soapra
05-19-2008, 03:51 PM
We are proud to announce that we will carry Tomei. We can get all parts that they offer in Japan here in the states. They Have available 1jz and 2jz pistons and rods. They have been making these parts for many years now and have been tested and raced on cars that have made over 1000 RWHP+ and also on boost levels that have exceeded 45 PSI.
If you have ever built a 2jz or a 1jz and turn over the pistons, you will see that the piston has a cooling channel. When the piston is at the lowest point, the oil squirter is lined up and travels inside the orifice of the cooling channel to allow oil to cool the piston. This allows temperatures of the piston surfaces to be cooler and make more power. Toyota has made all the pistons on 1jz and 2jz this way and it could explain why stock jz pistons can handle abuse better then any other stock piston. All of Tomei pistons are made this way.
Tomei Piston rings are Ti coated. Ti coated rings will have 30times friction durability and 1.4 times scuff durability to the stock ring.
Best of all is that the piston is made again like the stock piston. Stock pistons are not round they are ovaled. This part I will copy and paste from the Tomei site.
"The expansion rate of running piston body will be various according to the structure and its condition of drive. To comprehend the subtle changing of the expansion accurately, we gave countless testing on the bench and it resulted in this oval-barrel shaped piston that is designed in 3 dimensions. Considering both pistonﾕs temperature distribution that is affected vastly from its shape and driven circumstances, and wide expansion rate character of the aluminium, it is necessary to understand the exact temperature and expansion rate of every parts of the piston body in order to give it a appropriate clearance from cylinder. We succeeded to calculate out this oval-barrel shaped piston in 1/1000 mm level accuracy under the highest pressure to correct the distortion.
Too much clearance between cylinder and piston will results not only in incomplete combustion and power down of the engine, but also cause the piston to rock inside the cylinder and oil to blowby. Blowby would tear the oil sealing between cylinder and piston ring, or mixed into the engine oil and spoil the oil. It is not rare that blowby cause the blown crank metal or worn out metal. Moreover, on such places where the expansion rate is high and clearance is narrow, piston rings would blow or the cylinder gets scuffed. Especially in the case of the perfect-circled piston, it is impossible to correct the heat expansion from top land to piston-pin-boss direction where the temperature gets highest, and this is why the "hit" tend to occur at vertical direction of the piston in some tuned engine that installed perfect-circled piston"
If you have ever built a 2jz or a 1jz and turn over the pistons, you will see that the piston has a cooling channel. When the piston is at the lowest point, the oil squirter is lined up and travels inside the orifice of the cooling channel to allow oil to cool the piston. This allows temperatures of the piston surfaces to be cooler and make more power. Toyota has made all the pistons on 1jz and 2jz this way and it could explain why stock jz pistons can handle abuse better then any other stock piston. All of Tomei pistons are made this way.
Tomei Piston rings are Ti coated. Ti coated rings will have 30times friction durability and 1.4 times scuff durability to the stock ring.
Best of all is that the piston is made again like the stock piston. Stock pistons are not round they are ovaled. This part I will copy and paste from the Tomei site.
"The expansion rate of running piston body will be various according to the structure and its condition of drive. To comprehend the subtle changing of the expansion accurately, we gave countless testing on the bench and it resulted in this oval-barrel shaped piston that is designed in 3 dimensions. Considering both pistonﾕs temperature distribution that is affected vastly from its shape and driven circumstances, and wide expansion rate character of the aluminium, it is necessary to understand the exact temperature and expansion rate of every parts of the piston body in order to give it a appropriate clearance from cylinder. We succeeded to calculate out this oval-barrel shaped piston in 1/1000 mm level accuracy under the highest pressure to correct the distortion.
Too much clearance between cylinder and piston will results not only in incomplete combustion and power down of the engine, but also cause the piston to rock inside the cylinder and oil to blowby. Blowby would tear the oil sealing between cylinder and piston ring, or mixed into the engine oil and spoil the oil. It is not rare that blowby cause the blown crank metal or worn out metal. Moreover, on such places where the expansion rate is high and clearance is narrow, piston rings would blow or the cylinder gets scuffed. Especially in the case of the perfect-circled piston, it is impossible to correct the heat expansion from top land to piston-pin-boss direction where the temperature gets highest, and this is why the "hit" tend to occur at vertical direction of the piston in some tuned engine that installed perfect-circled piston"