The reconditioning of a Recomotec Marine Engine involves many steps: here are a few, these steps are among the most important.
Engine Block also called short block
One of the first steps will be to disassemble and clean the old engine block at very high temperature and high pressure.
We will use a pyrolytic oven, solvents, scrapers and large metal brushes to achieve a perfect and meticulous cleaning of the engine block.
Then comes a careful and conscientious control, both visual and to the instruments of measurement of the whole engine. For this purpose, an "AC electromagnet" device will be used. The latter is a perfect cracks-detector in the casting of an engine.
Thanks to our machine "Rottler F68A" we will obtain a perfect surfacing of the planes of gaskets of heads. Always thanks to this extremely precise machine, the cylinders of the block will be rectified, bored and "honed" according to specific and extremely precise dimensions provided by the marine industry and all this in order to obtain an absolute finish.
The block is finally ready for an align-boring for the camshaft and mainshaft lines. This step is very important because it allows to obtain a constant clearance for the oil and to confirm a good oil pressure. After these various important steps, we will carry out a final cleaning of the block at high pressure and very high temperature in order to evacuate all the iron filings still present in the oil galleries.
Like all internal parts of an engine the crankshaft has its importance.
We will first measure it and then rectify it if necessary. Before this important step of grinding the crankshaft bearings, always following the marine specifications, we will proceed to its complete cleaning, hot, high pressure and shot blasted.
The oil galleries are then carefully cleaned, the oil passage holes chamfered, the crank journals polished to ensure a perfect lubrication.
The connecting Rod
Each of the connecting rods of the engine will initially be weighed and its bore will be checked with a precision measuring device.
These latters will be bored and "honed" in order to obtain an irreproachable roundness. With an electronic axis control device, we will check the straightness and curvature of its axis as well as the length from center to center of pin axis. After all those operations the rod will be honed.
The cylinder Head
To find out if a cylinder head is cracked, it must be tested under hot pressure.
Before this step, it must be understood that the latter must have been cleaned at high pressure and shot blasted by spraying micro-beads of steel.
The face of the cylinder head is necessarily surfaced, all the valve guides are replaced by new parts and the valve seats are ground to obtain at least 3 angles. These 3 angles on a valve seat will give it an optimal seating in order to give it a perfect heat transfer.
Then, the cylinder head is assembled with new and high quality seal for valves.
The pressure of the valve springs is checked separately in order to have the same pressure for each valve and to provide an optimum seal when the valve is closed.
All the internal parts of the block will be assembled in a structured, Cartesian and conscientious way. Most parts are new. Throughout the assembly, many controls, measurements and tests are carried out in order to guarantee maximum quality.
At the end of the assembly, the engine is tested on a bench test and the valves are adjusted.