[Gigaherz]

Hey eric what's up!

I'm going to be running their rings with my probe racing pistons. I've heard ross makes good stuff.

How much whp are you shooting for?

 

[Gigaherz]

Hey eric, sucks to hear about your car, i wasn't aware anything happened to it.

As far as probe pistons goes here are some pics of my spi ones, the pistons are nice but the tops had some sharp edges. Just to be safe I rounded the heck out of them and polished them up to get rid of stress risers.

forged probe piston and stock spi

after alot of tlc

Basically, whoever sells the cheapest forged pistons you can find is the way to go. They are all alot better than stock be it Je,Weiseco,Ross,Probe..etc.

.

 

[Gigaherz]

TLC = Tender Loving Care


As far as detonation goes, I think it will definately help becuase having heavily rounded and smooth edges will help the airflow over the piston top which will lead to a more uniform mix and burn which will help prevent detonation hopefully. It also got rid of the hot spots on the piston top.

 

[Gigaherz]

Basically, I took a die grinder with a carbide bur on it and grinded at all the edges alot. Once all the sharp edges were gone I used 120 grit sandpaper to get rid of all the bumps left by the grinder. Then I switched to 400 to get rid of the 120 grit scratches which were pretty deep. Went from 400 to 1000 and then buffed up the piston top with this special diamond polishing compound using a big dremel and a brush wheel. That got rid of any remaining scratches in the piston.

The main reason I did it was because right around the valve reliefs there was alluminum that came to a point. It was just the way they had machined the piston. I didn't like that so I grinded it down and rounded it so there is no chance of it ever breaking off there or becoming a hot spot because it was thin there. It might have been fine if I left it but I wasn't going to take that chance. The grinding alone took care of that but now becuase of the grinding marks the piston had stress risers everwhere which could lead to cracks or fracture points. So, you have to get rid of any scratches you put it. There is a process called shot peening which get's rid of the scratches and also strengthens the outer skin of whatever gets blasted but my way was free except for my time. If I recall it took me like 6-8 hrs to do the four pistons start to finish.