Abstract: An engine valve actuation system includes a rotatable camshaft, a first valve lifter, and a second valve lifter, structured to actuate valves in an engine in response to rotation of cams of the camshaft. The engine valve actuation system includes an anti-rotation device having a collar with a sleeve portion and a boss portion, and a bridge connector structured to couple with one of the valve lifters. Another one of the valve lifters is slidably received in the sleeve portion. The anti-rotation device reciprocates with the one of the valve lifters, and each of the valve lifters is restricted from rotation during service.

Abstract: An engine valve actuation system includes a camshaft, rotatable in an engine, and a compound collar including a mounting sleeve, a guide sleeve, and a bridge cantilevering the guide sleeve to the mounting sleeve. A first valve lifter is interference-fitted in the mounting sleeve, and a second valve lifter is slip-fitted within the guide sleeve. First and second lifter bores receiving the first and second valve lifters are congruent, and the first and second valve lifters may be substantially identical. The compound collar reciprocates with the interference fitted first valve lifter, slidably receives the slip-fitted second valve lifter, and limits in-service rotation of both.

Abstract: An engine valve actuation system includes a camshaft, rotatable in an engine, and a compound collar including a mounting sleeve, a guide sleeve, and a bridge cantilevering the guide sleeve to the mounting sleeve. A first valve lifter is interference-fitted in the mounting sleeve, and a second valve lifter is slip-fitted within the guide sleeve. First and second lifter bores receiving the first and second valve lifters are congruent, and the first and second valve lifters may be substantially identical. The compound collar reciprocates with the interference fitted first valve lifter, slidably receives the slip-fitted second valve lifter, and limits in-service rotation of both.

Abstract: An engine valve actuation system includes a rotatable camshaft, a first valve lifter, and a second valve lifter, structured to actuate valves in an engine in response to rotation of cams of the camshaft. The engine valve actuation system includes an anti-rotation device having a collar with a sleeve portion and a boss portion, and a bridge connector structured to couple with one of the valve lifters. Another one of the valve lifters is slidably received in the sleeve portion. The anti-rotation device reciprocates with the one of the valve lifters, and each of the valve lifters is restricted from rotation during service.

Abstract: A valve lifter assembly for an engine may include a valve lifter body, a roller pin mounted in the valve lifter body and having a crowned barrel portion, and a substantially cylindrical roller mounted about the crowned barrel portion of the roller pin. The roller may have a crowned outer surface with a cylindrical center portion having a constant outer diameter equal to a roller maximum outer diameter, and oppositely disposed variable outer diameter outer portions extending outwardly from either side of the cylindrical center portion toward corresponding roller ends of the roller with a roller outer diameter decreasing as the variable outer diameter outer portions extend outwardly from the cylindrical center portion. The valve lifter assembly may further include a clip having engagement surfaces that are machined to have complimentary shapes to corresponding engagement surfaces of the valve lifter body.

Abstract: A valve lifter assembly for an engine may include a valve lifter body, a roller pin mounted in the valve lifter body and having a crowned barrel portion, and a substantially cylindrical roller mounted about the crowned barrel portion of the roller pin. The roller may have a crowned outer surface with a cylindrical center portion having a constant outer diameter equal to a roller maximum outer diameter, and oppositely disposed variable outer diameter outer portions extending outwardly from either side of the cylindrical center portion toward corresponding roller ends of the roller with a roller outer diameter decreasing as the variable outer diameter outer portions extend outwardly from the cylindrical center portion. The valve lifter assembly may further include a clip having engagement surfaces that are machined to have complimentary shapes to corresponding engagement surfaces of the valve lifter body.