Ibreakstuff Posted May 4, 2013 Share Posted May 4, 2013 I have been researching forged pistons/rods for a few weeks now, just wanted to post an idea for more advice. I only found 1 post with a similar idea but nothing came from it. It should be possible to use off the shelf ej20 92mm pistons with custom connecting rods (shorter, length not yet calculated) with the EA crank pin bore size (48mm) right? I understand that the dish volume will have to match to keep the CR close but flat top off the shelf pistons should be doable. Are there any other issues that could arise from this that I have not thought about? The benefits would be a larger (offset?) wrist pin and possibly more affordable vs both custom forged rods and pistons. Please don't tell me to ej swap, I'm being serious here. Link to comment Share on other sites More sharing options...
ivans imports Posted May 4, 2013 Share Posted May 4, 2013 have tried thiss a bitt the 2.0 pistons fitt the bore on ea81 and ea82 and if you press out the wrist pin bushing the ej pin fitts the ea rods have not put a engine together yet but should work i have a 2.0 piston here and a ea piston here to compare the 2.0 turbo pistons in a ea engine whould be good upgrade Link to comment Share on other sites More sharing options...
Gloyale Posted May 4, 2013 Share Posted May 4, 2013 "stroker" rods made for putting a 2.5 crank into a 2.2 might be just the right thing. They are shorter than 2.5 rods, have the same 48mm crank pin should fit EA82 crank, and correct wristpin size for EJ pistons? Link to comment Share on other sites More sharing options...
NorthWet Posted May 4, 2013 Share Posted May 4, 2013 I have been "blue skying" on this issue before. I hadn't considered EJ25 rods. You could also take a page out of Jeszek's book and look for piston's from alternate Makes. Nissan VG33 0.50 over pistons have looked like a possibility. IIRC they have equivalent bore, same wrist-pin size as the EA82 and about the same compression height. They are also used in the supercharged versions of that engine. Domes are kind of wonky, and they are not lower compression on the supercharged engines. 1 Link to comment Share on other sites More sharing options...
Ibreakstuff Posted May 4, 2013 Author Share Posted May 4, 2013 have tried thiss a bitt the 2.0 pistons fitt the bore on ea81 and ea82 and if you press out the wrist pin bushing the ej pin fitts the ea rods have not put a engine together yet but should work i have a 2.0 piston here and a ea piston here to compare the 2.0 turbo pistons in a ea engine whould be good upgrade Interesting. Ea wrist pins are 21mm, ej's are 23mm. I never considered that an EA rod would fit an EJ wrist pin. I'll to take another look at the ea rods. Can you measure the compression height of the ea and 2.0 turbo pistons (center of wrist bore to top of piston)? This is the one measurement I have not been able to take yet. "stroker" rods made for putting a 2.5 crank into a 2.2 might be just the right thing. They are shorter than 2.5 rods, have the same 48mm crank pin should fit EA82 crank, and correct wristpin size for EJ pistons? Yep, the 48mm crank bore rods are from phase 1 ej motors. The deck height on the EA82 block is much smaller (~184.15mm) than the ej205 (201mm) so the rod might have to be even smaller. I'm waiting on more accurate mics and a new bore gauge (in the mail), when they arrive I'll measure everything out and confirm. I have been "blue skying" on this issue before. I hadn't considered EJ25 rods. You could also take a page out of Jeszek's book and look for piston's from alternate Makes. Nissan VG33 0.50 over pistons have looked like a possibility. IIRC they have equivalent bore, same wrist-pin size as the EA82 and about the same compression height. They are also used in the supercharged versions of that engine. Domes are kind of wonky, and they are not lower compression on the supercharged engines. Lol, blue skying would pretty much sum up every idea I have had for this car. Interesting idea there tho, I'll look at other makes too then. When I get everything measured out I'll start contacting all the pistons makers, they could have an off the shelf piston for another make with the right specs. I'm jumping a similar hurdle for head studs. Link to comment Share on other sites More sharing options...
Ibreakstuff Posted May 5, 2013 Author Share Posted May 5, 2013 (edited) By my redneck calculations, I need rods in the neighborhood of ~118mm 4.6457" (center to center) depending on several variables yet to be determined.. which seems very short. I guess shorter = stronger? The rod:stroke ratio would actually be ideal if close to that. dh - (ct + ch) bore: 3.622" 92mm stroke: 2.6378" 67mm deck height: ~7.25" ~184.15mm crank throw: 1.3189" 33.5mm compression height of ej20 cp piston: 1.285" 32.639mm Edited May 5, 2013 by Ibreakstuff Link to comment Share on other sites More sharing options...
WoodsWagon Posted May 5, 2013 Share Posted May 5, 2013 Skip the rods and the forged pistons and just go straight to the water/meth injection. Without detonation and high egt's the stock parts will hold up to a lot of power. ea82t's are a disposable engine anyway, so go for massive power the cheap way and if it doesn't work, then build a fancy engine. Link to comment Share on other sites More sharing options...
