Ring Fitting

Call us for expert advice and a quotation for your engine machining requirements.

Whenever piston rings are replaced it is always good practice to check the piston ring end gaps in the bore.  Ring gaps which are too large can cause issues with poor running including high oil consumption, loss of compression and blow by.  If ring end gaps are found to be out of tolerance it is a good indication that the cylinder is probably worn and in need of a re-bore.

Where the original pistons are to be re-used as part of an engine rebuild the piston rings should always be replaced in conjunction with honing to de-glaze the bore surface.  Correct honing will achieve the required surface finish for the new rings to bed in however the fitting of the new piston rings is equally important.

Piston Re-Rings

As piston rings wear, the back clearance between them and the piston ring groove increases.  As part of the combustion process this extra gap will gradually fill up with carbon deposits.  If these deposits are not removed when rings are replaced, the new rings will be unable to fully retract into their grooves.  The lack of clearance behind the ring will result in them being forced into constant high pressure contact with the cylinder wall.  This situation will result in cylinder bore scoring and in severe cases lead to upper cylinder seizure.

H T Howard offer a piston ring fitting service and ensure that all ring grooves are correctly cleaned before new rings are fitted.  As part of this service, we also check for excessive ring groove and piston skirt wear.  Additionally and where practical, we are able to remove and refit the pistons onto their connecting rods and check for small end bush wear as well as a number of other piston and con-rod related problems.

Call us for expert advice and a quotation for your engine machining requirements.