I am preparing to install a set of CP pistons in my EJ257. I have a few questions for the people that have been there before me:

1) Is there a specific sequence in which to loosen / tighten the camshaft retaining "caps" in the head to prevent warpage? I would think inside-out slowly, but I'd like to know for sure. When reinstalling the camshafts, must the head be torqued onto the block?

2) I'd love to have a service manual, anyone have a p.n.? I have the WRX manual, but not the USDM STi.

3) When facing the engine, which way does it rotate when running? (I know I could figure this out by watching the valves, but I'm not at home, and I'd like to get it sorted out) :lol:

4) Make absolutely certain the I keep the cams matched to the appropriate buckets, correct? They are shimless, right?

5) I have a set of v7 STi valvesprings/retainers. Can anyone tell me whether or not these springs would be any better than the EJ257 springs? I imagine due to the difference in duration, the v7 would have a little more seat pressure, but I have no idea what the EJ257 springs specs are. I'm not planning on revving past 72-7400, anyway, so it probably doesn't matter.

Thanks for the time!

Steve

I have a service manual for the 04 STi engine that I would sell you for $20. I got two of them.

I have a service manual for the 04 STi engine that I would sell you for $20. I got two of them.

CD or paper? I'll buy it, PM me with details. It's not just the engine, but the entire manual, correct?

Is it necessary to remove the cams to remove the heads?

Is it necessary to remove the cams to remove the heads?


Yepper. You can't access the head bolts, otherwise. Wish you could; it would save time...but on the other hand, you can't have too many head bolts. ;)

Bummer about the cams being in the way. Are you just going to slap the new pinstons in? Are you using new rings? If yes, do you feel it's necessary to rehone the bore? I think that this will be something that many of the people here are going to be doing. I for one I'm hoping that it will not be a necessary thing for me to do with my modest goals but with my luck being the way it is it does not hurt to have a how to for something like this. Take some pictures and do a write-up. The community will certainly appreciate it.

Are you just going to slap the new pinstons in? Are you using new rings? If yes, do you feel it's necessary to rehone the bore? Take some pictures and do a write-up. The community will certainly appreciate it.

I never "slap" anything together :lol: I'm using new rings. I'll mic the cylinder walls to make sure I have .0035" clearance (tough with the rods in the way, but it can be done), if I have more than I think is safe, I'll be totally disassembling it, and sending it out for the "big" treatment. I'm in no rush; it's a winter project.

I'll do a write-up and pics if someone can host them.

Man this scares me, I hope you have some prior experience?

"1) Is there a specific sequence in which to loosen / tighten the camshaft retaining "caps" in the head to prevent warpage?"

Yes, evenly as to not wedge the cam on the head. Please be careful because you could do some major damage here!

"When reinstalling the camshafts, must the head be torqued onto the block?"

It would be kind of hard to torque the bolts after since they are under the cams.

"3)When facing the engine, which way does it rotate when running? (I know I could figure this out by watching the valves, but I'm not at home, and I'd like to get it sorted out)"

clockwise

"4) Make absolutely certain the I keep the cams matched to the appropriate buckets, correct? They are shimless, right?"

Yes they are shimless, Just use a sharpie to number the buckets as the exhaust ones will want to fall out.

As for your last question you would have to measure the springs force to see if they are different. IMHO they will be since the V7 revs higher. If your not sure dont use them the conciquences of coil bind can be devistating!

BB

Bummer about the cams being in the way. Are you just going to slap the new pinstons in? Are you using new rings? If yes, do you feel it's necessary to rehone the bore? I think that this will be something that many of the people here are going to be doing. I for one I'm hoping that it will not be a necessary thing for me to do with my modest goals but with my luck being the way it is it does not hurt to have a how to for something like this. Take some pictures and do a write-up. The community will certainly appreciate it.


:rolleyes:

Its Nickasil

n2xlr8n:


Since you are going to be there have you concidered replacing the cams to the v7 or v8? You can move that power up above the 5500.