Ibreakstuff Posted May 5, 2013 Author Share Posted May 5, 2013 (edited) Skip the rods and the forged pistons and just go straight to the water/meth injection. Without detonation and high egt's the stock parts will hold up to a lot of power. ea82t's are a disposable engine anyway, so go for massive power the cheap way and if it doesn't work, then build a fancy engine. While I do see your point, this project is strictly for learning purposes.. So why the hell not go full tilt and have some fun with it. I have an ej255 wrx motor waiting to be built as well, but I've always wanted to build a monster ea82t. This motor will be beat on in autox/rallyx so I don't expect to get 100k out of it, but I would like to see what it is actually capable of. When I get bored with it, I'll move on and swap it. I thought all motors are disposable? This whole project came along due to a car crash and a whim.. Edited May 5, 2013 by Ibreakstuff Link to comment Share on other sites More sharing options...
NorthWet Posted May 5, 2013 Share Posted May 5, 2013 (edited) How fancy do you need your studs? I plan to get some B9 threaded rod, and cut to length. Not pretty, not ideal, but cheap and available. OOps! Typo: should have read B7 threaded rod. Edited May 5, 2013 by NorthWet Link to comment Share on other sites More sharing options...
Ibreakstuff Posted May 5, 2013 Author Share Posted May 5, 2013 How fancy do you need your studs? I plan to get some B9 threaded rod, and cut to length. Not pretty, not ideal, but cheap and available. I wanted to increase the head torque to at least 60-65 psi, with timeserts so I don't chew threads. The jury is still out, but I would love to find a common thread size/pitch arp studs in the correct lengths. The alternative is to have some paeco studs made (grade 8). What is the tensile strength of B9 threaded rod? And is it torque to yield? I'll be running a stock wrx TD04L, so I don't expect to be pushing the boost pressures beyond its efficiency. And not even close until all the supporting mods are sorted. And I am going to try a MLS head gasket first, If that doesn't hold I'll look into ringing the block and/or copper gaskets. Link to comment Share on other sites More sharing options...
Subruise Posted May 5, 2013 Share Posted May 5, 2013 where did you find a mls headgasket for a ea82t? Link to comment Share on other sites More sharing options...
Ibreakstuff Posted May 5, 2013 Author Share Posted May 5, 2013 (edited) where did you find a mls headgasket for a ea82t? "Gaskets to go" Its a company ran by an ex-pat based in Thailand. They are fairly popular in the VW scene. They make custom MLS gaskets with no min quantity or tooling fees. The alternative would just be to run felpro permatorques and cross my fingers. Edited May 5, 2013 by Ibreakstuff Link to comment Share on other sites More sharing options...
NorthWet Posted May 5, 2013 Share Posted May 5, 2013 Sorry, my earlier post had said "B9" when I meant to type "B7". ASTM A193 Grade B7 Chromium Molybendum steel, normally AISI 4140, heat treated to28-32Rockwell Hardness, 125,000 PSI tensile strength, 105, 000 PSIyield. It will hold it’s strength to 1000 degrees F. Link to comment Share on other sites More sharing options...
Ibreakstuff Posted May 5, 2013 Author Share Posted May 5, 2013 Sorry, my earlier post had said "B9" when I meant to type "B7". ASTM A193 Grade B7 Chromium Molybendum steel, normally AISI 4140, heat treated to 28-32Rockwell Hardness, 125,000 PSI tensile strength, 105, 000 PSI yield. It will hold it’s strength to 1000 degrees F. That would probably work fine, definitely better than stock bolts. I still have not crossed this road yet tho, I'll post here if I find any other solutions for studs. Paeco studs are grade 8, which is around 150k PSI tensile strength (~400$ for a set with nuts, ).. Arp is around 180k PSI, but custom 11mm studs would kill a good portion of my budget. Link to comment Share on other sites More sharing options...
NorthWet Posted May 5, 2013 Share Posted May 5, 2013 Really and truly, tensile strength is not much of an issue here. I have never heard of anyone breaking a healthy (non-corroded) headbolt/stud in a Subaru. It is far more common to pull the aluminum threads out. Since I was going to go with non-standard studding, I was not going to worry about maintaining the original thread. 7/16". 12mm. or 1/2" rod is readily available and cheap. Link to comment Share on other sites More sharing options...
rpholz Posted May 11, 2013 Share Posted May 11, 2013 I'm curious on these MLS gaskets. TimeCerts should allow you to torque headbolts to desired lbs I believe I tightened mine down to 56lbs-ish without touching a thing. Still sorting out the haltech system before any street time, I think my biggest challenge is 550cc injectors were a tad too big, but with a TD04 and AWIC I should be able to put down good numbers Will let you know the outcome. Link to comment Share on other sites More sharing options...
ivans imports Posted May 11, 2013 Share Posted May 11, 2013 Had a broken head bolt on ej 2.2 other day was 3 in of bolt in case was no way to save it had to change block one out of 100 but very diffacult to deal with. I had tried to run a ea81 with ej 2.2 pistons i bored the block to the 2.2 piston size but was not enuff liner left but the 2.0 pistons are very close. And i dont think running without a wristpin bushing whould be a problem as its a floating pin Link to comment Share on other sites More sharing options...
