Technical data

TAMD71

Each piston has three compression rings (early ver-

sion), or two compression rings (later version)* and

one oil scraper ring.

The upper compression ring on the early version is

chrome plated and has a turned internal chamfer, and

on the later version it is molybdenum coated and must

be fitted with the TOP marking** uppermost. The

TAMD71B has a top ring of the “Keystone” type.

The second ring, and on the early versions, the third

ring as well, are slightly conical and have to be in-

stalled with the TOP marking** upwards. On the early

versions, the rings are coated with Ferrox. (Ferrox at-

tracts oil and thus has a lubricating effect.)

The second compression ring also has three Ferrox

filled grooves, and the third compression ring has a

turned internal chamfer.

On the later version, the second compression ring is

chromed and has an internal chamfer, the third com-

pression ring has been abolished.

The oil scraper ring is of the same type as on the 6(x)

series.

* The pistons on the later version still have 4 piston ring

grooves, but the third groove is empty.

** TOP, TOPCX TOPCF or a machined mark (-).

Design and function

TAMD72

Each piston has two compression rings and an oil

scraper ring. The upper compression ring is of the

“Keystone” type and is unique to the 72 series (differ-

ent height), and is installed with the “TOPCD” marking

upwards.

The other rings are similar to the TAMD71B.

TAMD 71 Early version TAMD 71 Later version

TAMD 71B

Piston ring profiles

TAMD 72