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-5650-GP 5/16 5/16 .083 8.40 750#
DMR-5651-GP 5/16 5/16 .083 8.50 750#
DMR-5652-GP 5/16 5/16 .083 8.60 750#
DMR-5653-GP 5/16 5/16 .083 8.70 750#
DMR-5654-GP 5/16 5/16 .083
9.70 750#
DMR-5655-GP 5/16 5/16 .083 9.80 750#
DMR-5656-GP 5/16 5/16 .083 9.90 750#
DMR-5657-GP 5/16 5/16 .083 10.00 650#
DMR-5658-GP 5/16 5/16 .083 10.10 650#
DMR-5659-GP 5/16 5/16 .083 10.20 650#
DMR-5691-GP 5/16 5/16 .083 Custom
TECH TIP:
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.
