Homemade lo-buck Cam Doctor

With a degree wheel and a notepad, I don't see why you couldn't measure your cam profile yourself.

My only question is what kind of follower would you use ?

It should not matter at all what kind of follower the cam was designed for,
what you are measuring is simply lobe lift at a degree position.

I disagree.. The follower has different contact area which alters where on the lobe you are measuring..
Look at this degree tool kit, specifically the followers. You will see what I'm talking about.

Degree Tool Kit

Dave

I'll also add your homemade setup will not measure ramp design without a lot of notebook space. Not sure how many calculations it would take to accomplish.

You could get rudimentary numbers, no problem.
It would be nice if it were that simple.

My opinion though..

Dave

An issue with flat tappets, yes. Not with rollers.

What does the actual Cam Doctor use for a follower ?

I guess I could look that up.

Crane Cams had a tech article on effect on duration w/ increase in roller wheel diameter from standard .750" to .810":

Example from R280/500
.020 = 0.8
.050 = 1.3
.100 = 1.6
.200 = 1.7
.300 = 1.4
.400 = 0.9

Lifter wheel diameter absolutely has an impact on the motion translated at the pushrod.

Yes the follower has an impact on valve lift.

I just want to measure lobe lift.

There is no better fixture than the block itself !!

Stanton, my thoughts exactly.

https://www.youtube.com/watch?v=cNy6iK_f0_4

It looks like the machine has a roller follower.

I'm not sure I could measure lobe separation. But maybe.

But measuring one lobe profile should be doable.

Measure one lobe then the other. Compare.

If you want the lobe info then measure the lobe directly. Use a small round tip on your dial indicator to minimize angularity error due to contact being slightly off to one side of the tip. Plot the results on graph paper.

Roller wheel size has a large impact on transferred motion from the lobe. Most lobe catalogs address this.

If you use the block, cam, and tappet that you will be using, you can measure pretty close to anything you want. Bonus if your lifter bores are not true you will see exactly what dimensions the engine is running at.
Doug

Done it using the block and lifters, and manually recording Intake and exhaust lift every degree for 720 degrees, or 1440 data points. Pretty time consuming.
I though about building a rotary encoder type degree wheel and using two indicators with the data outputs for each lobe measurement, and have all the data logged into a computer which would record each lobe lift for each increment of the encoder output.