What makes an engine efficient, and long lasting?

[SteveU.]

Hi All
I believe it was Mr Biohazard who did put up the Marathon Engine site first here.

My points were to not become myopic over any one factor.
Plenty of engine examples that have operated thousands of hours at medium 1200-3000 RPM and even 3000+ RPM with proper design, manufacturing, operation and maintence.
Longest I ever saw a NO maintenance/never oil changed engine run was a leased towed in Chrysler car at 24 months with 33,000 miles, ~750 hours by a rush-rush traveling "making money" salesman. All aluminum DOHC 2.7L V-6. What a sludge bucket then. Everyone having worked rental/leased returns has seen this.
There is no magic oil. There is no magic design that will survive stupidity and outright neglect.
You, and no one else controls the maintenace aspect. M-a-y-b-e a manufacture can slip you a design banana - but that should only happen once.

It is the AVERAGE condition of the fluids that the engine sees that will determine how well it can hold contaminets in suspension, buffer the acid build ups and renew minerals/metals balances. Why I dump and fill, or suck out and top up so much - to keep my average fluid conditions up. My labor is free. My equipment replacement money is not.
To think you can flush out a worn out contaminated fluid post-late and restore the worn away and acid damaged metals, hardened seals and remove the dropped out clogging  solidified participates sells a lot of chemicals and services. Won't put back the damaged metals or replace the cracked brittle seals. And will only remove some of the internal frozen on crusty systems crap.

I chose my equipment for what it will do for me. Not for the installed engine, for the "brand", or to look pretty. Then if it cannot do the job and will not last 2X-3X the time the manufacture expects me to be down spending money again with all my obsessive anal dump and fill fluid maintenaces then it will get dumped, sold and replaced. If it works and lasts then I'll even blow it off/wash it twice a year. Would not want to transit bus wear off the paints.

Actually Tom my alt-energy views are exactly like yours. It is all about the FUEL. Only fuel I have completely under my control is wood fuel.
Woodgas is hard on engines.
I needed an easy to clean upper end with parts availability or one with readily available cheap tip off complete replacements. My Listeriod had the first, but now with the EPA squeezing-out of the dealers, parts are not so available. Not an engine I could just phone call replace anymore either. My 12/1 now lives with a fellow who wanted the big cool looking nostalgic flywheels.
Got a V-twin Kohler now for gasoline and gaseous fuels. A three cylinder Yanmar for serious spec grade diesel/bio-diesel work and a Jiang Dong R185 clone for the fun experimenting.

Henry I agree that the proper spec fluid for the design is important. Why I stock on hand, three different anti-freeze coolants, two different PS fluids, five different gear box oils. Ha! Ha! At least for the current fleet I can use the same brake fluid and windshield washer fluids. Motor oils are easy - only three needed for me.

Anybody want, I put out ~3 gallons a month to the curbside recycle of "only half used up!!" very mixed bag motor oil. Metals, moisture, acid contaminants, with maybe a little bit of PS/gearbox/brake fluids mixed in for free. The every 15K auto trans drain and fills, or suck out and refills I keep for no smoke brush burning.

Regards
Washington State Steve Unruh

[Henry W]

Here you go guys. I found a piece of equipment with the Marathon engine in it. I decided not to write what it is so members to this forum has the first shot at it. It is posted in our members only section.

Please do not write what it is and where it is here in this topic. Post about it in the members only section that I linked below.

http://www.microcogen.info/index.php?topic=1593.0

Henry

[BioHazard]

I'm the same way about fluids. I have trouble making it to 3000 mile oil change intervals. I drain my transmission pan (about half the fluid) at every oil change. A lot of people never touch their differential fluids, mine gets Amsoil about every 50k. It all just gets dumped into a drum where one day I might burn it for something. Right now my dirty oil is just "aging".  

I always buy tons of oil when I find it on sale, so I have like 500 quart bottles sitting around. Worst case scenario, I can use my supply of fresh motor oil as diesel fuel in an emergency...