On 7/31/2011 2:43 PM, Greg Solow wrote:
> First you need to determine exactly where the leakage is coming from
> by close examination of the back of the engine and the flywheel. is
> the leakage out of the seal itself onto the flywheel and then covering
> the front face of the flywheel? Is the leakage from the sides of the
> main cap where it meets the block?
> For years we have used "silicone sealer" along with the felt
> packing on the sides of the main cap. We cut the packing into pieces
> about 3/8" long. During the packing process we look for the sealer to
> come out in a solid line beginning at the very bottom corner (as the
> block is upside down) and continuing all the way up to the pan gasket
> surface. Then we wipe off the excess.
Tnx Greg, that's what I was looking for. What "silicone sealer" did you
use? I had a thin line of shellac down both sides of the cap and used
lacquer thinner sparingly to clean it on the inside, left it alone on
the outside.
> As for the seal itself. I would get a round piece of stock the same
> size as the seal surface on your crank. Fit the seal around that
> surface with the spring in place on the seal. hold the seal in one
> hand and look at the way it fits against the metal surface. Is the
> sealing lip deflected (it should be), you should be able to move the
> seal radially from side to side up to
almost 1/8" and not see light anywhere around the seal lip where it
fits against the "dummy crank".
Yup, did that, even put oil on the "dummy crank" to see if it seeped
thru ("down") after a few days - it was dry (this after trimming the
spring and seal again).
> Lastly, it is imperative that the aluminum seal holder halves fit
> tightly against one another while at the same time not holding the
> rear main cap up from seating firmly against the block! We have seen
> this situation where the cap will not seat all the way down against
> the block because the seal holder is mismachined and when it is bolted
> to the block and cap, the holder faces touch before the cap will touch
> the block. The center of the seal holder must also be nearly perfectly
> centered on the crankshaft. You must use a centering tool of some kind
> to make sure this is so.
That may be an issue, as I put a thin film of RTV on the seal holder
mating faces as the cap was installed. After the cap was tight I tapped
the seal holder along the axis of the cap and tightened it. The holder
on the cap was loose-ish, so should not have prevented the cap from
fully seating, but who knows? I guess I need to have an alignment tool
made to key on the journal OD and seal holder ID, just to be sure. But
at this point I'm fairly convinced that the problem is the shellac
turning to goo, as the seal holders are dry.
Another issue could be how saturated the felt strips were. Steve Belfer
suggested soaking them for a few days, I only soaked these for a couple
of hours. I may have pounded the surface shellac out of them, leaving
rather dry felt.
> If you get all of this right, the seal should only leak a tiny bit.
> We have never been able to make this type of seal completely dry as we
> have our Chrysler seal conversion. But without building the size of
> the crank back up you are stuck with the seal you are tying to use.
>
> Greg Solow
>
Tnx again to all who responded, I'll post results later.
j
--
Jim Hassall
Blacksburg VA
'63 TR4 in autox preparation
99% finished, 90% to go
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