engine and drivetrain Lets Play, Identify the Camshaft! (also known as, did i get suckered)

[2002Scoob]

I can't claim to be an expert on cams and re grinding, but according to those who know more than I, it's not a regrind.

 

What I have learned in the time it's been collecting dust is that triangle stamp on the nose of the camshaft that people were referencing is actually a MFG Insignia mark of Schliecher camshafts here in Germany, who was producing for Alpina back in the day, and still produces some really nice stuff. I considered one of their cams when I rebuilt my top end.

 

http://www.schleicher-fahrzeugteile.de/index.php?en_produkte

 

 

 

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[AceAndrew]

Nope, should have clarified.

 

Reducing the x-axis/base-circle does not increase lift (contrary to my comment).  What I should have said is that during a regrind the base-circle is still going to be reduced as any regrind profile is also going to augment the y-axis/duration (contrary to the simplified image).  Checking the base circle for a reduced diameter compared to stock is just the quickest way to tell if a regrind has been done.

[TobyB]

Daniel, what you draw doesn't work-

the base 'circle' is actually a part of the lobe,

and it's doing some important things.

First, it makes sure that the valve gets onto its seat as quickly as possible so that it can conduct heat into the head

Second, it makes sure that the valve gets gently set down onto its seat as smoothly as possible so that it doesn't weld to the seat, or pound it out.

 

And yes, those two goals are exactly opposed to each other!  So there's a real set of compromises in HOW each cam sets down the valve.

 

Third, it makes sure that the valve ALWAYS lands on the seat- thus, it has to UNLOAD the valve under all conditions, just to be sure...

 

And certainly not last, it picks up the valve gently to make sure it doesn't 'slap' the rocker and stem any harder than it has to.

 

...things I learned by surfing the internet...

 

t

 

[GoldLion]

On 26 May 2017 at 3:16 AM, TobyB said:

Daniel, what you draw doesn't work-

the base 'circle' is actually a part of the lobe....

 

 

Many thanks for your replies @TobyB and @AceAndrew.  Makes a lot more sense to me now.  The diagram was just cut and pasted from an article I found when doing some research, and does oversimplify things indeed.  I had no idea about any of this stuff before this thread.  Every day's a school day!

 

Daniel