Altering Rocker Arm Ratio By Varying The Length Of The Pushrods

Fig A.A unique feature with the shaft mounted rocker arms such as those found on the Y-Block (as well as the FE, MEL,  and LYB) Ford engines is that the solid lifter or lash adjusting versions can be measurably variable in the rocker arm ratio depending upon where the lash adjusting screw is positioned within its range of travel. Continue reading “Altering Rocker Arm Ratio By Varying The Length Of The Pushrods”

Rocker Arm Geometry

Rocker arm geometry is an area that’s very often overlooked when modifying an engine for increased power output and/or efficiency. Besides the obvious advantage of reducing valve stem and guide wear by minimizing the “scrubbing” action that can take place when the rocker arm geometry is optimized, the maximum or advertised lift at the valve for a given camshaft profile can also be obtained. Continue reading “Rocker Arm Geometry”

Building the foundation for an eight second Y-Block.

When Randy Gummelt and I set out to build a Y engine for his rear engine dragster, the plan was to have an engine combination that would run an eight second quarter mile. And Randy also had his sights on the Australian Y record and with a target of an 8.99 or better et, that plan would achieve both goals. By now, it’s pretty well known that Randy ran a best of 8.15 @ 162mph at the Y Shootout during this past Labor Day weekend at Columbus Ohio so the plan was definitely a good one. Continue reading “Building the foundation for an eight second Y-Block.”

Blueprinting for an eight second Y-Block

Like any engine that’s in its planning stages, particular care must be paid to that engines intended use in  order to select the correct parts and maintain those clearances that would be considered optimal for that combination.  In the case of the blown engine for Randy Gummelt’s rear engine dragster, I’ve already covered some of the parts selection as well as the main support girdle construction in previous articles.  At this point, I’ll cover in more detail some of the specific clearances and specialized machine work that was required to make Randy’s engine a reality. Continue reading “Blueprinting for an eight second Y-Block”