EJ24 stroker questions

[Caboobaroo]

I have an EJ22T in my possession and am planning to stroke it out.

First off, I have a set of EJ20G heads and intake for this build as well. I can get a phase 1 2.5 rotating assembly for next to nothing for the build but I have a few questions and looking for some input on the build as well.

I plan on boring the block out .020 over and use the Wiseco pistons made specifically for this setup found on their website here Part number K602M975. I also plan on using ARP headstuds too.

Now a couple questions. Is there any sort of custom crank bearings I have to get or do stock bearings for the EJ22T match the EJ25(D?) crank? What headgaskets would you recommend and are there aftermarket rods for this setup?

When it comes to the heads, I've never built up Subaru heads before but I was thinking some stainless steel valves, some sort of aftermarket springs and so on. Also looking for some cams that have a 272 duration to them.

So where would one get aftermarket parts for the 'G' heads?

I'm still trying to think about a turbo setup and fuel system for it as well.

This is going into my '87 RX BTW and I want to put out at least 300whp

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[reddevil]

The "stock" ACL bearings for the phase 1 2.5 are fine and dandy. They both use the #3 main thrust bearing.

Headstuds FTL if you are not shooting for more than 400 whp... My opinion...

Head work... contact Delta Camshaft. They are now specializing in subies... They are working on a set of heads for me right now.

[Caboobaroo]

Originally Posted by reddevil

The "stock" ACL bearings for the phase 1 2.5 are fine and dandy. They both use the #3 main thrust bearing.

Headstuds FTL if you are not shooting for more than 400 whp... My opinion...

Head work... contact Delta Camshaft. They are now specializing in subies... They are working on a set of heads for me right now.

well I'd like to make more from this setup which I think I could but I've also dealt a lot with the EA82T and headbolts ftl which is why I want studs. I know the EJ22T is superior to the EA82T but overall experience in the past hasn't gone so well

[Homemade WRX]

wiseco (ugg) does make some pistons for the EJ22 bore that will allow you to use the standard 130.5mm rods...check their site.
Then you can use any standard length EJ20/22 rod (EJ25 turbo too).

[All_talk]

Originally Posted by Homemade WRX

wiseco (ugg) does make some pistons for the EJ22 bore that will allow you to use the standard 130.5mm rods...check their site.
Then you can use any standard length EJ20/22 rod (EJ25 turbo too).

True, but the "standard" 130.5 rods will not fit the Phase I 2.5 crank.

The Phase I EJ25 rods are the weak link in the Wiseco EJ22T stroker formula, its not due to the smaller rod journal its more that they have the longest and thinest beam section. Unfortunately, I dont think there are any aftermarket rods for this setup.

Personally I have chosen to used the STi crank and rods and machine my block for the phase II thrust bearing. The shorter rod does pull the piston below deck by 0.75mm so a thinner head gasket will be required.

I would also caution against the using the early EJ20G heads with the large chambers as the compression ratio will be pretty low. If you are going with a big turbo and lots of boost it might make for a good top end motor but the bottom will be weaker. I’m going to use the phase I EJ25 N/A DOHC heads on my build and set my compression between 8.0 and 8.5. But I’m building a daily use street engine and power lower in the RPM range is important to me.

Just some thoughts
Gary

[reddevil]

48mm rods!

http://www.outfrontmotorsports.com/s...cting_rods.htm

[All_talk]

Originally Posted by reddevil

48mm rods!

http://www.outfrontmotorsports.com/s...cting_rods.htm

Well there ya go, good find Doug.

[graphtricks]

I am also planning the same build with the STI crank, rods and wiesco pistons. Which head gasket to use? 2.5 STI or Cometic 40 mm for the 2.2T? Also I have heard the the new STI cranks are machined for both thrusts 3 or 5 is that true?

[gold rush]

TWE has 98mm pistons for a phase 2 crank for this exact set up.

[Homemade WRX]

Originally Posted by All_talk

True, but the "standard" 130.5 rods will not fit the Phase I 2.5 crank.

oh, I assumed he was switching to the phase 2 crank...my mistake. In that case pauter has the correct rods...In that case, outback and TWE might have some items on the shelf. I still have to custom order all my parts at the moment (none on the shelf).

just be sure you have the right compression (pin) height and rod length and rod journal before ordering any parts.

