severedevil Posted December 15, 2011 Share Posted December 15, 2011 Ok i replaced the valves and got my head gasket kit in the mail so im putting it back together. now the book says for torquing the heads, step 1 22ft lbs, step 2 51 ft lbs, step 3 loosen 180 deg, step 4 loosen another 180 deg.... now ive never done a motor in which the torque was so low(my grand am heads went on with 110ft lbs) and heads which u have to loosen the bolts after torquing them. is this really necessary? Link to comment Share on other sites More sharing options...
subikid90 Posted December 15, 2011 Share Posted December 15, 2011 YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I think I made that clear lol You must follow the torque sequence. Cast iron block you can just torque the sh*t out of the bolts and call it a day lol -Subikid90 1997 Legacy GT 5spd & EJ251 w/EJ25D heads ~10.5CR 1998 Legacy GT Limited waiting for EJ22T hybrid swap Link to comment Share on other sites More sharing options...
bmx045 Posted December 15, 2011 Share Posted December 15, 2011 Dont compare this car to a grand am for the love of god. The head bolts are stretch bolts and you need to back them off and retorque. Link to comment Share on other sites More sharing options...
johnegg Posted December 15, 2011 Share Posted December 15, 2011 i read some where that the final torque value ends up being ~95 ft lbs. but that is just what i have read. don't forget, middle first , then the corners. Link to comment Share on other sites More sharing options...
jamal Posted December 15, 2011 Share Posted December 15, 2011 it end up being around 60-65. after you loosen them you go to 25/15 and tighten another 180 degrees total which is on there pretty good. ARP's final spec is 90, and when you have thing that tight you have to hone the block with a deck plate torqued to that spec because the bores distort so much. Link to comment Share on other sites More sharing options...
severedevil Posted December 16, 2011 Author Share Posted December 16, 2011 ok well i put da bitch back together. TIMING SUCKED!!! took about 3hrs to get the timing right. i didnt let it go back together unless it was perfect because there were so many close calls and didnt look like it would match up perfectly. but i got it lol but i didnt have the right tools to tighten the cam pullys or harmonic balancer... how bad might this turn out? the car runs and drives(only drove 5miles) i tightened them the best i could but i dont know if it would be enough.... oh yeah and a dumbass buddy of mine chipped a tooth on the driverside exhaust cam.... about 1/3 of 1 tooth is gone. not a big deal....right? Link to comment Share on other sites More sharing options...
BAC5.2 Posted December 16, 2011 Share Posted December 16, 2011 Well, this rebuild has fail written all over it. 1) The cam sprockets and crankshaft pulley need to be tightened. Leave them loose, destroy engine. 2) Your dumbass buddy needs to buy you a dumbass cam sprocket. Chipping a tooth is going to cut the hell out of the belt, or simply explode. Don't replace, destroy engine. I hope you used new head bolts, but I'm sure you didn't. [URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard Link to comment Share on other sites More sharing options...
GTTuner Posted December 16, 2011 Share Posted December 16, 2011 New head bolts are not necessary. Inspection for necking down and cleaning, lubing and I have never had a problem reusing head bolts on a Subaru. Those cam sprocket bolts need a final angle torque. Better get on that quick! I think it is 45 degrees. Link to comment Share on other sites More sharing options...
BAC5.2 Posted December 16, 2011 Share Posted December 16, 2011 1) You think he checked for necking? 2) Based on the method of torquing, new head bolts are good practice. They are cheap, just replace them. I've explained, in great depth, the mechanics of the torque process and what kind of strain the bolts undergo. If you are DEFINITELY sure you are the first to take the engine apart, then you could PROBABLY get away with using the bolts again (just twice, not more than that). If you aren't the first person to take down the block, replace the bolts. [URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard Link to comment Share on other sites More sharing options...
Kennyfvholla Posted December 16, 2011 Share Posted December 16, 2011 They really don't need to replaced. If you've reused them more than a few times, it might be a good idea to get new ones just in case they've stretched from being seated through the torquing sequence multiple times. But I doubt it. As long as they are clean and you've layered them with a little bit of fresh oil before putting them back in you'll be fine. You absolutely need to get a new sprocket. It will cut up the belt. Is your car a MT or 4EAT? Do you have a Haynes manual or downloaded the factory service manual? If not, get one, and make sure you have a torque wrench. To keep the engine from spinning while torquing the bolts down, do a search and you find an entire thread on all of the ways to do this. Link to comment Share on other sites More sharing options...
bmx045 Posted December 16, 2011 Share Posted December 16, 2011 Retorquing bolts that are already stretched is not good practice. Link to comment Share on other sites More sharing options...
overspool Posted December 16, 2011 Share Posted December 16, 2011 these aren't "torque to spec" bolts. these are "torque to yield" bolts. The reason why you tighten, then loosen, then tighten, is so that the head gasket spreads evenly, seals evenly, and so that the bolts thread in smooth. Honestly, anything past ~50 ftlbs isn't accurate because of all of the dirt and things in the bolt holes. I would measure the thread pitch on the old bolts and see how close it is to factory. I calculated the length of the threaded area (or how long it should've been), then measured with a digital caliper to get the actual length. Mine was close enough that I was comfortable using them again. Also, applying a little bit of fresh engine oil to the bolt before threading it in is a good practice. Link to comment Share on other sites More sharing options...
