stroked ej

[RSTID]

So ive just recently blown apart my ej25 and am wondering if anybody knows if i put my 2.5 crank and rods into a closed deck 2.0 block running 2.0 forged pistons, will it be stroked or will it just still be a 2.0????

[funkytown]

yup this is exactly what im currently doing.

dpending on phase one or two crank changes which combo you use but the result is 2.133L.

for best results a factory geometry rod should be used with a custom (but no more $$) piston. you can reuse normal 2.0 pistons

[Markmcrs]

It will be a lot of mucking around....

Can't use regular 2 litre pistons - need custom ones with offset gudgeon pin.

Closed deck block is centre thrust and 52mm journal - have to assume you have a phase 2 2.5 crank (like EJ257) which is rear thrust.

So will need to either machine block or crank to get thrust to line up.

Lot of stuffing around for such little (read fuk all) gain.

You would be TEN TIMES better off getting a 2.2 block and buying some pistons to suit that = 2.35litre with the 2.5 crank.

Can even get away with stock Subaru rods.

Same cost and 200cc more capacity.

I've built several of them, here a pic gallery of one;

http://s29.photobucket.com/albums/c279/markmcrs/EJ%20235%20Budget%20Build/

[funkytown]

I've had my closed deck set up for a rear thrust crank. Its not hard to get done, just a $$ thing.

You can also opt for a phase 1 crank with 48mm journals. From my research this option is actually easier given the amount of parts available form the US for this combination (longer rod).

Back the phase 2 crank, you use a standard EJ25 or Ej20 rod.. they are 130.5mm center to center commonly available. The piston you need to suit is a 92 / 92.5mm bore piston that is expecting a 79mm stroke.. Quite a few people stock these including Mahle, Manley, Wossner and JE.

Here is the Mahle piston # - SUB193642P16 that i will be using. I'll be ordering a set of Argo i-beam rods direct from Argo in Auz. EJ25 crank will be order of the day, ARP case and head studs holding it together, factory bearings. 600hp build to hold 500 daily hp.

Its then easy to set up for good gains. I disagree that the gains are stuff all.. Although the increase in CC is low, the change in geometry is quite large and the thrust better so will spool turbos much better, as referenced from other builds around the world.

You are going to sacrifice a little top end RPM as a negative, the overal bearing speed will be increased by about 10% and slightly more side loading on the pistons.

I do agree a 96.5mm based bore would make an better engine from an engineering POV. however.. the cost to make it as strong as your EJ20 closed deck is epic in comparison im sorry.. A stroked ej22 based deck to 2.35 runs into the same engineering problems as a stroked ej20. imo.

A destroked 2.5 is a much better way of doing a 2.35.

The beauty of the 2.1 stroker (imo) is the use of the standard CDB, rods and crank. all freely available off the shelf. As are pistons if you know where to look. Setting up the 2.2 stroker to Closed deck spec is very expensive although the benefits more. The increase in performance in a 2.1 is more than justified if you are cost conscious and hunt around.

everyones milage will vary though. I got a CDB for nothing, and a crank from Strongs in AKL for very cheap. I've hunted for well priced pistons and rods and getting a deal on those. If you didnt care about $$$ it would cost you double easily. I just beleive cost conscious or not the other options mentioned would all cost lots more than either a factory ej20 rebuild, or the 2.1 stroker

[Markmcrs]

There are several points to be made here.

Firstly, for your AVERAGE JOE, 500-600HP is beyond their aims.

Chasing that amount of power costs exponentially more than a more reasonable target of 400hp.

A 500+HP 2.137 = the result of 2 litre bore and 2.5 crank will be an absolute pig to drive and will require a stupid amount of $$$ to get there.

So looking at a more sensible and realistic build - say 400hp, how does a CD 2.1 compare to a EJ22 OD build?

CD2.1;

CD block, Pistons, rods, crank, thrust conversion.

OD2.2

OD block, pistons...that's it!

Result...

The 2.2 is cheaper to assemble, has more cc's and will make more power = epic win.

In my sig, at the drags in my RS, that is the setup I had - a bog stock EJ22 out of a N/A car with forged pistons, nothing else.

Garrett GT3071 @ 25 psi making pretty much bang on 400hp - STOCK SUBARU RODS.

If i was to take it a step up from there ( have already done it), there is 2 ways to increase the block strength of the EJ22.

1) ghetto JB Weld CD - I have done one of these for a mate.

Wiseco pistons, Manley rods.

He's currently making in the region of 280kw's ATW's - TD06 Variant, 25 psi and E85.

Time will tell how much abuse the engine can take.