[All_talk]

Originally Posted by graphtricks

I am also planning the same build with the STI crank, rods and wiesco pistons. Which head gasket to use? 2.5 STI or Cometic 40 mm for the 2.2T? Also I have heard the the new STI cranks are machined for both thrusts 3 or 5 is that true?

I am using the off the shelf Wiesco pistons which were designed for the phase 1 EJ25 131.5mm rods, so the STi 130.5mm rods will drop the piston 1mm. The normal pistion position is 0.25mm above deck so I will end up with 0.75mm below deck. The right head gasket has a lot to do with which heads you are going to run and your target CR. I'm going to use the EJ25 DOHC heads with the 46.6cc chambers and a thin gasket to hit a 8.5ish CR. With this setup the thinner gasket will also preserve a tighter squish area which is important for anti-detonation, fuel mileage and emission. The consequence of messing with the HG thickness is slight changes in the cam timing. With respect to cam timing its ideal to use the HG thickness that goes with the head, this will preserve the stock cam height from the crank. To keep everything simple and in its place its best to use a piston with the proper wrist pin location for the rod length you will be using.

I have heard that about some 2.5 cranks but the STi crank I have is not properly sized for thrust on #3. With the #5 thrust bearing I get a nice tight 0.0015" of backlash. With the #3 thrust bearing I get a super sloppy 0.015". And the thrust surface on the #3 crank journal has a rough finish that would tear up the bearing anyway.

Gary

[Kosmic]

K1 technologies make a nice 5.180" rod set. That's the one I choose for my 22T with STI crank (phase II) build. Might make your build easier quench wise, just like Wiseco spec sheet.

EDIT for link.

http://www.k1technologies.com/Rods/t...7/Default.aspx

[Kosmic]

Originally Posted by graphtricks

Also I have heard the the new STI cranks are machined for both thrusts 3 or 5 is that true?

I've heard that also but my 2006 USDM STI crank in a EJ22T block and I have 0.013" walk using the old 22T bearings. Using the original 22T crank the walk was within tolerance (~0.005"). I will messure again the crank walk with new ACL race bearings and phase II crank (USDM STI 2006) at main #3. Might need to machine the block to accept thrust bearing at #5.

[redrex2002]

i am contemplating this motor and a green or gt52 or a 207 with a 20g and there is only one guy i would talk to about these motors and that is ron at raw performance he quoted me a fully built motor for 3600 as long as i supply the block and that is quite tempting to have a bullet proof rev happy motor that can take one hell of a beating

[Caboobaroo]

So what I've gathered so far is in order to use a EJ257 crank, the block has to be machined for the thrust bearing which instead of being in the middle of the block, is at the back end of the block. Really, how hard is it for a engine machinest to do this procedure? Would it be better for myself to stick with the phase one crank and use some aftermarket rods with the aftermarket pistons?

So with my punched out EJ22T, use these rods with the Wiseco pistons #K602M975. I couldn't find anything on TWE's site about the EJ22T pistons, maybe I didn't look hard enough? Then use some ACL bearings and ARP headstuds but what headgaskets should I use? I mean, I'm planning on using the EJ20G heads from a '94 closed deck block (I think its a '94, maybe I'll have to get some numbers off of it and see what it really is but I know its a 20G). So is it a good plan so far for shooting for like 400whp or am I nuts to think this? Turbo setup might be a FP Green but I'm not sure yet.

[Homemade WRX]

the EJ257 crank can accept a thrust bearing in the #3 position too...I'd really suggest running dual thrust bearings however, if you are planning to make big power. (helps with the heavy clutch issue from wearing your bearings).

[All_talk]

The machine work to move the thrust bearing to #5 shouldn't be a big issue for any good machine shop. Its just a matter of using the right numbers. I can post the numbers I used if anybody wants to see them.

But the phase 1 crank is a good option too, for the power level you are seeking I would say aftermarket rods will be a must.

Again I caution about the early ej20G head choice, I'm not saying it wont work, many have done it, but you should be aware of the CR. Here's some food (math) for thought...

