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I have heard differing opinions on this question and wanted to ask the experts out there. Also, what weight of oil would you suggest?
Zinc for roller cam engine?
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I have used Rotella in the past, but did not have a roller cam. Was not sure if there is a difference when running a roller.
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ZDDP is an extreme pressure lubricant that is necessary to prevent scuffing when using a flat tappet hydraulic or flat tappet solid lifter camshaft. No such extreme pressure lubricant is needed with roller tappets. Just clean off the preservative oil that the factory puts on them to prevent corrosion, dip them in off-the-shelf engine oil, install 'em and run 'em.
Here's a tutorial showing the procedures to prevent "fraggin" a flat tappet camshaft....
http://www.crankshaftcoalition.com/wiki/Camshaft_install_tips_and_tricks
In today's world, it makes little sense to jump through all the hoops to use flat tappets, when for just a little more dough, you can install rollers and forget about it. There may be better deals around, but Competition Products sells a set of Howards retrofit hydraulic roller lifters and a roller cam for about $600. Add a Howards composite distributor gear for about $100 and you're done. No worries, no headaches and much better performance due to the increased "area under curve" of the roller cam.
Here's a tutorial showing the procedures to prevent "fraggin" a flat tappet camshaft....
http://www.crankshaftcoalition.com/wiki/Camshaft_install_tips_and_tricks
In today's world, it makes little sense to jump through all the hoops to use flat tappets, when for just a little more dough, you can install rollers and forget about it. There may be better deals around, but Competition Products sells a set of Howards retrofit hydraulic roller lifters and a roller cam for about $600. Add a Howards composite distributor gear for about $100 and you're done. No worries, no headaches and much better performance due to the increased "area under curve" of the roller cam.
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Zinc additive is not needed for a roller cam; the wear pattern on a roller is much different from that of a flat tappet to where ZDDP brings no benefit.
The causes are this:
Flat tappet cams have a taper to their lobes while the lifter has a slightly convex shape to its foot. The lifter has essentially a sliding motion over the lobe to which the combination of the lobe and lifter foot shapes cause the lifter to rotate about its long axis in its bore. This motion prevents the formation of an oil wedge or at least a consistently good enough wedge as happens inside the bearing clearances of the crank and cam bearings. When moving beyond anything more than very mild lobe profiles and low rate valve springs wear of the lobe and lifter becomes a large issue even when both are suitably surface hardened. Through the 1950's and early 60's many types of dry lubes like graphite, moly-disulfide and Zinc dithiophosphate (ZDDP) among others were tried as a means of imbedding a high pressure lubricant into the pores of the lobes and lifters that would provide continuing lubrication when the oil was squeezed out. Of all that was tested ZDDP remained in suspension with the oil where other chemistries tended to coagulate forming groups of molecules large enough that the oil filter gradually took them out of suspension with the oil. When this happens and there is no ZDDP the lifter just begins to scrape along the lobe till the rubbing surfaces are worn away.
A roller lifter's, roller rotates over a lobe that is not tapered which a contact patch that is constantly renewed like a tire rolling on pavement. The scraping motion of a flat tappet on the fine contact edge of the tapered lobe and convex lifter face is replaced by a rolling contact patch. The loads on the contact patch are very high but rather than scraping the surface off these loads want to unwind the surface material giving it a shape the reverse of the lobe. This can be thought of as using an English Wheel to shape sheet metal into curved body shapes. Neither oil nor additives are of any benefit in stopping this. The control must come from stronger materials and surface treatments that provide the cam lobe with enough surface hardness and strength to resist the unraveling forces that would unwind the lobe surface. These stronger base materials and surface treatments are why roller cams are so much more expensive, plus all the additional gadgetry needed to keep the lifter's roller aimed into the direction of lobe rotation.
ZDDP is or has been removed from motor oil over the past 26 years because when an engine begins to burn oil the ZDDP gets into the exhaust and contaminates the catalytic converter stopping its action. So the EPA has required it be phased out. So the auto manufacturers started to phase in roller cams to production with the 1986 model year with completion by the 1996 model year. Only the aftermarket persists with flat tappet cams over the past 16 years (1996-2012). Here in Washington state like California and Oregon the continuance of ZDDP oil available to the general public is ending as are heavier weight oils, the thick stuff now is 5W-30 not 15W-40 or 20W-50. But you can still buy ZDDP additives, but I'm less than optimistic that 5W-30 and thinner oils whether dyno or synthetic with ZDDP added will prove to be adequate for flat tappet cams as we move ahead. Certainly somebody will come out with heavier weight oil sold like today’s additives and leaded racing fuels but like them it will be costly stuff to obtain.
