How to Set Perkins Engines Bridge Pieces and Valve Clearance

Perkins Engines Closed Circuit Breather System

The closed circuit breather separator is mounted on the right hand side of the gearcase and is connected to the air inlet system between the air cleaner and turbocharger via the breather valve (see Fig.38).

It consists of a filter separator (1) and two breather valves (2) with a pipe feeding into the air inlet system (between the air cleaner and turbocharger).

To clean the breather valves release the pipe clips (A) and pull away the breather valves and the valve manifold from the engine. Release the clamp (3) see Fig.39 and remove the breather valves from the valve manifold. Wash the breathers thoroughly in a suitable solvent paying particular attention to any deposits on the internal area of the breather. Shake as dry as possible and blow dry compressed air.

Before refitting ensure that the cup at the base of the two breather valves are full of clean engine oil and the 'O' ring at the base of the breather valve is in tact.

Release the retaining clips and remove the top. cover (1) see Fig.40 from the filter separator body (2) remove the foam element (3) and the gauze strainer (4) check it for oil sludge saturation wash thoroughly in a suitable solvent, shake off excess solvent and blow dry with compressed air. Clean any oil sludge deposits from the filter body re assemble and fit to engine.

NOTE: Cleaning agents must not enter the engine via the breather system as oil dilution may occur causing engine damage.

Equalizing Rocker Bridges and Setting Valve Clearances

NOTE: The bridge pieces must be set before attempting to set the valve clearances. 

Remove the 4 screws (l) from each rocker cover (2), lift off the covers and peel off and throw away the old gaskets Fig.41.

To equalize the bridge pieces the appropriate valves must be rocking. In order that the engine may be rotated while the batteries are disconnected a special cranking device (SE253) can be fitted to a starter motor hole in the flywheel housing see Fig. 42. 

The flywheel housing has an inspection hole directly below the turbocharger through which the flywheel markings may be seen to line up with the pointer set in the flywheel housing Fig.43.

Using a socket and ratchet wrench press against the spring loaded bolt head until the pinion engages with the flywheel gear then crank the engine to the desired position.

Equalizing the Bridge Pieces

Having rotated the engine to the correct position, check that the inlet and exhaust rockers have clearance before continuing with the next operation. Loosen the lock nut (1) on each bridge piece, screw the adjuster (2) out until the fixed side of the bridge piece rests on its valve, hold the top edge down with one hand, then screw the adjuster down until you feel it touch the valve, thereby equalizing valve lift. Tighten the lock nut without moving the adjusters (see Fig.44).

Setting Valve Clearance

With both bridge pieces equalized check the valve clearance of 0.4 mm (0.016") inlet and exhaust using a feeler gauge (1). If adjustment is required loosen the lock nut (2) and using the adjuster screw (3) set the clearance (see Fig.45). Tighten the lock nut without moving the adjuster. The feeler gauge should be a slide fit between the rocker and bridge piece thereby giving the correct clearance. Refit the rocker cover with a new gasket.

Schedule for Engines in Stand-by Duty

For engines which are in use for a total of fess than 400 hours in every twelve months, the schedule below must be used:

The preventive maintenance operations must be applied at the interval (hours or months) which occurs first.

A-Monthly

B-3 Months

C-Every 200  hours or 6 months

D-Every 1,000 hours or 12 months

NOTE: All bolts, hose clips, terminal connections, pipes and joints must be checked for tightness and leaks every 3 months unless stated otherwise.

* By a person who has had the correct training.

Schedule for Engines in Continuous Duty

A-Daily

B-Every 250 hours or 6 months

C-Every 2500  hours or 12 months

As Perkins genset OEM, our Starlight diesel generating sets apply diesel engines from Perkins Engines Co.,Ltd, equipped with brushless self-excited AVR. We can provide 25KVA to 2250KVA Perkins diesel generator with good quality and performance.