Brad Penn/Penn Grade "green oil" turning black

Discussion in 'Engine Topic' started by Lynd McCormick, Nov 6, 2019.

  1. Lynd McCormick

    Lynd McCormick Member

    Messages:
    87
    Likes Received:
    3
    Joined:
    Oct 6, 2017
    Location:
    Finleyville, PA
    I've got a BB 468 full roller making 550 or so, it was professionally built about 2000 miles ago and I've been using 20W50 Penn Grade green oil. The prior owner used only Rotella. I have a 10 quart oil pan so there's quite a lot of it, no racing, I do cruises only with it. When I drain the oil after a summer's cruise season, that oil is BLACK. Even if I change it and check it soon after, its black already. Not sure if this is normal, I've heard one say not normal. Could it be due to the motor breaking in? I did a fresh rebuild on the Demon 850, so it shouldn't be flooding although my exhaust fumes are noxious and I get about 6-8 mpg. Any comments?
     
  2. John Wright

    John Wright Veteran Member Lifetime Gold Member

    Messages:
    15,245
    Likes Received:
    414
    Joined:
    Aug 9, 2002
    Location:
    Rustburg, Va
    Maybe send some of the black green oil to the lab for a check. Many of the quickie lube places try to pawn this service off on every oil change, but it maybe worth a few bucks to see what's going on with that oil.
     
  3. G72Zed

    G72Zed Veteran Member

    Messages:
    3,138
    Likes Received:
    1,594
    Joined:
    Sep 8, 2015
    Location:
    Canada
    I used both the old Rotella 15/40 T3 and Brad Penn years back. They did go somewhat dark after some usage including steady rate cruise and racing, but not in the way your stating the "blackness" after a few thousand miles of "cruising" without racing or hard use.

    But, in reading into your post, if it's been properly broken in, with fresh oil afterwards, if I had to guess, I would say your AFR's may in fact be on the fat side at cruise when your on the primary booster and main jet.

    An oxygen sensor would tell you this pretty quickly. If that's the case, you would use the pri. main jets as the cruise jets, and then work with the PVCR's to bring back your WOT AFR based on what you had in the first place, then finish with the HSAB to flatten out the fuel curve.

    What was the jetting in the rebuilt 850 Demon to start, power valve size?. Do you have a vacuum reading at cruise speed, If this engine was pro built, do you know if it was dyno'd and/or tuned for best TQ/HP with the carb your using, if so, that may be some good info to start from.

    Hope this helps you out.
     
  4. Lynd McCormick

    Lynd McCormick Member

    Messages:
    87
    Likes Received:
    3
    Joined:
    Oct 6, 2017
    Location:
    Finleyville, PA
    Unfortunately all of my jet and pwr valve info is written in a notepad in the glove box of my Camaro that just went into storage last Sunday.

    I’m at a bit of disadvantage when it comes to what testing was done by the builder. The builder was Shehan racing and it was probably 3-4 years ago. Since that time Harry Shehan passed away and the business closed. The previous Camaro owner retired and moved south a year or so ago. He was butt hurt over what I paid him for the car when he was forced to sell or ship it. He has since ignored my calls and texts after he assured me he’d answer any questions that I had.

    I assume that the carb was tuned when the motor was broken in, a few years later it ran good but had some throttle dead spots when I got it. The previous owner had this motor built for a pro street project that he had, he sold the car with the existing engine in it while this engine sat on a stand for a year or two. Once I rebuilt the carb I lost the dead spots and it runs like a raped ape.

    I don’t doubt it’s running a bit fat, my eyes proved that when I ran it into the garage last weekend where I store it. I guess I’ll have to check tho ha once spring hits, that or find a good carb guy with equipment.
     
  5. Vettenick

    Vettenick Vettenick

    Messages:
    350
    Likes Received:
    67
    Joined:
    Jul 17, 2019
    Have you looked at the plugs recently? That will tell you if the motor is running rich. If the plugs are black, chances are that's what's turning your oil, especially if the rings/piston are a loose, low friction set up. If you smell the oil, does it have a gas smell, even slight? The other thing you mentioned was "cruises only". Your oil may not be getting hot enough to burn off any contamination. Short trips are killers on oil, especially since you have a big pan, the oil will never get hot.
     
  6. Lynd McCormick

    Lynd McCormick Member

    Messages:
    87
    Likes Received:
    3
    Joined:
    Oct 6, 2017
    Location:
    Finleyville, PA
    I have in fact sniffed my oil and smelled no fuel. My typical cruise night is a short 5 mile trip each way, at 6mpg I don’t go far. I have not looked at my plugs yet this year but should. I put new wires on this year but should have bought 45 degree boots instead of the 90 degree ones. I’ve also not yet changed #7 wire, it’s pretty much inaccessible.
     
  7. Vettenick

    Vettenick Vettenick

    Messages:
    350
    Likes Received:
    67
    Joined:
    Jul 17, 2019
    5 miles is a very short trip. Your oil is never getting hot enough. Basically it's getting contaminated, probably from moisture/condensation. Not a big deal, just that you should change it before you store it.
     
    carr911 likes this.
  8. COPO

    COPO Veteran Member Lifetime Gold Member

    Messages:
    21,095
    Likes Received:
    2,616
    Joined:
    Sep 15, 1999
    Location:
    Ontario, Canada
    Synthetic oil will clean the grime of an engine that was run with conventional oil for many oil changes. That’s why it gets black fast.
     
  9. xten

    xten Veteran Member

    Messages:
    4,391
    Likes Received:
    3,416
    Joined:
    Sep 24, 2014
    Location:
    Pittsburgh, Pa.
    Lynd, I watched a short video once at a repair shop. They showed a gallon of brand new oil, and put a table spoon of old black oil in the new oil. Turned all the new oil black. I don't think I'd worry much. IIRC, your car runs hot, so it's probably getting up to temp quicker than most.
     
  10. 80sz

    80sz Veteran Member

    Messages:
    3,930
    Likes Received:
    750
    Joined:
    Feb 2, 2014
    Location:
    Buffalo,n.y.
    I use 20/50 brad penn and noticed same thing.
     

Share This Page