| [GMCnet] Pushing against the wind [message #269523] |
Mon, 12 January 2015 19:08  |
Advanced Concept Ener
Messages: 112
Registered: December 2014
Karma: 0
|
Senior Member |
|
|
Running oil temperatures at 250 deg may be fine for a race car that changes the bearings after every race but it leaves no room for error. A blue printed balanced engine probably puts the same stress on each bearing but if it doesn't it could result in a bearing wiping. Bearing temps are usually about 50-75 deg above oil temperature. Most bearings with a bait base material will start to wipe about 325-350 deg. Harder aluminum bearings may not start to wipe until 400 or so but then fail catastrophically by welding to the shaft. Oil lubricates fine at 135 deg. The cost of changing oil more often is cheap compared to loosing bearings or shafts.
On another note the gentleman that just passed must have been a great guy to command as much respect as expressed on this site. It is my misfortune that I didn't get the opportunity to meet or exchange ideas here with.
Sent from my iPad
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Pushing against the wind [message #269570 is a reply to message #269523] |
Tue, 13 January 2015 10:38  |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
Advanced Concept Ener wrote on Mon, 12 January 2015 20:08Running oil temperatures at 250 deg may be fine for a race car that changes the bearings after every race but it leaves no room for error. A blue printed balanced engine probably puts the same stress on each bearing but if it doesn't it could result in a bearing wiping. Bearing temps are usually about 50-75 deg above oil temperature. Most bearings with a bait base material will start to wipe about 325-350 deg. Harder aluminum bearings may not start to wipe until 400 or so but then fail catastrophically by welding to the shaft. Oil lubricates fine at 135 deg. The cost of changing oil more often is cheap compared to loosing bearings or shafts.
On another note the gentleman that just passed must have been a great guy to command as much respect as expressed on this site. It is my misfortune that I didn't get the opportunity to meet or exchange ideas here with.
Jon,
It is interesting that your observations are accurate, but the cause/effect relationship missed by a little.
There is a simple fact that dino based lube oil changes when it hits 305°F. This is not a time/temperature thing. It is simply that when that molecule hits the aforementioned T, it comes apart and ceases to be a film lubricant ever again. One of the problems with monitoring lubricating oil temperature outside of a development laboratory setting is that you don't know the temperature of the hottest place that the lube oil cools. Underside of piston crowns is almost always a winner along that line.
Lubrication is low on the list of what the oil in an engine actually does. This list - pretty close to importance - says a lot:
A - Coolant for parts not cooled by jacket water (most important is piston crowns in most engines)
B - Flushing debris - metal and combustion from clearances
C - Motion damper for parts with that require clearance (largely valve gear)
D - Working fluid for lash and tension adjusters
E - Metal contact prevention (this is close but not true lubrication)
F - Hydraulic wedge load bearing (this is also close, but still not true lubrication)
G - Film based lubrication *** (this is bearings at starting speed and cam lobes)
(there are some more but CRS always strikes about here, but when G is at 7th or 8th...)
*** That last is where bad/failed lube oil strikes and you get wiped bearings and such.
While a student, I had the opportunity to run a special engine at the Esso lab in NJ. It had no oil in the crankcase. Most of the functions of oil were done with distilled water. Some parts also had special wear surfaces. It had be warm and spun to speed before it could be fired. That distilled water could then be analyzed for combustion by-products.
Those combustion by-products that accumulate in the lubricating oil are what turn acid and then attack the anti-wear additives in the lube oil and in higher concentrations the can damage the actual oil. Keeping the water out is why any engine should be run with a lube oil temperature over 220°F. The reason for a warning about 250°F is simply that oil going to hot surfaces at that can be pushed over the NO-GO limit at 305°F.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: [GMCnet] Pushing against the wind [message #269581 is a reply to message #269570] |
Tue, 13 January 2015 12:25 |
Emery Stora
Messages: 959
Registered: January 2011
Karma: 4
|
Senior Member |
|
|
> On Jan 13, 2015, at 9:38 AM, Matt Colie wrote:
>
>
> While a student, I had the opportunity to run a special engine at the Esso lab in NJ. It had no oil in the crankcase. Most of the functions of oil
> were done with distilled water. Some parts also had special wear surfaces. It had be warm and spun to speed before it could be fired. That
> distilled water could then be analyzed for combustion by-products.
>
>
Was that the Atlas Laboratories in Edison, NJ which wss the testing lab for all of the Standard Oil companies (Esso, Amoco, Exxon, Standard, etc.) or was it the Esso lab in Paulsboro, NJ?
I have been to them both in years past.
Emery Stora
77 Kingsley
Frederick, CO
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Pushing against the wind [message #269582 is a reply to message #269570] |
Tue, 13 January 2015 12:31 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
|
Senior Member |
|
|
I am quite surprised that lubrication is so far down the list.
Us grunts just think thats all oil does...
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
|
|
|
|
| Re: [GMCnet] Pushing against the wind [message #269609 is a reply to message #269581] |
Tue, 13 January 2015 16:16 |
|
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
Emery Stora wrote on Tue, 13 January 2015 13:25
> On Jan 13, 2015, at 9:38 AM, Matt Colie wrote:
>
>
> While a student, I had the opportunity to run a special engine at the Esso lab in NJ. It had no oil in the crankcase. Most of the functions of oil were done with distilled water. Some parts also had special wear surfaces. It had be warm and spun to speed before it could be fired. That distilled water could then be analyzed for combustion by-products.
>
>
Was that the Atlas Laboratories in Edison, NJ which wss the testing lab for all of the Standard Oil companies (Esso, Amoco, Exxon, Standard, etc.) or was it the Esso lab in Paulsboro, NJ?
I have been to them both in years past.
Emery Stora
Emery,
That is interesting and that facts even more interesting.
I was employed by Esso labs div. and my paycheck came from Paulsboro, but I was placed at Edison.
An amazing place. Too bad I was not allowed pictures of any kind.
Sometimes samples got packaged up and sent to Paulsboro (near Phili for those that don't know) and we would get results as fast as if they came from the other end of the building. Those were the first faxes (1968) that I ever saw.
The people both places treated NJTP as a road built just for them. (Edison is not far from NYC - why I got the job as a student at SUNY-Ft. Schuyler)
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: [GMCnet] Pushing against the wind [message #269614 is a reply to message #269582] |
Tue, 13 January 2015 16:26 |
|
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
Keith V wrote on Tue, 13 January 2015 13:31I am quite surprised that lubrication is so far down the list.
Us grunts just think thats all oil does...
Keith,
Don't feel like a lone ranger....
If you look at that list, it is pretty clear that anything above film lubrication will be a major issue if it is missing.
This is also why old slow hand lubed engines had such limited power output. You could do the film lubrication with grease and some did, but all that other stuff particularly the cooling really has to be there if you want anything like real specific (Hp/cuin) power output.
Want a stopper??
Big engines - like 1m bore and 2m stroke 2 stoke diesels - like that are in big fast container ships - don't have a piston cooling problem. The piston is water cooled. There is a coaxial piston rod (not connecting rod) and there are coolant hoses to the crosshead (the connection between the conrod and the piston rod). But then, they run at about 100 RPM.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
[Updated on: Tue, 13 January 2015 16:27] Report message to a moderator |
|
|
|
GMCforum
Search
Help
Register
Login
Home
