What pistons to run?

I run stock so pistons with 150 thous reliefs cut. I did not touch the bowl as i didnt know about that until it was allready back together. I run 34* timing and can hit 5300 on the line but with this turbo i cant get it to turn much over 4300 on tight tracks.
 
Anyone know what the specs are on the rv275 pistons? Larger bowl than a SO piston or no?
 
I measured a 2.411" bowl on mine ~61.2mm

Top ring is 10.6mm down

1310 grams bare

48cc bowl in stock form
 
probably do, I just don't have the part numbers for those. Give Jeff a call at Mumau...
 
Ok cool thanks, and a few more questions...aren't those specs about the same as a stock SO piston? What's the advantage of a RV275 over a SO piston? Are they lighter in weight or a deeper bowl? Made of a better material?
 
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They are squeeze cast and use a fibre reinforced material for added stability. Suppose to be a better material. They come from cummins with a ceramic coating on the top and in the bowl as well.
 
GOT-Torque said:
They are squeeze cast and use a fibre reinforced material for added stability. Suppose to be a better material. They come from cummins with a ceramic coating on the top and in the bowl as well.
Click to expand...

Thanks for the info man!
 
Jesse thanks for the info. Sounds like im gonna go that route but do you or anyone else by chance have the specs on a SO piston to compare?
 
Wesley B said:
Ok cool thanks, and a few more questions...aren't those specs about the same as a stock SO piston? What's the advantage of a RV275 over a SO piston? Are they lighter in weight or a deeper bowl? Made of a better material?
Click to expand...

SO bowl is 59mm if I remember right, so the RV's are 2mm wider.
 
I don't have the numbers in front of me right now but I think wesley listed them right. The bowl wasn't alot bigger if much at all I don't think. I had HO pistons previously so I needed to upgrade and the RV pistons are supposed to be a better material (and already coated on top).

If your stock SO pistons are still decent, just machine the reliefs into them and run them. Use the money elsewhere.

However if you need pistons, they are a cheaper alternative to forged pistons...
 
HO

286090.jpg


SO

286150.jpg
 
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