IRP EJ25 Forged Piston Set 8.2CR

DESIGN INNOVATION AND ADVANCED TECHNOLOGY

RalliSpec has adopted IRP across our engine product line owing to their advanced design features and unmatched quality control protocols. Every piston starts with the latest material technology from the highest quality sources. IRP forgings are 100% machined meaning all surfaces are machined using the latest generation 5 axis CNC equipment in a temperature-controlled environment ensuring precise dimensional control. All IRP pistons incorporated bridged and strutted construction for strength and stiffness and a skirt coating for friction reduction. Each piston undergoes extensive quality controls and every critical dimension and weight is recorded in their systems for future reference.

These EJ25 pistons utilize a 2618/A1 material for high strength and detonation resistance. The crown and ring land surfaces have been hard anodized for wear resistance and thermal control. A sacrificial skirt coating reduces friction and allows the piston to precisely conform to the bore. A short length high strength piston pin with a 0.250in wall thickness supports extreme loads. Piston rings are the highest quality Japanese-sourced reduced-tension rings for superior blow-by and oil control.  Top ring sealing is assisted by lateral gas ports machined into the piston.

We highly recommend these pistons for all types of applications and power levels. They can and should be run with tighter clearances than might be typical for a 2618 piston due to the precise dimension control and crown coating. For this reason, along with the wear resistance provided by the hard anodizing, these pistons can be used without compromise in everything from a daily driven street application to a highly competitive racing application.

Piston Specs:

• Compression Ratio = 8.2 (8.6 w/ D25 cylinder heads)
• Cylinder Bore Sizes = 99.50mm, 99.75mm, 100.00mm
• Compression Height = 30.7mm
• Piston Alloy = 2618/A1
• Recommended Bore Clearance = .0022 to .0030in
• Piston Pin Wall Thickness = .250in
• Applications = EJ257/EJ255