Aluminum valve spring retainer

Abstract

Serious racers strive to squeeze as many revolutions per minute as possible out of their engines. They often use exotic metals like titanium in efforts to minimize the weight of some reciprocating parts. Almost exclusively, serious racers use titanium valve spring retainers to obtain higher speeds. This invention relates to an improved valve spring retainer for use in high performance engines. More particularly, it relates to an aluminum valve spring retainer which is lighter and less costly than titanium retainers of approximately equivalent strength.

Description

Claims

1. An improved valve spring retainer for use in an internal combustion engine having a valve stem, an engine block, a valve spring retainer having a bore encircling a portion of said valve stem, keeper means mounted on said valve stem and engaging said valve spring retainer, valve spring means encircling said valve stem engaging said valve spring retainer and pressing against said engine block, said valve spring retainer characterized in that said bore is a smooth surface of revolution having a first angle of taper at the end of said valve spring retainer adjacent to said valve spring means and a second angle of taper at the end of said valve spring retainer opposite to said valve spring means said second angle of taper being at least about 10.degree. larger than said first angle of taper.

2. The valve spring retainer of claim 1 wherein said first angle of taper is between about 0.degree. and 10.degree. and said second angle of taper is between about 10.degree. and 40.degree. and the difference between said first angle of taper and said second angle of taper is between about 10.degree. and 30.degree. .

3. The valve spring retainer of claim 1 wherein said surface of revolution has a substantially constant local radius of curvature over at least 75% of its area.

4. The valve spring retainer of claim 1 wherein said retainer is comprised of aluminum.

5. In an internal combustion engine of the type having a valve stem, an engine head, valve spring retaining means having a bore defining a smooth surface of revolution encircling a portion of said valve stem, keeper means mounted on said valve stem and engaging the interior surface of said valve spring retaining means formed by said bore, valve spring means encircling said valve stem and engaging said valve spring retaining means and pressing against said engine head, wherein said valve spring retaining means comprises: a valve spring retainer having a bore therethrough the area of said bore engaging said keeper means increasing more rapidly in the portion of said valve spring retainer away from said valve spring than in the portion adjacent to said valve spring and said valve spring retainer having at least one thrust surface formed therein.

6. The device of claim 5 further comprising an annular thrust plate interposed between said valve spring means and said thrust surface.

7. The device of claim 5 wherein the interior surface of said valve spring retainer is a surface of revolution having an angle of taper which is greater in the portion of said valve spring retainer away from said valve spring means than the angle of taper in the portion adjacent to said valve spring means.

8. The device of claim 7 wherein the generator of said surface of revolution has a substantially constant local radius of curvature over at least 75% of the area engaging said keeper means.