Selection of Material for Tappets

• Mar 6, 2004

• #2

Metalguy

Materials

Jan 2, 2003

1,412

US

Chilled iron (white cast iron) was tried for tappets many years ago by Iskenderian (Isky), and possibly other cam grinders. They did not work well, but I don't know why.

Some of his ads stated that his lifters were not made of chilled iron.

 

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• Mar 6, 2004

• #3

CoryPad

Materials

Apr 15, 2002

5,192

US

The chilled cast iron process is supposed to result in a high hardness, high wear resistance part. The problem is that it requires cast iron, which has major problems with low mechanical properties (strength, toughness) and with high dimensional tolerances. The future for automotive tappets is high-hardness, low-friction coatings like Diamond Like Carbon, etc.

By the way, the cold forging process results in high mechanical properties (but not always wear resistance) and small dimension variation.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

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• Mar 7, 2004

• #4

venghatesan

Materials

Jun 25, 2003

4

IN

Hi Cory,

I found your information valuable. Thank you for the same. Can you please elaborate on "low-friction coatings like Diamond Like Carbon, etc."

Is it similar to "Molycote", used by Toyota and other Japanese OEs?

 

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• Mar 8, 2004

• #5

CoryPad

Materials

Apr 15, 2002

5,192

US

No, DLC's are not like Molykote. Look at this site for more information:

http://www.morganadvancedceramics.com/diamonex/

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

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