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Old 04-15-2002, 01:35 PM   #1
Chuck
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Default piston/rod/crank help for my frankenstein

Fisrt off... will these parts fit together?

Phase II 2.5 block
'91 Turbo Legacy Crank
'91 Turbo Legacy Rods
Paeco pistons

And if so...

I know the stroke for the Legacy Turbo is a bit shorter than the 2.5... can that slack be compensated by some custom piston work? Otherwise the compression ratio will be way too low. I want the CR to be at about 9.0:1.

Thanks!
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Old 04-15-2002, 04:07 PM   #2
Really_Soaked
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I did some measurements on a 2.2L Legacy block the other day. It's 97mm like my EJ25. The extra displacement seems to come from the stroke. The 2.5L crank would definitely not clear the 2.2 block. Now, you're going the other way, it would probably clear, but would yield a compression ratio way too low for what you're looking for.

Why not stick with the EJ25 crank with lower-compression, lighter weight pistons? 9:1 should be easily feasible.

(And while you've got it open, dig up a set of corillo rods )
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Old 04-15-2002, 04:25 PM   #3
Happy
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RS,

I think you'll find that the EJ25 is closer to 100mm bore. I also think that you'll find, that with a bit of work, the EJ25 crank will fit the EJ20/22. Most of stroker stroker kits use the EJ25 crank, with some using an even longer stroke crank.

Chuck,

If you've got a VERY GOOD engine builder, the phase 1 EJ20 crank can be made to fit into the phase 2 block, but it's not ideal. I would go for either a phase 2 EJ20, or EJ25 crank.

I agree with RS about junking the rods too. Any good piston manufacturer will be able to make a set of suitable custom pistons. Or speak to Trey Cobb.

Happy.
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Old 04-15-2002, 11:14 PM   #4
Scoobie Steve
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I am wondering why you want to use T Legacy crank and rods? They are NOT forged like some want to believe. The cranks main bearings are different sizes on Phase II, but the block can be machined. Why bother doing extra machine work when its really not nessasary. I think the 2.5l crank will spin no problem in 2.2l block. I will try it and get back to you
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Old 04-16-2002, 01:01 AM   #5
XT6Wagon
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I'd use the EJ-25 crank, custom EJ-25 rods, and pistons.

The EJ-25 bottom end will spin to 8,500 easy, while the top end will definitly need some work to reach that.

I'd only use the EJ-20 crank for a 10K rpm motor.
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Old 04-16-2002, 01:44 AM   #6
inpreza kid
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if you want to go all out, why not get a set of sti heads too. built up low compression ej25 bottom end with sti ej20 heads. can spin 8000-9000rpm.
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Old 04-16-2002, 09:51 AM   #7
Chuck
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OK... I guess I was under the same misinformation about the parts being forged.

I was already planning on new pistons, but the cost of rods is a bit astonomical, from what I've found. If it comes to paying about $100 each, that would be do-able. But $570 each.... there's just no way.

Can anyone recommend some decent rods in the $100 range?
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Old 04-16-2002, 10:00 AM   #8
Really_Soaked
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Mine were around $750 for the set of Carrillo rods.
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Old 04-16-2002, 10:19 AM   #9
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Chuck - $570 each? Most places have them for about $200-$250 each... even if you custom make them, I believe.

Really_Soaked - Where did you get Carrillo rods for $750? Best I've seen is a dealer account for just over $900 for the set.
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Old 04-16-2002, 10:42 AM   #10
Really_Soaked
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Well, I'm converting back from CDN prices. I got them some time ago and the exchange rate might have been different. Though I'm sure they were less than 900.

I got them locally through a performance engineering shop. They seem to have a relationship with Carrillo where they do some of their testing. If anyone is looking for rods I'm sure I could have them price them out again.
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Old 04-16-2002, 11:35 AM   #11
Chuck
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Heh... Yeah, Paeco's Titanium rods go for $570 each. That number just stuck in my head.

Since you guys seem to have done all of this already, I've got another question. Are there any bolts in the engine that require less than 25 ft/lbs of torque? I'm hoping I won't have to go out and buy another torque wrench.

Thanks!
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Old 04-16-2002, 12:03 PM   #12
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Actually, in the head torqueing procedure, I think there is a section where you tighten the outer bolts to 12 ft.lbs. and the inner to 22 (25?). Other then that, anything that is looser then that can probably be hand-tightened with good judgement.
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Old 04-16-2002, 04:38 PM   #13
XT6Wagon
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Uhh, you NEED a torque wrench that is good down to 8 ft-lbs or so if you plan on ever working on a AL motor. I've even encountered places where you need to only run 10ft-lbs instead of the reccomended 12ft-lbs because the AL gets a little weak over the heat cycles, and the spec was written on a fresh motor.
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Old 04-16-2002, 04:45 PM   #14
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Hmmm... that's what I figured, I was just hoping. Off to ebay I go.

Thanks!
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Old 04-16-2002, 05:02 PM   #15
8Complex

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If you can wait a week or two, try www.harborfreight.com - they usually have real cheap tools that work pretty well. I haven't had any problems with my 1/2" torque wrench just yet.

XT6Wagon - I'm going to kick myself for asking, but... AL?
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Old 04-16-2002, 05:21 PM   #16
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8- AL= Aluminum.

XT6 Wagon knows his periodic table.
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Old 04-16-2002, 05:43 PM   #17
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Doh! I knew I'd kick myself for asking.
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