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Originally Posted by CarsByCarl
Well, a stock roller cam with low duration and low lift isn't subject to the same abuse as a performance roller with long duration, more aggresive lobe profiles, and higher lifts. Anyone expecting 100,000+ mile durability from a 385 series with a roller cam of any kind is going to be sorely dissapointed.
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Two maybe three words, Corvette Z06 and Viper. Both production based and making well over 500 hp. This cannot be done with displacement alone. Corvette, 505hp@6300rpm with a bore x stroke of 4.13 x 4.00. Viper, 600hp@6100rpm with a bore x stroke of 4.06 x 3.96. That's some mighty high hp numbers AND rpm for a 427 and 505 cu/in. without the help of a mighty stout cam
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Originally Posted by CarsByCarl
The biggest problems with hyd rollers in the 385 series are the weight of the lifter itself, and the undesirable pushrod angles resulting from the taller lifter. Some people run them without any problems, but as an engine builder it's not something I'm going to recommend to anyone. At the end of the day, If you're looking for more performance than a hyd flat tappet can offer, a hyd roller is not the answer in my opinion.
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I've done a few flat cam to hyd. roller conversions and an invaluable tool in my box is a pushrod length checker. I trust you do a sweep on the valve stem to check the rocker arm contact area?? If the lifter is too tall, use a shorter pushrod. This is another plus in the roller hat in that a shorter pushrod flexes less.
Please dude, I'm not picking on you personally. If you have been in business for any length of time you KNOW how customers are.
Here's the scenario:
YOU SAY, "Now, mr. customer, be sure to add a bottle of GM Engine
Oil Suppliment at every
oil change to your 460 and your cam won't flatten a lobe and it will make 500hp forever."
THEY HEAR, " BLAH, BLAH BLAH, BLAH BLAH BLAH BLAH BLAH BLAH BLAH
your 460 BLAH BLAH BLAH BLAH BLAH
will make 500 hp forever."
I am finished, you have your mind set and I cannot change it. How about this, throw a hyd. roller in one of your engines and see what happens. I'm not talking a radical change, roughly the same duration, lift, lobe center and separation.