little known fact
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Le Mans Master
Joined: Mar 1999
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From: delmont pa
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little known fact
any time you raise your engine oil pressure or go to a heavier weight oil and you are running hydraulic lifters you must increase the spring seat pressure to prevent lifter pumpup. :chevy
Burning Brakes
Joined: Aug 2000
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Re: little known fact (clem zahrobsky)
Thanks Clem, learn something new everyday!!!
Can you remind me again why it is that they recommend going to a slightly taller rocker arm stud when you switch to full roller rockers? Is it because of the possibility of interference with the rocker arm and the outside of the valve spring or something else? Also, does using the taller stud affect the valvetrain in any way? Such as, does it affect the lift of the valves or perhaps does it slightly alter the rocker ratio? Does it mean you might possibly have to run a shorter pushrod also? Or, none of the above?
Thanks again, Mark :flag :chevy
Can you remind me again why it is that they recommend going to a slightly taller rocker arm stud when you switch to full roller rockers? Is it because of the possibility of interference with the rocker arm and the outside of the valve spring or something else? Also, does using the taller stud affect the valvetrain in any way? Such as, does it affect the lift of the valves or perhaps does it slightly alter the rocker ratio? Does it mean you might possibly have to run a shorter pushrod also? Or, none of the above?
Thanks again, Mark :flag :chevy
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Le Mans Master
Joined: Mar 1999
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From: delmont pa
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Re: little known fact (marky mark)
the longer stud is needed to get more thread engagement for the adjuster. your cam selection determines the length of the push rods and you need to check this because too short a push rod for the cam you are using will cause rocker arm/ retainer interference. the pivot point of the roller rocker is sometimes different than stock stamped rockers so you must check all the above items. :chevy
Race Director
Joined: Oct 2000
Posts: 14,994
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From: central FL, near the beach.
Re: little known fact (clem zahrobsky)
clem,
that is interesting. have you seen any tests where a change of oil from say 50w to 30 extended the rpm range? Are we taking 50 rpm? 250? 500?
that is interesting. have you seen any tests where a change of oil from say 50w to 30 extended the rpm range? Are we taking 50 rpm? 250? 500?
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Le Mans Master
Joined: Mar 1999
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From: delmont pa
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Re: little known fact (Matt Gruber)
the lifters are designed for what the manufacture of the engine recommends for oil and any change from that will cause lifter pump up. i have been told this by the cam manufacture. i do not know what the RPM difference would be. :chevy
Race Director
Joined: Oct 2000
Posts: 14,994
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From: central FL, near the beach.
Re: little known fact (clem zahrobsky)
according to the chart in my Owners Manual, 5w thru 50w is what is recommended, depending on outside temp.
so the answer to my question is 0 rpm. :seeya
so the answer to my question is 0 rpm. :seeya
