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Old 10-28-2007, 08:19 AM
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Jerry Clayton Jerry Clayton is offline
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Join Date: Jul 2005
Location: Bartlett, Ill
Cobra Make, Engine: Everett-Morrison LS1
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Wellllllll-----
I didn't say Old Fart---I just said old--

Now I'm going to say a few things that I want you all to think about and not just jump on the hydraulic roller band wagon( we use a lot of them too and I don't remember when I used a flat tappet solid lifter cam.


FIRST Mr. Kraft, Sir----there is nothing in what I said that should lead you or anyone to assume that I'm talking about anything that would normally see operation above the posters stated RPM range---a little over 6000 rpm would be right on target for a normal street range of 2500-5500.

Second----Those blocks weren't set up for hydraulic lifters----in fact in 1958 when they started putting hydraulics in some of the 332 and 352 they marked them with a splatch? of orange paint on the timing cover----The high per blocks WERE NOT drilled for oil to the lifters--this is a very delicate operation to do and most people won't be able to do it

The practice of restricting oil flow to the rocker shafts is a contributing factor to the flat tappet cams failing---there is then an lessor amount of oil returning to the sump to add to the oil for the cam. In the blocks that aren't drilled for hyd. lifters there is even less oil for the cam.

And the use of the new after market rods ---the hole that formally sprayed oil up in the crankcase has been removed--the only oil ( SPLASH< SLING< FLING, etc) for the cam now comes solely from the side clearance of the rods and it generally will be much tighter than stock resulting in even less oil on the cam---

In summation----people have done a number of things that have contributed to this problem in these engines, and the flat tappet cam gets blamed!!!!The cam failures are not just a result of poor oil, but a combined modernization process that has ignored basic mechanics and engineering---

I do agree that a modern Hydraulic roller is a way to get horse power---it just isn't in the FE high performance engines

In a standard 390 and all the 428 blocks the passages are drilled and a hydraulic setup will work, but not in the high performance blocks----

Jerry
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