• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Winter Oil, Aviation oil/auto oil

And yet Lycoming recommends a mixture of STP and mineral oil for engine assembly. Which was part of why I talked to those experts about STP and similar additives.

The science question remains.....
 
I believe that the sticky thick STP and mineral concoction is to ensure that the parts all have lubrication in place for the initial startup. After it is run the regular oil will be dispersed throughout the engine. The STP will be diluted and removed at the first oil change.
 
skywagon8a said:
I believe that the sticky thick STP and mineral concoction is to ensure that the parts all have lubrication in place for the initial startup. After it is run the regular oil will be dispersed throughout the engine. The STP will be diluted and removed at the first oil change.
Click to expand...

This is exactly what I was taught when building car or aircraft engines. The pre lube is only there for the first minute, strictly to protect moving parts until the oil has began to circulate. Just an observation, but I don't believe that some of these additives should be in car or aircraft oil in normal ops.

Any one here know an engineer from Philips or Shell?

Web
 
The zinc content of ZDDP is an anti-wear component that is thought to be possibly problematic in aircraft engines, but I had a friend who ran several O-470's to overhaul with minimal wear using (pre-cat converter) STP in the oil regularly. I recall that he only used half a can per oil change. I think you would need only half of that as ZDDP-free 'motor honey' to coat the cam....

My dad was an engineer for Mobil, does that count a little?
 
What was the 'problematic' part? Did it have to do with heat or pressures. Fuels or other materials?

Web
 
I know guys who use STP in their summer aircraft oil and I've been told a respected engine builder in Wasilla advises it. I asked Ed Kollin about it and he told me it was a bad idea. I already was a Camguard user so he didn't need to sell me on that. I had been curious so I asked the best expert I had access to. Ed used to chime in here a little. Maybe he will again. I do remember asking what oil he used in his own plane. Phillips X/C with Camguard.
 
When we were having a discussion here about Camguard and other things, Ed "speculated" that ZDDP would bond to various metals in the engine and that probably wouldn't be a good thing.....

By the way, 'motor honey' is the same stuff in your multi-vis oils that thickens up when it gets hot....that makes it multi-viscosity.... The low number is the regular oil viscosity, and the high number is the viscosity it simulates when hot.
 
Last edited:
If I was to guess, I would guess that the ideal aviation oil would be: 5 qts of Phillips XC with 1/2 pt of Camguard, 1 pt of kerosene or Stoddard solvent, and 1/4 pt of motor honey. I would say 90 weight gear lube, but that has sulfur in it, which could be a mistake.
The kerosene to scavenge carbon deposits, and the motor honey to coat the cam. Thoughts?
 
Lol, and you guys called my 5w30 oil a "risky" experiment. Let me know how that turns out.
BTW, my local ame likes Rislone.
 
Well, I didn't....BUT, the average viscosity probably needs to be a bit higher....bear in mind, that with wear, the max viscosity tends to lower as molecules get sheared, and approach the lower number...and due to the large clearances in air cooled engines, the minimum viscosity needs to higher than auto engines. According to my dad, any given weight oil needs to have a mixture of shorter and longer molecules mixed in it to penetrate smaller spaces and cling to surfaces for startup lube.
They kinda helped that with multi-vis , but not completely, IMHO...
 
fobjob said:
If I was to guess, I would guess that the ideal aviation oil would be: 5 qts of Phillips XC with 1/2 pt of Camguard, 1 pt of kerosene or Stoddard solvent, and 1/4 pt of motor honey. I would say 90 weight gear lube, but that has sulfur in it, which could be a mistake.
The kerosene to scavenge carbon deposits, and the motor honey to coat the cam. Thoughts?
Click to expand...

Hey guys, don't be playing witch doctor with your engine oil. The oils that we use in our airplane engines are formulated and tested to run safely by engineers and chemists that have the required knowledge. Our airplane engines run at much different speeds and have different tolerances and cooling methods than automotive style engines. This makes the lubricating requirements much different. Mixing oils on your own is asking for trouble, even between different brands. Additive packages between brands and especially oil additives may not be compatible with each other. This can create issues with contaminants precipitating out, sludge buildup, degradation of lubricating properties and a whole host of other bad stuff to occur in your engine. Cam Guard is a good thing to run with your oil. It has been tested and is compatible with the aviation oils we use. I don't think I have ever heard of anyone having an engine problem that was caused from using the correct oil changed at the correct intervals. Most engine issues are caused from improper engine usage/management, lack of use, or abuse. Engine problems are not caused by using the correct oil.
 
"Engine problems are not caused by using the correct oil."

Speaking of "correct" oil, I had two cylinders lock up their rings and burn 6 qts in 20 minutes, most likely from shell 15-50 and lotsa tetraethel lead.... left a nice smoke trail, along with a nice stain down the right side of the fuse....
 
I suspect that those two cylinders had some other issue other than the oil. I have been using Shell 15W-50 for more than 40 years without any ring or other problems which could be traced to oil.
 
Forget all these comparisons with water cooled auto engines, I think I'll just ask what was used in thousands of 1950-60s & 70s air cooled Harley engines, seems they run forever with little or no cooling while negotiating in the city, ample bearing clearances & about the same operating rpm :roll:
 
A steady diet of avgas and 15-50 was the only common factor we had after eliminating all others...if it was only one cylinder....but two? You are aware of the history of complaints about oil consumption and 15-50?
 
Senior said:
Forget all these comparisons with water cooled auto engines, I think I'll just ask what was used in thousands of 1950-60s & 70s air cooled Harley engines, seems they run forever with little or no cooling while negotiating in the city, ample bearing clearances & about the same operating rpm :roll:
Click to expand...
Do they have pressure oil systems or are they splash systems?
 
Senior said:
Forget all these comparisons with water cooled auto engines, I think I'll just ask what was used in thousands of 1950-60s & 70s air cooled Harley engines, seems they run forever with little or no cooling while negotiating in the city, ample bearing clearances & about the same operating rpm :roll:
Click to expand...

As I remember, H-D marketed their own oil. I don't remember anyone using anything else except one buddy who had a worn out 61 cube springer. He only got about 50 miles to a quart until he started using 90 weight gear lube. That really cut back his oil consumption but boy did the exhaust stink. Every ride turned into a race to keep him at the back of the pack. jrh
 
Gear lube has a lot of sulfur in it....my bud has a Sportster, and uses a synthetic, but still has CHT issues in the rear cylinder, and won't run it above 95F OAT....
 
You must log in or register to reply here.

Similar threads

CamTom12
Weird oil temp issue on an exp. Pacer
Replies
6
Views
3K
CamTom12
CamTom12
AlaskaAV
How media and special interests can change facts
Replies
2
Views
10K
AlaskaAV
AlaskaAV
C
Have you ever spent the night in Corsicana, Texas?
Replies
9
Views
6K
dreamer
dreamer
180Marty
GM bets on $1/gallon ethanol
Replies
11
Views
5K
Christina Young
Christina Young
sj
Waynesville to Alaska - Week One
Replies
4
Views
4K
cpalmer
C
Back
Top