Flat Tappets and ZDDP again

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I just found the original specifications for the valve spring pressures for my '72 440-4bbl engine. These spring pressures don't seem that high to me so I was wondering what everyone thought for oil. I have been using HDEO. At these pressures do I need the extra zinc ZDDP protection?

INTAKE & EXHAUST VALVE SPRING PRESSURE: 234 LB/IN, INTAKE LIFT .449, EXHASUT LIFT .464. FOR REFERENCE, THE 440-SIX PACK HAD 310 LB/IN AND THE SAME LIFT. THANKS!
 
It might not matter if it's flat tappet. A roller cam wouldn't care so much though.
 
As a rule of thumb, you need more than 800 PPM ZDDP for well broken in flat tappets that, as a class, do not exhibit much cam failure. That would include your 440 if it's all OEM. Chrysler cams and lifters are not known for excessive failures. These are not soft core GM cams ...

But, to me, that's living on the edge. Yours is a carb'd engine, so fuel dilution can be an issue unless the carb is kept well tuned ... So I like to run older engines on slightly more ZDDP. If the oil thins out some you are still well protected
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Chevron Delo 400 15W-30 SD (severe duty) oil has about 1,200 PPM.

If you want to go up to 40 grade for summer, Mystic JT8 has about the same levels and is a very good oil. Used to be available at Tractor Supply. But I'm sure it's available elsewhere
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http://pqiadata.org/Mystik15W40.html

Valvoline VR-1 (silver bottle) is readily available and it's about the same level. Just do some research at PQIA and see what you want to use that's available in your neighborhood
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I've always believed the amount of miles put on the oil between changes helps determine the amount of ZDDP needed at the beginning. For those collector cars that only do 1000-2000 miles between changes; the current amount of ZDDP in any oil will protect well. More miles on the oil and more ZDDP can be needed. You can always start with the basic oil and add an ZDDP additive if you feel the need.
 
You'll need to add a little to your 15W-40 oil at each oil change, maybe 1/4 bottle each time


GM Performance 88862587 E.O.S. Additive

It's darn expensive - but cheaper than a new cam!

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The Crane Cams stuff is also very high in ZDDP and Moly

Crane Cams 99003-1 Super Lube Engine Oil Break In Additive

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Originally Posted By: Building3
I just found the original specifications for the valve spring pressures for my '72 440-4bbl engine. These spring pressures don't seem that high to me so I was wondering what everyone thought for oil. I have been using HDEO. At these pressures do I need the extra zinc ZDDP protection?

INTAKE & EXHAUST VALVE SPRING PRESSURE: 234 LB/IN, INTAKE LIFT .449, EXHASUT LIFT .464. FOR REFERENCE, THE 440-SIX PACK HAD 310 LB/IN AND THE SAME LIFT. THANKS!


Did you also find the spec for installed load? The spring rate and lift are not enough to calculate the actual peak load.
 
I have used Rotella 15w40 in my original 68 L36 Corvette Roadster and 65 4-4-2 (96K miles, always garaged).
There are a number of oils formulated for flat tappet engines, such as Lucas Hot Rod, Brad Penn and Amsoil.
I like Rotella, but will use a specialty oil going forward.

I have a 5 quart jug of 10w30 something sitting the garage; I forget.
I would not use racing oil, as it does not have the additive package for street cars.

If I ever pull these engines apart again I will do a nice, mild roller and be done with it.
Good luck.
 
Rotella oils are still high in Zddp, reasearch in the 70s found most typical OHV Flat tappet engines show the least cam/tappet wear with around 1200ppm ( Rotella still has 12-1300 ), and that more than 2000ppm is corrosive and causes pitting.
Most standard cams that are well worn in don't need a super high amount of Zddp, but ti stilll is not a bad idea to run an oil with high Zddp specialy when Rotella, Delo 400 are so available and cheap and at the same time you can have peace of mind that your cam is happy.
 
I daily drive my 83 caprice all winter with the 305 that was know for camshaft failures back in the day. I don't know whether mine had the cam replaced or not but it has 227k on it now and runs fine other than a little piston slap on a cold start. At 3500 miles the oil looks like I just put it in. I run 0w40 synthetic with some GM EOS in it. It uses/leaks about a qt in 2k miles. I'm actually more concerned about my girlfriend's 2013 Sonata with the GDI engine that's currently under a recall for rod bearing failures. Her oil turns black immediately after an oil change.
 
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Valve seals leak on my caprice but only visible blue smoke in the summer time. So I run 0w40 or 0w30 winter time and once it warms up I'm switching to 10w40 or thicker. Maybe 20w50 this summer. I replaced the missing catalyst to help disguise blue smoke. I'm replacing the engine with a 2000 gm 5.3 next summer so I don't need to make this engine last much longer. Hopefully I'll have it pulled before it hits 250k miles. I might try 20w50. It always seemed like overkill before since it doesn't use much oil.
 
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