TECH TIP: These pushrod ratings are for naturally aspirated engines. Engines with blowers, turbos, or superchargers will need heaver wall pushrods.
Call tech at 662-233-2301 to discuss any of these needs.
The following sizes are common sizes however we will make any length necessary.
Part Number Tube Ball Wall Length Max Open Pressure
DMR-5680-GP 3/8 5/16 .120 8.40 1200#
DMR-5681-GP 3/8 5/16 .120 8.50 1200#
DMR-5682-GP 3/8 5/16 .120 8.60 1200#
DMR-5683-GP 3/8 5/16 .120 8.70 1200#
DMR-5684-GP 3/8 5/16 .120 9.70 1200#
DMR-5685-GP 3/8 5/16 .120 9.80 1200#
DMR-5686-GP 3/8 5/16 .120 9.90 1200#
DMR-5687-GP 3/8 5/16 .120 10.000 1100#
DMR-5688-GP 3/8 5/16 .120 10.100 1100#
DMR-5689-GP 3/8 5/16 .120 10.200 1100#
DMR-5694-GP 3/8 5/16 .120 Custom
Valve float is normally associated with valve lifters or valve springs. Valve float (valvetrain separation) is the non-ability of the cam follower to stay in contact with the cam lobe. Flex in the valve train is the major cause of valve train separation. Test have shown that the majority of the time it is caused by pushrod flex.
The load put on a pushrod can cause it to act like a pole vaulters pole in that it will bend in the middle under load and then snap back to its original shape. This can in turn unload the lifter causing it to bounce on the cam which can cause premature cam and lifter wear and also unloads the valve spring causing the valve to float or bounce.
In dyno testing horsepower has been gained by simply going to a heaver wall pushrod. That is why all DMR (non adjustable) premium pushrods are now1 piece, a minimum of .083 wall thickness, case hardened for guide plates (.012 - .015 deep), 4130 chrome moly and have .040 oil restrictors to provide less oil to the over oiled upper end of the valve train and keep it down in the pan for bearing lubrication.