On Tue, 24 Feb 2004 11:46:41 GMT, "Blueskies" wrote:

Corky,

Do you have any details available about your engine test stand, such as how you restrain it, instrumentation, cooling?

Also, a buddy of mine was talking about an engine build he did, and how he used water to match each header tube volume,
old news I'm sure...

--
Dan D.

I fabricated the engine stand using a lot of OTLAR measurements.

I pulled some 1 1/4" tubing out of the pile (I bought a pile of tubing
for a Skybolt kit years ago and still have at least half of it left.
I always seem to find enough of what I need for projects like this. I
think the cost for the tubing worked out to something like 10 cents on
the dollar.) and welded a large rectangle. Then I welded plates on
each of the corners and scrounged up four casters from around my shop
and drilled bolt holes in the plates and bolted them on. It has two
swiveling and two that don't. They are largish,solid rubber
commercial casters and I have no idea where I found them originally
but I've had them in the shop for years. I didn't pay anything for
them, I remember that.

Then I duplicated the engine mount rails and bolted them to the
engine. I suspended the engine over the base and fitted and welded
support legs from the rails to each corner of the base. Removed the
engine and welded everything.

Then I added 3/4" diagonal tubing fore and aft between the support
legs so that the engine could not shift or sway. That REALLY
solidified things.

What I'd **like** to do is remove the instrument panel from the
cockpit and mount it on the stand and use what instruments are
necessary to monitor engine performance. That way I don't have to
fabricate two instrument panels. I have not cut any holes for
instruments yet so that's in the near future. Actually buying some
instruments is also in the near future. ;-)

I'll need: Oil pressure, oil temperature, tachometer, water pressure,
water temperature and an EGT guage. It probably wouldn't hurt to have
a cylinderhead temperature guage too. I'm leaning towards digital for
the tach and possibly the temps as well but have not made up my mind
on which of the numerous choices to use.

Or I could just use some scrap plywood since I only need the
instruments that monitor engine performance so the test stand panel
could be smallish. Or I could cut up some of the 1/8" sheet aluminum
from the huge panel I scored for free. Using that stuff takes a lot
more work than using plywood though.

The radiator is sitting below the engine at present, but I think I'm
going to have to move it a bit so that the exhaust system can clear
it. The plan is for the exhaust to wrap under and behind the engine
and tuck right behind the Griffin radiator, when I get it. But for
now, the radiator I picked up from the auto parts place will do the
job. It's a Ford Taurus radiator so I know it's adaquate for the
task. If I pick up the custom radiator before all is installed back
on the airframe, I'll likely fabricate the entire cooling duct system,
including the exhaust augmentation, just to make sure the system cools
properly.

I will leave the engine installed in the fuselage for the moment, so I
can fabricate the exhaust and make sure that it fits the airframe
properly, then the exhaust will be removed from the engine and the
engine transferred to the test stand and the exhaust system
re-installed.

I'll route hoses to the radiator as necessary and weld on a pan to
hold the battery. I'll also have a "gas tank" somewhere on the base
of the stand and will have to use a fuel pump to get the gas up to the
carburetor, probably a submerged type, or something that goes in-line
and I'll just bond on a fuel line out of the gas tank.

I've built the stand tall enough that the prop can be mounted to the
engine.

When I get ready to fire it up, I'll literally have to chain the stand
down so that it does not try to hurtle off into the woods like some
demented woods buggy run amuck.

I may lift the whole thing into the back of the pickup and drive up
into the woods to do the extended running so that the neighbors don't
complain. I'll strap it down for the trip, and for running it, of
course.

I'll probably pitch the prop so that the engine can run to it's
maximum rpm while on the test stand. This will be necessary because
I'll need to make sure the engine can manage full power for extended
periods, plus there may be some tuning and adjustments required that
show up only at full power.

The test stand is roughly patterned after the engine test stands I
worked with while training as an auto mechanic at the Rhode Island
Trades Shops. Those engines did not have props bolted to them though.

If anyone would like to see what the test stand looks like, send me an
e-mail and I'll enclose a picture and send it to you. It's in rough
form right now, not completed, but I have some shots of the engine
bolted in place so you'll get a good idea of what I'm trying to
accomplish. Plus, since it's in the unpainted stage, I can still make
lots of modifications to it, should anyone have any ideas.

Corky Scott