Camshafts - Triumph Vs Aftermarket - Advertised Vs Actual Duration?

[Anthony]

I'm currently playing with some unknown aftermarket camshafts.

 

I'd like to see how they compare to the original Triumph camshafts, as well as those offered by the likes of Kent, Newman, and Piper, etc.

 

Is anybody able to confirm how each of these parties measure their duration?

 

i.e. Is list measured as soon as the valve leave the seat? -- Is is at 5 thou lift? -- Is it at 50 thou lift?

I'm guessing the aftermarket manufacturers start the measurement as soon as possible to make their cams should "bigger", but wondered if anyone knows exactly what their measurement methods are? 

Thanks.

[Amy Wade]

This should help.

https://www.jegs.com/tech-articles/understanding-camshaft-fundamentals/

[Anthony]

Thanks Amy.

I'm already well-verse in camshafts.

I'd like to know, how did Triumph, and how do Kent, Newman, and Piper measure their duration -- as I know for a fact they don't use 50 thou.

Thanks.

 

Edited December 3, 2023 by Anthony

[Nick Jones]

I think you’ll struggle to get reliable information. 
 

You can try asking the makers. Newman might tell you. No idea about Kent. Triumph….. maybe somebody knows… 

This doesn’t answer your question but you might find it interesting 

https://sideways-technologies.co.uk/forums/index.php?/topic/8106-how-to-measure-a-cam-in-the-hand/#comment-108100

[Anthony]

Thanks, Nick.

That's an interesting thread.

I've spoken with the manufacturers about their measuring methods in the past.

Newman were extremely helpful indeed. They answered every question I had without hesitation.

Kent and Piper were far less receptive of my questions.

Looks like I might end up having to measure (and probably purchase) more camshafts than I'd originally anticipated.

I'll add my findings to the forum when I get round to it. This is a side-project so it might be a while.

Edited December 4, 2023 by Anthony

[Nick Jones]

Will be very interested to hear what you discover.

Might be worth a call to Chris Witor or Dave Pearson ref. The Triumph cams. Dave might even comment on here….