V-Twin Forum banner
1 - 17 of 17 Posts

·
Banned
Joined
·
169 Posts
Discussion Starter · #1 ·
If full synthetics have the ability to carry/absorb more heat (mostly because they don't foam up as easily (less air mixed in = denser oil = more heat absorption) shouldn't oil tank temps be just as high as with conventional oils?

Shouldn't this be even more obvious in motors that squirt oil against the underside of the piston crown (hottest place in motor) for the precise reason of removing heat (cooling) ?

Are you people observing lower oil tank temps after switching to full synthetic suggesting the lower temps are due to less friction because the synthetic is slipperier?

:cheers:
 

·
Registered
Joined
·
98 Posts
I tryed syn oil a few times and never seen a temp difference..hot weather ill reach 250 oil temp at highway speed....and 10 15 deg less on side roads..same temp with any oil i use...I dont run a oil cooler 87.000 miles on motor 113
 

·
Banned
Joined
·
2,735 Posts
I thought that the big advantage that syn has over dino is the fact that it doesn't break down or start to varnish up until over 300 degrees. George Douglas, the Oil Guru, will hopefully jump in here.
Semper Fi,
Steve...Pensacola (73 degrees today)
USMC 1972 - 2003
 

·
Registered
Joined
·
98 Posts
steveusmc said:
I thought that the big advantage that syn has over dino is the fact that it doesn't break down or start to varnish up until over 300 degrees. George Douglas, the Oil Guru, will hopefully jump in here.
Semper Fi,
Steve...Pensacola (73 degrees today)
USMC 1972 - 2003
I believe syn its good to 400 deg,,,,cant go wrong using syn but i change my oil every 1000 to 1500 miles with dyno if i use syn ill change it every 2000...never seen anyone have oil problem who changes oil often
 

·
Hellbound Train
Joined
·
5,595 Posts
Synthetic does help your engine run cooler due to less friction in the engine components and better heat transmission characteristics. Plus you have the added benefit of higher break down temperatures in case you are stuck in traffic on a really hot day. I think HDWrench uses it when he rides in the Easter parade in Phoenix.
 

·
Registered
Joined
·
129 Posts
csoday said:
Synthetic does help your engine run cooler due to less friction in the engine components and better heat transmission characteristics. Plus you have the added benefit of higher break down temperatures in case you are stuck in traffic on a really hot day. I think HDWrench uses it when he rides in the Easter parade in Phoenix.

This IS the reason less friction=less heat. Syn is good to 300F. Dino 250F. Anybody South of Alaska should be using Synthetic oil.
 

·
"What's this do?"
Joined
·
230 Posts
When I switched to Amsoil in my truck I pick up an extra 1.5 miles per gallon. I’m not an oil scientist, but I figure there is less friction to achieve that kind of gain. Less friction should mean somewhat less heat.
 

·
Premium Member
Joined
·
206 Posts
My oilhead beemer ran quite a bit cooler with synthetic in it than it did with dyno (the temp gauge never rose above 6 bars, with dyno it'd hit 7) and that sold me on synthetic. I plan on using Mobil 1 in my FXST come spring.
 

·
Hellbound Train
Joined
·
5,595 Posts
KBFXDLI said:
This IS the reason less friction=less heat. Syn is good to 300F. Dino 250F. Anybody South of Alaska should be using Synthetic oil.
I believe you are very low on both on those temps. The Twin Cam comes from the factory with Dyno oil recommended and the Engine Heat Management doesn't begin to make adjustments until 300f.
 

·
Banned
Joined
·
169 Posts
Discussion Starter · #11 · (Edited)
I've been doing some reading on synthetics as of late and have noticed the makers are pretty careful with their words when describing "reduced friction"

As an automotive machinist it's common knowledge that 70% + of the friction produced in a motor is from the rings. You don't have enough reduction in ring/cylinder wall wear from running syn over conventional to account for such reduced temps due to less metal to metal friction in that area.

The way it reads to me is there is less pumping loss with syn oil because for a better word, It is less "viscous" and the heat reduction is in the oil itself. As the oil is being pumped and squeezed the oil molecules slide past each other easier creating less heat.
 

·
Premium Member
Joined
·
2,242 Posts
KKRider said:
I've been doing some reading on synthetics as of late and have noticed the makers are pretty careful with their words when describing "reduced friction"

As an automotive machinist it's common knowledge that 70% + of the friction produced in a motor is from the rings. You don't have enough reduction in ring/cylinder wall wear from running syn over conventional to account for such reduced temps due to less metal to metal friction in that area.

The way it reads to me is there is less pumping loss with syn oil because for a better word, It is less "viscous" and the heat reduction is in the oil itself. As the oil is being pumped and squeezed the oil molecules slide past each other easier creating less heat.
KKRider is getting close to one of the reasons. When forcing oil through bearing clearances etc., more fluid friction heat is developed with dino oils due to the squeezing of non uniform sized molecules. With synthetics the molecule structure is uniform and they don't fight each other so to speak like in dino oil. Also they transfer heat faster than dino oil does. All liquids have different characteristics of heat transfer with water being one of the better.
 

·
Knower of Stuff
Joined
·
1,978 Posts
Most Syn oil begins thermal breakdown at over 400*. Dino oil thermal breakdown is usually 300-350*.
 

·
Registered
Joined
·
393 Posts
LittleBear said:
Most Syn oil begins thermal breakdown at over 400*. Dino oil thermal breakdown is usually 300-350*.
man if it is that hot find a shady place and chill. i will hit my heat limit before the bike does, full face helmet and ballistic jacket, thank god for cooling vests
 

·
Registered
Joined
·
30 Posts
plasterhead said:
I believe syn its good to 400 deg,,,,cant go wrong using syn but i change my oil every 1000 to 1500 miles with dyno if i use syn ill change it every 2000...never seen anyone have oil problem who changes oil often

Wow Plaster...will you start sending me your old oil? Cant even look used at 1000 miles!:Banadance
 

·
Premium Member
Joined
·
2,242 Posts
plasterhead said:
I believe syn its good to 400 deg,,,,cant go wrong using syn but i change my oil every 1000 to 1500 miles with dyno if i use syn ill change it every 2000...never seen anyone have oil problem who changes oil often
What about worn out drain plugs? Big oil and filter company's love people that like to change oil more often than necessary. Keeps the economy going.
 
1 - 17 of 17 Posts
Top