2) CNC closed decking - I can get an EJ 22 CNC closed decked for about $650 AUS

this would make it good for 450-500hp easily.

I would look to do a 2.35 over a 2.2 if I went down this path - I am actually about to do this very thing - block is ready to be sent of to have the CNC'ing done.

If I was to chase 600HP, I would be doing it with a Sleeved CD block and 99.5mm pistons (2.5 spec). You would achieve the power target much easier and you could actually drive the car on the street with some degree of enjoyment - ie a reasonable boost threshold.

As the old saying goes; "there's no replacement for displacement".

I have already build a 600hp capable EJ bottom end, it has all the good/necessary things like sleeved CD block, ARP case studs, oil phase mod on crank and 12mm head studs etc, etc;

http://s29.photobucket.com/albums/c279/markmcrs/EJ%20235%20Forged%20build/

I would not want to put ARP head studs in if the aim was 600HP, I have personally known them to not be up to it.

As it is, the 2.2 JB block I built (sub 500HP) uses the better and more expensive ARP custom age head studs.

[funkytown]

Why is a 500-600hp build beyond their aims? From the information given by OP you have purely made that assumpion up..? I only assume one goes done the path of strokers and oddball stuff when aiming to make big(ger) hp and would expect to start spending some cash as a prereq... my point was to show the cash required on a higher hp ej20 re/build was ~ to a similar high hp ej21 build. Who says a 2.0 or a 2.1 is piggish to drive. I thoroughly disagree on the former through personal experience. If anything the 2.1 is set out to make the car more drivable? As the 2.0 is very drivable at ~500hp its only win..

I've driven 3 ~500hp and they are all easily as good as stock output, easily as much down low and up heaps heaps more up top. gt3071r @25psi just under 500hp, gtx3076 @ 25psi over 500hp, on ej20s for reference, the 3rd was an ej25. Everyones experience is different but the third 500hp car had AVCS, gt3582 @19psi.. and its horribly linear and lacks punch up top, it felt lazy and wont rev.. just from my own real seat o meter experience.

My current open deck motor that just popped has shown signs of the bores going walkies. as would be expected with Open Decks at raised HP. In the pursuit of longevity (and understanding race driven kms is exponentially higher wear that road kms) even 400hp it will be a matter of when not if a open deck will walk.

your 400hp @25psi on a gt3071 doesn't add up to me given my own personal results - are you talking whp or fwhp?

Im not discrediting other types of stroker, or ways of increasing cc's over ej20 but trying to show an ej21 isnt actually any more expensive than your average ej20 rebuild for a given power level. In most cases poeple might just reuse their open deck ej20h/k further saving themselves ej22 cases $$ if your point is about saving cash??

The other ej22 /25 options you've stared diverge from the point you're trying to make i think, as you reuse less and less factory bits (lets assume the OP is ej20 to begin with given they are asking about and ej20 based stroker) which is going to cost you $$ to sourse, where as is with the 2.1 build, as you have most of the bits already required Open deck included, why try and get 2.5pistons and cases and potentially having to swap to a longer rod... (and if an "AVERAGE JOE 500-600hp" isnt required?). Theres a trade off that i tried to point out above in p1 crank = longer rod, p2 crank = standard rod.

Out of interest what are your thoughts on the different rod ratios and engine charactoristics between the destroked 2.5 (2.35) and stoked ej22 (2.35)?

Also out of interest what are the thermal expansion properties of that ghetto JB weld in relation the alloy open deck?

 Markmcrs said:

It will be a lot of mucking around....

Can't use regular 2 litre pistons - need custom ones with offset gudgeon pin.

really i was diagreeing with this - showing OP the off the shelf pistons available and correct P/N and correct rods that need to be used. no bothering around - problem solved? and the gains are equated to being very good by others experience (this i take as written, i have no personal xp, only a lot of overseas commentary).

There are many ways to skin a cat, its all interesting stuff right

[rex-leggy]

center to rear thrust conversion on my 2.2 block was only $150, amongst the rest i had done that peanuts. also a 2.2 engine is cheep.

but i must say i love my 2.35 8)

only thing i did wrong was used h beam rods rather then i beam.

im with markmcrs if your going to do a stroker go for a bit more displacement for some more power

[RSTID]

thanks to all for ur help, i think im going to go with a ej257 CDB, ive been to the 400hp bracket on a 2.0 so next step for me will be the 257, was just wondering if it is possible to mix and match ej blocks without going all out.

Why are these engines so demanding to get decent hp out of haha

Thanks again.

[RSTID]

on that note, if i run with my ej257, can i lower the compression threw low comp forged pistons or do i still havto mill the heads out? my heads are V4 sti solid lifter??

