sorry, all. (I would say guys but I am not yet sure if there are women in
this group too). The engine is a GT6 MkII. I think that the problem stemmed
from the cap having been machined to accept a thrust washer- apparently this
was done from time to time. I had this apart this summer, but there were
only two thrust washers - in the block, though thinking back I do remember
two small holes in the rear one, so maybe it had been pinned in place. I
checked the clearances, put in oversize ones, and put it back together. The
rear one rotated, as the cap did not hold it in place, and there you have
it.
The engine is now apart, and goes to the machinist tomorrow. John, I think
you nailed the scope of work:
"So, it's engine out,
crank out, grind crank thrusts, repair main bearing cap, reassemble, refit
engine. New thrusts fitted without regrinding the crank will last a few
miles, main bearing caps can't be interchanged without having the block line
bored."
I am going to take a cap off of a spare block and have the existing block
line bored. I suspect that if the existing cap is repaired with weld, it
will distort and still need the line bore treatment. If the block has other
issues, well, I have a spare block, crank, etc.
----- Original Message -----
From: "Walt Hollowell" <walt@hot-tr6.com>
To: "Scott Janzen" <s.janzen@comcast.net>
Sent: Tuesday, June 01, 2004 9:12 PM
Subject: RE: #4 Main thrust Bearing Question
> Scott- just for fun, what kind of an engine are we talking about?
> My engine builder and I have done some extensive thrust washer upgrades
for
> a
> TR6. This includes a full circle thrust washer on the outside of the rear
of
> the block/rear main cap that cannot spin. I don't know if this upgrade
would
> be of any help to a TR4 etc.
> Walt Hollowell
> Abq., NM
>
> -----Original Message-----
> From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net]On
> Behalf Of Scott Janzen
> Sent: Monday, May 31, 2004 9:51 AM
> To: fot@autox.team.net
> Subject: #4 Main thrust Bearing Question
>
>
> I pulled the pan off of the engine to replace a leaky pan gasket. Found
> nasty looking metal chips that appeared to be a thrust bearing. Now I'm
> looking at the main bearing cap on the engine. It has a groove on the
> flywheel side that would appear to accept a thrust bearing. The manual
only
> seems to show thrust bearings in the block., not one on the flywheel side
of
> the cap as well, and there was only a bearing installed in the block. It
is
> also clear that the bearing has been rotating through the cap (cap's all
> scored in this groove). Now, I pull the bearing cap off of a spare engine.
> No groove for a thrust washer, so the cap keeps the bearing from rotating,
> and the bearings in the block take all the thrust.
> Which is correct? Did Triumph change things along the way? Can I switch
> bearing caps between engines, or was the cap machined in place?
> Fortunately, the crank bearing surfaces (all three of them) look fine, as
> does the journal bearing.
>
> Help! Thought I would be putting the engine back in the car today, but it
> does not look good at the moment.
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