Man this scares me, I hope you have some prior experience?

BB

Yes, I have roughly 25 years experience building engines, just not EJs or DOHC heads.


....and the reason I asked about torqueing the cam caps down without the head on the block is....the person doing your headwork doesn't have your block, but he may have a deckplate. What does one do? Do you wait until you have the heads torqued down before you install the valvetrain?

Thanks for answering my questions, I think. :lol:

n2xlr8n:


Since you are going to be there have you concidered replacing the cams to the v7 or v8? You can move that power up above the 5500.

No, I'm not concerned about rpm.

Do you know for sure that v7/v8 cams will go?

I'm not convinced that the engine will not breathe above 5500 with the stock 257 cams.

:rolleyes:

Its Nickasil


To quote my Chief Physicist: "How sure are you?" Are you repeating something Ron @ Axis told you? ;)

Yes, I have roughly 25 years experience building engines, just not EJs or DOHC heads.


....and the reason I asked about torqueing the cam caps down without the head on the block is....the person doing your headwork doesn't have your block, but he may have a deckplate. What does one do? Do you wait until you have the heads torqued down before you install the valvetrain?

Thanks for answering my questions, I think. :lol:


Good deal you should be fine just RTFM (love that TXS quote) Lots of Newbies here just trying to make sure you are safe.

I tighten the cam caps down with one cam in place all the time when I bench shim heads, no biggie. That way they are ready to put on the block and things are much easier.

No, I'm not concerned about rpm.

Do you know for sure that v7/v8 cams will go?

I'm not convinced that the engine will not breathe above 5500 with the stock 257 cams.

Yes the cams will work, others like Jun or HKS will work but not the AVSC.

It is a pritty well known fact that the cams on the USDM STI are killing it above 5500 due to the lack of duration.

Do a search in the 2.0 forum for the cam specs thread, its all in there.

BB

:rolleyes:

Its Nickasil

When you don't know you have to ask. In any case this type of thing is probably beyond my shade tree skills. It's still interesting to see/know the how-tos. I personally would probably not do this but it's cool to take a peek over the shoulder of soneone who knows.

n2xlr8n I can host the pics for you. Try to keep them on the non gigantic side (<50 K each). I'll put them up and send you the pointers so you can put together the write up.

To quote my Chief Physicist: "How sure are you?" Are you repeating something Ron @ Axis told you? ;)


:lol: Good point, I do not know for sure the exact compisition of the plating but Japanese man. have been using Nikasil plating for years.

and no Ron didnt tell me :huh:

When you don't know you have to ask. In any case this type of thing is probably beyond my shade tree skills. It's still interesting to see/know the how-tos. I personally would probably not do this but it's cool to take a peek over the shoulder of soneone who knows.



I guess I didnt see it as a question. I was not trying to make it as a dig sorry.

Do a search on google for nikasil plating to learn more.

BB

Yes the cams will work, others like Jun or HKS will work but not the AVSC.

It is a pritty well known fact that the cams on the USDM STI are killing it above 5500 due to the lack of duration.

Do a search in the 2.0 forum for the cam specs thread, its all in there.

BB

When i had my V7 swapped wrx i was talking to Ron about some custom grind cams, i was going to get 264's that were set-up for AVCS but they were "a month away" This was about 2 months ago.. I would give him a holler, as that would be a pretty cool set-up.

It is a pritty well known fact that the cams on the USDM STI are killing it above 5500 due to the lack of duration.

Do a search in the 2.0 forum for the cam specs thread, its all in there.

BB

It is? Where's the data? Just because pk power tapers as you approach 7000 rpms doesn't mean the cams are "killing" top end. I agree that the v8 cams' duration with the EJ257's lift would have been better, perhaps, but I believe I can make do without spending exorbitant $$$ on camshafts. ;)

:lol: I've read it, thanks.

