Alex:
It looks like you are going backwards in terms of performance. Your
new cam is the earlier, lower performance stock cam, intended for use with a
higher compression ratio (at least 8.5:1). Your current cam seems to be the
later cam, which is a higher performance profile, intended to replace lost
power due to the lower compression ratio in the later motors (as low as
7.7:1).
I recommend the later cam (256 adv duration) rather than the earlier
cam (240 adv duration) for performance. While the earlier cam will get you a
slightly better idle and fuel economy, the differences are extremely small.
Both cams have a very smooth idle.
It sounds like your DPO tossed in the later cam to get some
performance, and boffed the install, resulting in some flat lobes. I suggest
that since you are going to all that trouble, you put in the later cam
rather than going back the to the earlier cam, even though your car came
originally with the earlier cam.
Vance
----------------------------------
-----Original Message-----
From: 6pack-bounces@autox.team.net [mailto:6pack-bounces@autox.team.net] On
Behalf Of Alex&Janet Thomson
Sent: Sunday, April 24, 2011 1:42 PM
To: triumphs@autox.team.net; 6pack List
Subject: [6pack] TR-6 Cam
To the Lists -
I am replacing a camshaft in a '73 TR-6 which had two lobes extremely worn
And one lobe nearly gone. Disappointing since this cam has only about 10,000
Miles of use. The cam lobes that were still good looking had a lift of about
0.240" but it is now history. I purchased a new camshaft from TRF, part #
307621/GP, which is described as a new, chilled iron, stock cam. I am not
looking for
any performance upgrades that would require re-working of the head or other
components. Before installing the new cam, I dial-indicated the lifts for
each lobe and was surprised that they are only 0.213". Is this the actual
specification for a stock cam? I did look at the results of a survey that
Ray Hatfield send out in October but felt that most cam upgrades would
result in
a power band at a higher rpm than I'm looking for, hence the stock TRF item.
Any suggestions?
Alex Thomson
_______________________________________________
_______________________________________________
6pack@autox.team.net
Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
|