Volumes

Swept - 97.5mm bore x 79mm stroke = 589.5cc
Piston - Wiseco Stroker = 24cc
Deck - 0.25mm above = -1.87cc
Gasket - 1.3mm thick x 98mm bore = 9.83cc
Head - early EJ20G = 56cc

CR = [Swept + Compressed (others combined)] / Compressed

CR = 589.5 + 87.96 / 87.96 = 7.70:1

Unfortunately, a thinner head gasket in not a good option because the quench height will get small, 1 to 0.75mm is ideal, closer than that and things could end badly. So if you sneek the gasket down to 1mm...

Gasket Volume - 1mm x 98mm = 7.54

589.5 + 85.67 / 85.67 = 7.88:1

MIght not be bad for a higher boost set up and the 0.3mm cam height change wont have a huge affect on timing.


Just some info
Gary

Edit for 1mm gasket thickness

[johnny p]

EJ20g cambers are 46cc.

[All_talk]

Originally Posted by johnny p

EJ20g cambers are 46cc.

There are a lot of Subaru engines with the EJ20G designation and they don’t all have the same heads or chamber volumes. I believe you are right if you are referring to the later USDM WRX EJ20G, they do have the 46cc chamber. But the heads in question are the earlier JDM EJ20G heads with the hydraulic lash adjusters and 56cc chambers. In any case I would always measure the chamber volume myself.

Gary

[hustleshark206]

Wow soo much grey area with this build. I have heard many great things about this motor but there does not seem to be any easy way to do it. I have been building my EJ24 for a few months now and I have been over and over this issue with people on these forums and my machinists.

Do you go with the phase one crank with the wimpy journals and impossible to find aftermarket rods? Do you go with the beefier phase two crank and have to deal with the whole thrust bearing situation?

Well I am by no means the an expert at building motors but here is what I decided to do for this situation. I bought the phase two crank and STI rods. Realizing the thrust bearing problem I talked to many people about the best way to handle it. The machinst told me that it would be difficult and expensive to machine thrust grooves into my block so we decided to modify the crankshaft to accept a thrust bearing in the #3 position. Machine shop did it for free ninety nine.

I talked to Brydon about this and he told me that Skully has been running this same setup and it seems to be fine. Brydon checked the crankwalk on the engine and said it was out by about double spec. The machinsts told me the same thing. Both people told me that the added clearence would not have devastating effect to my motor but it could very well effect the life of the motor. Seeing as this is performance build I am not expecting it to last 200,000 miles (or even close to that) I decided to let the crank walk slightly. I also will not be using this car as a DD.

Only time will tell if this was a smart move or not.

The fact remains that somebody otta make a kit for this motor.

[reddevil]

The rods are not that hard to find, as posted in multiple post above.

As for running the crank with that excessive play.... I did it. I will not do it again. However, I was running a 550 ftlb dual diaphram pressure plate, which I am sure helped chew the hell out of the thrust bearing... But it did work, and while the bearing failed early on the face, I had no issues.

[Caboobaroo]

So Gary, is there anyway to tell exactly the year heads I have? I can get pics and whatnot but I can also look at them if they have some sort of identifying marks or casting numbers to help determine the exact heads I have.

So since I'm doing a pretty decent build and plan on driving it regularly, a phase 2 2.5 crank will be the ideal way to go. Phase 2 is 99+ correct? How would the crank be different between an NA 2.5 and a EJ257?

I want like 8.5:1 cr for this motor. I've done the 7.7:1 EA82Ts and the 9.5:1 EA82Ts and neither worked out right for me so something in the middle would be best, like the 8.5:1 range.

[All_talk]

Pics of the heads would be a start but measuring the chambers would be best. It not hard to do, you'll need a plastic plate a syringe graduated in cc’s and a thin oil like ATF. You can also by ready made cc kits.

If you are going to be near Ellensburg you could stop by my place with a head and we could sort it out.

Gary

[Caboobaroo]

I might have to get a head from my buddy's shop and bring it out there

[gold rush]

The TWE pistons gave me a CR of 8.5 with my ver. 8 JDM heads (49cc if I remember).