[Judge not]

Hi, I took my engine apart to find the source of my clattering. I found three lobes flattened and three lifter bottoms dished. The cylinder walls are smooth, no scratches and the visible area of the piston skirts look good. The oil looks good and the filter has no metal in it. My machine shop says I need to totally disassemble the engine to look for metal. He also told me more cams are failing because the oil companies have recently removed an additive that was causing catalytic converters to fail. He said Shell Rotella for diesels is a better oil, he said the additive was a cam additive and with todays roller cams the additive was not necessary any more. What do you guys think? Should I gut my engine? What oil should I use? Synthetic or the Rotella? Thanks.

[Judge not]

Hi, I took my engine apart to find the source of my clattering. I found three lobes flattened and three lifter bottoms dished. The cylinder walls are smooth, no scratches and the visible area of the piston skirts look good. The oil looks good and the filter has no metal in it. My machine shop says I need to totally disassemble the engine to look for metal. He also told me more cams are failing because the oil companies have recently removed an additive that was causing catalytic converters to fail. He said Shell Rotella for diesels is a better oil, he said the additive was a cam additive and with todays roller cams the additive was not necessary any more. What do you guys think? Should I gut my engine? What oil should I use? Synthetic or the Rotella? Thanks.

[74Grandville]

I had a pontiac 350 wipe some cam lobes, i changed the filter and change the cam/lifters. 800 miles later I spun a bearing and the total engine is worn. wish I cleaned the motor the first time, it probably would have survived.

I would say take it apart, clean everything really well and put it back together.

[grandville455]

same thing here except it only took about 100 miles....live and learn.....

[bmpmdf]

Take it apart and clean every passage in the block and crank. The "dust" metal is too small to be stopped by oil filters, but will act like a grinder on the crank journals and bearings. That makes since on the oil because I know serveral guys that recently have engines that has been eating cams. And these guys have never had that problem before, some have been in racing with flat tappet type cams for over 50 years. It has been a very hot topic lately with these guys on trying to figure out if it was bad lifters, cam cores, or ???? The oil has been getting changed and it would be nice to find out for sure.

[bmpmdf]

Oh, Synthetic oil is clearly the best choice. I like the Amsoil and Royal Purple oil along with Mobil 1, But I prefer the first two. Besides, I think we have a Royal Purple poster on here. You know, support our end of the hobby.

[buwalda]

The additive is Zinc dithiophosphate.
And like you, I have also heard/read that some oils don't have it anymore. And, like many others, I keep hearing of flat tappet lobe failures on a greater scale than ver before. Yet, todays oils are supposed to be better??? One oil that DOES have Zinc d/t/p, and DOES NOT have friction modifiers [ to thin the oil ] is Penrite, made in Australia & also exported to the US. I have used it for 20 years, as have others, for many years. Have NEVER heard a complaint about Penrite.
Interesting info on their website: www.penrite.com.au

[David Jones]

I wiped 1 lobe on an 068 cam about 2 years ago. This was after I changed lifters trying to lower the clatter level some. Made it thru breakin and about 20 miles and it began clattering loudly. Took it back apart and discovered the 1 bad lobe. Put a new cam and lifters in and some fresh oil. Broke the new cam in. Changed the oil. Drove it a few miles and changed the oil again. Drove it a few miles more and changed it again. I've been a few thousand miles since with no ill affects.

[PONTIAC DUDE]

John's Gto 48164:
How did you break in the engine?
What step did you use?
Did if fire right up on initial cranking?

[Judge not]

Thanks for all the replies so far. Dude the engine did not start immediately do to a voltage issue to the hei. The cam had the Red line ass. lube on it and the lifters also. But I did crank it for awhile before I found the problem. Do you think this caused my failure? The cam was a CC xe-268. I have hte 995-16 springs installed at 1.7 and the seat pressure is about 100#. David Jones had good luck without tearing his engine down, but others did not. Do you think I should do a total tear down? If I tear it down can I re use the parts again. The engine has about 1,000 miles. Do I need new rings and do I have to hone the cylnders. This stinks

[evilpeanut]

I have heard that Valvoline Racing 20W-50 still has the zinc additive. It says on the label that it not intended for "street" use so it makes sense with the zinc additive and catalytic converter failures scenerio. Might be worth looking into...

[Jeff Walker]

STP also has the zinc additive in it.

[Mr. P-Body]

Evilpeanut, check out my response on PSP board.
One should never use racing oil in a street engine. Racing oil, while having very good lubricity, has no stabilizers necessary for long-term use. It's good for around 500-1,000 miles, no more.

[68lemans462]

tear it down. no question.

[PONTIAC DUDE]

Yes. I have seen that most cam failures are a result of cranking the engine over and not firing. Same deal with wiping rod bearings out as the spark plugs are installed and creating excessive load on the pistons and rods.
Haven't had a cam failure in over 3 years with Comp and install them exclusively.

Knock on wood.

If there is no scaring in the cylinder wall, the rings will be fine. Same deal with bearings. I re-use my race bearings if they show no signs of wear.

But tear it down. Pull all the galley plugs, flush it out & wash it down. And also make sure the underside/inside of the valley pan is totally clean!!! You might only be out the gaskets.

[GoatRider]

Possible contributing factor: "Redline assembly lube"

I think this is intended for bearing surfaces only. Most cam manufacturers specify their own brand of "cam break-in lube" or "moly paste lube" for the specific reason that it will not a) drip off the cam lobes while you are putting the top end together before firing; and b) not be completely whiped off the lobes during the first revolution. Either condition leaves you with a pretty dry surface which is going to be galled unless it fires up right away and gets oil pressure.

JMO

[Formula8]

Here's a link to Mr. P-Body's response on the PSP board:

http://members.boardhost.com/boyleworks/msg/97237.html

[Formula jg]

Don't forget to flush inside the distributor shaft and oil filter housing or hoses if you have a remote oil filter.

[mikeb]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Geoff:
The additive is Zinc dithiophosphate.
And like you, I have also heard/read that some oils don't have it anymore. <HR></BLOCKQUOTE>

Also known as ZDDP. It has been steadily removed from oil because it has an adverse affect on cat converters. SUPPOSEDLY mobil1 has one of the lowest levels of ZDDP (this is supposition by some from looking at the MSDS put out by mobil for the product). Zinc is the "last line of defense" before direct metal-to-metal contact occurs.

You can get ZDDP in any number of additives - STP, GM's EOS, and others. I run mobil1 5w30 & STP just to boost up the ZDDP level.

If you want some interesting discourse on motor oil do some reading in the forums here:

www.bobistheoilguy.com

[bmpmdf]

Good info. Thanks for the link.