PERFORMANCE DIESEL NOZZLES
Performance nozzles, in most cases, are nozzles that have the spray holes enlarged allowing the injector to produce a higher fuel delivery than the stock setup. The Modifications done to the nozzle will vary in both the method vendors choose to produce an increase in fuel delivery from the nozzle and the method they choose to confirm the accuracy of flow increases, and balance as a set, after the modification is made. The following lists some of the various ways horsepower gains are achieved by enlarging the spray holes of an injector:
Some stock nozzles are simply replaced with OEM nozzles that happen to be for higher horsepower applications yet fit your engine. Marine or Military application nozzles would be an example of this.
Some nozzles are misapplied to an application because someone feels they work better than the stock nozzles. We have seen this practice first hand from several vendors. The R & D and design investment the OE manufacturers make to create quality products should not be ignored.
Some nozzles are modified with the EDM process (Electronic Discharge Machine). In almost all cases your stock nozzles spray holes were probably created with the EDM process, or precision drilled, and in every case the nozzle was then treated with some sort of abrasive flow treatment (Extrude Hone is one type of this process) to remove the re-deposited metal from the backside of the spray holes. The metal debris from the forming or enlarging of a hole by an EDM is relocated to the surface around the hole and must be removed. Just as with any machining process the finished product is only as good as the tooling and the technician combined. There is certainly an art to this process and the best in the business seem to stand out miles ahead of the others. Just because someone has an EDM does not in any way guarantee a successful product. The machine itself must be of a certain type. Much of the used EDM equipment shops are picking up is medical surplus and not the style needed or intended for correctly modifying nozzles. EDM processed nozzles should be finish processed with some type of Abrasive Flow Technology (Extrude Hone is one type of this process) to remove material build up on the back side of the holes.
Some nozzle spray holes are simply drilled oversize. Drilling nozzles to oversize is very difficult but a few shops have this process down. Drilled nozzles should be finished processed with some type of Abrasive Flow technology to remove spiral score marks in the spray holes.
Some use the Extrude Hone Process. Depending on the size of the desired horsepower upgrade , in most pick-up truck applications hp gains up to 175hp would be the top of the range, Extrude Hone is a one process modification that not only delivers increased horsepower but also extreme balance and reliability. Confirming the flow levels and balance after modification is the key to success with the Extrude Hone processing or any other process for that matter. Some vendors use air for this step the most accurate form of this testing is done by fluid flowing the nozzle after modification. MFE uses fluid flow technology traceable to the National Institute of Standards and Technology meeting ISO 7440 specifications.