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RE: [TR] Timing chain - update!

To: "'Cosmo Kramer'" <tr4a2712@yahoo.com>, <triumphs@autox.team.net>
Subject: RE: [TR] Timing chain - update!
From: "Randall" <tr3driver@comcast.net>
Date: Mon, 2 Oct 2006 18:54:04 -0700
> Set engine to TDC & make sure the cam is in the
> correct position (#7 &8 Rocker arms should be closed
> fully. Thus sitting on the side of their lobes ready
> to open).

Unfortunately, that's not quite right.  There is a lot of cam rotation where
both valves are fully closed, almost the entire compression and power
strokes.  Instead, you want to look for the overlap period, where both
valves are normally open slightly (exhaust closing and intake opening).  The
factory cam is timed "straight up" meaning both valves are open equally at
TDC.

One way to find this point is to set both valves on #1 cylinder (or #4) to a
larger than usual gap, then measure the gap when you think the cam is at
TDC.  I don't recall the gap to use offhand, something like .050", but the
exact value is not important as long as it's equal for both valves, and big
enough to leave some gap at the center of the overlap period (what the book
calls "point of balance").

> Install the Gasket on the T-Cover &
> assemble.

Don't forget the fiber washer that goes on the timing cover support stud.
Good place for some Hylomar, IMO.

> I HOPE that you marked the order or the
> bolts when you 1st removed the T-Cover, because there
> is one (1) short bolt that is to be placed back in the
> came hole as before, as written on my repair manual. 

Hmm, I don't remember that way.  ISTR there were maybe 3 different lengths
of bolts, with the one that gets the ground strap from the frame being
longer than all the others.  But it's been a long time, perhaps I'm
mistaken.  

At any rate, it shouldn't be too hard to figure out bolt lengths.  As a rule
of thumb, for any bolt that screws into a blind hole, you can test it by
screwing it in by hand without a lock washer.  If the head will come up
tight under those conditions, it's probably not too long.  And if it takes a
minimum of 7 turns for a coarse thread or 10 turns for a fine thread, it's
probably not too short.

Randall


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