Actually, what you need is called "crocus cloth." It's burgundy in color, 3M
makes
it, and it's available at your better auto stores. When I rebuilt the bottom
end
of my TR6, I cut it into strips the width of your bearing journals, lubricated
w/WD40, and pulled it back and forth shoeshine-style. It took about 2 strips
per
journal to get the entire journal to a satisfactory state.
--
Martin Secrest
GT6, TR6
Arlington, VA
erl@unix.mail.virginia.edu wrote:
> I would be very careful with wet-or-dry. It can leave microscopic
> particles behind. Get the standard very fine emory cloth, which is
> actually used by machine shops for this very purpose.
>
> On Thu, 28 Sep 2000
> CarlSereda@aol.com wrote:
>
> >
> > Bruce - you've lost your mind so might as well go for it
> >
> > if it were my crank I would buy a small very fine cut file to take down the
> > nick protrusions to the level of the surrounding bearing surface. Then I
> > would take the finest 'wet and dry' sandpaper like 600 grit and cut a 1"x3"
> > strip and wrap long ways onto a piece of glass or other VERY FLAT small
>panel
> > (would not wrap the outer sides around the panel as that would create high
> > edges).
> > I would get my face right in there with good light and carefully address the
> > areas in an attempt to make bearing surface an even plane and finish. I
>would
> > use light weight oil to lubricate the work. It seems critical not to lower
> > the height of surrounding bearing surface. I would be hesitant to use crocus
> > cloth because it conforms to the surface. You want to lower the protusions
> > but not alter the low spots. A firm flat surface will help you hit the high
> > spots and leave the lows untouched.
> > Flooding it with WD 40 seems uneccessary unless you making a big mess.
> > Dragging the car to break in the motor seems a waste of time to me.
> > The bearings will settle in how they're going to settle in within the first
> > ten minutes of running - and probably be ok - you may not get as many miles
> > on these bearings .. but then again maybe you will get 30,000.
> > While you're at it: big-end rod bearings go out even faster than crank mains
> > I believe- you may want to refresh those while you're in there..and you
>won't
> > need bang 'em up as they're easier to get out!
> >
> > no guarantees of course - good luck -
> >
> > Carl
> > '63 TR4 since '74
> >
> > >>Subject: Decision on TR7 Bearings from Hell
> >
> > Well, with the posting of this email, half of you will think i have lost my
> > mind, and the other half will be saying "go for it!"
> >
> > After a closer look at the scratches and burr on my TR7s crankshaft, I'm
> > going to rely on my trusty Dremel and yards of Crocus cloth to smooth out
> > these blemishes caused by my carelessness, instead of pulling the crank
>which
> > I have neither appropriate space or cash to do, but would probably end up
> > being a heck of a lot quicker.
> >
> > What I do have is plenty of time and sweat-equity to put into the project,
> > and for you who are still interested, a couple of additional questions:
> >
> > 1. I finally got the #1 bearing out by taking the camshaft caps off and
> > raising it enough to reduce the chain tension. The upper bearing slid right
> > out. My question is whether the chain is suppose to be so bloody tight, and
> > is there an adjustment I should be looking for?
> >
> > 2. My strategy is to clean up all the scratches and burrs, then spray a
> > couple of gallons of WD40 over everything to clean out any grit, then put in
> > some extra new shells on the bearings that were scratched, turn the engine
> > over several times by hand, and then take the caps off again to see if any
> > scratches appear on the shells. What do you think?
> >
> > 3. After I reassemble everything, including brand new bearing shells, I
> > thought I would leave the sparkplugs out, and pull the car in gear to help
> > the engine get "broken in" without the heat and pressure of actually
>running.
> > Maybe pull it for a couple of miles, then replace the oil and filter. But
> > then I thought maybe this would cause accelerated wear because the engine
> > wouldn't be running at its normal temperature, so the oil might not be as
> > fluid. Thoughts?
> >
> > After re-reading all of the above, I can't believe the effort I am about to
> > go through. But there's something about the challenge that is irrestible.
> >
> > Of course, just to be safe, anybody got a spare crank they don't need?
> >
> > Again, many thanks for all the comments and advice.
> >
> > Bruce
> > 1980 Inca Yellow TR7 5-speed convertible
> > Chapel Hill, NC<<
> >
>
> James A. Ruffner
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