August 10, 200520 yr Does it matter which pistons go in which cylinders? I noticed the letters "UPR" and "UPL" on a couple of the pistons...should this mean something to me?
August 10, 200520 yr if the pistons came out of the block you are putting them back into, then yes, it does matter. you always stick them back in the same hole they came out of if you are building a motor from scratch, they should all be the same part number. but you have to make sure they fit like they should.
August 10, 200520 yr If they're new then no, but if they came out of that block then its a VERY good idea to put them back into the same bores. Gary
August 10, 200520 yr Author doh! that's not good to hear.... anyone know a good place to get oversize pistons for a resonable price? Don't need any of that performance racing stuff tho
August 10, 200520 yr Let me throw my .02 into this, and maybe clarify what others have said: It matters somewhat which cylinders a used piston goes into... IF you do not put new rings on them. Cylinders and rings are the contact/wear/sealing point, and they take a little bit of a set. If you use new rings, then it doesn't matter at all which exact cylinder the piston goes into. And if you have done even a light cylinder hone (I would recommend doing so) then it also doesn't matter. What DOES matter, and which you brought up but hasn't as yet been addressed is the "UP L" and "UP R" markings. The piston pin bosses have an offset. The UP markings mean just that: That part of the piston is meant to be UP relative to the top of the block. The L and R should refer to left or right bank of cylinders, although without going out to look I couldn't tell you for sure which is left and right by their definition.
August 10, 200520 yr Author good times! thanks for the replies thus far... the cylinders were honed and new rings were installed during the rebuild. However, I've had a serious problem with blowby since then and burned a lot of oil (maybe a quart every 500 miles.) I figure I could only have done two things wrong...either put the cylinders in the wrong holes or installed the rings incorrectly. Could the offset to which you refer cause this problem? And is there a wrong way to install rings? I followed the instructions that came with them. Granted, those instructions were probably written by some guy in Bangladesh...what are some common mistakes for rings? (If i remember, the thicker oil ring went in the bottom groove, and the wavy ring in the top groove with the thinner compression ring on top of that.) Let me throw my .02 into this, and maybe clarify what others have said: It matters somewhat which cylinders a used piston goes into... IF you do not put new rings on them. Cylinders and rings are the contact/wear/sealing point, and they take a little bit of a set. If you use new rings, then it doesn't matter at all which exact cylinder the piston goes into. And if you have done even a light cylinder hone (I would recommend doing so) then it also doesn't matter. What DOES matter, and which you brought up but hasn't as yet been addressed is the "UP L" and "UP R" markings. The piston pin bosses have an offset. The UP markings mean just that: That part of the piston is meant to be UP relative to the top of the block. The L and R should refer to left or right bank of cylinders, although without going out to look I couldn't tell you for sure which is left and right by their definition.
August 10, 200520 yr Another (third) possibility... rings seal in two places (well three), the cylinder wall and the ring lands in the piston. How did you prep the ring lands for the new rings? New rings also require break in, you want to avoid constant engine speed, accel/deccel is the normal procedure to get both the uppper and lower lands to seat. Just a thought Gary
August 11, 200520 yr The UP L and UP R refers to SPFI pistons. Carb pistons are UP only. L = left, R = right, so the L goes in left side, R in right side. This is not left as you are facing the front of the block: this is left as you are sitting in the driver's seat. So the L goes in the right side of the block as it is facing you, get it? (Confusing, huh?) The ring landings must be absolutely clean and free of old, gunked up oil and dirt. Once that's all out, wash away old stuff with a stiff, non scratching brush and let dry. You should be ok if you followed ring mgfr. instructions carefully. As for the blowby, since you obviously have a SPFI, did you replace your PCV valve? I'd highly recommend it. Subaru Genuine only, of course. And clean out the PCV hoses too. It could also partly be the old crud cleaning out of the exhaust system. And some engines will use oil, even brand new, off the showroom floor. Keep a close eye on it. Emily http://www.ccrengines.com
August 11, 200520 yr The UP L and UP R refers to SPFI pistons. Carb pistons are UP only.L = left, R = right, so the L goes in left side, R in right side. This is not left as you are facing the front of the block: this is left as you are sitting in the driver's seat. So the L goes in the right side of the block as it is facing you, get it? (Confusing, huh?) Not too confusing... so 1&3 are R (right) and 2&4 are L(left).. right?
August 11, 200520 yr ...Emily http://www.ccrengines.com What more could be said??? SuBrat84, it sounds like your statement is correct.
