Corky's engine choice

Hey Corky,

What was your beef with the 13B? I have to replace a car coming off
lease in the next few months and I'm seriously looking at older RX-7s
just to get a flavor for the power plant.

I like the idea of a no-seize failure mode and the idea of it being 2
co-axial engines in one. The higher fuel burn I can deal with,
especially since its mogas.

Regards

(Corky Scott) wrote in message ...
I thought I'd bring everyone up to date. It's true that I had
basically given up on using an auto conversion as I was having trouble
justifying the cost of the PSRU. I'd started with a Buick/Olds 215
cid aluminum block V-8 and then switched to the Mazda 13B. I disliked
all the problems associated with the 13B so I sold that too.

John Thompson wrote in message ...
Corky,
I think one of the biggest roadblocks in autoconversions is the lack of
"cookbooks". Instructions that cover things like that "stud stretching"
tip, why you might want to use this camshaft, or replace this part or
other, lifter bearing replacement, etc. and where to get them.

SNIP

John

Amen to that, but what scares me about auto conversions is the that
the design parameters for the auto engine are based on 25-30% constant
power at hiway cruise.
The reliability of the engine in automotive use is therefore not a
meaningful indication of fitness for flight.
Even with the engine blueprinted and a beefed up cooling system and
oil cooler added, when you run that engine at constant 75-80% power in
an aircraft you are likely to have 'hot spots` in there somewhere
which can play hell with reliability.
Do a lot of base testing Corky, and good luck to ya.

We have been flying the Ford V-6 for almost 20 years now with several
installations making 2000 hours TBO. All of the idiosyncrasies have pretty
well been figured out. Same is true for the Chevy V-6s. "Not designed to put
out 60, 80, 100% power," was the cry 20 years ago. "They'll be falling out
of the sky and will destroy the homebuilt movement," was the second most
bandied phrase. You should do a search and read Corky's past posts (he has
said it all very succinctly) to read what an auto engine goes through before
the manufacturer installs it in an automobile model. Automotive durability
tests exceed, by about 400%, anything required to certify an aviation type
engine. (both in hours and precentage of power output)
--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
Homebuilt Aircraft Newsletter"

| Publishing interesting material
| on all aspects of alternative
| engines and homebuilt aircraft.


"pragmatist" wrote in message
om...
John Thompson wrote in message
...
Corky,
I think one of the biggest roadblocks in autoconversions is the lack of
"cookbooks". Instructions that cover things like that "stud stretching"
tip, why you might want to use this camshaft, or replace this part or
other, lifter bearing replacement, etc. and where to get them.

SNIP

John

Amen to that, but what scares me about auto conversions is the that
the design parameters for the auto engine are based on 25-30% constant
power at hiway cruise.
The reliability of the engine in automotive use is therefore not a
meaningful indication of fitness for flight.
Even with the engine blueprinted and a beefed up cooling system and
oil cooler added, when you run that engine at constant 75-80% power in
an aircraft you are likely to have 'hot spots` in there somewhere
which can play hell with reliability.
Do a lot of base testing Corky, and good luck to ya.

There is nothing wrong with the Mazda engine. All of the earlier problems
have been dealt with effectively and you are likely to see more and more
installations as the word gets out that the Mazda DOESN'T use excessive fuel
or burn up properly designed exhaust systems. But it is loud and most
builders seem to eventually opt for a muffler of some kind. Pound for pound
here is no higher horse power output in a normally aspirated auto conversion
than that of the Mazda Wankel.

Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
Homebuilt Aircraft Newsletter"

| Publishing interesting material
| on all aspects of alternative
| engines and homebuilt aircraft.




"Jay" wrote in message
om...
Hey Corky,

What was your beef with the 13B? I have to replace a car coming off
lease in the next few months and I'm seriously looking at older RX-7s
just to get a flavor for the power plant.

I like the idea of a no-seize failure mode and the idea of it being 2
co-axial engines in one. The higher fuel burn I can deal with,
especially since its mogas.

Regards

(Corky Scott) wrote in message
...
I thought I'd bring everyone up to date. It's true that I had
basically given up on using an auto conversion as I was having trouble
justifying the cost of the PSRU. I'd started with a Buick/Olds 215
cid aluminum block V-8 and then switched to the Mazda 13B. I disliked
all the problems associated with the 13B so I sold that too.

In article
, BRUCE
FRANK wrote:

Automotive durability
tests exceed, by about 400%, anything required to certify an aviation type
engine. (both in hours and precentage of power output)
--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL

I am happy to concede that some automotive engines may have undergone
durability testing that is more severe than that required for aviation
engines. However, it is overstating the case significantly to say that
these automotive engine tests exceed by 400% the power output required
for the aviation engine tests.

The aviation engine tests have many sections at 100% power. If you
exceed that by 400% you have to run at 500% power.

It doesn't help your credibility to state "facts" that are obviously
wrong. Type a bit slower next time.

--
Kevin Horton - RV-8
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/

I just had the head gaskets in my Windstars 3.8 replaced last year.
about 115K miles at that time, I think.

John

On Fri, 25 Jul 2003 11:05:21 GMT, Kevin Horton
wrote:

In article
, BRUCE
FRANK wrote:

Automotive durability
tests exceed, by about 400%, anything required to certify an aviation type
engine. (both in hours and precentage of power output)
--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL

I am happy to concede that some automotive engines may have undergone
durability testing that is more severe than that required for aviation
engines. However, it is overstating the case significantly to say that
these automotive engine tests exceed by 400% the power output required
for the aviation engine tests.

