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<<
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