2jzgte Pistons in a 1jz

[Dirgle]

You affect displacement with Bore and Stroke. Bore is affected by the size of the piston, and stroke is affected by the radius of the crankshaft. Changing the length of the rod does not affect either of these two , piston or crankshaft. All the rod does is connect one to the other.

Total Engine Displacement (cc) = (.0031416 / 4) x Bore x Bore x Stroke (mm) x Number of Cylinders

1JZ
Bore = 86 mm
Stroke = 71.5 mm

(.0031416 / 4) * 86 *86 * 71.5 * 6 = 2491.98 cc

2JZ
Bore = 86 mm
Stroke = 86 mm

(.0031416 / 4) * 86 *86 * 86 * 6 = 2997.35 cc

7M
Bore = 83 mm
Stroke = 91 mm

(.0031416 / 4) * 83 *83 * 91 * 6 = 2954.19 cc

 

[group a supra]

You affect displacement with Bore and Stroke. Bore is affected by the size of the piston, and stroke is affected by the radius of the crankshaft. Changing the length of the rod does not affect either of these two , piston or crankshaft. All the rod does is connect one to the other.

Total Engine Displacement (cc) = (.0031416 / 4) x Bore x Bore x Stroke (mm) x Number of Cylinders

1JZ
Bore = 86 mm
Stroke = 71.5 mm

(.0031416 / 4) * 86 *86 * 71.5 * 6 = 2491.98 cc

2JZ
Bore = 86 mm
Stroke = 86 mm

(.0031416 / 4) * 86 *86 * 86 * 6 = 2997.35 cc

7M
Bore = 83 mm
Stroke = 91 mm

(.0031416 / 4) * 83 *83 * 91 * 6 = 2954.19 cc

an excellent info post can we sticky that equation somewhere please

 

[OneJoeZee]

werd to your mother.

so next time someone tries to tell me the 1J and 2J cranks are the same, i can just show them this

 

[IJ.]

IJ are you serious?

100% serious it has no affect on displacement at all.

You could have Rods 2 feet long but if the Stroke remains the same the motor will have the same displacement.

To change displacement change>

Stroke Length

Bore size

Number of Cylinders.

These are the basics some people seem to have trouble accepting.

 

[Dirgle]

an excellent info post can we sticky that equation somewhere please

Ok, sure. It's in MK3 tech now where it will easier to find.

http://www.supramania.com/forums/showthread.php?p=168658#post168658

 

[The Doc]

So, basically what you're saying is to buy/use the 2JZGTE pistons if I want to buy CP pistons for my JZA70. correct?

 

[Ric]

Do the 2JZGTE pistons weigh more? Turning 8000rpms that might cause some issues

 

[annoyingrob]

100% serious it has no affect on displacement at all.

You could have Rods 2 feet long but if the Stroke remains the same the motor will have the same displacement.

Yeah, there seems to be a mis-understanding with how everything works.

Let's have a hypothetical example where you had motor X. It has some displacement, but it's not important. Now, say you took the rod out, and replaced it with a rod 10mm shorter. How is this going to effect the motor?
Well, the top dead center position of the piston will be 10mm lower due to the rod. But..... the bottom dead position will be 10mm lower too. Overall, the linear distance the piston travels has not changed. Stroke has not changed. Displacement has not changed.

What has changed? Compression ratio has for one. Let's say the stock combustion chamber had 100cc of volume when the piston was down, and 10cc ob volume when up. This would give you a CR of 10:1. By shortening the rod, lets say it adds 50cc of volume to the chamber. It will do so linearly, making piston down volume 150cc, and piston up volume 60cc. Your CR is now 2.5:1