CFR Cylinder Overhaul

Our Service

Mark's Knock Engine Service's accepts complete cylinder head units for overhaul shipped to our shop. We accept the entire unit including the valve gear, clamping sleeve, worm wheel, worm gear, and CR Box still assembled together. This allows our technicians to check tolerances and wear on the apparatus ensuring long, dependable use.

After running an engine for some time, it becomes more difficult to temperature tune with toluene and have the intake air temperature come with spec for the prevailing air pressure. This is because the valves, valve seat inserts, and piston rings wear during the normal life of the engine.

Over time, or if some particulate is introduced, the valves will start to lose their seal to the valve seat inserts. Also, some pressure in the compression chamber can escape past the piston rings. Irregular heat and pressure patterns due to leakage causes problems in rating an engine. In addition, the valves, ports, piston and cylinder bore accumulate a coating of carbon.

This carbon glows cherry-red and will produce more heat in the chamber necessitating a lower intake-air or intake manifold temperature to properly certify an engine fit to use. A cylinder overhaul is necessary at regular intervals.

Clamping Sleeve

They cylinder is reassembled with clean clamping sleeve, worm wheel, and worm shaft, and CR box.

Worm shaft is properly fitted with shims to the clamping sleeve
Worm wheel and clamping sleeve wear tolerance checked
Springs polished, checked, and replaced if necessary
Clamping sleeve fittings and bolts are updated if necessary
Cylinder is set to a standard height
If you still have a hand crank that's all right, we'll fix that up too!

Valve Gear

The valve gear is inspected, thoroughly cleaned, and rebuilt with attention to:

polishing of shafts and replacement, if necessary,
rocker arm bearing quality,
valve lifter cups wear
valve adjusting screw wear
proper yoke height set

MKES will only sell you parts if they are necessary because of damage or wear beyond the mechanical tolerances of the ASTM specification. This can save your company hundreds of dollars per overhaul.

Dependable functioning of the cylinder and its ability for consistent rating is our number one priority.

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