Corvair conversion engines

On Fri, 20 Jan 2006 13:17:48 -0600, "Montblack"
wrote:

wrote)
I bought two 3.8L Ford V6's for $150 each, bought new pistons from Roush
racing, new rings, had the best block shot peened bored and honed, had the
best crank turned and nitrided, bought new bearings, new cam, new
distributer with two sensors installed for dual ignition, new pistons, new
timing gears and chain, planed the heads, had four new intake valves
installed and new guides installed as well, new valve springs, roller
rockers, new lifters, new carburetor, old style NWAero psru, ARP studs for
the crank bearings and cylinderheads, fabricated my own headers, and STILL
spent only about $6,000.


Why not fuel injected?

Also, is that two for $3K each?

What does that setup weigh?

Was matching a prop to your engine a problem? 3 bladed prop?

Curious...


Montblack

I didn't go fuel injected for two reasons, simplicity and safety.
Carburetors don't need an electrical system to operate and are
basically pretty simple. If you are a mechanic, carburators are easy
to diagnose and repair. Fuel injection requires a relatively high
pressure fuel pump and of course, the injectors. Both of which are
likely electrically operated. The carburetor *may* use a fuel pump,
but it's of the 5 - 7 psi variety, and with a high wing airplane,
isn't absolutely necessary in order to get fuel to the carburetor. So
if the fuel pump fails, you likely will still be running.

Plus, my entire premise was to not reinvent the wheel. Using the auto
fuel injection requires the use of the car's computer. Using the
computer requires all the sensors and sometimes faking the sensors out
so that they give the proper information. It all seemed too arcane
and difficult for me.

Carburation does not produce less power than fuel injection, but it
might be slightly less efficient, depending on how the engine is
leaned, and how much the pilot pays attention to it.

I paid $150 for each engine, and built one engine, not two.

The weight of the setup is one of those "not sure's". It likely
weighed in excess of 400 lbs, but probably not by much. The block is
cast steel, but it's a thinwall design. The heads are aluminum, as is
the timing chain cover, and intake manifold. It was the lightest V-6
being built, and may still be in it's 4.2L form.

I also used the lightweight geared starter, rather than the routine
Ford beast. The NWAero psru is noted for it's relative light weight
compared to the Blanton version, which was it's genesis.

I also used a lightweight aluminum machined flywheel, rather than the
suggested Ford flexplate. Probably no gain or loss there.

As to the prop, I bought an IVO Magnum and ran it using that while I
tested the engine.

I added largish mufflers to the header system I fabricated (header
length and diameter suggested by "Headers by Ed". Ed sizes header
tubes scientifically to promote maximum flow at the power settings
most often used and altitude at which I would normally be flying. That
required relatively small diameter header pipes (1 3/8), which is
considerably smaller than the exhaust ports in the heads (1 3/4). The
length of the headers tubes was also specified to maximise torque,
which meant that they had to be 40" long and feed into 3" diameter
collector pipes, which had to be at least two feet long each.

When I first fired the engine up, all animals in the vicinity headed
for the hills. It seemed like I was standing next to two machine guns
blasting away. Of course, I was inside the shop at the time (with the
sliding door open).

I had to add two hefty mufflers to the exhaust system in order to run
it outside the house without being attacked by the neighbors, even
though I live in rural Vermont, with lots of trees between me and my
neighbors. They were big and unwieldy and I wasn't planning to use
them in the airplane. But I was unhappy with how noisy the engine was
and was concerned about being a good citizen when flying in the area.
I tried several inserts to try to quiet the barking down some, but
nothing but actual mufflers helped. With the mufflers, you basically
only heard the soft clicking of the lifters and the hiss of the
carburator, over the whopping of the prop. As I advanced the
throttle, the carburetor began moaning/roaring and the noise of that
big prop took over with a whapping blatting roar.

I literally had to chain the test stand/engine down securely or it
would have tipped over for sure.

I had built a test stand that was basically a fully instrumented
vehical on casters. It had a battery, radiator and fuel tank. I
could have strapped it into a flatbed pontoon boat and gone air
boating.

I had the engine up to around 3,500 or so for the last run before I
shut it down and sold it and the airplane. At that rpm, lots of air
was being blown back and things like rakes and shovels were flying off
the walls of the car port. The test stand was tied down to the car
port posts, which is why the air was blowing into the bays. It was
obvious I would have needed to back off on the prop pitch a bit to get
more rpm out of the engine, if I had continued.

Corky Scott

Is there any good reason to use the Ford instead of the Buick V6?
There are a lot more Buick V6s out there. Also, there is a lot of
support from the aftermarket, hot rod and racing business for the Buick
engine and apparently none at all for the Ford V6.