My suggestion is use a roller cam. Even non roller blocks, especially the SBC are easily rebuilt to accept a factory roller which really holds the costs down. You don't even need one of those super expensive retro-kits. You need the valley spider, dog bones, cam thrust plate, (Hydraulic Roller Lifter Installation Kit from Summit is 90 to 120 dollars whether you buy the 90 dollar take out, or the 120 new from Comp), a set of 16 OEM style lifters, OEM style cam whether factory or aftermarket, three 5/16th bolts long enough to reach through the main oil galley to thread on both sides, some 5.16th washers to build a stack on top of the oil galley to properly locate the spider on the dog bones, proper length 7.1 inch push rods that are hardened if you're using guides, a cam thrust button. Drill and tap three spider mounting holes in the main oil galley. Cut the ears off the thrust plate use the OEM roller cam style timing set (gears and chain). The thrust plate becomes a spacer between the timing gear and block for the step on the OEM roller cam. Set the thrust button to between .005 and .007 clearance to the timing cover. Weld reinforcement on the outside of the cover where the thrust plate will push or use an aftermarket water pump that has the bolt boss used to reinforce the timing cover. Get a couple extra gaskets as the timing cover may need to be fudged for timing set clearance. If the cam does not have a mechanical fuel pump lobe use a pump block off plate on the block and hook up an electric fuel pump. Engines so modified don't seem to have oil problems but if you're concerned you can trim the threads where the bolt is inside the oil galley and or drill the galley oversize to provide more flow space. Now that's hot ridding the old fashion way of buying what you can and modifying it to what you need. This actually was a very popular modification several years ago to put OEM rollers into earlier flat tappet blocks, there are thousands of these running around out there.
Bogie
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Like Tech said zddp is an extreme pressure lubricant , the main reason its content has been reduced or removed is it ruins cat. convertors! But engines have other areas that need zddp like the fuel pump actuating rod that rides on the cam on older engines and timing chains any where there is metal to metal contact that has friction!! If your not running a cat. it wont hurt a thing to add zddp for an extra precaution in high friction areas of any engine especially air cooled, and at the valve tip if there is any sliding of the roller rocker or at the push rod ends that make contact with the lifter and rocker arm Etc!!
Jester
Jester
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Thanks bogie and jester, good points.
bad info.. deisel oils DON't have it and haven't since 2010
even with fully rollerized engines.. things they don't tell you
1) the new car engines have alum heads with selflubing valveguides..
of a bronze alloy of some type
2)most if not all don't use a ball and socket set up on the rockers anymore..
3) the rockers have hardened ball sockets for the pushrod to ride on in the rocker. and hardened tip push rods...
4) no guide plates for the pushrods..
why does it matter.. everything above needs the zinc to not wear at the metal to metal pressure points...
an issue new cars and their powerplants don't have to worry about.. but YOU might... as they are metal to metal points never mind a cam and lifter...
why might you say there isn't an issue in the bearing area.. well because that is not metal to metal.. the crank and rods float on a film of oil.. when they do become metal to metal bad juju..
piston pins, the piston bore is the bearing.. and on most new engines they spray oil on the back of the piston face... to cool the piston.. and in doing so.. lube the piston wristpin and bore..
the zinc removal isn't just about cams lobes.. it's just the highest stressed area and the spot that failure shows it's face first..
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Not necessary related to a roller cam and zink,but a common mistake guys make it when priming oil system they over prime it washing away the break-in lube.The correct way to do it is the 1/2 drill motor will slow down once while filling the oil pump and once again while filling the oil galleries.You should stop priming at that point.
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So should I just use Rotella or similar to be safe?
not sure if the shell you get up there is the same as the usa.. but the epa emmission laws on over the road deisels... they pulled most of the zinc out.. as the converter in the 2010 up trucks can't live , and the epa mandated they last x amount of miles...
telling people to use big rig oil was good info years ago.. and may still be up in canada.. but not in the land of the EPA
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Okay, thanks for all of the great information. All I am running is a mild pretty much stock Chevy small block (vortec) with a roller cam...headers with glass packs and that is it. It is a new engine so I want to make sure it is protected well. Sounds like I just need to run some Rotella or similar.
Thanks!
Thanks!
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i would agree in principle, but what, exactly, would be needed to be done to a gen 1 SBC to convert it over to roller lifters?
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Well, if you have rollers then you can run "any old" oil. The controversy is for people like me, who live in the stone age, who still run flat lifters.
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Read the last paragraph of my post. This is for a Gen I that has no provision for the OEM roller. Probably the easiest and least cost approach is to locate a pick-up with a provisioned block, many were used with flat tappet cams in them from 1986 through 1995. For 350 roller tappet blocks look for casting numbers 10243880, 14011148, 14088526, and 14093638. There is a block in this period casting number 14101148 this is a flat tappet truck block, its casting number is very similar to 14011148 which is a roller provisioned block. the 880 is the L31 Vortec block but it actually starts to show up in 95 production with a flat tappet cam and the pre L31 steel timing cover.
Bogie
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This has nothing to do with the tread : I ran roller cams back in the 1960s, and my father did in the 50s!! With Zddp!!! A lot of young hot rodders and enthusiasts think roller cams are a new innovation! LOL 
Jester
Jester
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I haven't been able to pin down the first automotive roller cam. I know the first automotive hemi was the 1912 Peugeot Grand Prix motor.
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rollerized lifer cams or rollerized cams.. that ran in roller cam bearings?This has nothing to do with the tread : I ran roller cams back in the 1960s, and my father did in the 50s!! With Zddp!!! A lot of young hot rodders and enthusiasts think roller cams are a new innovation! LOL
Jester
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That IS funny. Roller cams were factory original on H-D, going at least as far back as the '20s.A lot of young hot rodders and enthusiasts think roller cams are a new innovation! LOL
Jester
For that matter my '64 Panhead had a roller cam/lifters. Hydraulic, at that.
Aftermarket hydraulic roller lifters for '53-up H-D. Note how large the roller is.
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