Fuel Injector Overhaul

[BrianBT]

I am currently looking at the procedure for overhaul of marine fule injectors.
Current practice is to lap in the HP faces between teh nozzle and body with fine paste.
This soes not appear to be a good working practice to myself. I have sent 3 injectors for analysis the report of which found defects including a domed face on the body.

I can put my foot down and demand this change in practice but I would rather back it up with any presidence as the guys are quite against changes I am looking to implement including the restoration of these faces by machine grinding.

Does anybody know of research or recommended practice in this area

 

[dicer]

Even if they are machine ground, they will still need to be lapped. With abrasive machine work (grinding), the media used wears as the process goes on. And will leave that deformaty on the part. Especially when a very small area is all that is machined. Constant dressing of the media will help limit it. Also remember there isn't much material to play with in the nozzle body. The fuel isn't going to care if those surfaces are a bit radius shaped, sealing is what is important. I think your trying to increase the cost for nothing. And by removing more material you are vey much reducing the number of overhaul cycles that the unit can be overhauled, and that is important if it is a very large expensive unit.