Hi Darrell-
Some info from my memory of keeping engines going with not enough money to
do it right....
> Just to confirm a fault diagnosis: Whist firing up Ugly, the VE 76 TR7,
on
> a cold day, I have heard a metallic tap that increases with revolutions.
> Once warm it will almost go away but can still be heard. I am going to
say that
> has to be a rod bearing going south. I am wondering if it is now too far
> south to simply replace.
In my experience, TAPPING is usually from the top end of the engine, and
KNOCKING is from the bottom end. You can isolate the noise with a
stethoscope or long screwdriver (the handle in your ear, the point on the
engine :-). If it's a valve, it might be as simple as adjustment. If it's
a deeper, heavier noise coming from the bottom of the engine, then first you
check the oil and oil filter for debris, and if present, you get to pull the
pan and check bearing caps.
> I must admit that I have never dropped a TR7 pan. I
> suppose the only way to find out is to drop the pan and take a look. If
major
> scoring is present what do I do? Install new shells anyway? I am not
going
> to rebuild this motor and that is not an option. I would go to a Sprint
> motor first.
You might get away with new shells, but if the bearing surface is badly
scored (which is likely if they've gone so far as to make noises), you get
to do a rebuild and/or replace. If they're only slightly scored, you can
smooth the surface with some fine emery paper. Use the kind that comes on a
long skinny roll, and make sure you hit all the surface equally so it stays
round. Then check the bearing clearances before you go further, for if it's
wrong, you'll hear a nasty noise far sooner than you expect.
You need to be looking for the root cause of the problem. If it's a valve,
why did the adjustment go out of spec? In the bottom end, it could be lack
of oil from a blockage in the oil system, but there might have been a
mechanical failure of the anti-rotation tab on one of the bearings, causing
it to spin.
> Trouble is Ugly is a real survivor with only 35,000 miles on her and dead
> nuts original. That is perhaps her only redeeming quality which is
probably
> very unusual for a TR7 Coupe. For sure a candidate for the HPOF class
that former
> VTR Board Member Bill Sohl has me been thinking about. HPOF would be
> "Historic Preservation of Original Features". Evidently, it is a class
offered by
> the one of the Antique Car Clubs here in America. Anyone familiar with
this?
I'm not familiar with the organization, but if they have an ounce of common
sense, they'd allow a new set of bearings and a crank grind. It comes down
to the definition of "features". All cars (that I know of) have crank and
rod bearings as features. If they've been replaced without upgrade or
modification, you haven't replaced a feature, just a part....
Best,
Skip Gurnee
64 TR4, 66 TR4A
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