When i had my V7 swapped wrx i was talking to Ron about some custom grind cams, i was going to get 264's that were set-up for AVCS but they were "a month away" This was about 2 months ago.. I would give him a holler, as that would be a pretty cool set-up.

Custom grind? from who? are they machined from blanks or the fatal regrinds?

Custom grind? from who? are they machined from blanks or the fatal regrinds?

From fresh billets..

From fresh billets..

You mean from fresh castings, doncha? AFAIK, the v7/v8 are cast, and the 257s are tubular. ;)

steve. I have all the info you need in PDF's. Just email me at the shop and I will hit ya back with them. We do cam/head swaps/ engine builds day in and day out. Clark@kingpinperformance.com

Cya

Clark

AVCS compatible cams are still in the works. It's really tough to come up with cams that will be an upgrade and still function properly with the avcs.

n2xlr8n- do not use the vers7 springs in the us sti heads. they are different length and different spring rate. You will not have enough seat tension on them to work correctly. If you need springs, let me know. I usually have them in stock. As for the cam caps, start in the back of the cam and work your way forward. And make sure you replace the front 2 bolts. They are the gold ones. Those are stretch bolts that should only be used once. Also, don't forget to use sealant on the front cam caps. They will leak if you don't.

Ron

Actually V7 or V8 cams will not work on Sti I do not believe. I do not think they have the pickup for the cam angle sensor. Am I wrong here? As for the procedure for the heads, it's not too bad. I always install new cam holder bolts on the end by the cam gear as boogerwrx mentioned. They are a bit small (smaller than the other 4) and tend to snap once you torque them down more than once. If you do, you'll leak oil past the cam seal. Make sure you torque them down half the spec of the other larger bolts. I use oonly Hondabond or Subaru bonding agent for the sealant. THe off the shelf stuff is crap.

Actually V7 or V8 cams will not work on Sti I do not believe. I do not think they have the pickup for the cam angle sensor. Am I wrong here? As for the procedure for the heads, it's not too bad. I always install new cam holder bolts on the end by the cam gear as boogerwrx mentioned. They are a bit small (smaller than the other 4) and tend to snap once you torque them down more than once. If you do, you'll leak oil past the cam seal. Make sure you torque them down half the spec of the other larger bolts. I use oonly Hondabond or Subaru bonding agent for the sealant. THe off the shelf stuff is crap.

Correct on the Cams. The STI Cams have insets, not pegs for the AVCS to pickup, and they are not in the exact same location. So no V7/V8 Cams in the US STI heads, and no STI Cams in the V7 heads. (that kinda sucks, since they are easy to get, and the first V7 STI cams sucks).

As well of course, the STI Heads are the small port heads. Another post I made had the measurements of the intake and exhaust ports for STI, WRX, and Spec C. Clark also has some great pictures of them.

As for the Fujibond, You are building a 2000$+ motor. why not spend the $23 to get the goof fujibond stuff. That's what we use!
Jeff Sponaugle

Thanks Clark, Ron, God and Jeff for the input.

Interestingly, Ron: I measured the seat pressure on the v7 springs based on the USDM STi camshaft; it is within 3 lbs (negligable). So if the spring doesn't bind, why wouldn't you use the v7 springs? (Besides the fact that you are increasing pressure @ lift ~30%?, and the cams are "done" waaay before that point in the rev range).

Thanks Clark, Ron, God and Jeff for the input.

Interestingly: I measured the seat pressure on the v7 springs based on the USDM STi camshaft; it is within 3 lbs (negligable). The pressure at max lift is 20% greater than that of the USDM STi......... So if the spring doesn't bind, why wouldn't you use the v7 springs? (Besides the fact that the cams are "done" waaay before that point in the rev range).

Bump for an answer...... :confused:

Bump for an answer...... :confused:


Okay.... :confused: I'll get back to you on this one. ;)

Boy, have we come a long way, or what? :lol:

Built engine forum?

S.

Haha I think a mod searched for all your threads and moved them.