Camshaft install question.

Hi
Wanting to install a new cam and was researching and read this. Can't quite get my mind around what they are saying.

Can someone explain this note from the Norvil tech library, please.

Coat the camshaft lobes with micrometer blue and fit the cylinder head and tappets (camfollowers). Rotate the camshaft. Remove the cylinder and tappets and check that the tappets are making full contact, if not DO NOT assemble the engine. Norton cylinder blocks are regularly radially out of position causing point contact of the camshaft and tappets. If full contact is being made, thoroughly clean the parts, oil and re-assemble.

IS the full contact the tappets are to make, mean across the full ground surface of cam lobe?
Does radially out of position mean to far right or left?
Anyone ever seen this condition.
Thanks in advance.

Norton46 said:

Hi

IS the full contact the tappets are to make, mean across the full ground surface of cam lobe?
Does radially out of position mean to far right or left?
Anyone ever seen this condition.
Thanks in advance.

Click to expand...

1. IS the full contact the tappets are to make, mean across the full ground surface of cam lobe?
Yes!
2. Does radially out of position mean to far right or left?
I believe they mean too much contact on either the left or the right side of the cam to lifter contact.

I believe the important thing here is that if you have a new cam, you need to either get the lifters ground or get new ones. You want to make this a match made in heaven. "CRITICAL"

They also speak of how the tappet bores are regularly out of radial position. And if so, then what? I will leave this question to the masses.

I should imagine they mean that the cam follower tunnels can be bored canted over sideways, which would mean that the follower face would be sat on the camshaft at an angle.
So, what if they are? Can't do much about it.
Maybe grind the follower face at the same angle to match?
I find this a bit hard to swallow & bordering on the line of rediculas.(I know I spelt that wrong)
I suppose then, the camshaft ought to be checked for parallel.
Check the regrind on the stellite face is dead square with the body.

A camshaft shop ground my tappets for $20.
Well worth it with the NOS standard cam I put in.

IS the full contact the tappets are to make, mean across the full ground surface of cam lobe?

Click to expand...

Should really fit new followers too.
Assemble, ride and enjoy. Eventually they will make full contact.

Raidial misalignment AT contact face , But Its Linear . A SLANT TO IT .

ROUND cam followers typically have a few thou angle on the cam lobes ( cone ing ) to ROTATE said round followers .

With a steady hand , a straight eye , and nerves of steel , one Stones the Steelite of the followers ,
laps them dead flat / smooth .

Some run in cams with 1/2 the springs out ( very cautiously ) to allow surfaces to mate at low pressures.

When Noah was a boy , any self respecting 8 yr old , would reweld and grind his Gold Star cam lobes ,
on the hand grind stone wheel in the garden shed . :wink: This is no longer regarded as olitically correct.

I think Flo has the right idea about the cause of the problem. I agree what to do about it. notice that the Norvil note does not say just says don't assemble the motor.
I think we all agree Commando tappet don't rotate and would be flat ground.
I guess it worth a check just to know.
Thanks

Flo said:

I should imagine they mean that the cam follower tunnels can be bored canted over sideways, which would mean that the follower face would be sat on the camshaft at an angle.
So, what if they are? Can't do much about it.
Maybe grind the follower face at the same angle to match?
I find this a bit hard to swallow & bordering on the line of rediculas.(I know I spelt that wrong)
I suppose then, the camshaft ought to be checked for parallel.
Check the regrind on the stellite face is dead square with the body.

Click to expand...

Right on the nail Flo!,
carn't imagin "all"the dim's being right, there is to many "out of square" and out of true faces for a perfect cam/follower contact, a roller follower with a rad may have a better life?

cam-followers-t10102.html?hilit=follower

Different thread, same question...

Hi folks

Just a point when you get the bike running you should run in the new cam at over 2500rpm as below this there is not sufficent oil to lube the new cam ( info on norvil motors web pages)