Cutting oil grooves in pistons?

Heard from a buddy this weekend that if you take your pistons and chuck them up in a lathe and add a few grooves down below oil ring on the skirts it helps with cooling/oiling. Anyone else heard of that, done that? My nailhead needs to be bored and I need a new set of pistons, but i sure would hate to **** them up

 

besides the risk of mangling your brand new (and probably very expensive) pistons,i don't think it's a good idea.
there's a lot of oil flying around up there already,which is why the lowest ring is for oil control.behind the oil control ring there are slots or holes for the oil to drain away.

 

Never heard of such a thing in my 30+ years of working for a piston manufacture. I see no benifit in doing such a operation. The oil ring and the design of the oil return in the oil groove of the piston as a combination contribute to the effectiveness of oil control.
Adding additional groves under the oil ring could possibly weaken the piston skirt area enough to allow it to crack and break.

 

Forgedtrue made full skirt racing pistons in the '60s with 8 shallow grooves around the cir***ference. FYI

 

Perfect Circle style knurling on skirt will prevent scuffing without weakening the piston.

 

i think another thing to consider is are they going to be for street or race?
the grooves and knurling you guys are talking about are typically for forged pistons with a lot (.010) of skirt clearance,but on the street w/low compression you can run a cast piston with a tighter (.002) fit.

 

this would be for just street use he said it helped alot with cooling which is something im always interested in being in phoenix. definatley dont want to mangle a set at $330 though so ill just leave them be

Edit: Looking at getting a set of cast pistons from TA Performance

 

That would be an easy way to create stress risers.

 

late 60'S early 70's use to do it to HD Stroker motor pistons

 

Piston manufacturers spend millions in R&D. If those grooves were an ***et, they'd be there

 

Don't screw up a set of new pistons. You want help cooling, plumb in an external oil cooler.

 

Unkl Ian is correct.
To try to clarify...the suggested groves could serve to focus mechanical
stress in these small areas rather than spreading the load evenly over a
smooth surface.

 

I've seen pistons that were "dimpled" to retain oil on the skirts, but never seen grooved - the thought process is similar though.

Have also heard of knurling, coating, and simply bead blasting them...

 

If you're worried about cooling and friction, why not get them coated? A moly on the skirts and a thermal barrier on top will do more good than anything else you could possibly dream up. Fairly affordable nowadays too.

 

Couldn't have said it better myself. They've been working on piston design for over 100 years now and they are putting the best technology they've got into them.

 

The only ones i have ever seen grooved are on slow running stationary engines hit & miss etc. They were made in the early 1900s most run about 300-600 rpm alot of these were grooved. Most were horizontal , had drip oilers and the grooves held some oil in. i don't know if it would help on a modern engine.