subikid90 Posted December 16, 2011 Share Posted December 16, 2011 Retorquing bolts that are already stretched is not good practice. I agree with this 100%. For some reason subaru owners always argue on this subject, since subaru does not say the bolts are stretch to yield. -Subikid90 1997 Legacy GT 5spd & EJ251 w/EJ25D heads ~10.5CR 1998 Legacy GT Limited waiting for EJ22T hybrid swap Link to comment Share on other sites More sharing options...
severedevil Posted December 16, 2011 Author Share Posted December 16, 2011 well i guess its good the headgasket kit i got off ebay had new head bolts. and HEY IT RUNS LIKE A BOSS im happy lol.... i did use a file and made the chip not so sharp. i plan on taking it to a shop to get the cam sprockets re-torqued. Link to comment Share on other sites More sharing options...
GTTuner Posted December 16, 2011 Share Posted December 16, 2011 Retorquing bolts that are already stretched is not good practice. I have built plenty of engines, in practice in cannot hurt but THE BOLTS ARE REUSEABLE!!!!!!!!!!!!!!!!!!!!!!!!!!! WTF, read the service manual. Dont waste money. Your not going to be able to torque those cam sprocket bolts without a tool to hold them! Link to comment Share on other sites More sharing options...
bmx045 Posted December 16, 2011 Share Posted December 16, 2011 you know what subaru service techs are instructed to do with pretty much any repair? reuse anything and everything. Link to comment Share on other sites More sharing options...
GTTuner Posted December 16, 2011 Share Posted December 16, 2011 you know what subaru service techs are instructed to do with pretty much any repair? reuse anything and everything. Ha ha so true. Link to comment Share on other sites More sharing options...
severedevil Posted December 16, 2011 Author Share Posted December 16, 2011 well hopefully the shop i take it too has the tools. Link to comment Share on other sites More sharing options...
Kennyfvholla Posted December 16, 2011 Share Posted December 16, 2011 well i guess its good the headgasket kit i got off ebay had new head bolts. Well, that ends that debate.. I you have new ones, why not use them. I still adamantly stand by my statement that they are perfectly reusable at least a few times. I've done it before. Link to comment Share on other sites More sharing options...
BAC5.2 Posted December 16, 2011 Share Posted December 16, 2011 you know what subaru service techs are instructed to do with pretty much any repair? reuse anything and everything. Bingo. Ford uses the same type of torque procedure in the Taurus. In their FSM it specifies new bolts. The headgasket kit from the dealer even includes them. Good practice says replace them. I'll see if I can find the technical post I made a while back. [URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard Link to comment Share on other sites More sharing options...
subikid90 Posted December 16, 2011 Share Posted December 16, 2011 I have built plenty of engines, in practice in cannot hurt but THE BOLTS ARE REUSEABLE!!!!!!!!!!!!!!!!!!!!!!!!!!! WTF, read the service manual. Dont waste money. Your not going to be able to torque those cam sprocket bolts without a tool to hold them! I saw this coming lol -Subikid90 1997 Legacy GT 5spd & EJ251 w/EJ25D heads ~10.5CR 1998 Legacy GT Limited waiting for EJ22T hybrid swap Link to comment Share on other sites More sharing options...
BAC5.2 Posted December 16, 2011 Share Posted December 16, 2011 The tighten sequence is called "Angle Controlled Tightening" which is designed to reliably torque bolts. Not all torque wrenches read the same, nor do they properly allow axial de-straining required to achieve consistent preload. The majority of ACT procedures are designed to bring the bolts very close to yield. In most cases, ACT processes provide less than 5% variation to yield. A slight over-torque makes the bolt no longer usable. If you are the first person to take apart the engine, they are probably safe to use again (assuming they were properly installed). If you aren't the first, or aren't sure, then don't reuse them. If the previous mechanic went just a little too far, the bolts are no longer usable. Best practice is to replace the head bolts every time. [URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard Link to comment Share on other sites More sharing options...
severedevil Posted December 16, 2011 Author Share Posted December 16, 2011 yeah i know there reusable and even if they arnt just torque em down alil more and they will stretch a lil tighter. now they can only tighten so far but most motors arnt taken apart enough to match the life of the bolts. ive rebuilt a 79 T bird motor 3 times and the specs on torquing the bolts were 85 ftlbs then 100 ft lbs then 115 ft lbs to a max of 130 ft lbs then get new bolts. this i told by a mech at the dealer. Link to comment Share on other sites More sharing options...
BAC5.2 Posted December 16, 2011 Share Posted December 16, 2011 All of that is both wrong, and not applicable to Subaru. [URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard Link to comment Share on other sites More sharing options...
bmx045 Posted December 16, 2011 Share Posted December 16, 2011 im just going to go ahead and unsubscribe from this thread because I'm about to gouge my eyeballs out with a screwdriver. Link to comment Share on other sites More sharing options...
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