Jonathan,
If you want to do a "correct" engine rebuild, particularly on an engine as
old as a 100, it is imperative that you check the cam timing using a TDC
measuring peg, a degree wheel and a dial test indicator as specified on
page D/26 of the factory workshop manual.
Just a little wear on keyways, keys or sprockets or a cam which has been
ground slightly ahead or behind center can make a considerable difference
to engine performance.
Take the time, do it right and don't forget to set the valve clearances
back to 0.012" when you are satisfied that you have it correct.
--
Michael Salter
*I have BJ8 water pump kits!!*
On Fri, Oct 26, 2012 at 9:21 AM, jerry adams <cjerryadams@yahoo.com> wrote:
> Jonathan,
>
> For all 4 cycle engines I am pretty sure ( taught this in
> Engineering school) that the crank and cam are geared so that the crank
> turns
> two revolutions for one revolution of the cam. So what you have said
> about
> the timing below follows the rule. I think that either of your gears
> could be
> marked 180 deg out or installed wrong. You need to check new gears against
> old gears and new crank and cam against old. This would entail a minor
> tear
> down by removing the gears and camshaft to check. Better be safe than
> sorry
> later.
>
> Jerry
> BN2
>
>
> From: Jonathan Quandt <jfaquandt@comcast.net>
> To:
> healeys@autox.team.net
> Sent: Thursday, October 25, 2012 7:15 PM
> Subject:
> [Healeys] Cam and crank gear timing update
>
> I have set #1 to TDC and revolved
> cam so that #4 cylinder valves are on the rock, #1 valves are fully relaxed
> but my cam gear timing mark is 180 degrees out as though the camshaft
> keyway
> is cut 180 degrees out. I
> decided to pull the timing cover after checking the
> cam timing according to Norman Knok's instructions in his tech talk manual
> and
> finding that rocker clearances on valves #7 & #8 were obviously different
> after undertaking the test indicating that cam timing was 180 degrees out.
> When I revolve cam so that timing mark matches crank gear mark #1 and #2
> valve
> are on the rock, again, indicating that cam shaft keyway is maybe cut 180
> degrees out. Have I miss read this and it is really my brain that is 180
> degrees out. Cheers, JQ
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