Dan wrote:

Bob wrote:
On Jun 12, 4:30 pm, "Morgans" wrote:

WoW! I can't even comprehend a compressor that big!

What is the power source; IC engine, or electric, and do you know how big the
power source is, in either HP or amps? That would help me try to put it into
size.
------------------------------------------------------------------------------

Dear Jim,

A modified VW engine makes a pretty good media blaster in the medium-
size range. This is a 96cid engine that is modified so that two
barrels are constantly pumping whilst the other two serve as the power
source (ie, about 15hp). Using a VW bug body as an example, it will
usually take from six to eight hours to strip one of paint, tar, etc.

Tthe really big units are found at dry docks, for treatment of
concrete piers and other heavily encrusted objects.

-R.S.Hoover
-(USN Retired)


The VW engine idea sounds interesting. Any suggestions where to find
plans? I don't think Id build one, but it should be an interesting read.

I would imagine such Navy machines would be a tad noisy. I have
never had the pleasure of hearing a rivet gun used in building large sea
going vessels. I have the feeling it also would be a bit loud.

Dan, U.S. Air Force, retired

Here is an exchange from several years ago hear on RAH.

========
"Bruce A. Frank" wrote:

I helped build a Chevy 327 into a compressor many years ago. We kept it
simple and crude. Every other cylinder in the firing sequence was made
into a pumping cylinder. The intake manifold runners to each compressor
cylinder was plugged with a chunk of wood and JB Weld epoxy to prevent
fuel mixture from flowing there. A hole was drilled in each compressor
cylinder runner between the epoxied plug and the intake valve. those
four holes were piped together to draw air from an air cleaner element.
The rocker arms on each of the compressor cylinders were removed and a
hardware store light spring installed in place of the normal intake
valve spring. This allowed the intake valve to open every time the
piston headed down, rather than just on the "intake cycle" of the
cylinder. A check valve replaced the spark plugs so every up stroke of
the piston compressed air. The Chevy 327 ran like a top and produced
enough air at 4000 rpm to power a small jack hammer. It seems we
calculated 200+ cfm at 100 psi. Intake and exhaust were muffled so it
ran very quietly.

--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
BAFRANK(at)worldnet.att.net Homebuilt Aircraft Newsletter"
| Publishing interesting material|
| on all aspects of alternative |
| engines and homebuilt aircraft.|
*------------------------------**----*
\(-o-)/ AIRCRAFT PROJECTS CO.
\___/ Manufacturing parts & pieces
/ \ for homebuilt aircraft,
0 0 TIG welding

While trying to find the time to finish mine.

========

Tony P wrote:

HI Bruce.

So YOU'RE the guy who built that one I saw! That explains it. I even
think it was an SBC engine.

Sounds pretty similar to what I saw, but somehow I think the thing
plugged along at idle most of the time and just accelerated as needed.
Maybe it vented off surplus?

Also had a neat loping sound. The powered cylinders clearly had no
difficulty keeping up, probably ridiculously overpowered.

Tony Pucillo

--


I speak only for myself unless otherwise stated.
One personality is enough, thank you.

"Irony better befits a gentleman than buffoonery;
the ironical man jokes to amuse himself,
the buffoon to amuse other people." (Aristotle, 'Rhetoric')

========

"Bruce A. Frank" wrote:

From empty tank to full, from start up to pop off, was about 20
seconds (50 gal tank). While we were using it it ran at about 1000 rpm.
With the jack hammer we turned it up to 4000 rpm and with the JH running
full bore the pop off valve was always blowing. When we put the
commercially mfg. controller on it the rpm hardly ever got above 500 (the
tank would fully pressureize before the engine reached its controller
set 2500 rpm). Last I heard it was still running just fine (30 years
now! and the engine had 90,000 miles when we converted it with no
overhaul) Ours had a sort of pocketta-pocketta sound, much like an
antique 4 cylinder engine.

An interesting side note, the air out of that engine was as oil free and
clean as if it had been charcoal filtered. There was no exhaust gas
blow-by smell or gasoline smell. A friend in PA built the same thing for
a sandblast outfit. It'll pump through 600 lbs of sand at 130 psi in
about 15 minutes.

--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
BAFRANK(at)worldnet.att.net Homebuilt Aircraft Newsletter"
| Publishing interesting material|
| on all aspects of alternative |
| engines and homebuilt aircraft.|
*------------------------------**----*
\(-o-)/ AIRCRAFT PROJECTS CO.
\___/ Manufacturing parts & pieces
/ \ for homebuilt aircraft,
0 0 TIG welding

While trying to find the time to finish mine.