Cam Timing

[JohnRoberts]

Hi Guys

 I am looking for advise on best way to time a CP camshaft.

35 degrees BTDC. is that the moment when the inlet valve starts move ?

Regards JohnR

[FatJon]

Yes and no. It takes no account of valve clearance so you can be a way out. The best measurement is peak lift. No idea what that figure is for the TR6 and I bet it depends a lot on the cam, there were many.

 

[Kenrow]

CP cam: 150BHP No. 307689 (identified by 2 rings on the front of the cam just by the drive sprocket). Timing for this cam is 36 65 65 36.

CR cam: 125BHP No. 311399 (identified by 3 rings at the front). Timing 18 58 58 18.

If a non-stock cam you need the manufacturers info.

Check out page 95 here: http://www.triumphexperience.com/article/triumph/Tuning_Standard_Triumphs_Vizard.pdf

This too: https://www.youtube.com/watch?v=wKoWwOWMpt4

Edited June 16, 2022 by Kenrow

[john.r.davies]

All Triumph camshafts (save an occasional extreme specialised one) are 'symmetrical'.   This means you can use "Equal Lift on Overlap" to time the cam, with no need to use protractors or worry about degrees.     Please see my article about ELoO here: https://sideways-technologies.co.uk/forums/index.php?/topic/7770-equal-lift-on-overlap-the-other-cam-timing-method/#comment-102165

But since writing that, which demands the use of dial gauges, I've discovered a variant of the method, which is even simpler.  Please see: https://sideways-technologies.co.uk/forums/index.php?/topic/9639-a-new-method-of-cam-timing/#comment-134275

Good luck!  I don 't think you'll need it!

John

Edited June 16, 2022 by john.r.davies

[Andy Moltu]

In some ways it's easier with non-standard cams as the suppliers tends to specify a timing figure of say No1 inlet max lift at 105 to 110 degrees after TDS (a few degrees either way depending on the individual cam)  This makes timing a doddle - just move the crank to the specified number of degrees ATDC, set no1 inlet to max lift attach the chain and bolt up the sprockets.

Does anyone know the figures for the CR and the CP cams?

[BlueTR3A-5EKT]

http://www.hottr6.com/triumph/tr6cams.html

 

does this help?  105 for CP.  110 for CR

[JohnRoberts]

Hi Guys 

Thanks for the replies.  

I tried setting timing inlet centre of full lift at 105 , must made an error somewhere, because when trying to run it inlet valve was about 20 retarded. [ 15 BTDC ]

Have after many attempts with dial gauge on top of the valve , not the rocker. Now starts to open at 35  BTDC closes at 65 ABDC.

Now runs well.  Also loaded new ECU file.

Regards JohnR