Max Capacity Posted April 25, 2016 Share Posted April 25, 2016 You need to have the cylinders matched to the each piston. You can't just drop them in and expect to be trouble free. Talk with a trusted machine shop. I assume the block has ARP head studs ? 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted April 25, 2016 Author Share Posted April 25, 2016 I am going with standard size pistons their is still cross hatching in all of the cylinders. I talked to a good machine shop and they said as long as the bore measure is still standard size I won't have to machine the pistons to fit. I'm not sure if the head bolts are arp but I am replacing them with arp. Can anyone tell me if I should still stick with oem head gaskets or not? Link to comment Share on other sites More sharing options...
Max Capacity Posted April 25, 2016 Share Posted April 25, 2016 My trusted machine shop will match forged pistons to each cylinder. Piston to wall clearance is key to a long life with forged pistons. If your using standard cast pistons, it might not be so much of a thing. ARP are studs not head bolts. OEM should be fine for HG's. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted April 25, 2016 Author Share Posted April 25, 2016 Je pistons are .004 to cylinder wall clearance which would be perfect as long as the bores in the cylinder are still 99.5 there is still crass hatching on the walls. This short block has 25k miles on it. If the walls are out of tolerance for forged pistons then I will not buy new pistons and just keep what's in ther. I have a cylinder bore gauge if the cylinder walls are +/-.001 of them pistons the shop does not feel any need to machine them to fit. So if the heads did not have arp "studs" then they re used the same head bolts. So I should not really use the same head bolts and buy arp studs then right? Link to comment Share on other sites More sharing options...
Max Capacity Posted April 25, 2016 Share Posted April 25, 2016 Yes, IMO, ARP head studs are a must for these boosted engines. If it all measure's good, you should be good to go. While the heads are off, will they be checked for flatness, may be skim cut to make sure you have a surface for the new HG to seal against ? Make sure the deck on the block is clean and flat. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted April 25, 2016 Author Share Posted April 25, 2016 Can I buy oversized pistons and have them matched to the bore? If the bore does not check right? Link to comment Share on other sites More sharing options...
Max Capacity Posted April 25, 2016 Share Posted April 25, 2016 You or the machine shop measure the bores and then decide which size pistons to buy, that's how it works for the most part. Unless you want to go with larger pistons from the start. Then the machine shop will measure each piston and bore each cylinder to match each piston. The cylinder bores are normally at least horned before new piston and rings go in. Even with your low mileage, I think honing is a good thing. I'll let the machine shop who do this work all the time, tell you the right thing to do if you can use the same pistons with new rings. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted April 25, 2016 Author Share Posted April 25, 2016 Yup I totally agree I gotta get the other head off then they are gonna get the heads and short block. I just don't want the heads or the short block disassembled if possible then that's more money and time. Link to comment Share on other sites More sharing options...
stikiller Posted April 26, 2016 Author Share Posted April 26, 2016 I got 04 sti b25 heads and an 08 or 2010 Sti block which headgaskets do I use? From what I've been reading the newer style from 2010 and up is better then the older style? Link to comment Share on other sites More sharing options...
seanyb505 Posted April 26, 2016 Share Posted April 26, 2016 Haven't seen anything about later years having better quality. I bought the engine gasket kit for the year heads I had. I think b25 was only used until 06, so you can't get too much newer year head gasket. Link to comment Share on other sites More sharing options...
Max Capacity Posted April 26, 2016 Share Posted April 26, 2016 I got 04 sti b25 heads and an 08 or 2010 Sti block which headgaskets do I use? From what I've been reading the newer style from 2010 and up is better then the older style? Well from what I understand, I was told to get the HGs for the year car when I ordered the ej257 using the heads that came on the car, a 05 GT wagon. So, I would think you'd have to order the HG for those year heads. Because the ej255 and ej257 blocks are the same. Does that make sense ? If there's any questions, I'd call Mike, aka m sprank at www.infamousperformance.net I'm sure he'd know. Rey at www.AZPinstalls.com may also know. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted April 26, 2016 Author Share Posted April 26, 2016 Seanyb505 Well on comparison from pictures if you pick the oem headgaskets from 2010 STI the headgaskets machine my head water design compared to the 04 style does not....there's not much of a difference but there is some. Also from what I read don't quote me the newer ones are also multi layered? Can anyone confirm this? I will take a pic of the gasket I have and the heads and short bock and then I will post a pic of the new style. I am at work so I can't do it till later. Max I sure will call one of them guys today and ask them also. I also got it contact with Mike at tuning alliance but we have been playing phone tag. Also I know I've been going back and forth on forged pistons. It's gonna come down to if the short block can be honed without splitting the cases. I checked the bores yesterday with my dad's sunnen dial bore gauge and the cylinders checked to within +\- .0007 of tolerance so if they can hone it without getting debris inside of the motor then forged I will go if not then it's stock pistons I stay with Link to comment Share on other sites More sharing options...
