The best way to set up a cam is to use the intake center, i.e. point of
highest lift. It should be 110 ATC for this cam. (the average of 18 BTC
and 58 ABC). Look at my webpage on degreeing a cam -
http://www.tildentechnologies.com/Cams/Tips_Takes.html There is also a
spreadsheet you can download.
Richard, the reason for the difference between .007 and .010 is what I
call "valve train squish", i.e. the amount of compression in the valve
train due to the springs. Integral cams listed the 0.050 specs at 210 also.
Larry
On 5/31/2011 9:27 PM, Richard Good wrote:
> Glenn,
>
> The timing specs for the late TR6 cam are:
>
> Intake open 18 deg BTDC, close 58 deg ABDC
> Exhaust open 58 deg BBDC, close 18 deg ATDC
>
> I believe these timing specs are supposed to be point of
> opening/closing. If that is the case, with valve clearance spec of
> .010" at the valve, the tappet has to move .010" divided by rocker
> ratio of 1.45:1 = .007" before the valve starts opening. So you
> should be able to time to these specs at .007" of tappet lift. Stock
> cams I have checked appear to have this advertised duration at about
> .010" tappet lift so you may have to go to .010" to get these timing
> points to hold out.
>
> I have never seen .050" timing specs for the stock cam but the ones I
> have checked appear to have about 210 deg duration at .050" so the
> timing specs would be:
>
> Intake open 5 deg ATDC, close 35 deg ABDC
> Exhaust open 35 deg BBDC, close 5 deg BTDC
>
> Regards,
> Richard Good
> Good Parts Inc.
>
> --------------------------------------------------
> From: "Glenn Franco" <gaf3@charter.net>
> Sent: Tuesday, May 31, 2011 3:05 PM
> To: "Friends of triumph" <fot@autox.team.net>; <6pack@autox.team.net>
> Subject: [Fot] Cam Timing Degree Specs
>
>> Hi
>> I putting a late model 74 TR6 back together after a rebuild.
>> I'm attempting to time the cam. This one has no marks on the gears
>> since it had been replaced.
>> I have the degree wheel set up but I'm having difficulty finding the
>> cam specs for a stock TR6 Cam?
>> And if found what amount of lift does the specs relate to (.050"??)
>> on this engine.
>> Can anyone out there point me in the right direction.
>> The head has not been installed and I have the degree wheel set and
>> the dial indicator taking measurements off the pushrod.
>> Thanks in advance
>> Glenn
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