nm9stheham
Well-Known Member
I have run full synthetic oil for years in street cars and racing (Mobil 1), and have always had some impressive results: Fuel mileage improvements, cylinder bores with the original hone marks and no ring ridge after 250k miles, race engines surviving for a 5 minutes of minutes at full racing speeds with erratic and then 0 oil pressure., etc.
With then 'new' slant 6 recently acquired, the engine was very badly sludged and the oil from the prior owner was like water due to a carb leaking constantly into the intake. So I ran a batch of 10W30 Rotella for about 250 miles so the dispersants could work on the sludge. The one thing that bothered me was that there was a mild rod knock on startup until the oil pressure light went out; not a big surprise with the way the oil was not taken care of.
So, I decided 2 days ago to see if the filter was sludged and drain the Rotella to see if it was working. See photo; yes, the Rotella dispersants work! I decided to put in 5W30 Mobile 1 instead of the Rotella to see if the lighter cold weight would pick faster at startup and just generally protect the engine more.
The results are worth reporting, IMO. The oil pressure light goes out faster now (4 seconds cold vs 7-8 seconds cold without revving at startup), and the mild rod knock is gone. What is most impressive is that the engine REALLY runs a LOT quieter and smoother. I thought it might be me, but my son drove it and was equally impressed with the change. And we both felt that the engine response was crisper; I'm not sure how an oil change can cause this. I was not expecting the smoother and quieter change; I came from a family with 5 /6's Darts in the late 60's and 70's and this engine now sounds like a new /6 and has the same degree of smoothness on the interstate.
If you drive a diesel engine, you know how noisy and clattery the engines will get when you run the oil too far and the anti-foaming agents wear out, and how much quieter fresh oil makes a diesel. The change in this /6 with the full synthetic oil is a bigger change than that.
So take it for what you will; you might be impressed with the change. Walmart is the chepest place to get all sorts of Mobil 1 grades ($23 or $28 at Walmart for 5 qts depending on grade vs $38 at Oreilly's). The dramatic reduction in bore and ring wear that I have consistently found in several engines with full synthetic oil makes it a winner for any engine that is rebuilt, after break-in. I was not expecting this improvement with a 52 year old orignal engine.
Yes this is oil after just 250 miles with Rotella; lotsa sludge!
With then 'new' slant 6 recently acquired, the engine was very badly sludged and the oil from the prior owner was like water due to a carb leaking constantly into the intake. So I ran a batch of 10W30 Rotella for about 250 miles so the dispersants could work on the sludge. The one thing that bothered me was that there was a mild rod knock on startup until the oil pressure light went out; not a big surprise with the way the oil was not taken care of.
So, I decided 2 days ago to see if the filter was sludged and drain the Rotella to see if it was working. See photo; yes, the Rotella dispersants work! I decided to put in 5W30 Mobile 1 instead of the Rotella to see if the lighter cold weight would pick faster at startup and just generally protect the engine more.
The results are worth reporting, IMO. The oil pressure light goes out faster now (4 seconds cold vs 7-8 seconds cold without revving at startup), and the mild rod knock is gone. What is most impressive is that the engine REALLY runs a LOT quieter and smoother. I thought it might be me, but my son drove it and was equally impressed with the change. And we both felt that the engine response was crisper; I'm not sure how an oil change can cause this. I was not expecting the smoother and quieter change; I came from a family with 5 /6's Darts in the late 60's and 70's and this engine now sounds like a new /6 and has the same degree of smoothness on the interstate.
If you drive a diesel engine, you know how noisy and clattery the engines will get when you run the oil too far and the anti-foaming agents wear out, and how much quieter fresh oil makes a diesel. The change in this /6 with the full synthetic oil is a bigger change than that.
So take it for what you will; you might be impressed with the change. Walmart is the chepest place to get all sorts of Mobil 1 grades ($23 or $28 at Walmart for 5 qts depending on grade vs $38 at Oreilly's). The dramatic reduction in bore and ring wear that I have consistently found in several engines with full synthetic oil makes it a winner for any engine that is rebuilt, after break-in. I was not expecting this improvement with a 52 year old orignal engine.
Yes this is oil after just 250 miles with Rotella; lotsa sludge!
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