Hi Randall,
Yes, Bentley is somewhat terse in that regard...
You have to set the gap at .120" on the base of the lobes in order to get a
decent gap once you rotate it 180 degrees to get to the lobe "overlap." It
actually has a very good (precise) feel to it once complete.
Because I doubted what I was doing, I repeated the process several times and
replicated the exact same position every time. I feel pretty good about it and
think I will close it up. Thanks for the feedback.
best,
doug
____________________
'72 BSA B50SS
'74 Triumph TR6
'01 HD XHL 883
'03 GMC Cargo Van
'07 Aprilia SXV 550
________________________________
From: Randall <TR3driver@ca.rr.com>
To: old dirtbeard <dirtbeard@pacbell.net>; triumphs@autox.team.net
Sent: Sun, February 5, 2012 5:49:37 PM
Subject: RE: [TR] Cam timing for 1974 TR6
> "With the crankshaft at TDC, set valve clearances for the #11
> and #12 valves to
> .120", oscillate the cam a few degrees so that valves eleven
> and twelve are on
> the 'rock,' whilst checking both valve clearances with two
> feeler gauges of the
> same value. When clearances are the same, the camshaft and
> crankshaft are in
> their correct relationship."
There is a 180 degree cam rotation missing somewhere in there. For the
initial clearance setting, both lobes must be on the base circle (eg #6 at
TDC on compression). Then for checking the cam position, both lobes must be
on overlap (ie #6 at TDC on exhaust).
The method also depends on the camshaft having symmetric overlap. The
factory cam does; but some aftermarket cams do not and must be timed by the
more tedious methods.
-- Randall
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