ROTELLA 15W 40 Oil

Many reasons for 'black' oil but most over looked is the fact if your driving your Model A without an air filter, sucking up all the turbulent dirt off the highway.


Boat owners have 'clean' oil much longer...
 
jb-ob said:
Many reasons for 'black' oil but most over looked is the fact if your driving your Model A without an air filter, sucking up all the turbulent dirt off the highway.


Boat owners have 'clean' oil much longer...
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I have an air and oil filter.
 

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Werner said:
Hallo!
"Rotella" oils are some of the few engine oils Shell manufactures specifically for diesel fuels. Unlike the same 15W/40 shell oil for gasoline engines, Rotella blends contain an increased proportion of high pressure additives, other cleaning additives, and less corrosion inhibitor / TBN neutralizer.

It's no problem to use Rotella in old-fashioned petrol engines. But there are no benefits. On the contrary. This results in more combustion residues and the lower corrosion protection / antixidants require shorter replacement intervals.
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Well said Werner.
 
Jim Brierley is the performance guru of the Model A having successfully 'run them' at Bonneville.


A stock era Air Maze on a stock Model A has been proven to actually restrict air flow thru a stock A carburetor.


From your photo you have a lot of performance breathing going on from headers, trick intake manifold, and a perfectly adequate Stromberg....all to be choked by possibly too small a flowing air cleaner.


Just a suggestion.....but excuse me, all this has nothing to do with motor oil.
 
jb-ob said:
Jim Brierley is the performance guru of the Model A having successfully 'run them' at Bonneville.


A stock era Air Maze on a stock Model A has been proven to actually restrict air flow thru a stock A carburetor.


From your photo you have a lot of performance breathing going on from headers, trick intake manifold, and a perfectly adequate Stromberg....all to be choked by possibly too small a flowing air cleaner.


Just a suggestion.....but excuse me, all this has nothing to do with motor oil.
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I have no problem with suggestions or recommendations for improvement, I have an ear for everyone.
 
I have a general note about engine oils.

I do not know how strictly that is regulated in the USA. But in Germany environmental protection has a very high say in the oil mixtures. For example, phosphorus and sulfur must very barely added.

However, phosphorus and sulfur are excellent emergency lubricants in the limit lubrication range. (Top dead center cylinder/piston, Outlet-valve stem.)
Overall, therefore, discussions are fruitless over then and now, because it did in the past not know better then today. And no lubricant manufacturers is interested today, because the sales volume of vintage oil is uninteresting.
 
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I would like to clarify something else:

No A-motor will be damaged if it is driven with "Rotella" for diesel engines. Everyday wear is no different.

But with this oil, more will deposit carbon residue and ash than with a similar Shell oil for gasoline engines.

The extent to which over the tens of thousands of miles to worse cylinder filling due to coked valves and combustion chambers (worse gas exchange) and perhaps glow-ignitions depends on how the car is driven and whether in the fuel cleaning additives (detergents, MMO) are added.

The Rotella oil is undoubtedly a good oil. But for the A, there are more optimal lubricating oils for the same money.
 
I know very little about air cleaners, I don't run them on my A's, or Bonneville engines. I do know they can be restrictive, and really complicate things when using Strombergs because the bowl vent is below air filter. I live on a dirt road, and my engines show very little wear after many thousands of miles, but still believe they are a good idea.
 
I have used diesel oil for a long time, yes it gets dirty quickly but that is because it's holding the contaminants.

Interestingly it erodes the sludge over a short time. But yuck, clean the sludge out first.

Somewhere i had a video of sludge and oil dissolving it but can't think where i left it...
 
I find Werner's post #10 interesting. Have a motor that was rebuilt last winter and have been using Rotella 15w40 diesel oil. Motor runs great, but 500 mile oil changes are a deep India ink black color. Have tried 2 different rebuilt carbs, no difference.
After reading the above, get the impression the oil should be in better shape at the 500 mile mark. Do not run an oil/air filter, but now think oil should be in better shape anyway.


Am running the hotter W18 spark plugs to keep soot down on the outer part of the plugs, and to keep the black off the center when driving low/medium speeds.


Am now wondering if the motor may being running dirty due to the Rotella oil.
Think I will try a different non-diesel oil nest year, perhaps Castrol GTX 20w50.


What you think? Comments?
 
30 Closed Cab PU said:
I find Werner's post #10 interesting. Have a motor that was rebuilt last winter and have been using Rotella 15w40 diesel oil. Motor runs great, but 500 mile oil changes are a deep India ink black color. Have tried 2 different rebuilt carbs, no difference.
After reading the above, get the impression the oil should be in better shape at the 500 mile mark. Do not run an oil/air filter, but now think oil should be in better shape anyway.


Am running the hotter W18 spark plugs to keep soot down on the outer part of the plugs, and to keep the black off the center when driving low/medium speeds.


Am now wondering if the motor may being running dirty due to the Rotella oil.
Think I will try a different non-diesel oil nest year, perhaps Castrol GTX 20w50.


What you think? Comments?
Click to expand...
I started this thread because the oil was on sale, I was curious myself about the quick change in color. This is the only oil I have used since my engine was rebuilt, and was told to use this and add ZDDP. I noticed some negative responses to the use of Rotella 15W 40, so I asked the rebuilder two days ago if I should continue the use of this oil, his response was, use Valvoline 20W 50 racing oil.Guess I will switch.
 
Check the gaps at the rotor tip on all contacts in the distributor cap body . A lot of times the gaps will be all over the place in some reproduction distributor caps . Ford recommended a conservative gap of twenty five thousands . For hotter spark at the spark plugs I run a gap of thirty five thousands at the rotor tip . Jumping a wider gap ,to a point will increase the spark intensity . Too much gap will advance the timing to the point that it will run poorly if at all . Running too rich could be the cause of darkening of the motor oil . A hotter spark should help ignite the raw gas .
 
I haven't visited fordbarn for a long time. Decided to see whats up and right there at the top is an oil thread. Nice to see I haven't missed anything
 
Purdy Swoft said:
Check the gaps at the rotor tip on all contacts in the distributor cap body . A lot of times the gaps will be all over the place in some reproduction distributor caps . Ford recommended a conservative gap of twenty five thousands . For hotter spark at the spark plugs I run a gap of thirty five thousands at the rotor tip . Jumping a wider gap ,to a point will increase the spark intensity . Too much gap will advance the timing to the point that it will run poorly if at all . Running too rich could be the cause of darkening of the motor oil . A hotter spark should help ignite the raw gas .
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"Too much gap will advance the timing to the point that it will run poorly if at all." Actually, the amount of rotor gap (or plug gap) has no measurable effect on timing. Secondary voltage rise in the coil is too rapid (milliseconds) to affect when the spark will occur, but if anything, in theory the spark will occur later with a larger rotor gap.
 
Purdy Swoft said:
I've used Rotella 15w40 in some of my model A's with no problem . I figure the 15 is a bit thin . I use Walmart 20W50 I figure that the 50 will better cushion the bearings on an eighty eight year old engine . I also use it in the professional rebuilt engine in another of my model A's .
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15w40 is only "thin" when the oil is cold which is a good thing because it flows to the bearings faster at start up. 15w40 oil doesn't stay at 15 when the engine warms up. When the engine is at operating temperature it is 40.
 
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