Flat tappet Engine Requirements

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Jan 22, 2011
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I am getting ready for my 3 year/3000 mile oil/filter change on my 87 Cougar (3.8) 75000 miles. The car is used for an occassional one tank trip on the highway during the summer with an average of 1000 miles per year.. The engine has flat tappets, old fashioned timing chain , valve spring tension of 215 LBS @ 1.79 " and 8.7:1 compression ratio. Is this engine a candidate for a high zinc oil? I have always used conventional Pennzoil 10w-30. My stash for this is depleted and was wondering if I should keep using what I always had?
 
You could frankenbrew one quart of Mobil 1 racing 0w30 that's selling for $2/qt at AutoZone right now with whatever else you want to run.
 
As mentioned above, your engine is not highly stressed. However, the 3.8 is known for cam, lifter and timing chain wear, sometimes severe. This is a pushrod engine, and even with low spring pressures and modest RPM, these parts often don't hold up as well as they should. Ford's choice of metallurgy and hardening was notably poor. Later years moved to roller cams.

As always, viscosity is your main protection in flat tappet cam engines. Using a low viscosity oil with high ZDDP is in essence asking the additive to do the work the low viscosity can't.

Choose a quality oil of adequate viscosity
 
I have always used conventional Pennzoil 10w-30. My stash for this is depleted and was wondering if I should keep using what I always had?
Are you asking for oil recommendation?

I'd definitely use high ZDDP oil in that engine. I don't know how much ZDDP the Pennzoil has but if I was you I would use Valvoline VR1 10W-30. It's the easiest and widely available high zinc/ZDDP oil, even at Walmart for about $25 for 5 quarts.
Don't buy any new API SQ, SP because they don't have enough zinc/ZDDP that your engine needs.
 
At the rate you're using your Cougar is there even a realistic chance that you'll ever come close to wearing the engine out? Any modern SQ 30 grade oil is going to be fine for the next 100k miles.
 
Those mild spring pressures would live fine on 10w30. Does that engine even see 3,000 miles per year? Remember, Zinc is a consumable so frequent oil changes can help flat tappet camshafts.
I would run Castrol Hot Rod oil.

Or stab a hydraulic roller and be done with it.
 
I would have thought you would have known the answer to your question?

Don't listen to the "you need ZN for this engine". What you have been using is just fine.
 
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