Max Capacity Posted April 26, 2016 Share Posted April 26, 2016 Based on your post #3, I thinking forged is what your going to want to use for pistons. I think they will hone the cylinders straight down the bore with the block vertical. So they may want to remove the crank. Ask the machine shop what they will be doing. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted April 26, 2016 Author Share Posted April 26, 2016 I've been thinking why wouldn't there be oil in the coolant reservoir or radiator? How can the oil not go into the tank but coolant gets in the oil? Link to comment Share on other sites More sharing options...
Max Capacity Posted April 26, 2016 Share Posted April 26, 2016 I think your asking about how coolant got into the oil system but not oil into the coolant. I think it has to do with the design and where the HG was leaking from. Actually coolant in the oil is worse the oil in the coolant. Boosted Honda Civic's put oil into the coolant, you see it as black spots floating in the coolant overflow tank. Coolant is not a good lube for engine bearings. So if your engine has had the coolant leaking into the oil system for a while, you'll want to replace the bearings. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted April 26, 2016 Author Share Posted April 26, 2016 I talked to azp and he said either oem or jp proseal headgaskets will work fine. I talked to mikr kinsman today too. I've decided now I am gonna do this right and give the block to the machine shop to do whatever they need to do to put forged pistons in and deck the heads. Like you said in your post gotta get it right the first time this time around. Link to comment Share on other sites More sharing options...
Max Capacity Posted April 27, 2016 Share Posted April 27, 2016 Thank you for doing that. You'll be happy with the result. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted May 2, 2016 Author Share Posted May 2, 2016 I've decided on King bearings rather then acl so I've been looking at them and I've got a question. What does thrust position mean and what does phase one and two mean? I don't know which ones I need to get? Link to comment Share on other sites More sharing options...
RustyRuu Posted May 3, 2016 Share Posted May 3, 2016 thrust position is the position of your thrust bearing. back in the day on the first EJ motors the thrust was in the number three positon. the dead center of the case and the middle main bearing. i believe that these were on the 2.2's and maybe a couple later year 90's 2.5's but that is more likely to be wrong. some people chose to machine and relocate the trust bearing back to the 3 position. all 2.5 ej's after 2000 have the thrust in the number 5 position. counting your main bearings from the front to rear number 5 is closest to the rear and thats your trust position. the trust bearing has walls that sort of hug the crankcase in a super sexual way, unlike all the other main bearings. phase 1 and 2 have to do with the heads phase 1 is all the DOHC when phase 2 is SOHC. sort of bass ackwards if you ask me. i decided to go with king as well and i thought that they fit all ej motors but you needed to tell what thrust it had. these guys helped me out a bunch so ill throw there name around http://www.flatironstuning.com/m-148-king-bearings.aspx correct me if im wrong, by all means, this is just what i think i know Link to comment Share on other sites More sharing options...
stikiller Posted May 3, 2016 Author Share Posted May 3, 2016 Thank you very much! Great info!! Link to comment Share on other sites More sharing options...
stikiller Posted May 12, 2016 Author Share Posted May 12, 2016 OK so I haven't posted anything in awhile. I've been waiting on the subaru wrenches to get the exhaust and intake cam gears off. Upon doing so I was able to finally able to get the pistons out. The #4 piston ringlands where cracked the bottom two. I originally thought and still kinda do think it was a head gasket failure also because my oil was milky but could that be because the e85 fuel was not cumbusting in the #4 cylinder and or the head gasket was blown? I also have a rust ring around the upper to turbo flange another indication to me of a headgasket blown. Here is the pic of it. Any thoughts? Link to comment Share on other sites More sharing options...
stikiller Posted May 12, 2016 Author Share Posted May 12, 2016 There was no oil mixture in my coolant tank or radiator so that rules out a bad coolant seal in my turbo? Link to comment Share on other sites More sharing options...
stikiller Posted May 12, 2016 Author Share Posted May 12, 2016 Here is a pic of my oil Link to comment Share on other sites More sharing options...
Max Capacity Posted May 12, 2016 Share Posted May 12, 2016 Is it me or does that oil look milky brown ? 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
stikiller Posted May 12, 2016 Author Share Posted May 12, 2016 Yes it is milky brown that's why I think it's coolant mixed in it from a head gasket leak on top of the ringlands being broken. Is it gas or coolant you think? Link to comment Share on other sites More sharing options...
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