spitfires
[Top] [All Lists]

Thrust washers

To: spitfires@autox.team.net
Subject: Thrust washers
From: Fred Griffiths <griffco@mail.cadvision.com>
Date: Sun, 20 Jun 1999 21:36:55 -0600
Well, the washers are in and the motor runs!  

        Finally got the washers in after a few modifications.  Because 
the crank had worn into the bearing cap, I machined a groove in it to 
take an extra washer for the lower half of the crank flange. I drilled 
the washer and bearing cap and tapped in 3 brass screws #4-40.

        I used a Dremel tool with rubber/abrasive tipped bit to polish 
away any high spots off the crank flange.  Then I polished the flange by 
hand with 1500 emery on a soft wooden stick.  Took great care not to 
scuff the main bearing journal.  The flange came out smooth, but of 
course still concave.  That would require removal and major machineshop 
work.
         I ended up fitting a +.015 washer at the front, a +.005 (ground 
down to +.003) in the rear upper, and a +.015 and a .007 shim for the 
rear lower.  I am not sure if the upper and lower are really in line, ie 
taking the same amount of thrust.       I tried Plastigage (red), but it 
requires more force to squash than I could apply with a 12" screwdriver 
against the crank counterweight.  So I eyed it !-)
        And because all this was done laying on my back under the car, 
it took longer than if the motor had been on a nice clean bench!
        When I got the washers in, I left ZERO clearance because the 
crank flange had worn concave (ie hollowed out). So I expected the 
washers to wear first at the outer and inner edges until the flange hit 
a little more surface.  That is what has happened so far, as I took it 
for a 30 mile run tonight. The clearance is up to about 7 ot 8 thou.

        Of course, while working on the washer problem, I found lots of 
other things that needed attention - like the stripped oil pan bolts 
into the front aluminum seal block.  I tried to find Helicoils for the 
5/16" X 24 bolts, but could find NONE.  So I tapped the hole to 8mm X 
1.25 and put in a metric bolt.  Seems to have held firm, but I sure 
didn't put the 20 Lbs torque on those two!

        Let you know later how it goes!
Cheers, Fred

-- 
Fred & Wendy Griffiths
Calgary, Canada
mailto: griffco@cadvision.com
http://www.cadvision.com/griffco/index.htm


<Prev in Thread] Current Thread [Next in Thread>