Ken
that's what I do but you need a good =
bore gauge.
I use a sunnen bore gauge it reads out in .0005ths increments. It takes =
allot
of rechecking and practice to get it right . measuring the bearings in =
the
case gives you a size of the bearing with the crush factor. the bearing =
ID.
does shrink when the case is torqued. I also look to makes sure=
the
case half's still touch with a flash light when I install the =
bearings to
check the crank to bearing clearance. As I said in the first post
preparation is key to getting a good reading of the actual dimensions. I =
use a
wire brush from the paint store to get the sealing surfaces clean. the =
brush
lasts just long enough to get the job done then I trash it. I also file =
the
case at the sealing surface to debure it.
we are talking about WBX engines =
here But I
think I should say that the above procedure is also mandatory on all=
type
2-4 blocks. most type 2-4 blocks wont pass this flash light
test
Harold wrote
Bob,
You told us the difference in=
size,
blue vs. red bearing, and that
the differences are
miniscule.
Question:
Are the red and blue dot larger or are they=
smaller than the
standard (no dot) main bearing?
And which is =
larger
of the 2 color coded, the blue or red dot?
Thanks for any
info.
Harald
Harold
I spent some time this AM with my bore=
gauge
and a few sets of 2.1 main bearings. I was quickly reminded that the =
tri
metal thin walled 2.1 main bearings are not round until they are
installed and torque into a case (sorry I don't have time for that =
Today but
soon). So with that in mind I found that the bearings where =
all
over the place. next I looked at the boxes and as you pointed out some =
read
.001 RED and some say .004 BLue This is hundreds of
a millimeter. Some of the boxes I opened had color =
codes
some did not. I think that the difference is so small that most folks =
could
not measure the difference. So it sounds like you want to what I would =
call
noodle around (I define noodling as spending way to much time fine =
tuning
something that might not matter) sounds like you want find out
if the crank main bearing needs to have a tighter fit =
for
longer life or increased oil pressure? And is it important to =
custom
fit the larger bearings to a warn crank? The 2.1 cranks for the =
most
part don't show allot of wear even at 150 K. As long as the =
clearance
are within the spec the then you are good to go. I have even used =
a set
of USED mains in my 84 Camper 2.1 big valve engine because =
the
measurements where within spec. NO PROBLEM I =
would
say there are more important factors that would determine the oil=
pressure or life of an engine. Some of those things would be setting =
the
fuel injection up correctly to prevent fuel dilution or creating a lean=
condition, making sure that the big =
end of
the con rods are round, rod bearing clearance, oil changes, load =
and
the performance of the cooling system over the life of the
engine.
Bob Donalds MN.
as always all rights reserved <=
/DIV>