Start up wear rate

[wally6934]

I found this thanks to an old post by friendly_jacek.

Piston Ring Tribiology
http://vtt.fi/inf/pdf/tiedotteet/2002/T2178.pdf

Middle of page 72

“According to experimental work presented by Henein and co-workers, the wear rate of a
cylinder liner is approximately 12 times higher during the first hour of operation than
during the subsequent two hours (Henein et al., 1998). Wear tests with neutron
bombarded compression rings in fired engine tests including a gamma ray spectrometer
have shown that the piston ring wear rate during the start-up period was up to 45 times
the steady-state wear rate, and that approximately 84 % of the ring wear occurred during
the first approximately 22 minutes of operation (Perrin et al., 1995).”

 

[Bluestream]

Yup, its a good reason to never start your car..

 

[spasm3]

Interesting mention of moly on page 59

 

[demarpaint]

Originally Posted By: Bluestream
Yup, its a good reason to never start your car..

That's what I was thinking. Drive your new car home, park it in the garage, and look at it. LOL Or start it up, and don't ever shut it off.

 

[TallPaul]

So it seems best to buy a used car from a traveling salesman.

 

[INDYMAC]

I enjoyed reading this. There is a lot to digest.

The quote posted above from page 72 only relates to the initial wear-in period of a new engine. So reading it out of context is not recommended.

Thanks for posting!

 

[wally6934]

Originally Posted By: INDYMAC
I enjoyed reading this. There is a lot to digest.

The quote posted above from page 72 only relates to the initial wear-in period of a new engine. So reading it out of context is not recommended.

Thanks for posting!



Good catch, i had to read it 3 times before i agreed with you.

 

[wally6934]

A little more on Moly.

Page 47

“Molybdenum dialkylthiocarbamate (MoDTC) is a base oil additive that reduces the
boundary friction in a surface contact. Engine oils with and without friction-reducing
additives have been investigated by Glidewell and Korcek, who conclude that friction in
fully flooded conditions with MoDTC is clearly lower than with non-friction-modified
oils. In starvation conditions the friction with the MoDTC-modified oil may decrease to
become equal to that of non-friction modified oils. With age, the friction-reducing effect
of MoDTC seems to degrade (Glidewell and Korcek, 1998).”

 

[spasm3]

Originally Posted By: wally6934
A little more on Moly.

Page 47

“Molybdenum dialkylthiocarbamate (MoDTC) is a base oil additive that reduces the
boundary friction in a surface contact. Engine oils with and without friction-reducing
additives have been investigated by Glidewell and Korcek, who conclude that friction in
fully flooded conditions with MoDTC is clearly lower than with non-friction-modified
oils. In starvation conditions the friction with the MoDTC-modified oil may decrease to
become equal to that of non-friction modified oils. With age, the friction-reducing effect
of MoDTC seems to degrade (Glidewell and Korcek, 1998).”



Interesting, and the mention of organic moly sulfur compounds forming lubicious mos2 on metal surfaces at high temps.