Corky's engine choice

On Thu, 24 Jul 2003 10:58:15 -0500, John Thompson
wrote:

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.

I'm mechanically competent, but I've never done serious work on a auto
engine beyong the shade tree stuff or replacing plugs, oil, hoses, etc.
I can tear down and rebuild a small gas engine no problem, but there are
a lot of little things that make big differences between a Briggs and
Stratton, and a ford V-6.

John

You are actually echoing something I've been saying in this newsgroup
for a long time: Building up your own auto conversion isn't for
everyone and one of the biggest problems is the lack of compiled
information.

There actually are some published manuals for the Ford. One of them
is written by Richard Finch. There was also a group of newsletters
written by David Blanton while the engine was in the early use stage.
These were important because there was a period of discovery going on
after the actual plans for the engine and PSRU were maketed. Things
were still happening to the engine that had not been anticipated and
everyone sort of dealt with them in different ways.

However, David Blanton was his own worst enemy. He was combative in
the extreme, very defensive, obdurate and sometimes ***wrong***. He
for instance misscalculated how much horsepower the engine would
develop, and refused to listen to anyone about the situation. This,
even when properly calculated dyno runs produced very respectible
power readings. But he became the butt of many jokes when he insisted
that his engines routinely put out over 240 horsepower and much more
at only 4,800 rpm. They weren't. A well built 3.8L engine will
usually make at least 180 hp, with many getting another 10 with minor
modifications. One guy got 235 hp but he was willing to rev it to
5300 rpm to do that. He'd put racing connecting rods and pistons in
it to withstand that rpm, which isn't high compared to racing
standards.

But I digress, there is also much useful information to be gleaned
from Bruce Frank's Ford 3.8L STOL newsletter, but the specific engine
information is spread out over a number of years and issues.

Part of the problem is that there remain a LOT of solutions for
various issues. For instance ignition: dual or single? How do you
trigger it? Many are going with dual ignition with the second
ignition running off an isolated battery. Some rig their ignitions to
run dual all the time, others want to switch from one to the other.
Still others trust one single source. You can trigger the ignition
either using a distributer with dual pickups, a distributer with a
single pickup and another pickup off the flywheel or crankshaft
damper, or have both pickups sensed remotely off the crank somewhere.

Then there's the engine itself. It's been modified by Ford over the
years since it's intruduction. It's grown to 4.2 liters now and
doesn't have a manifold that works for carburation anymo it's
strickly an air manifold, not fuel/air. Also the lifters have gone
from simple standard type lifters to roller lifters. The latest
castings do not have a provision for a distributer.

Some of the engines have the dual balance shafts, some don't.

Then there's Jerry Schweitzer who used to build these engines for the
homebuilt community, for all I know, he still may. He put out a video
of what he thought was important and a lot of the information is
really good stuff.

For instance, he talked about drilling and tapping a hole through the
intake manifold into the block where a coolant passage is. This is
done on both sides. Then a pipe fitting is threaded in and the tubing
routed back to another pipe fitting on the suction side of the water
pump housing. What this does, he says, is draw off the "bubble" of
air that always seems to form in the block/cylinderhead and tends to
stay there causing the cylinderhead to improperly flow coolant.

There are other things like an air/antifreeze seperator that needs to
sit above the engine on the firewall that is pretty much standard on
all auto conversions.

Then there's the issue of a heater for the cockpit. One of the
blessings of using a liquid cooled engine is that it can give you LOTS
of heat with absolutely no danger of carbon monoxide poisoning. But
the manner in which it is installed is different in just about every
conversion.

Some guys use it in such a manner that it helps the engine cool by
routing coolant through it and dumping the airflow outside the
cockpit. If heat is desired, they shut off the flow to the outside
and the air blows into the cockpit. An awful lot of this depends on
how you've built your airplane and how much room you have.

For a look at how to build an auto conversion REALLY cheaply, you
should get the Reverend Ron Van der Hart videos. The guy's kick and
FAR more entertaining than Schweitzer and he's very talented to boot.


Corky Scott