Proper oil for VW lifters

Hot Rod magazine published an article in the June 2006 issue on the topic of flat tappet and cam failure caused by changes in the formulation of motor oil. Tappet is another name for lifter, as also is follower. Although it is written with the big displacement Chevy/Ford/Mopar engine crowd in mind, this article is still of use to the aircooled VW crowd since our cars come with flat tappets.

The article is found at:

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is on three pages (screens). You can also click on PRINT THIS at the bottom of each page so that you can read it without the ads and banner. The gist of the article is that flat tappet and cam failures are caused by the reduction of antiwear additives, particularly zinc dialkyl dithiophosphate (ZDDP), in traditional motor oils. Traditional oil means Valvoline, Castrol, Quaker State, etc. The problem does not show up in today?s cars since they use roller tappets that develop less pressure than flat tappets do at the point where the cam lobe contacts the roller. The high pressure on flat tappets combined with the lack of ZDDP is what causes the excess wear.

The solution to the problem is to use oil that still has the ZDDP additives. The article mentions (with accompanying image and caption) Shell Rotella as one of those oils. I found Rotella at Pep Boys for just under $9 per gallon, which makes it competitive in price with the non-ZDDP oils. Racing oils usually have those additives too, although they don't usually make a point of it in their advertisements.

Gene Berg came out with a discussion on this same topic in their newsletter dated April 1998. His shop, and others in the business, were having trouble with cams going flat. Berg bought an additive containing moly, phosphorus, and zinc to add to the oil, and the cams stopped failing. I tried to find mention of this in the Tech Tips section of their web site but came up empty.

Reply to
Randall Post
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One of the tricks for break-in involve using GM EOS (Engine Oil Supplement) which has extra zinc in it for the camshaft. One could add a 1/2 bottle every oil change or switch to a diesel engine oil which has enough zinc in it.

I use Chevron Delo 400 - 30W in my type 1 for this very same reason. It's got the extra zinc and it's also designed for "closed crankcase systems" which our aircooled engines are closer related to than modern engines. That little slinger groove on the pulley is a far cry from a modern PVC system.

Rotella T is a premium diesel oil also, but the problem is finding the right weight. 15W40 is sold just about everywhere for the big rigs but it's not the right weight for an aircooled engine.

RT

Reply to
Raymond T. Lowe

a "closed" crankcase system is a 100% closed system...meaning *all* blowby/vapors/etc from the crankcase are collected and fed back through the engine....our vw engines are not "closer" but actually couldn't be much further away from being a "closed" system....the crank pulley groove is a "far cry" from a modern pvc system, but our engines are not closer related to a closed system than modern engines...quite the opposite....not that it matters to our oil....

Reply to
Joey Tribiani

Most HD diesel engines simply vent crankcase pressure/fumes to the atmosphere, usually through a strainer of sorts, and then to only the road through a tube (not "fed back through the engine"). This is precisely the "closed system" that Chevron is referring to when they developed their Delo oil. Other than an elite few with an OEM German pulley on a bone-stock blue-printed engine, most air-cooled engines operate with positive crankcase pressure far in excess of the original design, thanks to after-market pulleys (with tiny, shallow grooves), large displacement engines, poorly seated rings, and non- stock air cleaners. These gasses are forced out of the crankcase in the same manner as a diesel with no assistance from manifold vacuum as with a PCV system. In fact, this has led to the 6 zillion posts about oil flinging from the pulley, venting valve covers, and slime buildup in filler necks. Not too mention, the robust after- market parts business selling additional venting products.

RT

Reply to
Raymond T. Lowe

i am running rotella 15w40 in my 71 beetle, could this be a cause for overheating?

Reply to
187

the vw engine does indeed have assistance from the engine(vacuum). the breather hose is hooked to the air cleaner.... this provides the vacuum to ventilate the "positive" crankcase pressure you speak of....(you do know what a PCV valve is, right? a crude checkvalve for venting Positive Crankcase(ventilation) pressure....

slime build up is a moisture and low temp problem more than the lack of ventilation....even my Chevy pickup has the white sludging in the winter....and it has two PCV valves....our engines are not a "closed" system but alot closer to that than just dumping to the atmosphere..(which was the only reason i posted, because you said our engines are alot closer to a "closed system" than modern engines....not so...)

Reply to
Joey Tribiani

Reply to
Ben Boyle

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