Fast Eddie
VIP MEMBER
- Joined
- Oct 4, 2013
- Messages
- 20,641
Right then chaps, I'd like to open said can of worms as I'm currently teetering on the brink of delving into the cam timing on my '68 T120 (I wasn't gonna, I was gonna do what most of us do and think "it ran OK before, so it must be fine" but the reality is that with 50 years of PO intervention, the cams could be bloody anywhere! And now I've started thinking about it, well, you know how it is...
An initial look at factory opening / closing methods caused much vagueness. When I look at lobe centre figures, my exhaust cam looks remarkably cock on. My inlet cam looks quite a way out, almost one full tooth. So I am pondering my options as to the best course of action to take...
Opening and closing timing figures are notoriously useless due to Triumphs manufacturing tolerances and the 'stack up of tolerances' of the many different components all interacting.
So, either lobe centre timing or lift at TDC seem more reliable / favourable.
Triumph opening / closing figures translate into 100.5 degree lobe centre timing (I think).
What's the opinion of our learned members on this, any strongly upheld views on ideal settings, alternatives, pros and cons of such?
Hit me...
An initial look at factory opening / closing methods caused much vagueness. When I look at lobe centre figures, my exhaust cam looks remarkably cock on. My inlet cam looks quite a way out, almost one full tooth. So I am pondering my options as to the best course of action to take...
Opening and closing timing figures are notoriously useless due to Triumphs manufacturing tolerances and the 'stack up of tolerances' of the many different components all interacting.
So, either lobe centre timing or lift at TDC seem more reliable / favourable.
Triumph opening / closing figures translate into 100.5 degree lobe centre timing (I think).
What's the opinion of our learned members on this, any strongly upheld views on ideal settings, alternatives, pros and cons of such?
Hit me...