dirty oil. Why so quick

[nbrskn]

I have an 8BA . Recently rebuilt. Since rebuild it doesnt take but a few short miles before the oil is dirty. 30 miles one time .this time from replaceing bad head 100 miles. Had pan off and black stuff in pan.
Any ideas? New carb from Dennis carpenter this last 100 miles.
Engine runs good and is pepppy. Compression runs 110 across all 8 cyl.
Had PVC on it and took it off and put road tube back on .
did not make any dif.

Thanks

[DD931]

It doesn't have a full-flow oil filter. Back in the day the regular interval for oil changes was 1000 miles. I remember Kendall Motor oil advertising that it was the "2000 Mile Motor Oil". Henry (and others) believed that the way to keep your engine clean was to change the oil frequently.

[19Fordy]

Has the engine been on the road long enough with enough miles for the rings to seat?

Additives in oils are designed to literally "clean" so the oil will get dirty pretty quick.

[G.M.]

I found if the engine runs hot the oil gets black fast. G.M.

[hardtimes]

Originally Posted by nbrskn

I have an 8BA . Recently rebuilt. Since rebuild it doesnt take but a few short miles before the oil is dirty. 30 miles one time .this time from replaceing bad head 100 miles. Had pan off and black stuff in pan.
Any ideas? New carb from Dennis carpenter this last 100 miles.
Engine runs good and is pepppy. Compression runs 110 across all 8 cyl.
Had PVC on it and took it off and put road tube back on .
did not make any dif.

Thanks

'recently rebuilt'...if original type rings, may not be seated yet ? If not seated yet, gas can/will pass by rings...and contaminate oil ! If you do not have an oil filter, oil has to catch and retain all by products of combustion.
Are you using multi-grade oil ? That is doing its job and keeping crankcase clean. If no filtering system, change whatever oil you use often enough to Ford specs.

[40 Deluxe]

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Originally Posted by DD931

It doesn't have a full-flow oil filter. Back in the day the regular interval for oil changes was 1000 miles. I remember Kendall Motor oil advertising that it was the "2000 Mile Motor Oil". Henry (and others) believed that the way to keep your engine clean was to change the oil frequently.

Interestingly, the original "Service Data Handbook" that came with my '40 specifies that the oil "be changed every 2,000 miles" for cars without an oil filter. For cars with an oil filter it states "that the oil be changed at 5,000 mile intervals. The filter should be replaced every 10,000 miles."
So Henry thought differently than we think he thought!

Now the kicker: The book also states "except for seasonal changes."

[rotorwrench]

Older engines with carburetors don't have near the efficiency in the fuel delivery system as the modern electronically controlled fuel injection. With new rings seating in as well, the combustion by products get into the oil pretty quick. The first 500 miles or so should be enough to bed things pretty well so an oil change is critical in that phase. From that point on the normal service interval would be in effect.

This is the way they always were so there isn't much that can change that other than fabricating a late type fuel injection system for it.

[Ggmac]

Originally Posted by 40 Deluxe

Interestingly, the original "Service Data Handbook" that came with my '40 specifies that the oil "be changed every 2,000 miles" for cars without an oil filter. For cars with an oil filter it states "that the oil be changed at 5,000 mile intervals. The filter should be replaced every 10,000 miles."
So Henry thought differently than we think he thought!

Now the kicker: The book also states "except for seasonal changes."

My 36 air leaner says 1000 miles or sooner if xxxxxxx . The rest was gone from the decal . Sorry

[50fordcoupeman]

Dirty oil with low miles is as others have said above doing its job.

[Kurt in NJ]

How are the plugs burning---if black too you could have too rich of a mixture

[nbrskn]

engine was rebuilt by a reputable shop. Has a full flow oil system from Mark Kerby. Has an oil filter. Has 10w40 oil . Pennzoil. Engine has a little over 2000 miles on it.

[Bored&Stroked]

There used to be a lot of oils that would turn black as they get hot - used to be a way for the manufacturer to increase oil changes. What I don't know is which oils actually do this today? One thing to think about is having the oil sent/tested at a lab - they can tell you what shape the oil is in. Me - I just run Penn Grade 'green oil' . . . tends to stay green and I change it about once a year . . . whether it needs it or not.

[Anteek29]

Kurt's recommendation to pull and check the plugs is a good one.

[JSeery]

Not sure about the current Pennzoil, but in the past it was a high sulfur oil. I have had (again in the past) a lot of bad experiences with Pennzoil and tend to stay far away from it. Some of the dirtiest engines I ever took apart had been using it.

[nbrskn]

i am 75 year young. Been using pennzoil all my life. Have rebuilt many of my vehicles engines. All were clean inside. Must be regular oil changes.
336000 1978 F150 , 226000 1968 F150 , 200000 1967 Galaxie 500 of which still own, 196000 2002 lincoln that I still own. thats Just a few

[JSeery]

Originally Posted by nbrskn

i am 75 year young. Been using pennzoil all my life. Have rebuilt many of my vehicles engines. All were clean inside. Must be regular oil changes.
336000 1978 F150 , 226000 1968 F150 , 200000 1967 Galaxie 500 of which still own, 196000 2002 lincoln that I still own. thats Just a few

Sure not my experience!

[40cpe]

Years ago it was common belief in my part of the world that Quaker State would sludge an engine. I wasn't a mechanic and didn't see any of the evidence but I didn't use it. It might have been from the base crude that came from Pennsylvania. Today, with modern refining and crude coming from all over, it could be different.