|01-27-2013 01:29 PM|
The Comp Cams push rods are excellent for adjustable hydraulic lifter camshafts where precise push rod length is not critical. That is why Comp Hi-Tech push rods are available in choices of .050" length increments and the Hi-Energy push rods are only available in OE lengths as determined by the year and make of the engine.
However, if you must have exact push rod length such as with a solid lifter camshafts or with LS engines that have net-lash adjustment, Smith Brothers offers custom made .083" wall, 4130 chromemoly push rods any any length you need for about the same price as Comp Hi-Tech push rods. In addition to custom lengths, Smith Brothers push rods are available with .030" or .040" oil feed holes in the lifter end for oil flow restriction. Restriction of excessive oiling to the rocker arms is often required in most engines at high RPM, especially engines using solid lifters, but that is a different issue.
|01-27-2013 11:31 AM|
As MouseFink alludes to, the application is the determining factor. What exactly are you doing with them? Stockish hydraulic flat tappet? Flat solid? Hydraulic roller? Solid roller? Race? Daily driver?
Comp's selection of pushrods is second to none. The "High Energy" series are for relatively stock engines. They DO need to say "hardened" or "for use with guideplates" if you use them with guideplates. The "Magnum" series is adequate for most street applications, including rollers. They're ALL "hardened". We use them until seat pressure exceeds 180. The "HiTech" series are among the best pushrods available, as already stated. MASSIVE overkill for anything but a solid roller with lots of spring.
|01-26-2013 07:50 AM|
The best push rods to use is 4130 chrome moly that has been case hardened. Chromemoly tubing has high resistance to bending and can be case hardened for a high resistance to wear. Factory and Comp Cams High Energy push rods are hardened by carburizing (heat treated) and are made of plain mild steel. Mild steel push rods can fold up like spaghetti with spring loads over 300 lb.
To save a few pennies, GM increased the diameter of their mild steel push rods in some of their high performance engines in order to resist bending. Larger diameter push rods are heavier, especially when they are filled with oil.
Comp Cams High Tech series are made of light weight SAE 4130, 5/16" OD, chromemoly .080" wall tubing and are case hardened for use with guide plates. Those are excellent quality push rods and should be considered with spring loads from 300 to 400 lb.
|01-25-2013 05:58 PM|
|01-25-2013 04:23 AM|
|Wage92||ahh okay, so if its heat treated i should be alright?|
|01-24-2013 07:27 PM|
|BOBCRMAN@aol.com||GM used steel pushrods with guideplates back in the sixties. The steel pushrod is heat treated.|
|01-24-2013 05:55 PM|
Pushrod choice with guideplates
May be a stupid question, but summit says these are for use with guideplates COMP Cams High Energy Pushrods 7812-16 - SummitRacing.com but they are only steel? I thought they had to be chromoly for use with guideplates?