The aviation engine tests have many sections at 100% power. If you
exceed that by 400% you have to run at 500% power.

It doesn't help your credibility to state "facts" that are obviously
wrong. Type a bit slower next time.

--
Kevin Horton - RV-8
Ottawa, Canada

Kevin, you have to read what Bruce said carefully. He said that the
**DURABILITY TESTS** "exceed, by about 400", anything required to
certify an aviation type engine." He did not say anything about
exceeding the 100% power tests for aircraft certification.

Looks like it's time for me to re-post that article from an automotive
engineer about the typical engine development durability tests. I'll
post it in a seperate article so as not to muck up this thread.

Corky Scott
http://go.phpwebhosting.com/~khorton/rv8/

On Fri, 25 Jul 2003 12:20:09 GMT,
(Corky Scott) wrote:

Kevin, you have to read what Bruce said carefully. He said that the
**DURABILITY TESTS** "exceed, by about 400", anything required to
certify an aviation type engine." He did not say anything about
exceeding the 100% power tests for aircraft certification.

Looks like it's time for me to re-post that article from an automotive
engineer about the typical engine development durability tests. I'll
post it in a seperate article so as not to muck up this thread.

Corky Scott
+++++++++++++++++++++++++++++++++++++

Post away. Repeat again and again, but...
a chain is only as strong as it's weakest link --
certified or Rube Goldberged. Not to mention,
form follows function where max safety is concerned.
So, blithely and happily, convert away. One soul claims
2000 hours.Why not you, too? You only live once.
So, go for it. What have you got to lose?

I know that you are comfortable with your endeavor,
but you'll not ever get me to fly outside gliding distance
of the airport unless I incur an unbridled passion to not
be pigeon holed in an nursing home for seniors.
And... that could happen. ;o(


Barnyard BOb -- 50 years of flight

On Fri, 25 Jul 2003 09:12:08 -0400, "Larry Smith"
wrote:


"Corky Scott" wrote in message
...
On Thu, 24 Jul 2003 02:33:33 GMT, clare @ snyder.on .ca wrote:
[...]they will hold constant pressure.

They were suggesting I use the old head gaskets for the initial
startup as it really didn't matter what you used. Cardboard would
work (they said) since you are just running it to temperature then
shutting it down again. Of course, I did not save the original
gaskets when I dismantled the two engines so I'll have to buy an extra
two.

Just another one of those tricks to remember when building engines.
I'm sure Lycoming and Continental engine rebuilders have their own
tricks.

For heads? Most aircraft engine heads screw onto the cylinders with an
interference fit. The process is always done at the factory or repair
station. And plenty of heat is required.

I didn't mean for heads specifically, just building the engine in
general. There are always some things you learn after building a few
that work well for that engine. When I was a mechanic, I ended up
sort of specializing in Subaru's and found out early on that Subaru
engines had this hidden bolt that held a part of the two block halve's
together. It wasn't a big bolt and one wonders why it was necessary
at all, but there it was. It was always hidden by encrusted oil and
dirt and you literally had to dig it out so you could get a socket on
it. Couldn't split the block halves without first removing that bolt.

Personally, I'm fascinated with your use of the Ford V-6 and commend you on
it. I wouldn't want to fly one here in the mountains, but where there are
plenty of fields to put down in, I'd make a go of it. Good slow stall
speed, halon fire extinguisher, and shoulder belts would be a must too.

Would you be interested to know that there are hundreds of this engine
flying and that many have accumulated significant hours of operation.

At least one ran to beyond 2000 hour before the owner/builder did a
preemptive teardown for inspection. He found little wear in the
engine and the belt drive showed no discernable wear either. He did
replace the drive belt anyway though.

Corky Scott

In article , Corky Scott
wrote:

On Fri, 25 Jul 2003 11:05:21 GMT, Kevin Horton
wrote:

In article
, BRUCE
FRANK wrote:

Automotive durability
tests exceed, by about 400%, anything required to certify an aviation type
engine. (both in hours and precentage of power output)
--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL

I am happy to concede that some automotive engines may have undergone
durability testing that is more severe than that required for aviation
engines. However, it is overstating the case significantly to say that
these automotive engine tests exceed by 400% the power output required
for the aviation engine tests.

The aviation engine tests have many sections at 100% power. If you
exceed that by 400% you have to run at 500% power.

It doesn't help your credibility to state "facts" that are obviously
wrong. Type a bit slower next time.

--
Kevin Horton - RV-8
Ottawa, Canada

Kevin, you have to read what Bruce said carefully. He said that the
**DURABILITY TESTS** "exceed, by about 400", anything required to
certify an aviation type engine." He did not say anything about
exceeding the 100% power tests for aircraft certification.

Looks like it's time for me to re-post that article from an automotive
engineer about the typical engine development durability tests. I'll
post it in a seperate article so as not to muck up this thread.

Corky Scott
http://go.phpwebhosting.com/~khorton/rv8/


You've got me really confused now. I thought that when he said "both
in hours and precentage of power output" he meant that the 400% claim
applied to percent power as well as to hours. If he didn't mean that,
what was the "... and precentage of power output" statement referring
to?

I assume that Bruce simply didn't proof read closely enough. If he in
fact meant what he said, I can't understand how it is supposed to be
interpreted differently than I have discussed here.

FAR 33.49 Endurance Tests requires specified times at specified power
levels, including quite a few periods at 100% power. The automotive
durability tests have long periods at 100% power. Thus the power
levels are the same. There is a big difference in the amount of time
at 100% power though, I am not arguing with you on that issue.

--
Kevin Horton - RV-8
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/