Triumphrat

lovecuba · 11-14-2012, 06:54 PM

Have just had cam and followers reground. The latter to 'R' radius.

The inlet cam part number is 71-2887 which does not relate to the T140 parts book number, it also has the number 20416 stamped on it.

The exhaust has been built up and ground in the past and again this time. It is difficult to read the part number but I can sight a 7--maybe a 0 a 6, 4 and a 2, it also has the number 20360 stamped on it.

Have cam lube ready for assembly, been told to wash and very lightly oil the bores and remember that the main bedding in for the rings will be on the first 18 revolutions of the crankshaft when started and then subsequently keep at high revs to bed in the followers and cams.

Both cam have the same profiles

1963wak · 11-15-2012, 04:32 AM

wash the bores with brake fluid its very searching and is great at removing honing dust.

Mr.Pete · 11-15-2012, 04:55 AM

M20416 is a T140 intake cam;I have one in front of me.

If the exhaust cam has been welded and re-ground,you must know what grind they used.That will affect the valve clearance you need.

lovecuba · 11-15-2012, 03:38 PM

Quote:

Originally Posted by Mr.Pete

M20416 is a T140 intake cam;I have one in front of me.

If the exhaust cam has been welded and re-ground,you must know what grind they used.That will affect the valve clearance you need.

Hi Mr Pete. All the machinest told Me was that both profiles were the same. I will check with Him wether He means 'same as when I bought them in or, each other (after being ground)?

Mr.Pete · 11-15-2012, 04:00 PM

This certainly changes things if you have T140 intake grind on the exhaust cam.
You would need to use 0.010" valve clearance on the exhaust.

I would also advance the exhaust cam at least 4.8 degrees,to give something like 72/42 timing.
Even 77/37 timing will give you a smoother running engine and more low-rpm/midrange torque,with a slight loss in maximum power.

lovecuba · 11-15-2012, 05:32 PM

Quote:

Originally Posted by Mr.Pete

This certainly changes things if you have T140 intake grind on the exhaust cam.
You would need to use 0.010" valve clearance on the exhaust.

I would also advance the exhaust cam at least 4.8 degrees,to give something like 72/42 timing.
Even 77/37 timing will give you a smoother running engine and more low-rpm/midrange torque,with a slight loss in maximum power.

Many thanks Mr Pete. Have been reading all I can on, timing cams, as both cam wheels were taken of without referencing which keyway went where. Have a timing disc but no dial gauge and am going to give it ago with the engine sitting on the bench, sans' cylinder head working off the tappets, then engine into frame and on with it's head!

lovecuba · 11-17-2012, 05:42 PM

Quote:

Originally Posted by Mr.Pete

This certainly changes things if you have T140 intake grind on the exhaust cam.
You would need to use 0.010" valve clearance on the exhaust.

I would also advance the exhaust cam at least 4.8 degrees,to give something like 72/42 timing.
Even 77/37 timing will give you a smoother running engine and more low-rpm/midrange torque,with a slight loss in maximum power.

Hi Pete. Excuse my ignorance but could you please explain the 77/37 timing measurement and briefly how to obtain that setting. The workshop manual is most berefit in this information.