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Old 09-20-2005, 08:43 PM
Super Streeter Super Streeter is offline
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There has been no change in the quality of cams or lifters in the past 40 years.All the recent cam failures are being caused by the fact that the treehuggers have forced the oil companies to remove Zinc Disphosphate from their oil.The additive had been being phased out over the past few years,but in the last year or so it has become illegal to sell oil containing Zinc Diphosphate for normal use.You can still get the correct oil for flat tappet cams by running valvoline racing oil,or by adding GM E.O.S. to the current street oils.Some mechanics have had sucess with shell deisel truck oil but this isnt a known fact.Broken in passenger car engine with higher milage wont have issue with the non zinc oil.

To put this into perspective.guys are talking about how they rebuilt their basic 350 chevy street engine with .450" lift cams and basically stock springs,and their cams are wiping out in a few thousand miles despote everything seemingly being"on the money".The same engines these guys are rebuilding ran for a hundred thousand miles or more as a daily driver before being built as high performance engines,so lifter bore alignment issues are not suspect.
Now here is the funny part,I build all my bigblock Chevy drag engines with flat tappet cams.I have found that roller lifters break too often in drag usage,and it is impossible to get 300 or 500 runs out of a set of roller lifters like I can out of a set of flat tappets{actually the rollers need to be rebuilt.replaced after every 200 runs or so even with a mild solid roller while the flat tapets seem to have an infinite lifespan}.I run nothing but stock replacement parts store lifters.In my own personal car I run a bigblock with a flat tappet cam.The block is a million mile washed out junkyard 454 block with no lifter bore indexing or bushings,just plain old lifter bores.The cam measures 310 intake 320 exhaust duration at .004,266/276 duration at .050",and .600/.620" lift at the valve with 1.7:1 rockers.I run 1.550" springs that spec at 130# at 1.900" and 510# at 1.150,but since I installed these springs after the cam was broken in{actually the engine has over 500 passes at 7500rpm on it and the old springs wore out },I put the springs in at 1.850",which puts the seat pressure at about 165#.I run 20/50 valvoline racing oil.This engine like my others has no camshaft failure issues.

With that said,you need to make note of the fact that the bigblock chevy and smallblock chevy use the same part number lifter.If this combo can support the level of punishment that I impose on it,there is no reason why "bread and butter" street engines should be wiping cams with stock springs and small amounts of lift.Take my word for it,the problem is the oil{or some other mechanical issue such as improper engine assmebly}.Dont use synthetic without EOS,but if you really want to make your cam happy,run racing oil and EOS.

Good luck.
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