Zinc

[bobs409]

I'm starting to have my suspicion about this whole zinc/oil topic.

If this new oil with lower zinc or no zinc is so bad, wouldn't there be cars/trucks broken down everywhere you looked? Wouldn't the garages be overwhelmed with work replacing all those cams?

Think about just how many people don't even know about this. Millions of vehicles out there being driven by people that never even heard of zinc being taken out of oil. No mention of it on any oil bottle to be found. School buses, delivery trucks & vans, personal cars, etc, etc and they all seem to keep going.

I won't take any chances with my 409 for now but unless someone here convinces me otherwise, I don't think I'll waste any more money buying additives for my other cars.

So what do you guys think about this "zinc" consipiracy? Let me know soon, I have to change my oil tomorrow in my 69 Chevy truck.

 

[Kdurgin]

I think it is mainly because most newer vehicles are going to roller lifters? My engine builder told me to use Brad Penn oil. It is an oil heavy with zinc and other additives good for flat tappet motors. I am in the group of doubting if it really matters , but for the price of the oil compared to the total money invested in the engine, and the number of times I will have to change it, I'm not taking chances. I have a 383 stroker, not a 409 or 348, just tossing in my view on it.

 

[boxerdog]

I also think it's the older flat-tappet lifters that are most vulnerable, most of the late-model stuff is roller. It seems like they are most at risk during initial startup and, to some extent, after long periods of storage. And the stiffer springs probably don'y help. Sound like anyone you know? That's exactly what many of us do!

So I use Brad Penn and additives also until I jump on the roller bandwagon. It's relatively cheap insurance.

 

[oldskydog]

All you need is an oil that has an SI or SJ rating. It has the necessary anti-wear additives. Don't waste money on snake oil.

 

[boxerdog]

to each his own.

I've never lost a cam lobe on an engine that I assembled, or wrecked anything on startup, so I will continue to use the same assembly lubes, oils and supplements for now. I tend to believe the cam grinders, some sell "snake oil" and some don't. I try to avoid having to work on engines in the car if at all possible, and I think chemicals and run-in procedures can make a difference.

I'd be interested in knowing what others do, especially the guys really working that flat-tappet stuff these days.

 

[Ronnie Russell]

Dave, I've never lost a cam either but when the scare started a couple of years ago, I did change a little bit. I use the Crane break-in lube ( CRN-99003-1 ) and an extra quart of oil during the first 15 to 20 min. at 2,500 rpm. I drain a qt. of oil and then run the car for about 100 miles, then a full oil and filter change. I use the Crane lube with all future oil changes. As I have said before, the Crane lube is probably not one bit better than other brands. I started with it, so I will stick with it. $8 seems like a reasonable price for extra protection even if it is probably not necessary. A little peace of mind for a big investment.

 

[jwhotrod]

Oil questions

Well, Im not completely sure myself, but I do have a friend here that lost a brand new engine build (cam went flat) in his corvettte 2 years ago that started me on this oil quest. Comp cams at that point told him it was the oil and lack of "high pressure friction modifiers" that killed the brand new cam he had. Comp replaced his cam and gave him the additive package they recommended, saying they wouldnt warrant the new cam without the modifer, and he hasnt had a problem since. He is using Amsoil since the break in.

Through this investigation I did and what I have read here and else where tends to make me believe the cam guys are concerned about this, but at the same time I dont know if it is them trying cover their *sses but as you say why not be safe. This motor was a large investment and I am trying my best to protect it.

Cheap insuraance???

Big jim

 

[DonSSDD]

Be careful on what "you always used" the oils have been changing specs very frequently and what you bought before that was an SI or SJ may now be an SM.

Like Rotella, etc. is now an SM. Most places, it is unusual to find anything but an SM, which is low zinc, if you look at every bottle on the rack.

I have heard that GM had major cam problems with 305's a long while ago- told everyone to use EOS?

I use EOS and then don't have to worry about the SM oil.

Don

 

[Speed]

flat tappet cam sales are "up".

 

[Tom Kochtanek]

An example

My local shop rebuilt a factory correct 1970 LS6 engine, the 454 with 450 horses. The owner took great care to go back with GM components as much as possible (except for the new cam). It was the original engine and part of a "numbers matching" 1970 Chevelle restoration.

I wasn't there for the (first) startup, but they chewed the cam, dropped metal down low and destroyed the crank. Since the owner wanted nothing but numbers correct, he had to go out and local that specific crank, cost him a bundle as I recall (like $1000 or something close). I asked if they used any additive, they said "No, just the good oil we used to use years past". For the second break in I spotted them my "Cam Shield" product and everything went well.

For my projects, I will always hope to err on the conservative side, and not trust my metal parts to past expectations.

Best,
TomK

 

[models916]

lots of pressure here

Spring pressure is the key to modern oil and cam lobes wearing out. Run of the mill 80's engines have little spring pressure and the cams are already run in.