Glass beads are an abrasive
media used for fine blast cleaning of parts. If left in your engine they
will destroy it through abrasion. It is just like having sand in your eyes.
Besides it hurting, if you don’t get it out it will eventually destroy
your eye. This too applies to your engine. However just by flushing your
engine out when it is together will not remove the glass bead.
Over a period of time there has been an
increase in premature engine failures due to glass beads being present
in the engine. Most of these failures have shown up in rapid wear in piston
rings, pistons and cylinder bores, in some cases in less than 200 miles.
We will limit the scope of this article to the engine but the same applies
to the transmission and primary drive.
The photos of the failed parts (piston
and rings) have been analyzed to determine what the cause of the failure
was. It is easy enough for many people to guess why something failed but
by digging deeper and doing analysis one turns up the real facts rather
than just ideas or theories. Hastings Rings Company has been kind enough
to conduct tests and supply the 2 highly magnified super duper photos of
the glass bead and rings for us. The other photos are ones that we have
taken of the same parts but not so magnified. During our discussions with
Hastings they have mentioned that they are seeing an alarming rate of engine
failures (auto engines) due to improper cleaning of glass beads.
For most people glass beading is a cheap
and inexpensive way to clean internal parts like flywheels, conrods, cams,
etc as well as crankcases and cam cover. The problem is in the lack of
proper cleaning of parts after glass beading and prior to installation.
Most people replace their old parts with new parts so glass beading of
surfaces won’t apply however way too many times we see used parts glass
beaded and then assembled into an engine. In some cases it is necessary
to glass bead some internal parts however it is not necessary just for
the sake to remove the oil discoloration and make them “look” pretty. For
general cleaning of internal parts(on non glass beaded parts), solvent
and good old fashioned hand scrubbing with a stiff brush is best and then
a final high pressure clean water blast (garden hose is ok) to rinse away
any contaminants left in the solvent.
In general it is recommended not to glass
bead internal parts and here are a few reasons:
1/ On machined surfaces like,
cam and pinion shaft gears, cam shafts, cam bushings, lower end shafts
and housings, valve stems, etc, these parts are manufactured with a specific
surface finish which is destroyed by glass beading. The worst of it is
that the nice polished surface finish has now been destroyed and we have
introduced a rough textured surface finish which now acts as an abrasive
on each of its mating surfaces.
2/ When glass beading cases
with cam bushings, drive and pinion housings, pushrod guides, rod races,
etc still installed, the glass beads have plenty of places to lodge itself
in and hide out and miss even thorough cleaning. Bushings have flanges
on them that the bead can become lodged behind, likewise with the drive
housing flange plus it also has an oil hole that glass beads can hide down
in and pushrod guide underside area in the cam chest just to name a few
spots. Valve ports with valve guides installed will allow glass beads to
become lodged between the valve guide and port and enter the combustion
chamber. Cylinder head combustion chambers can also hide glass bead in
their pores due to their porous castings. If cases or cylinders need to
be glass beading, make sure all parts like bushings, housings, cylinder
base studs, pushrod guides, etc are removed first. So as you can see there
are many places that glass bead can be hiding in.
At times it may become necessary to glass
bead cases especially the exterior as we all want our cases to look like
new. Here are a few ways to minimize the risk of glass bead to inside parts:
1/ Remove exterior parts like
cylinder base studs from the cases
2/ Use ductape to mask all
the inside areas.
After glass beading, give parts a blast
off with air and then a blast off with water from the garden hose.
Tap out ALL threaded holes. Use dish washing
detergent on the tap. This will aid as a lubricant and a cleaning agent.
We don’t need a cutting compound as all we are doing is cleaning out an
existing thread. After the threading process, pressure blast the hole with
the garden hose.
Thorough and final cleaning of your parts
from glass beads can only be achieved by using very hot soapy water (solvent
does absolutely nothing for glass bead cleaning). The most ideal way to
handle this is to use the kitchen sink. My wife Carolyn has come to accept
this however some of you may want to wait for your Mrs to be out shopping
or way out of town. This depends on the consequences if she unexpectedly
stops back home and catches you at it.
Dish washing liquid (plenty of it) is
ideal to use in the hot water. Use a firm scrubbing brush as well as a
small hole brush and don’t forget to stick the hole brush down all the
threaded holes and twist the brush around.
Repeat this process (the cleaning process)
several times. Drain all the water out and rinse the parts and sink each
time.
The final step is to blast each part off
with the garden hose with the nozzle on jet stream. We want to blast every
little nook, cranny, blind and threaded hole, etc. We know this water is
clean so it’s a slam dunk deal. Blow dry parts with compressed air.
As a final step paint all inside casting
surfaces with an epoxy high heat internal engine paint. This will become
your insurance policy. Do not paint gasket surfaces. If you have still
not been convinced to remove the bushings and housings, etc, make sure
the paint gets between the flanges and the casting as this is where the
glass bead will be just hanging out. Once all these steps have been, done
don’t leave your nice clean parts out in the open if it will be a while
before you get around to assembling them. Wrap them in a nice new clean
plastic bag.
Of course there are other associated parts
that also have to be looked at for cleanliness. It is worthless if you
have thoroughly cleaned your engine but not your oil tank, lines, pump,
carb, etc. |
Close up of glass bead found
in ring land. Note: The piston and ring photos are out of an engine with
200 miles on it.
Close up of abrasion on
ring face.
Close up of oil ring face
showing abrasive wear in 200 miles.
Ring pack showing abrasive
wear in 200 miles.
Piston skirt showing abrasion
in 200 miles of use.
Many places for glass beads
to hide out:
Pinion housing
Cam bushings
Lift pin bushings
Push rod guides
Places for glass beads to
hide out:
Pinion housing
Cam shaft bushings
Lift pin bushing
Lift pin
Hiding places for glass
beads:
Oil hole
Nut around outside dia,
slots and threads
Nut locking dimple
Drive housing photo to show
that when glass beads enter the crankcase oil hole that they become lodged
in the drive housing groove area. No amount of brushing can can get in
here to remove it.
Hiding places for
glass beads:
Cam bushings
Lift pin bushings
Threaded holes
Oil transfer holes |
