Black oil quick
 

Have a fresh rebuilt 36LB engine, with about 700 miles on it. First oil change at 300 miles. Brad Penn, 30wt, green oil. After a couple hundred miles, not much green left, oil is black on stick. There is no oil filter. Is this typical for flathead engines?

Re: Black oil quick
 

Re: Black oil quick
 

The old flat motors were carbureted, they had old style piston rings for the most part, and they don't always have the right combination of F/A mixture for good service. If it is running rich at all, that won't help and carbs just naturally are less efficient than the modern EFI systems. Oil will turn dark slower if everything is in good working order and mixtures are within OEM specs. Rings should be fully seated in by 500 miles after O/H. It will still turn black but it will take longer. This is why they recommended frequent 2000-mile oil changes back in the day.

Re: Black oil quick
 

I do notice a gas smell all the time. I have a 97 carb, and just sent my fuel pump to Charlie for a rebuild, hope that helps, thanks

Re: Black oil quick
 

The engine rebuilder suggested single weight oil? Is that non-detergent?

Re: Black oil quick
 

Yes, detergent, your thought?

Re: Black oil quick
 

My thought is to follow your rebuilders oil suggestion. I too would recommend detergent oil usually see 10W-30 for a new engine during break in. The straight 30 weight should be good also.

Re: Black oil quick
 

Black is not bad. I question the straight 30wt.

http://www.valvolineeurope.com/engli...ID=2269&cp=cp1

Re: Black oil quick
 

I'm with Frank here, modern detergent oils suspend contaminants so they do not settle on engine parts and form sludge. So in a way black means it's doing it's job. I'm not touching the viscosity topic though.

This is from the Valvoline page Frank references...

Myth: You can tell the condition of an oil by its look, smell and color. If it turns dark or goes black quickly, it’s not good.

Fact: Nothing could be further from the truth. If an oil is doing its job cleaning the engine, then it will be dirty when it is drained. In the case of diesel engines, the oil may look dirty within a few hours of operation. This indicates that the motor oil is keeping soot, dirt and other combustion contaminants in suspension. These will then be carried to the filter or removed from the crankcase when the oil and filter are changed. Good quality motor oils are formulated to hold these contaminants in suspension until the oil is drained when the oil and filter are changed.

This page has interesting thoughts about modern vehicles... Motor oil myths and facts.
http://www.nordicgroup.us/oil.htm#Introduction

THE way to know what is going on is to do an oil analysis. Here's a place I found with google that will do one for $28... https://www.blackstone-labs.com/free-test-kits.php

Re: Black oil quick
 

33 years ago I installed a brand new WWII engine in my 39 convertible. I used
Castrol 20/50 from day 1. The engine ran the typical hot, up near 200 and the
oil got black in a few hours. It also used a quart between changes. About 9 years
latter I installed Skips pumps and cooled the engine down to 180 with
Bob Shewman's 180 degree stats that allow a non restricted full flow of coolant
through the engine. The engine ran at 178 to 182 on days in the high 90's. It
stopped using any notable amount of oil between changes and the oil don't get
black but is a dark yellow. At 85,000 when changing the oil I stuck my finger up
in the drain hole and the pick up screen moved, I did it again and the pump
moved so I pulled the pan and the pump was loose where it was welded to the
flange. I brazed it and put it back together. Also the Castrol kept the engine
looking almost new and had no sludge at all in the pan. It now has over 130,000
miles, runs perfect, is quiet and burns no oil. Attached is a picture of when I had
the pan off. G.M.

Re: Black oil quick
 

I shouldn't be surprised, the flathead V8 is a well-engineered powerplant made of quality materials, but racking up 130,000 trouble-free miles with an engine designed and manufactured in the 1930s is nothing short of amazing. This clearly demonstrates the power of proper maintenance.

Re: Black oil quick
 

True dat!

A related comment. I have always been religious about changing my oil, maybe even too often. I don't do that any more on my modern cars, but my 2013 Ford Focus tells me when to change the oil. I had no idea how long it would be and I was getting nervous, because it seemed like it had been a long time and I had not written down when I had last changed the oil.

Last week my change oil indicator came on, so I changed the oil and wrote down the date and mileage. I also looked up on the vast information storehouse that is our Internet, what the oil change interval on my Focus was? Turns out I have Intelligent Oil Monitoring, so the car keeps track of the kind of driving that I do and adjusts my oil change interval accordingly - between 7,500 and 10,000 miles. Nice to know that, but I am still going to track my oil changes just because.

Re: Black oil quick
 

Sorry I have to vent. I end up searching for how to reset the systems. One of my cars has a button under the dash. One has me patting the pedal three times after pressing the odometer stalk. I'll scribble the process inside the cover of the owners manual. Other folks' cars baffle me every time until I go searching. Annoying.

I show my age when I say it also really doesn't seem right to go 7500+ miles between changes, but that's what the books say to do with our modern stuff.

Re: Black oil quick
 

Higher running temperatures, lower viscosity and better quality oil, etc. Much longer engine life. It's nothing to get over 200,000 miles out of an engine now.

Re: Black oil quick
 

Hey that's great to hear your story and see that photo. Thanks!

Re: Black oil quick
 

Or apparently then... G.M. is well on his way to that milestone! :)

Re: Black oil quick
 

Stock intake? I came across a situation recently where an aftermarket intake didn't have an exhaust crossover, but also nothing to block it off, so if you didn't block the ports in the block, it would put exhaust in the valley, which would make the oil black, among other issues.

Re: Black oil quick
 

IMHO; I always take a paint pen & put the mileage or hours & date on all my oil filters (on the bottom) when I change my oil. Besides my trucks & suv's I have 5 four wheelers & do this with them also. Bill

Re: Black oil quick
 

Cretin, I believe the block ports are plugged, stock aluminum intake. I need to check my build pix.

If they are blocked, it could cause dirty oil?

Re: Black oil quick
 

Ok we are off topic but if the ports are not on the manifold then by default the exhaust will exit the exhaust. It is common to block these off with copper pennies. Not the ones today but the wheat ones made of real copper.