apex seals shotpeened? what does that mean and how to do it?
 

apex seals shotpeened? what does that mean and how to do it?

Shot peening is used to relieve surface tension in parts. I don't see how you could use shotpeening on an apex seal without basically destroying it. Cryotreating would be a better option. There is another way to relieve the surface tension but I don't remember what it is.

Hmmm...I always thought shotpeening is shooting a special media to compress the surface?


-Ted

thats what i thought...by shotpeening u encourage strain hardening......which gives u stronger finished product....downside is.....shotpeening has a chance of warping the part and the part is not as ductile as before....i think u meant to say annealing...which is heating the part until it reaches softening temperature

Shotpeening INDUCES residual surface stresses by shooting a media (shot) at the part causing localised compressive platic deformations in the surface. It would be bad on apex seals, because, well you want them to seal, and shot peening will put little bumps all over them which will stop them from sealing as effectively.

Definition from: http://www.ndt-ed.org/GeneralResourc...y/letter/s.htm

Shot Peening - A carefully controlled process of blasting a large number of hardened spherical or nearly spherical particles (shot) against the softer surface of a part. Each impingement of a shot makes a small indentation in the surface of the part, thereby inducing compressive residual stresses, which are usually intended to resist fatigue fracture or stress-corrosion cracking.


more info here:

http://www.metalimprovement.com/shot_peening.php

Short answer, its a means of hardening a part. Should you do it to an apex seal, probably not

That was the point I was trying to get at. We had a connecting rod have a spot about the size of a pencil eraser where it wasn't shotpeened, it let go on the dyno before it even got through break in.

Shitty, that was "apparently" done to my newist engine's apex seals. I am just constantly getting bad surprises from this engine. Oil pressure and now this.

shoulda consulted the forum before u spend all that money...if it hasnt been done, or isnt popular....maybe its that way for a reason......

too late.