I don't have personal experience. However, my fellow chapter members have
told me that the Ford V6 engine is considerably lighter as it comes in (or
from) a car.

That said, the aluminum heads and blocks alleged to be available should make
a lighter and stronger engine. BTW, the name "Bow Tie Racing" was
mentioned, but yielded no plausible result in my quick web search.

The only word of caution to which I can personally attest (from my younger
and crazier days) is to be *very* careful of racing and hot rodding parts
designed to give you oversized ports and manifolds. As you increase the
diameter of the passages, you also decrease the velocity of the gasses;
which will result in a very "cammy" high speed engine with poor pulling
power and a poor ability to turn a fixed pitch propeller.

wrote)
[good report snipped]
I didn't go fuel injected for two reasons, simplicity and safety.


Thank you for the report.


Montblack

"RapidRonnie" wrote in message
oups.com...

wrote:
On Fri, 20 Jan 2006 08:06:33 -0600, Cal Vanize
wrote:

I don't think there's any dispute over the relative cost of engines.
This issue is longevity and whether one wants to fly an airplane with an
engine that might not make it to the next airport.

Cal, the statement I was responding to was from the guy who said that
auto engines end up essentially costing as much as an aircraft engine.
I was posting my actual costs to suggest that the costs are, or can
be, very much lower for the auto engine conversion than for a rebuilt
aircraft engine.

But I chose to do all the work, except for the machining of the engine
parts, myself. If you do not wish to put in that kind of time, or do
not have the knowledge to do so, then the options tend to be a lot
more expensive.

Buying a firewall forward package and simply bolting it in place and
connecting the wires and fuel lines will of course cost a bunch more
than doing everything yourself. Perhaps this is what that gentleman
was talking about.

Is there any good reason to use the Ford instead of the Buick V6?
There are a lot more Buick V6s out there. Also, there is a lot of
support from the aftermarket, hot rod and racing business for the Buick
engine and apparently none at all for the Ford V6.

The other engine to look at in my opinion is the Honda/Acura engine,
because they are readily available cheap from JDM pulls. The Japanese
have laws designed to encourage vehicles to be junked or exported
young, and those that do not get bought by Australians or Brits usually
get scrapped because Japan is a RHD market.

My neighbor's son bought the back half of a Toyota MR2 in absolutely
beautiful shape-and I do mean "the back half", as in "the car was
sliced in half by a colossal bandsaw"-for $1200 when his transaxle
failed. He got a engine, trans, rear brakes, halfshafts, everything.

I enjoyed it.

On Fri, 20 Jan 2006 08:06:33 -0600, Cal Vanize
wrote:



I don't think there's any dispute over the relative cost of engines.
This issue is longevity and whether one wants to fly an airplane with an
engine that might not make it to the next airport.

You mean like a Lycoming? or an old Franklin?

clare wrote:
On Fri, 20 Jan 2006 08:06:33 -0600, Cal Vanize
wrote:



I don't think there's any dispute over the relative cost of engines.
This issue is longevity and whether one wants to fly an airplane with an
engine that might not make it to the next airport.


You mean like a Lycoming? or an old Franklin?

Can't speak for Franklins. But I've never had even a skip on Lycomings
with with over 400 hours flying PIC in plances with Lyc engines nor with
any Conti with over 500 hours PIC in those. These weren't in homebuilts.

On Wed, 18 Jan 2006 22:49:19 -0600, Cal Vanize
wrote:



Morgans wrote:


"Cal Vanize" wrote


The article does indicate that the cranks were from engines in planes
that were flying. That's the good news. But does that also mean that
the engines need a teardown and inspection as part of every oil change?


If you are running a conversion that is different from William's
conversions, it could be a good idea. g

If people take the time (yeah, lots of it) to read the whole article,
you will notice a few things, and I will attempt to point out some of
the more significant (to me) points.

Biggest point. Do not use corvair engines outside of the recommended
operating parameters. Some sub points.

Biggest one, don't use longer prop extensions. Big time no-no.

Others include, don't use heavy props, or hand carved props. Don't
overstress the prop with some aerobatic maneuvers, or hard landings.
Make sure the crank is properly ground. Oil systems must provide for
consistent oil flow to all parts, at all times; stay away from two line
cooler and filter systems. Use low RPMs and big props, rather than
smaller props and higher RPMs. Avoid detonation, which is easy to let
happen, if treated like an aircraft engine.

Obey all points of his conversion manual. Nitrated cranks are a good
way to add an extra margin of safety, when obeying the conversion
manual, but the other examples that have followed the manual have been
OK for long operational periods, even without the nitrated cranks.

Avoid other's add ons, like extra bearing hubs, as they have not been
tested.

