When cylinders are bored to oversize, they are generally bored or rough honed to within about .0025″ to .003″ of final size to allow for finish honing. The finish honing step removes the fractured and torn metal created by the boring process, and produces the kind of surface finish and crosshatch. After this process the cylinder block is then Honed. this can be the old style normal honed, plateau honed or diamond honed
The short and sweet version of all 3 processes
Most OEMs and ring manufacturers say the angle of the scratches in the crosshatch pattern should be about 45° to each other, or about 22° to 32° to the horizontal deck surface. You must refer to the OEM manual specification to confirm your crosshatch requirements.The crosshatch angle should be the same throughout the length of the cylinder and not flatten out at either end.
If the crosshatch angle is too steep
- the rings can pump oil or experience excessive rotation which will accelerate wear in the rings and piston lands.
If the crosshatch angle is too shallow,
- it can have a ratcheting effect as the rings pass over the valleys, preventing the rings from receiving proper lubrication.
* note * The old Style Flexi Hone or Bottle brush hone are NOT suitable for the modern engines of today and are old technology, and should not be used even as the 1st hone or to try and deglaze a cylinder bore.
Advantages of Plateau Honing on a Diesel Engine, Gas , Bio Fuel and Petrol cylinder bores.
- Significantly shorter break-in time;
- Reduced blow-by for cleaner emissions;
- Reduced oil consumption in a new engine;
- Less ring and bore wear for improved engine longevity
Diamond is the next technology of honing. It Has all the advantages of plateau honing and more
Diamond honing lowers the honing costs per cylinder, saves labour, lasts longer (fewer stone changes), and gives better overall bore geometry (straighter and less distortion).
Has a better RA finish , the finer the finish the better the seal, the better your engine will perform, most high performance engines are Diamond honed
Laser honing will Be Next, or just 3D print yourself another cylinder block !!!