Oil

[inanecathode]

Did thoese engines have combined cases? those tranny gears do horrible to things to engine oils

Syn molecules are the same size as conventional oils? bull shite  Cylinder glazing when running full syn in an engine that has not been broken in is no myth.

Yeah sure if you're breaking in your studebaker, modern engines (including the vision, all aluminum, water cooled) dont need nearly the same amount of break in time engines used to need. Cylinder glazing isnt from using synthetic it's from not breaking the engine in in the first place.

And synthetic base stock molecules are the same size as conventional base stock molecule size, just waaaay more uniform. I can sell people 30 dollar a quart oil that's got little pieces of gold leaf floating in it, would that make people feel better about the oil they're putting in? Engine longevity has as much to do with how you drive the thing, how it's been treated, and how often you service it with what kind of oil you happen to put in it. The only true difference you could possibly measure is starting an engine out BRAND spanky new on JUST synthetic from the very first mile, then revisiting things a hundred k down the line or so, if you're lucky enough to dodge the friday night parts runs from the factory in your engine.

I dunno, debating synthetic versus conventional in a bike thats older than 25 years old, is a motorcycle period, multi-owner, probably sat forever, and was once considered basically a boat anchor seems bizzare to me. Just put fresh oil in it every 1500-2500 miles and you'll be a-ok.

[Kid Jedi]

Yeah sure if you're breaking in your studebaker, modern engines (including the vision, all aluminum, water cooled) dont need nearly the same amount of break in time engines used to need. Cylinder glazing isnt from using synthetic it's from not breaking the engine in in the first place.

Its the machining tolerance, not the materials used that necessitate engine break in procedure.

[lexx790]

I'm not a mechanic but I have worked in an engineering factory for 27 years and I thought breaking an engine in was to do with burrs, small/minute particles of metal that are left over after being machined. The cylinder bores will gradually smooth themselves out within the 1st 10-100 miles and thats why old cars/bikes would have the 1st service so soon from being manufactured.
Now technology has moved on and theres a whole host of things that deburr parts prior to assembly from roto vibrating stones to thermal deburring which is why most new cars hardly need running in.
My 2pence worth anyway.  ;D

[Tiger]

I dunno, debating synthetic versus conventional in a bike that's older than 25 years old, multi-owner, probably sat forever, and was once considered basically a boat anchor seems bizarre to me.

Just put fresh oil in it every 1500-2500 miles and you'll be a-ok.

8) Now this I DO agree with...

                   8).......TIGER....... 8)

[YellowJacket!]

I change mine every fall...unless I ride more than 1000 miles, which I have far exceeded this year.  :-)

David

[Kid Jedi]

I change mine when the oil looks worn out
I ride about 3k a month
With castrol 20w-50 I was changing my oil every 1000 miles with filter ~84 a month with 3 changes per month
With castrol syntec 20w-50 I was changing my oil every 1500 miles with filter  ~63 a month with 2 changes per month
with motul 300v 15w-50 i am changing my oil every 5000 with filter ~41 a month with .6 changes per month

lazy and save money in the long run? yes please.

[inanecathode]

Yeah sure if you're breaking in your studebaker, modern engines (including the vision, all aluminum, water cooled) dont need nearly the same amount of break in time engines used to need. Cylinder glazing isnt from using synthetic it's from not breaking the engine in in the first place.

Its the machining tolerance, not the materials used that necessitate engine break in procedure.

I dont get even where you're coming from, you're apples and oranges, machining tolerance has nothing to do with break in. Break in has to do entirely with the application, materials, and very basically at what angle, how quickly, and how completely a new set of rings wipe the hone angle off the cylinder. We could get into breaking in valves but thats just more materials and application variables.
Chromemoly plain rings, nickasil liner, how long do you figure that'll take till it's broken in? How about iron rings in an iron block? How about tapered iron rings in an iron lined aluminum block? How about iron rings with expanders in an air cooled cylinder? How about plain iron rings in a plain iron block with a slipper skirt, buttons?
Machining tolerance is a good catchall for why modern applications are different from days of yore, sure it makes a difference, but you could have the best machined set of cylinders and pistons on the entire planet for all ages, and if you run them in an aircooled setup they'll sieze. You could put the absolute nicest set of accurate and perfectly balanced and machined valves into your sbc head, but neglect to use the appropriate alloy valve guides and be smoking like the mystery machine in 500 miles.
Point is, there's bazillions of combinations of variables. No matter how cool it is to have canned opinions about synthetic oil, etc, etc theres always variables to think of, not everything is straight forward.

[Kid Jedi]

our visions have the same materials as modern race bikes, aluminum heads & jugs, steel sleeves and water cooled, yet the breakin procedure is radically different.  I believe that machining tolerances are the difference.

I was only comparing our visions to modern engines

[Rick G]

As mine has gotten older I change the oil more frequently .  Used to be every 2500 to 3000 miles , but it dirties up sooner, so now its 1500 to 2000 miles . The main reason I like a synthetic blend, is that it makes shifting so nice.

[Kid Jedi]

here is an idea rick, could the fact that your oil is getting contaminated so quickly be that you have gunk in her cases? i Wonder if an oil treatment, like running seafoam in the cases, would allow you to go back to your old oil schedule?

[louie]

just a thought but i would never put a cleaner through a old engine again. I have yet to do it on a bike engine but i watched it blow three car engines, cause not only did it clean the pans up, it also cleaned the shit and guck outta everything. causeing all the bearings to get play in them.

  So just a thought but watch it doesnt clean everything up to much

[Lucky]

dirt shouldn't be keeping your clearences tight, if so you have bigger problems.

GM crankcase clean does wonderful things.

when my bike was new (to me) i had leaking carb overflows, & not knowing any better i plugged them.  a couple of days later i came out to a nearly empty gas tank (from 1/2 full) and didn't realise it was all in the crankcase.  i started the bike & blew streams of fuel out the exhaust! by the grace of God i didn't grenade the bike, but when i figured out what happened, & drained the oil, the crankcase was as clean as a whistle!

never had engine problems with that bike other than a stator or 3...

--Lucky

[Kid Jedi]

ya had the same thing happen on a 1980 honda ct 70. the case was FULL of gas. that engine is VERY clean though!