CLANK III: The Saga Continues.
Bought an engine stand this past Friday. Bolted the engine to the stand
with $7.00 worth of grade 8 hardware scrounged at the local hardware store.
The convenience of having the engine bolted in midair, and being able to
rotate it, seduced me into stripping the block for a wash. Out came the
pistons and liners and the crankshaft. Then I rolled now bare block down the
driveway, and sprayed it full of "Gunk Foamy Engine-brite". Great stuff. It
expands when it hits, so you shoot it in one hole, and it oozes out of the
others. After about a half-an-hour spent with scrub brush, spray can and hose,
the block fairly sparkled. I cleaned off the gasket surfaces with a 3-M "metal
stripper wheel". This took off the old gasket material, goo, stickum, paint,
and rust, leaving nice clean metal. Then an extended session with my
compressor and blowgun left the block dry as a bone and completely clean.
Now, some people might ask me why I didn't just have the block hot-tanked.
Well, in the SCTOA Triumph tech tips book, Ken Gillanders tells us not to do
that. He states that the inside of these blocks were painted with a durable
black enamel by Triumph, and that the sliperiness of this coating is valuable
in reducing oil flow friction. He also states that you can't repaint it, as
the secret of adequately durable internal engine paint has been lost in the
mists of time. Be that as it may, I was not adverse to saving the $25 that the
machine shop charges for this service :-).
Unfortunately, upon removing the crankshaft, I discovered that the main
bearings were completely trashed. Bummer. And the rod bearings were all
scratched up, apparently by the network of score marks around the crank
journals. So apparently I will need to have that crank reground. And I will
have to buy a complete set of rod and main bearings. Sigh. All this for a
clank....
The SCTOA tech book has a thing or two to say about these cranks. Let me
paraphrase ( I don't have the book handy ):
"The construction and stresses of the TR 4-cylinder crankshaft are such
that if the journals are ground .020 undersize, the resulting part has only
half the service life of a brand-new crankshaft. If they are ground .030 or
more undersize, their service life is a matter of a few thousand miles (!)."
So I dearly hope that my journals are standard size, and that going .010
under will clean them up. If not, Mr. Gillanders recommends the following
procedure:
1) Have the crank magnafluxed.( Good idea in any case )
2) Have the journals hard-chromed oversize, then ground back down to
standard size.
3) Have the crank shot-peened for increased durability.
4) Have the crank, flywheel, pistons, and rods balanced.
Now, I wonder, is all this really necessary? Is there any net.experience
out there with the life-expectancy of reground TR3 cranks? Are these more
exotic services done anywhere besides L.A., where everything automotive is
obtainable? What kind of $$$ are we talking about here?
- Jerry
p.s. Took the camshaft out to get reground. Funny, everybody I talk to about
camshafts tries to offer me a competition grind. Stock is OK, the engine has
plenty of beans! Later that day, I found that TRF has BRAND NEW CAMS for $200!
So if the cam grinder tells me I have an unusable core, I'll just laugh and
call Pennsylvania....
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