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