Chain wheel on the camshaft, chainwheel on the crank shaft and timing chain

[Paul Garvey]

About to overall my engine. New chain wheels do not have any marks on them to line up the 2 chain wheels. The new camshaft chain wheel doesn't have a punch mark either.

Can anyone give me a link to a Youtube site or similar that explains exactly what to do. I have watched the one by Elin Yakov and it is very Heath Robinson.

I look forward to any help.

[RogerH]

Hi Paul,

Removed wrong answer

 

Roger

Edited November 13, 2023 by RogerH

[BlueTR3A-5EKT]

2 hours ago, RogerH said:

Hi Paul,

have you got the original wheel?

If so, set it up with these then transfer the new wheels in place.  And then mark the wheels.

 

Roger

No!

That only works if the repro gears are cut identical to the originals.

Look at the Macy’s Garage link.    This is the method I use and it requires jigs and  dial indicators https://macysgarage.com/myweb6/cam_degree.htm 

 

Which cam are you using?   

Equal lift at overlap is the other chosen method for cam timing for standard cams.  
From a forum contributor.

Please consider abandoning the practice of 'degreeing' the cam shaft, and use the "Equal Lift on Overlap" method?

Your camshaft, indeed almost any Triumph shaft, is 'symmetrical' - see the figures your quote above "38/78/78/38" which refer to the angular distances between cam peaks.     Such cams will, at No.1 TDC show ' equal lift' of both exhaust and intake valves on No.6.   As one four stroke cycle is completed and another starts, the valves 'overlap'.   The lift on either is small, and may be measured with two dial gauges, or else I have another way, using a spririt level!   Please see:

https://sideways-technologies.co.uk/forums/index.php?/topic/7770-equal-lift-on-overlap-the-other-cam-timing-method/#comment-102165

for a full explanation of the theory and technique

 

Beyond this you could resort to the TR2/3 factory service manual instructions of pdf page 106  

This is for TR2-3 but is not the wrong technique for TR4-4A.  

The difference is the cam opening and closing degrees.  The TR4/4A standard cam is (17-57:57-17).    Instead of (15-55:55-15) on TR2-3.   There is an additional 2 degrees on the opening and closing values of the later standard cam.
 

 http://tr4a.weebly.com/uploads/2/1/9/8/21980360/triumph_tr2_tr3_tr3a_factory_service_manual_part2.pdf
 

 

 

 

Edited November 13, 2023 by BlueTR3A-5EKT

[RogerH]

Thanks Pete.  I thought that was a little easy.

 

Roger

[BlueTR3A-5EKT]

19 minutes ago, RogerH said:

Thanks Pete.  I thought that was a little easy.

 

Roger

That might work for the cam wheel as it can be turned over etc.   The crank wheel teeth position are set by the woodruff key, but who knows what the gear teeth were indexed to when cut. 

[Michel Higuet]

16 hours ago, Paul Garvey said:

About to overall my engine. New chain wheels do not have any marks on them to line up the 2 chain wheels. The new camshaft chain wheel doesn't have a punch mark either.

Can anyone give me a link to a Youtube site or similar that explains exactly what to do. I have watched the one by Elin Yakov and it is very Heath Robinson.

I look forward to any help.

I liked the version of Elin Yakov  but like everything you can have fine adjusting of approximation. the difficulty is the "plateau moment" the degrees change but not on the micrometre, at the TDC point and the cam lobe too. Is there too a "plateau moment" with Equal lift at overlap I don't know but I will certainly not use a spirit level! :-)

 

 

[Paul Garvey]

23 hours ago, BlueTR3A-5EKT said:

No!

That only works if the repro gears are cut identical to the originals.

Look at the Macy’s Garage link.    This is the method I use and it requires jigs and  dial indicators https://macysgarage.com/myweb6/cam_degree.htm 

 

Which cam are you using?   

Equal lift at overlap is the other chosen method for cam timing for standard cams.  
From a forum contributor.

Please consider abandoning the practice of 'degreeing' the cam shaft, and use the "Equal Lift on Overlap" method?

Your camshaft, indeed almost any Triumph shaft, is 'symmetrical' - see the figures your quote above "38/78/78/38" which refer to the angular distances between cam peaks.     Such cams will, at No.1 TDC show ' equal lift' of both exhaust and intake valves on No.6.   As one four stroke cycle is completed and another starts, the valves 'overlap'.   The lift on either is small, and may be measured with two dial gauges, or else I have another way, using a spririt level!   Please see:

https://sideways-technologies.co.uk/forums/index.php?/topic/7770-equal-lift-on-overlap-the-other-cam-timing-method/#comment-102165

for a full explanation of the theory and technique

 

Beyond this you could resort to the TR2/3 factory service manual instructions of pdf page 106  

This is for TR2-3 but is not the wrong technique for TR4-4A.  

The difference is the cam opening and closing degrees.  The TR4/4A standard cam is (17-57:57-17).    Instead of (15-55:55-15) on TR2-3.   There is an additional 2 degrees on the opening and closing values of the later standard cam.
 

 http://tr4a.weebly.com/uploads/2/1/9/8/21980360/triumph_tr2_tr3_tr3a_factory_service_manual_part2.pdf
 

 

 

 

Hi

Thanks for the reply.

I spoke with the person I bought the car from and he believes it is the standard camshaft.

Luckily a member of the LVG group has put me in touch with Rob Taylor a whizz with TR's who has agreed to help me out.

Thanks to all 

Regards

Paul