R680 Powered Beech 18

In article EhXub.249932$HS4.2225277@attbi_s01,
"Robert Bates" wrote:

The only one I saw was at Steve Wolfe's hanger in the early '90s and I
thought that it was interesting at the time but I didn't learn any more
about it than the engine installation. The performance specs for the Jacobs
powered version would also work. What I am trying to accomplish is an
interesting, but affordable to fly classic by re-powering an engineless
Beech 18.



What you would end up with is an underpowered, overweight,
underperforming paperweight, as the STC process would be overwhelming.

Big John wrote in message . ..
Robert

The Beech 18/ C-45/ AT-11 were the same 'basic' airplane.

The first 40 built in the late 30's had 330 HP Jacobs with P & W 450
HP engines in the Military C-45/AT-11/etc.

I got some time in the C-45.with the 450 HP P & W engines.

Your R680 is the 300 HP Lycoming (Model HRE). Didn't find any mention
of this engine in the early D-18's but may have been a proto or first
engine before they went to the 330 Jake?


Don't forget that the early aircraft certified under TC's 630 and
A684 could have been powered by Wright 760's....

Craig C.

TC,

The AT-10 you mentioned did ring a few bells. Talk about an
incredibly rare airplane that wasn't built to last...wooden fuel tanks
wrapped in rubber, amazing. I wonder if any are in existence outside
of museums, they'd be even more costly to keep flying than a Cessna
T-50.

I've flown the 300 hp Boeing Stearmans and have always thought that
was the correct engine for that airframe as the original 220 hp
version is pretty badly underpowered. I had no idea that the engine
mod was essentially a bolt on from the AT-10. I had a vague
understanding that a lot of BT-13s gave their all for the R-985 mount
so the Boeings could become crop dusters.

So, AT-10s from Beech live on (in part) on Boeings built about five
miles southeast...

Now, as to putting an R-680 on a Beech 18 airframe that wasn't
originally designed for the small engines....well there are
'interesting' ideas all the time in aviation. Just yesterday I got
word of a guy who droped a Chevy V8 into a Cessna 150, used rubber
hoses for the fuel lines and couldn't seem to understand why the FAA
was a little less than understanding about the whole thing. Just
because he hadn't sought to get any sort of approval before deciding
to fly it...

All the best,
Rick

wrote in message . ..
On 19 Nov 2003 08:02:58 -0800, (Rick Durden)
wrote:

snip

Where in the world have you found an R-680 powered Twin Beech? That
has got to be an incredibly rare beast. I thought only one or two of
the very first ones had other than Pratt and Whiskey R-985s. The
early ones were much lighter, but, still, the performance had to be
marginal at best.

Have you ben able to get your hands on a manual for the R-680 powered
model? Given that it would have been written in the 1930s when most
manuals were pretty basic, I'd be curious what it reported about
performance. Does the airplane even have feathering props? What is
the serial number of this airplane?

snip

My initial thoughts are that Beech made a twin trainer similar to the
Bamboo Bomber that was powered by 300 hp R680's.

There are quite a few Stearmans flying around with 300 hp 680's that
are an STC'd install using the modified engine mount, dishpan, etc.
from the the Beech twin trainer.

http://www.wpafb.af.mil/museum/early_years/ey23.htm

TC

("Rick Durden" wrote)
snip
Now, as to putting an R-680 on a Beech 18 airframe that wasn't
originally designed for the small engines....well there are
'interesting' ideas all the time in aviation. Just yesterday I got
word of a guy who droped a Chevy V8 into a Cessna 150, used rubber
hoses for the fuel lines and couldn't seem to understand why the FAA
was a little less than understanding about the whole thing. Just
because he hadn't sought to get any sort of approval before deciding
to fly it...

Wonder if he took the engine out of his hot-rod Chevy Vega? You know the
Vega - Monster slicks in the rear (along with wheelie bars) and a gigantic
hood scoop for the engine. In about 1976, every neighborhood had one of
these creations - tooling around, doing burn-outs at stop signs, etc.

That was my first thought when I read your post ...can the pilot see over
the hood scoop?

--
Montblack

"Rick Durden" wrote in message
m...
TC,

snip lots of good stuff

Now, as to putting an R-680 on a Beech 18 airframe that wasn't
originally designed for the small engines....well there are
'interesting' ideas all the time in aviation. Just yesterday I got
word of a guy who droped a Chevy V8 into a Cessna 150, used rubber
hoses for the fuel lines and couldn't seem to understand why the FAA
was a little less than understanding about the whole thing. Just
because he hadn't sought to get any sort of approval before deciding
to fly it...


Sounds like someone was watching too much "Monster Garage" on Discovery. Makes
the banner tow company I worked for look good and professional.

--
Mike

On 20 Nov 2003 07:36:47 -0800, (Rick Durden)
wrote:

TC,

The AT-10 you mentioned did ring a few bells. Talk about an
incredibly rare airplane that wasn't built to last...wooden fuel tanks
wrapped in rubber, amazing. I wonder if any are in existence outside
of museums, they'd be even more costly to keep flying than a Cessna
T-50.

I've flown the 300 hp Boeing Stearmans and have always thought that
was the correct engine for that airframe as the original 220 hp
version is pretty badly underpowered. I had no idea that the engine
mod was essentially a bolt on from the AT-10. I had a vague
understanding that a lot of BT-13s gave their all for the R-985 mount
so the Boeings could become crop dusters.

So, AT-10s from Beech live on (in part) on Boeings built about five
miles southeast...