I am sure I missed some points, or miss stated some, but if you are
using corvair power, it would be wise to investigate what this man has
to say, and not take my word on it.

I remember saying a long time ago, that I would feel better (or
something like that) if a redrive was used to take the stress off of the
crank. I think I will still stand by those words. Of course, It would
need to be a properly researched and tested redrive, which at this time,
does not exist.

Good points all.

The point that stood out most for me was the part about the crank from
the engine that William built for his own demo 601. From the article:
"This engine represents a standard installation, albeit one that was
flown at its limits by Gus"... "showed stress fractures on both sides of
the area in question." at 200 hours. "no nitride"

Note with particuclar interest the phrase "represents a standard
installation" regardless of how his pilot flew the plane (it was HIS
pilot after all). The statement goes on to say that the engine "was
flown at its limits" not beyond its limits.

What William wrote is that an engine he purposefully built himself for
his own 601 demo plane had a not insignificant crank issue. If he was
following his own recommendations, why did he use a crank that wasn't
treated?

He may be the Corvair conversion expert, but I'd like to read an
explanation as to why he wasn't following his own specs.

I have read every word on William's web site. It would appear that he
has done his homework and research. He may be the most credible source
for Corvair conversion aircraft engines. But yet, this discrepency
sticks out sorely.


It was built BEFORE the crack issue came up and BEFORE the
recommendation to use a nitrided crank. VERY simple.

On Thu, 19 Jan 2006 09:05:51 GMT, Richard Lamb
wrote:

Morgans wrote:

"Cal Vanize" wrote

Good points all.

\
Yes, that paragraph does seem to run contrary to the rest of the _long_
website's information. So what gives, others in the know?

Or could it be that it's just taken a few years to rack up 200 hours?

I didn't catch a time span reference on any of the example engines.
But I thought it has been years?

About one year of flying - MAX.

clare at snyder.on.ca wrote:
On Fri, 20 Jan 2006 08:06:33 -0600, Cal Vanize
wrote:

I don't think there's any dispute over the relative cost of engines.
This issue is longevity and whether one wants to fly an airplane with an
engine that might not make it to the next airport.

You mean like a Lycoming? or an old Franklin?


Oh for Pete Sake...ok.

A couple of years back, I picked up an Aeronca Chief down in Florida and
flew it home. Real nice airplane, and a real bargain - because - the
engine wasn't all that great. Continental 85 with metal prop.

It had been "overhauled" by one of the club members (not A.P.) and
they (the sellers) were honest about it up front. It leaked (a bit).
And they were right reasonable on the price.
So a deal was offered, $1000 earnest money sent.
And Leo and I went down to see?/fetch?

We flew it around for a while and determined that the plane was rigged
nice and straight, stalled straight ahead, and with the 85 and a climb
prop, it could for sure and certain - climb!
The little engine ran strong.

Checking the oil level shortly after landing (yeah, I know) showed it
had indeed lost some oil, but we found it - all on the belly.

Oh well, I'm not going to have to clean it. Not part of the deal.

The seller offered to "wipe her down and top off the oil and gas".
(yeah, I know - now.)

So, next morning, oil and gas are full and we headed off for home.

It took 3 days to get home and about 12 hours flying.
Two hour legs left an hour fuel reserve for the Chief.
And the climb prop doesn't go anywhere in a hurry - except up.

This engine leaked so much oil it would embarrassed a Harley.
I mean really!

But something else was wrong.

The engine ran fine, but it felt a little sharper than normal
during climbs, but smooth out fine at cruise.

For the next three days (over swamps, timber, and once VFR on top,
I could actually hear/feel/taste it getting worse.

A little sharper at first. Then louder. Each takeoff.
Only while climbing.

On the last leg home I thought maybe an exhaust muff was opening
up maybe? And then thought - or a cracked mount?
But it smoothed out at cruise.

When we rolled out at home, I was glad to be there, because I had
decided that the engine was indeed failing and needed to be looked
over.
Very carefully.
BEFORE flying it again.

It still ran strong, but something was really major league wrong
somewhere during climb out.

When Bob (A.P.) tore it down he found the bad seals, sure, and some
other minor stuff, and one cylinder with a crack about 1/4 of the
circumference of the flange.

The crank and cam were ok. Mags ok.
A (as in one each - count it) new jug, bearings, seals, etc.
signed off major overhaul cost 4 grand.

Grandpa, the new owner, it totally tickled with his Chief.

He learned to fly in it.
Took his PPSEL check ride in it.
Took his _wife_ flying in it!
Someday his boys will have their chance to learn to fly in it.


So, what exactly is the point, you ask?

This issue is longevity and whether one wants to fly an airplane with
an engine that might not make it to the next airport.

Right
Hell if I know.
But it was a fun trip otherwise...

Richard