TK88: I came across several quarts of "Aviation" "Ashless" motor oil; Is that the same as non-detergent? Sorry for the lame question, too lazy to look it up on the WWW. Thx. JM

Most engine oils are fine as long as clean and undiluted with fuel , you can never change it too often , especially if it’s been neglected in the past because new oil will stir up gunk and sludge , which isn’t good due to the lack of filter , as others said change it every time you use it and if can drain it as soon after you stop it before the gunk settles.. just my two pence or cents..

juiceman wrote:

TK88: I came across several quarts of "Aviation" "Ashless" motor oil; Is that the same as non-detergent? Sorry for the lame question, too lazy to look it up on the WWW. Thx. JM

not sure but I think it’s generally applied to two cycle engines   Low ash = doesn’t foul or whisker the plugs ..
 

no ash isnt anything to do with detergentcy. its more a contaminant in modern oils, sulphur was traditionally used as a extreme pressure lubricant gear oils contain lots of sulphur well used to hence why they stunk. now other things are used such as moly and ptfe.

detergency is more about the oils ability to hold soot and other byproducts in suspension the idea being this material is then trapped by the filter. and thus the engines does form coke deposits like they used to back in the 30's and you would got to a mechanic for a decoking. also forms less sludge.

I ask because there must have been a case full of quart bottles, all aviation grade "ashless" oil here. Previous home owner did not have an airplane...
I have a green riding lawnmower that began using oil at 50 hours total use; bad valve guides? Anyways, I always had to add 1/2 to 3/4 quart to the engine after 1.5 hours use; I decided to use some of the ashless oil in it (what could hurt that sick thing?) No more smoke and no more fouled plug, and consumption reduced. I will nurse the mower along until I get a replacement engine or new mower. Just curious! Thanks, JM

There is also an aviation preservative oil. At the cost of rebuilding plane engines it is worth the extra bucks to keep rust down. It slowly vaporizes and keeps the insides oiled. It can also be run for 50 hours as a regular oil. If you have too many projects (like many of us) that might sit for a few (maybe many) years, a preservation oil might save a lot of grief when you start to work on it. I am sure there are other preservation oils, but that is the one that I am familiar with.