Now, as to putting an R-680 on a Beech 18 airframe that wasn't
originally designed for the small engines....well there are
'interesting' ideas all the time in aviation. Just yesterday I got
word of a guy who droped a Chevy V8 into a Cessna 150, used rubber
hoses for the fuel lines and couldn't seem to understand why the FAA
was a little less than understanding about the whole thing. Just
because he hadn't sought to get any sort of approval before deciding
to fly it...

sig snip

I'm one of those picky IA's that thinks "An aircraft or part is in an
Airworthy condition if it conforms/meets its type certificate data
sheet or proper altered condition" isn't an optional kind of
statement.

So when I dug into the maintenance records of a 300 hp Stearman at
annual time, the aforementioned STC got my attention. Thought the
AT-10 designation was vaguely familiar, dug out my dog-eared copy of
the The Immortal Twin Beech (Larry Ball) when I got home and found a
reference to it.

Have spent a lot more time working on the R985-AN14B than I have on
the 300 hp R680(don't remember the suffix). The R680 on the Stearman
wasn't exactly my favorite engine. I enjoyed driving it around, but
spent too much time working on it.

The R680 wasn't originally a top-oiled engine, instead had hollow
rocker shafts equipped with grease zerks. The 300 horse version I
worked on had an internal orifice that had to be inspected/cleaned
regularly to ensure/insure said top-oiling was present.

The valve train required frequent inspection/adjustment/rocker bearing
replacement (200 hours/annually tops). Was never sure whether this was
a lubrication issue, or an issue with the replacement parts that were
available.

The upper cylinder castings were kinda scary. Again, not sure if this
wasn't in part due to the "parts" available. All I know is that I blew
the sidewalls out of several of them while carefully r/r'ing the
rocker assemblies.

Contacted the guy that had overhauled the engine I was working on, he
told me in regards to TBO "if you think it's getting shaky, yank that
bitch-it will come apart on ya"-to paraphrase slightly.

Can't compare the 300 hp Stearman to any others, it was the only one
I've ever had the pleasure of flying. Couldn't get it to snap to save
my life, later found out that the military added extended stall/spin
strips on the bottom wing to aid the airflow in leaving the wing when
desired. Have looked at a bunch of other examples, have yet to come
across one with the strips installed.

Worked on "Super" 18's in the early 80's, performed all the
maintenance related to about 12,000 operating hours hauling auto
parts. Wish I had one to play with now...

Regards;

TC

On 20 Nov 2003 07:36:47 -0800, (Rick Durden)
wrote:

TC,

The AT-10 you mentioned did ring a few bells. Talk about an
incredibly rare airplane that wasn't built to last...wooden fuel tanks
wrapped in rubber, amazing. I wonder if any are in existence outside
of museums, they'd be even more costly to keep flying than a Cessna
T-50.

I've flown the 300 hp Boeing Stearmans and have always thought that
was the correct engine for that airframe as the original 220 hp
version is pretty badly underpowered. I had no idea that the engine
mod was essentially a bolt on from the AT-10. I had a vague
understanding that a lot of BT-13s gave their all for the R-985 mount
so the Boeings could become crop dusters.

So, AT-10s from Beech live on (in part) on Boeings built about five
miles southeast...

Now, as to putting an R-680 on a Beech 18 airframe that wasn't
originally designed for the small engines....well there are
'interesting' ideas all the time in aviation. Just yesterday I got
word of a guy who droped a Chevy V8 into a Cessna 150, used rubber
hoses for the fuel lines and couldn't seem to understand why the FAA
was a little less than understanding about the whole thing. Just
because he hadn't sought to get any sort of approval before deciding
to fly it...

sig snip

I'm one of those picky IA's that thinks "An aircraft or part is in an
Airworthy condition if it conforms/meets its type certificate data
sheet or proper altered condition" isn't an optional kind of
statement.

So when I dug into the maintenance records of a 300 hp Stearman at
annual time, the aforementioned STC got my attention. Thought the
AT-10 designation was vaguely familiar, dug out my dog-eared copy of
the The Immortal Twin Beech (Larry Ball) when I got home and found a
reference to it.

Have spent a lot more time working on the R985-AN14B than I have on
the 300 hp R680(don't remember the suffix). The R680 on the Stearman
wasn't exactly my favorite engine. I enjoyed driving it around, but
spent too much time working on it.

The R680 wasn't originally a top-oiled engine, instead had hollow
rocker shafts equipped with grease zerks. The 300 horse version I
worked on had an internal orifice that had to be inspected/cleaned
regularly to ensure/insure said top-oiling was present.

The valve train required frequent inspection/adjustment/rocker bearing
replacement (200 hours/annually tops). Was never sure whether this was
a lubrication issue, or an issue with the replacement parts that were
available.

The upper cylinder castings were kinda scary. Again, not sure if this
wasn't in part due to the "parts" available. All I know is that I blew
the sidewalls out of several of them while carefully r/r'ing the
rocker assemblies.

Contacted the guy that had overhauled the engine I was working on, he
told me in regards to TBO "if you think it's getting shaky, yank that
bitch-it will come apart on ya"-to paraphrase slightly.

Can't compare the 300 hp Stearman to any others, it was the only one
I've ever had the pleasure of flying. Couldn't get it to snap to save
my life, later found out that the military added extended stall/spin
strips on the bottom wing to aid the airflow in leaving the wing when
desired. Have looked at a bunch of other examples, have yet to come
across one with the strips installed.

Worked on "Super" 18's in the early 80's, performed all the
maintenance related to about 12,000 operating hours hauling auto
parts. Wish I had one to play with now...

Regards;

TC