Quidam Posted September 20, 2013 Share Posted September 20, 2013 Just found this thread yesterday. Here's the specs on a piston I have installed at the moment in an EA82.I installed top and second rings and the inner pin lock. I installed a .065 headgasket and snugged the head bolts down, installed the cam case. Rotated cam both ways, valve interference with that dome. I hand polished the pin bore after knocking out the bushing. I also upgraded the piston pins to a thinner "bearing steel". The piston sits .020 above the deck, I'm not positive how much I took off this block...mabie .006? I've repeated the camcase to heads off and on a few times. I stacked two headgaskets and bolted it together with no valve to piston interference. Of course, using two of those headgaskets wouldn't work for me. Too much piston to head clearance. Anyway, conclusion, I'd need to have the pistons fly cut for valve clearance. and the piston doesn't fit the combustion chamber. It's adds quench in that trench that circles around them. I can get .040 quench. piston to head, with this piston. That's right where it should be for the piston. Anyway, when I pull it apart again, I'm selling these. Brand new, unused set of ARIAS Custom Pistons for Subaru EJ20 WRX 2.0 liter, with turbo, supercharger and/or NOS. Fits stock OEM Subaru sleeve bore, no boring required. Brand: ARIAS PISTONSMaterial: Forged 2618 non-siliconBore diameter in./mm: 3.622 / 92 (OEM)Stroke in./mm: 2.953 / 75 (OEM)Compression ratio: 8.5:1Crown style: Thermal dishCompression height: 1.295 in.Pin diameter: .905 in. (OEM)Wrist Pin Style: FloatingPin brand: ARIAS 1018Ring brand: ARIAS 1.2-1.5-4.0mmPin Material: 1018 case hardenedWeight Matched Set: YesQuantity: Sold as a set of 4 (pistons, pins, rings, single locks) These ARIAS pistons were custom made in batches of 40 for a customer who declined the order. The pistons, pins, rings and locks are in new excellent condition. They are precision machined and fitted with a medium-duty pin guaranteed up to 20 pounds boost. Stronger pins are available - please email for an additional quote. This application is not available in the ARIAS catalog as a shelf part number. Comparable sets cost up to $585 on the ARIAS website. Five (5) kits are available. Link to comment Share on other sites More sharing options...
ivans imports Posted September 22, 2013 Share Posted September 22, 2013 nice job looks good Link to comment Share on other sites More sharing options...
LeoneTurbo Posted September 24, 2013 Share Posted September 24, 2013 Still that leaves the piston pin diameter issue unsolved, doesn't? By the way, the EA rod journals are 45 mm... So the EJ25D rod does not fit (48 mm journal). Link to comment Share on other sites More sharing options...
Turbone Posted September 24, 2013 Share Posted September 24, 2013 This is a long read but worth it, lots of good info. http://subaruxt.com/forum/viewtopic.php?f=13&t=3575&st=0&sk=t&sd=a Link to comment Share on other sites More sharing options...
ivans imports Posted September 25, 2013 Share Posted September 25, 2013 press the bushing out and pin fitts fine taht part is easy Link to comment Share on other sites More sharing options...
LeoneTurbo Posted September 26, 2013 Share Posted September 26, 2013 You mean running no bronze small end bearing in the rod? Unfortunately direct contact between wrist pin and rod are not a good pairing when it comes to friction. Link to comment Share on other sites More sharing options...
Quidam Posted September 27, 2013 Share Posted September 27, 2013 (edited) You mean running no bronze small end bearing in the rod? Unfortunately direct contact between wrist pin and rod are not a good pairing when it comes to friction. If you look around, no pin bushing has been done and is being done. Pin material is crucial and or the coating. Coating for the bores or the pins could be dry film lube too or diamond like. I have a set of rods I've reworked extensivly. I need to post a pic...There are ways to increase oil to the pins, clearances play a factor. Bearing steel pin with coated pin bores is what I have in mind. Pin bores are very smooth typically even after pressing the bushing out. I've got a set polished with 1000 grit wet after I knocked the bushings out. I chamafered the oil supply passeges in the rod end and chamfered the pin bore it's self. Edited September 27, 2013 by Quidam Link to comment Share on other sites More sharing options...
Quidam Posted September 28, 2013 Share Posted September 28, 2013 Been working on a set of rods. Bushings out, lots of grinding so far. Then to the machine shop for shot peening and big end rebuild. The fatter pin is oem sti. Link to comment Share on other sites More sharing options...
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