Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (http://www.hotrodders.com/forum/)
-   Engine (http://www.hotrodders.com/forum/engine/)
-   -   Zinc for roller cam engine? (http://www.hotrodders.com/forum/zinc-roller-cam-engine-225345.html)

engine24355 10-24-2012 11:28 AM

Zinc for roller cam engine?
 
I have heard differing opinions on this question and wanted to ask the experts out there. Also, what weight of oil would you suggest?

hcompton 10-24-2012 11:40 AM

ZDDP is what its commonly called. zinc is just one part of it. Motorcycle oils still have zddp same goes for rotella and a few of the desiel oils. They are recommended for cam break in.

Normal car oil no longer has zddp in it. Not sure about royal purple and the performace synthetics.

engine24355 10-24-2012 11:51 AM

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.

techinspector1 10-24-2012 12:07 PM

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/w...ips_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.

oldbogie 10-24-2012 12:57 PM

Quote:

Originally Posted by engine24355 (Post 1602667)
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 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

painted jester 10-24-2012 01:11 PM

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

techinspector1 10-24-2012 01:35 PM

Thanks bogie and jester, good points.

E.Furgal 10-24-2012 01:41 PM

Quote:

Originally Posted by hcompton (Post 1602670)
ZDDP is what its commonly called. zinc is just one part of it. Motorcycle oils still have zddp same goes for rotella and a few of the desiel oils. They are recommended for cam break in.

Normal car oil no longer has zddp in it. Not sure about royal purple and the performace synthetics.

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..

1Gary 10-24-2012 01:54 PM

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.

F-BIRD'88 10-24-2012 01:57 PM

There are other points in your new engine that need the anti scuff anti wear properties of zinc and moly di sulfide
oil additives, besides the camshaft.

I use and recomend this stuff. Its got both in it. helps the new engine break in properly and gives you the metal on metal
anti frictrion,,, anti wear protection needed for long engine life. Including flat tappet cam and lifters.

MOLYSLIP E

Molyslip Canada Inc. :: Molybdenum Lubricants, Performance Lubricants, Copaslip Anti-Seize, EP2 Grease, Wear Reducing Lubricants, Oil Additive

i use the GM EOS too.

engine24355 10-24-2012 01:58 PM

So should I just use Rotella or similar to be safe?

F-BIRD'88 10-24-2012 02:06 PM

Quote:

Originally Posted by engine24355 (Post 1602723)
So should I just use Rotella or similar to be safe?

The new Rotella T oil still have Zinc in it. Just not as much.
It's still very good oil. They just adjusted the anti-wear formulation.
There is a lot more to it than just the Zinc.

Its still one of the best oils you can buy.

There are still lots and lots of speciality "racing" oils that still have all the zinc you will ever need.
It is the over the counter-off the shelf- parts store passenger car motor oil that got the reduction in Zinc.

E.Furgal 10-24-2012 02:18 PM

Quote:

Originally Posted by F-BIRD'88 (Post 1602725)
The new Rotella T oil still have Zinc in it. Just not as much.
It's still very good oil. They just adjusted the anti-wear formulation.
There is a lot more to it than just the Zinc.

Its still one of the best oils you can buy.

There are still lots and lots of speciality "racing" oils that still have all the zinc you will ever need.
It is the over the counter-off the shelf- parts store passenger car motor oil that got the reduction in Zinc.

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

hcompton 10-24-2012 04:40 PM

Rotella covers about 25 oils all for different types of engines. They have oil for trucks older than 2010. They also have the new stuff and off road for equipment.

Zddp does not trash your cats it shortens the life of them in engines burning oil. Zddp and cats have been mated together for 30 years its just better for the cats if its not in there. Your car will still be just fine with it. Your cats will still go for 100k miles if the engine runs clean.

Yep the cam is important but not all of your worries when it comes to breakin. Alot of other parts really need the additives. Roller or not. It wouldnt hurt your roller cam either since it is still under alot of stress and friction. But the cam gets tons of oil other parts of the engine dont see pressurised oil. These parts still need some protections.

Bearings are made from a molly and zinc compond. Ever wonder what you were rubbing off everytime you ran your thumb across a new bearing.

I am stunned at the crap ppl give flat tappet cams. 99% of the problem is ppl trying to find more "area under the curve". Cam manufactures have an issue with new cams because there not for new engines. All the best designs have pattens on then but the cam makers still put out new cams every year. How many of the new grinds do you think are better? You can only slice up 360 so many ways. Before you start putting out crap.

Eos is good as well. Its out there on shelves for a reason.

engine24355 10-25-2012 10:54 AM

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!


All times are GMT -6. The time now is 10:16 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.