hp. I'm not entirely convinced that this conversion makes a
meaningful improvement in actual performance. A full explanation as to why is
rather involved and more than I will attempt herein.
Because C-75/C-85 cranks are increasingly hard to find, several STCs have been
approved allowing use of C-90/0-200 cranks, rods and pistons in overhauling
C-75/85 engines. This conversion is quite worthwhile. Knowledgeable "fine
tuning" of such can yield climb and/or cruise performance equal or
exceeding a C-90 or 0-200 (depending on propeller and pitch selected). If the
overhauled engine has a good crank, it might sell on eBay for something near
the cost of the STC and necessary parts! If the crank is bad, you need a crank
anyway.
Forneys, Alons and M10s originally fitted with the C-90 tend to weigh 100 lbs +
more than an Ercoupe due to metal wings, additional equipment and upholstery.
This seems to usually cancel out any performance advantage the
"extra" 5 hp might otherwise offer the original airframe.
Any facility run by an A&P or IA is "qualified" according to the
FAA to do this, but you would best search for one that has successfully done
the operation once (or more, as you would a doctor). You should not volunteer
yourself, your plane and your wallet as a guinea pig for anyone to learn on at
your expense.
Best of luck,
William R. Bayne
<____|-(o)-|____>
(Copyright 2004)
--
On Nov 18, 2005, at 5:21 PM, Al Ebbers wrote:
Hi: Right now I'm a Coupeless member. As I shop around for an aircraft
I was wondering what it would cost to convert a 65 hp engine to a 75 or 85
hp engine. And if such an engine was converted to the higher horsepower, would
the work performed qualify that as a major overhaul for engine
time. And, along the same line does anyone know of a facility or AP
that is qualified in
Al Ebbers
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