August 11, 200520 yr Author what's a ring land? I replaced the PCV. Speaking of which...the oil filler cap would rattle loudly as the engine vibrated. I turned the cap back just enough that the two flanges pulled it tight against the tube. This kept the cap from rattling but also in effect sealed the tube shut. Once this happened, I had all sorts of crud blowing up into the PCV and breather tubes. I had to clean them out and loosen the filler cap again. Just too much pressure inside the crankcase.
August 11, 200520 yr http://www.hastingsmfg.com/Service%20Tips/compression_ring_installation.htm thats a good one too. ring installation is very key
August 11, 200520 yr Author mmm, good bookmark...probably would've helped before :-\ thinking I might just pop that crankcase open and take a look at what I did. Or at least move the pistons to the correct sides. The problem I had last time was that I didn't have the tool to remove the wrist pin and don't have the means to fabricate one. I gave it to the machinist to have the pins removed and he returned a box of pins, pistons, and rods with no idea of where they came from. Sure would be nice to do it myself this time...anyone know where a guy can get one of those tools for a reasonable price? Or anyone sells homemade versions here? http://www.hastingsmfg.com/Service%20Tips/compression_ring_installation.htm thats a good one too. ring installation is very key
August 11, 200520 yr There is one more step that everyone is missing about Ring installation, you must make sure when installing rings on a piston that you offset each ring from each other by about 90degrees. Some manufactors even have a spec on how many degrees each ring should be from each other. I rebuilt my EA82-T from scratch with all new parts and assembled it myself and did the ring offsetting I learned from a 20-year SOA Tech. My ea82-t is not burning any oil and never did even from day 1 when the motor was first installed. Within 3000miles I dont even burn 1/8th of a qt. If you have a few of the ring gaps in the same spot oil will pass through thus making excessive oil consumption. Start simple first tho : 1. Replace your oil cap since thats what they do when the seal gets old 2. Replace your PCV Valve with a Subaru OEM 3. Inspect PCV Hose Routing and Replace cracked or clogged hoses Then if you still have issues tear it down. Emily is right about normal break-in oil consumption to a point, It's normal for a "NEW" engine to use SOME oil during the first 500miles or so. But it should QUICKLY go away after that, I would say 1/2qt to 1 full qt. AT THE MOST within the first 500miles would be ok.
August 11, 200520 yr Steve, Actually, I thought about that, but I don't install rings (don't have the time) and I didn't want to give misinformation. I've done that before and it's caused some real heated discussions, to say the least! I was hoping, not assuming, that the manufacturer instructions would be clear about that. You're right: that can lead to excessive oil consumption. Emily http://www.ccrengines.com There is one more step that everyone is missing about Ring installation, you must make sure when installing rings on a piston that you offset each ring from each other by about 90degrees. Some manufactors even have a spec on how many degrees each ring should be from each other. I rebuilt my EA82-T from scratch with all new parts and assembled it myself and did the ring offsetting I learned from a 20-year SOA Tech. My ea82-t is not burning any oil and never did even from day 1 when the motor was first installed. Within 3000miles I dont even burn 1/8th of a qt. If you have a few of the ring gaps in the same spot oil and pass through thus making oil excessive consumption. Start simple first tho : 1. Replace your oil cap since thats what they do when the seal gets old 2. Replace your PCV Valve with a Subaru OEM 3. Inspect PCV Hose Routing and Replace cracked or clogged hoses Then if you still have issues tear it down. Emily is right about normal break-in oil consumption to a point, It's normal for a "NEW" engine to use SOME oil during the first 500miles or so. But it should QUICKLY go away after that, I would say 1/2qt to 1 full qt. AT THE MOST within the first 500miles would be ok.
August 13, 200520 yr The problem I had last time was that I didn't have the tool to remove the wrist pin and don't have the means to fabricate one. .............................................. What tool is needed to remove wrist pins??? New too this and gathering info for my winter project.... rebuild. "Noob with a wrench".
August 13, 200520 yr A slide hammer can be used to remove the pins. No one has mentioned here that rings have to be the right way up, they have a marking indicating the top (or in the case of a subaru, closest to the head).
August 17, 200520 yr Author how do you use the slide hammer? somehow you have to grab the inside edge of the pin. A slide hammer can be used to remove the pins.
August 18, 200520 yr I just used the head of a bolt - small enough to fit through the pin, then you can hook the head on the end of the pin. Not perfect by any means, but it worked.
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