Engine assembly secrets/tips

[Samiam1017]

I'm starting to assemble my engine tomorrow from my factory shortblock. Install heads and so forth. I've been reading the FSM and it seems like you need to start in the back and work your way forward. Lol. Does anybody have and tips or secrets to help out. Any tips on torqueing the cam gears on with out the factory tool? Or info like. Install this before that. Seems stupid but there's accually a ton of stuff that gets put onto these motors. Thx for your help

[Ironhydroxide]

I'm starting to assemble my engine tomorrow from my factory shortblock. Install heads and so forth. I've been reading the FSM and it seems like you need to start in the back and work your way forward. Lol. Does anybody have and tips or secrets to help out. Any tips on torqueing the cam gears on with out the factory tool? Or info like. Install this before that. Seems stupid but there's accually a ton of stuff that gets put onto these motors. Thx for your help

Heads, if you have the FSM, make sure to torque them to spec. COMPLETE with the 2x 180deg Reversing of the bolts. A lot of people think thats a typo, it's not.

cam caps. make sure they are in propper order, on the propper cam, on the propper head. there's stampings on them denoting which cam (intake or exhaust, I or E) then which Cylinder they are on. (furthest forward is 1, then counting back, through to 4). then the head stamping code. a 2 letter code aa-zz that MUST match the head (or be custom ground to match the head and cam)

so, for cyl3 the passenger rear cylinder, you have a code as such, I3RT --> where the arrow points to the cam gear. meaning this cap is for the intake cam on the 3rd cylinder position, with head stamping "RT"

Head stamping can be found on the upper corner away from the cam gear iirc. near the valve cover seal surface.

[Ironhydroxide]

oh, and MAKE SURE YOU DO NOT HAVE THE ENGINE AT TDC, but at mid stroke. this is CRITICAL to not bend a valve.

[Samiam1017]

Thx ironhyroxide. I'm actually using ARP they have there own specs. I guess my other question should be what different sensors or other parts might not work. I started with a 05 ej20 and am building it into a 06 ej257. I'm using d25 avcs heads. Are the crank sensors the same? Any other problems I might run into?

[Ironhydroxide]

Thx ironhyroxide. I'm actually using ARP they have there own specs. I guess my other question should be what different sensors or other parts might not work. I started with a 05 ej20 and am building it into a 06 ej257. I'm using d25 avcs heads. Are the crank sensors the same? Any other problems I might run into?

sensors have to match the engine control. so, if you're using EJ205 engine control, you have to plug the AVCS and run 205 cable intake manifold..... you can do the 04sti stuff and go with AVCS control and electronic throttle if you'd like....

it all has to match the ECU though. .


ARP i'd use the factory spec as well.... but probably go to 90FT/lb instead. stepping up from the 52 spec.

[BrandonDrums]

Thx ironhyroxide. I'm actually using ARP they have there own specs. I guess my other question should be what different sensors or other parts might not work. I started with a 05 ej20 and am building it into a 06 ej257. I'm using d25 avcs heads. Are the crank sensors the same? Any other problems I might run into?

This is actually my build almost exactly. I'm using a D25 head'd Ej257 from an 05 Legacy GT although that's the same engine and heads as an 06 sti.

Here's what you'll need assuming you're using the 05 WRX harness and ECU

Plug the AVCS cams OR use your 2.0L cams. Many argue the 2.0L cams are better for non AVCS setups but it's give and take. The 2.0L camss will give you better spool and low end torque but will sacrifice some top-end performance vs. the 2.5l cams. AVCS is only active down low in the RPM range so the 2.5l cam profile is designed for better high-end performance and the AVCS comes into play to beef up the low end response. Without AVCS, the 2.0L cams will do better but I run the 2.5L for a wider power band overall.
http://forums.nasioc.com/forums/showthread.php?t=1356918&highlight=AVCS

Leave the AVCS solenoids unplugged (there's no AVCS connection on the 05 wrx harness anyway) but you'll still need to run the oil feed to the AVCS actuator port on the top front side of the head.

You'll need to fabricate two block-off plates to plug te D25 cam position sensor holes UNLESS you have the original cam position sensors for the STI engine which you can just leave them in the heads uplugged. I'll add a picture of my fabbed up sensor block off plates later tonight. They look kinda like this but with only one hole since there's only one screw. If you use plates, you'll need to put some permatex on the plates to seal off the hole.
http://www.kstech.biz/media/00/a20791a124d10979d0612_m.jpg

You'll need a Cam position sensor adapter. There are a few manufacturers, I think Cosworth is the most available. It looks like this:
http://blog.lightningmotorsports.com.php5-1.ord1-1.websitetestlink.com/wp-content/uploads/TS-SU-203-620x413.jpg

I'd reccommend using the 2.0L solid metal intake cam gears. They don't have the avcs gizmos in them so they are lighter and less complicated (and won't ever leak oil since the AVCS stuff isn't there). On top of that, the wrx cam sensor will line up perfectly with the sensor dowel in the 2.0L cam. If you use the AVCS gears you'll need to space the sensor out a few mm with a little washer which makes the sensor a little wobbly for my liking.

That's it!

AVCS is awesome but it isn't worth the work needed to swap IMO. However, for an 818 build I might recommend it since you already have the harness and ECU out. There will jsut be a few other sensors and things you'll need to source on top to make full use of the sti ECu with 2.0L donor parts.

Have fun!

[Samiam1017]

Thx Brandon. I'm trying to work a deal for a hydra ecu. Which I would be able to control the avcs with. I remember a while back you mentioned the Jdm ecu and I really don't feel comfortable finding a tuner around that might be able to tune it for me. I may plan on running the wrx cams if I can't swing the deal for the hydra. I put the heads on today and I only have the drivers valve cover and I need to get the avcs oil feed line also. So I'm on hold with the assembly for a bit.

[rjh2pd]

I have a FSM for a 2.5L NA Legacy, so it should be the same for the Impreza. If anyone would like it PM me and ill send it to you. Btw im doing my headgasket this week so if i find anything ill let you know.