Please Comment!

[PolarisLaw]

After reading the following Blackstone "test" what do you think?
http://www.blackstone-labs.com/Newsletters/Gas-Diesel/November-1-2010.php?utm_source=Nov+2010+Gas%2FDiesel&utm_campaign=490af17038-Nov_2010_Gas_Diesel_Newsletter11_22_2010&utm_medium=email#page=5

 

[daman]

linky no worky...

 

[nwjones18]

link worked for me. Very interesting article. I really don't know that much about the subject, but he makes a very convincing argument that ZDDP isn't that big of a deal.

 

[PolarisLaw]

Is This Better?

BlackstoneArticle

 

[Boomer]

So in an aircraft engine, what are the pressures exerted by the valve springs compared to an auto engine? Is this a rotary engine or a flat four cylinder or does it not matter? What are the typical rpms seen by an aircraft engine? Don't they seem to operate at a rather fixed rpm level for long periods of time without accelration or deceleration? Are the shape of the cam lobes significantly different (less aggresive) than an auto engine? Is the metallurgy different in the cams of the two types of engines? Just a few questions as we explore this topic.

 

[spasm3]

i would expect that there are far less cold starts with an aircraft engine.

 

[PolarisLaw]

Sorry Johnny,
I didn't notice you already posted this under the oil additives forum, but I'm sure you and I would like more responses. Comments?

 

[rclint]

I'm not so sure on the cold starts, many people have personal aircraft they use, and some of these as a hobby, but most of the non commercial planes don't fly round trips non stop etc.. I would even venture to say that these type of engine applications get the worst kind of cold start extended times of no use where the oil does have more of a chance to migrate from the parts.. yet just the same I have seen post that years, and years of engine sitting with no use still every part that should be coated with oil is coated with oil.. even the old no good junk oils from the past that seems to be so inferior compared to todays oil.. so I'm not sure, but on the cold starts I do think they would get plenty of long extended no use cold starts which still in my mind is the very wrost on an engine.

 

[tomcat27]

certainly cool. of course, airplane engines are required to be rebuilt every 2000 hours. Not saying that has any affect on the need for ZDDP... I also believe the engines run cooler - although its been a couple of years since I have flown.

 

[SwampDweller]

Typical small aircraft engines turn a max of about 2700 rpm. My last plane had a Lycoming IO360. Thats 360 cu in on 4 cylinders, or 90 cubes per cylinder. Large pistons, bore, long stroke operating at relatively low RPM. Not a lot of throttle movements compared to an auto engine. Cylinder temps would vary a lot, idling around in summer on the ground to operating at altitude at 160mph. Don't know what add pack the old Aero Shell 50 had.