gklein@erols.com wrote:
>
> Fellow Scions
>
> Well, my TR6 engine's bottom end has been completely disassembled and
> for info I plastigauged the rod and mains. Rod bearings clearances fell
> between .002 and .003 and the mains were a solid .003. No guessing the
> source of my low oil pressure, a common thread on this list.
?????? These tolerences are well within spec. Whey would you suspect
this as a source of low oil pressure?
>
> This is my first bottom end rebuild and I was wondering what, if
> anything, should I do with the cam? I'm looking to rebuild and return
> the car to daily driver status so I'm not particularly interested in a
> hot cam. Is there something I or a shop should/could check on the cam?
> No cam bearings in the TR6 block; anything there to check for?
> Bentley's manual doesn't say much about the cam.
>
Cam journal diameter should be 1.8402 to 1.8407 in.
Clearence should be not more than .0004 so the block journal openings
shoud be in the neighborhood of 1.8404 to 1.8410. Anything over that
will indicate that the block journals should be bored out and shell
bearings pressed in.
Triumph engines don't normally require cam bearings.
>
> Gary Klein
> '75 TR6 with a '72 engine
Gary,
Probably the most important single thing to be absolutely sure about is
the thrust washers.
If you get .0008 end float, I would suggest replacing thrust washers.
Even if end float seems okay, as a matter of course, it is a good idea
to replace the thrust washers.
As for low oil pressure, I think the oil pump would be the best place
to begin.
Pumps in these triumphs should have a lobe clearence of not more than
.0010.
While you have the oil pump apart to check clearence, it is a good idea
to check the surface of the rotor for gouges and chips. Anything that is
noticible as far as flaws can be lapped out using valve grinding
compound, but pump replacement is the best alll around solution.
Even a new oil pump should be lapped in with the valve compound to be
sure of its performance.
If you choose to go the machine shop route, check around and find one
that is known for turning out quality work.
Hope this is of some help.
Regards,
TonyR
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