Gen 1 vs Gen 2 piston and rod differences

[Lex]

If some of you still remember, there was a time when zoom zoom boom occurred often and I did some in-depth investigations of the parts the were part of the carnage.

There has been speculation that the Gen 2 rods were stronger since the Gen 2 cars didn't suffer from as much initial boom as the Gen 1s and the speed6s.

Well, I got my hands on a Gen 2 piston and rod from a car that blew (thanks @Ckmazdaspeed3) so I had a chance to bust out the calipers and compare these.

Here's what I found:

- The rods are identical between the Gen 1, Gen 2 and MS6 cars.
- The wrist pins have thicker walls on the Gen 1 and MS6 cars. I doubt this affects much as I don't see too many people breaking the very stout wrist pins. Other things will go first.
- As it has already been mentioned on the forums, the pistons are different for the Gen 2 cars.

The Gen 2 piston has been designed to improve combustion and direct the fuel spray upwards and AWAY from the cylinder wall. Cylinder wall wetting and washing is a common issue with these cars and they addressed this with the Gen 2 piston. We see a lot of the older cars lose compression and this may have something to do with it. Otherwise, the ringlands, oil passages, coatings, piston skirt design, etc appear identical.

Also the Gen 2's have modified ECU tables which are also responsible for averting the boom. The MS6s are the most likely to blow not just because they are the oldest but also because the AWD drivetrain loads the motor more and the Gen 1/MS6 ECU calibrations were just too aggressive for how the motors heatsoaked.

We've learned a lot and the aftermarket tunes address these issues in the Gen 1/MS6 cars. IMO unless the damage was already done, with a proper tune, a Gen 1/MS6 car is just as unlikely to blow as a Gen 2.

So, what have we learned from here:

1. The rods are identical for all years and for a stock application they have proven plenty strong.

2. The Gen 2 pistons have a better design that prevents fuel wash down and improves combustion. If rebuilding a motor, consider a piston design similar to what is used in the Gen 2 cars - otherwise, with a proper tune, all speed motors have similar strength internals.

On to the pictures. Gen 1 piston and rod are on the left and Gen 2 are on the right.