Arias RB25 pistons

[Roy]

So anyone running old Arias RB25 pistons?

I'm having trouble finding info on the pistons in my engine. They have 371521 engraved in them and sit proud of the deck by ( from memory) about 16thou

[KiwiRS4T]

What do you want to know? Google Arias Pistons  and there are heaps of entries including the makers.

[Roy]

Ideally compression height and dome cc.

My google search comes up with nothing reliable. Some RB30 pistons for twin cam conversions etc and the catalogue doesn't list that piston number.

If my pistons are the same as the catalogue and the CH is 31.369mm vs the std RB25 piston having a CH of 31mm  (0 deck same as RB26, 2mm stroke difference and JE state CH of 31...whilst some others like Wiseco and CP seem to be 31.5mm)

If the std RB25 piston has a CH of 31mm then that is about right as it means the piston will be 0.369 above the deck. I measured 16thou/0.4mm so in the hunt. 

Trying to suss a head gasket for std squish or perhap tighter squish if there is a more optimal target 

 

[KiwiRS4T]

Try an email to the factory quoting your part number.

[Dale FZ1]

9 hours ago, Roy said:

 

If the std RB25 piston has a CH of 31mm then that is about right as it means the piston will be 0.369 above the deck. I measured 16thou/0.4mm so in the hunt. 

Trying to suss a head gasket for std squish or perhap tighter squish if there is a more optimal target 

 

You've done the hard work by measuring actual deck height of the piston in your engine.

Target clearance to the quench pad should be about 1.0mm, plus/minus 0.1mm.

Order HG to suit your measurements.

 

[Rusty Nuts]

12 hours ago, KiwiRS4T said:

What do you want to know? Google Arias Pistons  and there are heaps of entries including the makers.

Or go directly to Arias website and send an email asking for info.https://ariaspistons.com/

[Roy]

Yeh, tried email the other week. May try again. 

Or as Dale FZ1 points out...just suss squish and ZFG about compression ratio...E85 etc.