Head stamp question

[just-rust]

With the newest searchings under the hood, I noticed this stamp. This is the driver side where the AC compressor would sit. Does this mean I have different heads installed on this motor already? I have searched through a lot of photos but haven't found anything conclusive. Any help is appreciated.

[mike-tracy]

My roomate and I were just joking about those on his SVX engine - his numbers are 3 4 5 1 (or something close to that). He was saying that's the theoretical limit to the WHP he could hope to obtain, lol. Honestly I don't know the answer.

[James614]

I always assumed it was a serial number of sorts.

[just-rust]

My roomate and I were just joking about those on his SVX engine - his numbers are 3 4 5 1 (or something close to that). He was saying that's the theoretical limit to the WHP he could hope to obtain, lol. Honestly I don't know the answer.

Haha! That is awesome. I am going to have to check out my whp limitation on my SVX now! I will be fine with anything over 1000.

The number made me think maybe I had some EJ25 heads on the car. Saves me some reading knowing they are just a serial number of sorts!

[James614]

The heads aren't stamped to identify the motor's displacement AFAIK, at least not without some decoding through info that's not easy to come by. But if they were EJ25 heads, they would either be DOHC, or if they were SOHC you'd be demanded to show us full detail on how your intake manifold, cam gears, sensors, and wiring harness were all made to work on them

[mike-tracy]

A phase II ej25/22 could be run on phase I electronics.

[James614]

Its far from a bolt-on affair, though.

[mike-tracy]

Its far from a bolt-on affair, though.

Everything except for the IAC is bolt on. swap the cam and crank sprockets and you have phase I timing, all the sensors swap over, TB swaps, the 99 ej22 manifold still uses sidefeed injectors, etc. Yeah, it'd be a bit of swap work, but the torque increase of the 2.5 over a tired old stock engine would be fun.

RS25 had a solution for the IAC when I looked into it a few years back.

[James614]

I recall reading on here that the for the EJ25 SOHC, it wasn't as easy as a simple cam gear swap.