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Dead cam... Again!

My friend has installed two Edelbrock cams in a 1968 Chevelle's 327 engine,the first one lasted about 2500 miles and the thing started popping back thru the carb...was installed with the proper lifters,springs and broken in right with proper lube,oil,etc..when he pulled it two lobes were flat as pancakes and two more were badly scuffed..so far the second one is holding up,but the guy only uses the caqr sparingly during cruise night" season ,so it'kk be awhile before it racks up any real mileage..

I dont know why cams are going south on Chevy's again so often..its almost like they dont harden ALL the lobes on them or something..either that or the "reformulated" oils they are selling us with low zinc content is hellbent on wiping out the remaining chevy V-8's of yesteryear with flat tappet camshafts..funny thing is I rarely hear of any oler Fords,mopars,etc, eating cams ,or any other brands..
 
..funny thing is I rarely hear of any oler Fords,mopars,etc, eating cams ,or any other brands..

I have noticed that too, but I just assumed it was because I'm not around them very much to hear about it.

I think I have bought my last flat tappet cam though. The extra cost of going roller is worth not having to constantly worry about losing a lobe or two.
 
Ive seen the ford and mopar guys bitching about it in Car Craft and Hot Rod magazines too.

It is a fairly expensive proposition, but Id rather go roller myself than gamble with a flat tappet cam anymore. Besides you can get a far more modern cam than something thats decent, but was designed 20 or 30 years ago.
 
As one of the other posts already said, and I just want to re-iterate, they have taken the zinc out of all the API oils, due to the stricter environmental regulations. The zinc poisons catalytic convertors. So if you want to run a flat tappet cam you have to use non-API oils, such as Valvoline racing oil, which is available at most O-Reily auto parts stores and can be special ordered at all of them by the case. That is why all the OEM's have went to roller cam engines.

If you are going to re-build your engine, it may cost a little more but it's really easy to convert to a roller cam. I forgot what year your block is, but from 87 on up they have the holes in the valley to bolt in the chevy spider to hold the dog bones down for GM roller lifters. And the front of the block should already have the cam plate hold back screw holes machined in.

Finally like the other guys said, you have to check your valve springs for proper installed spring weight.
I would also be sure to blow out the oil holes in your block that feed your lifters & cam bearings.
Also what oil pressure were you running?

Just some ideas. Good Luck,
 
Like the post above me said, roller cams can be cheap, just use a roller block.

Martin
 
As one of the other posts already said, and I just want to re-iterate, they have taken the zinc out of all the API oils, due to the stricter environmental regulations. The zinc poisons catalytic convertors. So if you want to run a flat tappet cam you have to use non-API oils, such as Valvoline racing oil, which is available at most O-Reily auto parts stores and can be special ordered at all of them by the case. That is why all the OEM's have went to roller cam engines.

If you are going to re-build your engine, it may cost a little more but it's really easy to convert to a roller cam. I forgot what year your block is, but from 87 on up they have the holes in the valley to bolt in the chevy spider to hold the dog bones down for GM roller lifters. And the front of the block should already have the cam plate hold back screw holes machined in.

Finally like the other guys said, you have to check your valve springs for proper installed spring weight.
I would also be sure to blow out the oil holes in your block that feed your lifters & cam bearings.
Also what oil pressure were you running?

Just some ideas. Good Luck,

Yes, I was well aware of the oil situation, and it was compensated for.

Also, not all of the '87-up blocks have provisions for the factory roller cam hardware. If they were from a truck, or a crate replacement, it's hit and miss.

Oil pressure never got below 30 psi at a hot idle in gear.
 
Hey don't mean to beat a dead horse to death. But there are a lot of other people running flat tappet cams and this problem should be explained some more.
According to David Vizard, author of "Max Performance Chevys on a budget" the problem started full force in 2006 when "ZDDP" was taken out of the oil, due to poisoning catalytic converters. Only API oils have this additive taken out. You can still get performance oils that are not API approved, but are very good, such as: Amzoil, Quantum Blue, Red Line, Royal Purple. "Most specialty oils have ZDDP, because they blend to meet hot rodders needs, not the EPA's oil standards".

He goes on to say that COMP (and others) offers a cam nitriding service. This puts a hard layer on the cam lobe and makes for a highly wear-resistant surface. "My personal preference here is to always use a nitrided flat tappet cam and then pair this with hard faced lifters".

He says earlier, that too much spring force, especially over the nose, wears out flat tappet cams fast.

How much is too much?
He says tests were run before ZDDP was taken out and 220# of force at full lift would last hundreds of thousands of miles, 240# at full lift would last 100,000 miles, 260-270# and you were down to 75,000 miles. At 280# your cam will only last 50,000 miles or less.

Last of all you want the lightest spring that will do the job for high performance apps.
If your running a stock engine, then "new" stock springs would probably due.
But the other guys were right, the springs are probably the culprit, for others, be advised that the new oils are your enemy now, if you have a flat tappet cam.
Even the earlier blocks can be converted to roller cam use. You just need to use a button on the cam along with a re-inforced timing cover, then the most expensive part of the conversion would probably be the "linked" roller lifters.
It's a little more expensive than the old flat tappet cams, but worth it if you can't guarantee you won't lose your flat tappet cam.

Most of you probably know all this, but there are always a lot of people who haven't been informed yet.

Good Luck with your engine.
 
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