I have been told that if i dont mill the heads then the ccompression will be too high and ill be unable to get decent boost out of it?

[rex-leggy]

i would be looking to get the heads milled as there's a 7.5 mm difference between 2.5 piston vs 2.0 cylinder head

from what i read/heard its not a good thing. (hot spots/decrease in available timing)

gotasuby had his heads worked so that there was no overlap. give him a pm to get specs of what he did

[RSTID]

sweet cheers man.

[rex-leggy]

no worrys dude

[Markmcrs]

 rex-leggy said:

I would be looking to get the heads milled as there's a 7.5 mm difference between 2.5 piston vs 2.0 cylinder head

from what i read/heard its not a good thing. (hot spots/decrease in available timing)

gotasuby had his heads worked so that there was no overlap. give him a pm to get specs of what he did

To me milling heads is skimming the deck/face to get it true.

I think you are talking about opening up the chambers to accommodate the larger bore.

That is to a large extent not worried about in Aus - yes the bore is 7.5mm bigger in diameter but that is only an increase of 3.75 mm at the edge = stuff all IMO.

I have only recently finished putting V4 WRX heads on a stock EJ257 bottom end - has been done stacks of times that I know of personally and no problems have come of this.

If your worried about compression, simply run the thickest head gaskets you can get = 1.6mm.

Up until a few years ago, the logic was to run lowish compression on built EJ's - now we have 70-85% ethanol fuels that are reasonably easy to buy the new hotness is BULK compression.

My next big budget 2.5 on the go at the moment will be running 9.5:1 CP's and I'm slightly erring on the side of caution as there is 10:1 pistons available.

I'll be going for the thinnest head gasket I can get away with also to help boost compression.

I take it you guys only have 98 to play with?

[Kiwi_Fozze]

98 is the easiest to get, as far as i'm aware e85 is only available so far in hamilton, and a 10% blend available from gull and some mobil stations below taupo

[Markmcrs]

 funkytown']

Why is a 500-600hp build beyond their aims? From the information given by OP you have purely made that assumpion up..?

I was NOT talking about the OP in that comment, I was referring to the community in general (hence the "AVERAGE JOE") comment - no assumptions here.

Why is it beyond most people's aims?

I don't know what you guys believe to be true in NZ, but over here, 300kw's ATW's is about as far as you would want to go with the stock heads - I'm not saying you can't get more power with stock heads, but I am saying that they start to become a restriction that increases the further you push past 300.

Above that, you need porting, cams, OS valves etc etc.

You also need to seriously upgrade the fuel system for 600hp - the whole lot, injectors, rails, lines, pump etc etc.

Above 300kw's ATW's the driveline also need looked at

So you can get up to 280-300kw's ATW's for a reasonably mild outlay - chase another 200HP and you will spend a significant amount more.

Thus this is why most people settle for 250-300kw's ATW's MAX

I only assume one goes done the path of strokers and oddball stuff when aiming to make big(ger) hp and would expect to start spending some cash as a prereq

And that would be your assumption. Funnily enough, to me, the 2.1 is by far the MOST oddball choice to make when spending $$$ for power.

There are circumstances when a 2.35 is a better option than a 2.5, hence why some people "go down that path" - but that is a whole other can of worms...

A few years ago, three of the biggest Subaru Specialist tuners/engine builders in Aus ALL had 2.35's in their personal cars', all making north of 300kw's ATW's

2.5's had been around for a while by then and all 3 shops had built many of them into big HP combo's yet they chose to go for a 2.35 for themselves...

... my point was to show the cash required on a higher hp ej20 re/build was ~ to a similar high hp ej21 build. Who says a 2.0 or a 2.1 is piggish to drive. I thoroughly disagree on the former through personal experience. If anything the 2.1 is set out to make the car more drivable? As the 2.0 is very drivable at ~500hp its only win..

That is how YOU feel and there is nothing wrong about that. But it's a case of perspective.

I had a modified VF22 (garrett Gt 30 comp wheel) on a V4 STi bottom end - freaking loved it. However it didn't see full boost till 4000+RPM's.

It was my race car so the lag didn't bother me one bit and the fact that I had a 7800RPM redline helped too.

You hand the car to someone with a stock MY 00 WRX with a TD04 to drive around town in and they'd whinge and whinge that it was a laggy POS.

My point, a 500hp 2.1 may "seem driveable" in the hands of some, but once compared to a 500HP 2.5 the difference would be noticeable instantly.

