Subaru WRX Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I am rebuilding an EJ205 after rod knock and I am just about to start reassembling it. I have bought two new rods and kept two from the last engine as they seemed fine and the clearances were just like new. The problem is that the new rods look a bit different than the old ones as you can see in the picture:

The bottom is different on both sides:
IMG_20180311_140927.jpg
IMG_20180311_140958 (1).jpg

The holes at the top are different sized:
IMG_20180311_140942.jpg

And the oil notches have more wear on the old rod:
IMG_20180311_141025.jpg

The weight is almost the same though (1 gram), both are OEM and the balance seems the same. The numbers are 25 inside the new ones and 18 in the old ones. So should I go for it, or should I order two more rods? Thanks!

Also I'm sorry if I posted this in the wrong place, I'm new to posting here.
 

·
Super Moderator
Joined
·
10,941 Posts
Are they the same length? I'm just taking a stab in the dark and guessing part revision or possibly different company made it for Subaru. I could be entirely wrong.

Are you sure you got rods for a turbo engine?
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #3 ·
Seems like the new ones are 1 mm shorter. I think you're right about being a different revision however I'm not certain they can be used together with the new ones.

I'm sure that the new ones are for the turbo as it is the part number listed at Subarus part-website, though I'm not so sure about the old ones.
 

·
Super Moderator
Joined
·
10,941 Posts
Why are you questioning using rods that are different lengths in the same build?

Unless I'm mistaken the 4 rods should be equal length and ideally balanced in opposing pairs.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #5 ·
Well it's basically because I forgot to measure them ...

Anyway, thanks for the help, ordering two new rods!
 

·
Super Moderator
Joined
·
10,941 Posts
Before you go further what length do you need
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #7 ·
Just standard OEM, I have a new OEM crank and pistons. The serial number is 12100AA310 which I bought from a local Subaru dealer who said they were correct, so I guess I buy two more of those.
 

·
Super Moderator
Joined
·
10,941 Posts
Ok. Just checking. Things can go south real fast if the rods are the wrong length and impact the head.
 

·
Æternum
Joined
·
15,538 Posts
Looks like an STI rod to me.



The STi rods are a good upgrade for the EJ205 to improve durability. Remember, rod length is measured from center-center. They should be the same length.

You will need to replace all 4.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #11 ·
Ah that explains it. I see now that the length to the center is the same now too, as I previously measured the full rod, though as you say I'll replace all and order two identical ones. It's my first rebuild so I'm a bit of a noob to some of this stuff, so sorry for that!
 
1 - 11 of 11 Posts
Top