A 2.5 will spool quicker and it will have much more max torque as well as "area under the curve" and as a result would be the quicker of the 2 all else being the same.

your 400hp @25psi on a gt3071 doesn't add up to me given my own personal results - are you talking whp or fwhp?

Actually yes, my maths was off on that one.

I made 235kw's @ 19.5 psi on a dyno which was just over 400 flywheel horsepower.

I ran 24 psi at the drags for nearly 121MPH and it was determined that the car showed 260-270kw's ATW's = 440 flywheel horsepower - which is what my turbo was rated too.

So really, even more kudos for the ol budget 2.2.

[quote name='funkytown said:

I'm not discrediting other types of stroker, or ways of increasing cc's over ej20 but trying to show an ej21 isnt actually any more expensive than your average ej20 rebuild for a given power level. In most cases poeple might just reuse their open deck ej20h/k further saving themselves ej22 cases $$ if your point is about saving cash??

I pick up EJ22 bottom ends for between $50 and $150 - 90% of the time the crank and rods are good to go - $550 for the pistons and $150 for the bearings and I have all the bits I need for 400+ HP 2.2 for under $1K.

I'll leave it at that for now.

We each believe fairly strongly in our own choices.

You have some good points and I think I have some too.

If this helps someone make up their mind one way or another then hopefully that is a good thing.

[pedro]

Excellent information guys...best thread of the year.

[lachlan]

 rex-leggy said:

center to rear thrust conversion on my 2.2 block was only $150, amongst the rest i had done that peanuts. also a 2.2 engine is cheep.

but i must say i love my 2.35 8)

only thing i did wrong was used h beam rods rather then i beam.

im with markmcrs if your going to do a stroker go for a bit more displacement for some more power

why do you say this about rods ?

[rex-leggy]

 lachlan']

[quote name='rex-leggy said:

center to rear thrust conversion on my 2.2 block was only $150, amongst the rest i had done that peanuts. also a 2.2 engine is cheep.

but i must say i love my 2.35 8)

only thing i did wrong was used h beam rods rather then i beam.

im with markmcrs if your going to do a stroker go for a bit more displacement for some more power

/quote]

why do you say this about rods ?

because i had 315kw\'s

for around that id be happy with h beams but im stepping the game up, so decided to bulk things up to make it more reliable at high hp and the car will be raced not just a spirited wot onto the motorway.

eagle from what i hear are not very truthful about there ratings. and i doubt ill be braking a brian crower i beam to quick they say there good for 1200hp (touches wood)

[lachlan]

Cheers for that man . There is a lot of info (and BS ) for I vs h beam . Good to hear from someone who\'s actually Been there

[funkytown]

i would confer with Josh - eagles particulary in H beam config / their 500hp rods... are rated up to about that at peak.

also had 305wkw on eagles and were showing signs of big end stretch. Have uprated to an Argo I beam.

H beams can be equally as strong and mechanically as good - but they need to be heavier to compenstate for a given strength rating of an I beam equivalent...normally.

reciprocating weight in the bottom end is teh bad.

[Joker]

we need a I vs H beam pic please

Edit : I googled and learned what you turkeys are on about

and

whoa

[lachlan]

Top find joker . Had never seen anything as simple as that .

did is say in which plane the stiffness was tested joker ?

depends if they were trying to bend them or compress them axially

So does anyone know why h beam rods even exist ? Cheap to make / sell ?

[Eight_dollar]

Yeah and nah to the rod pics

Its a HYPOTHECTICAL stiffness based only on cross section area

You also need to consider in which direction the forces are applied to the rod inside the engine and where the strength needs to be

Forces not only as rotational whip but also shock loading fron det

I beams are stronger but they are often heavier as the centre section HAS to be much thicker than an H beam to stop it bending

(ever tried to carry a long bit of timber say 200x50, and noticed which way it bends and which it doesnt?)

[lachlan]

now for the complete opposite of the timber

also a dor that is i beam and h beam

http://www.f1technical.net/forum/viewtopic.php?f=4&t=9346&start=30

also it has big ends that are not round .

[titian]

 Eight dollar said:

Yeah and nah to the rod pics

Its a HYPOTHECTICAL stiffness based only on cross section area

You also need to consider in which direction the forces are applied to the rod inside the engine and where the strength needs to be

Forces not only as rotational whip but also shock loading fron det

I beams are stronger but they are often heavier as the centre section HAS to be much thicker than an H beam to stop it bending

(ever tried to carry a long bit of timber say 200x50, and noticed which way it bends and which it doesnt?)

aHH...

The "which way is it likely to bend" theory for even less rotational weight compromise for required/estimated power before Ka..BOOm equation. ??? :-[