idosubaru Posted July 12, 2008 Share Posted July 12, 2008 I've seen the EA82 (and ER27) cracks between the valve seats a zillion times, i'm very familiar with them. I decided to check this one out and removed the valves. The crack between the valve seats passes down into the exhaust manifold, very close to the valve seat and is about a half inch or more long. That sounds bad, i'm not encouraged to use this head. Does that sound right? Weird, this thing is only supposed to have 30,000 miles on it in a non-turbo vehicle. Cylinder number 1. Link to comment Share on other sites More sharing options...
Gloyale Posted July 12, 2008 Share Posted July 12, 2008 I've seen the EA82 (and ER27) cracks between the valve seats a zillion times, i'm very familiar with them. I decided to check this one out and removed the valves. The crack between the valve seats passes down into the exhaust manifold, very close to the valve seat and is about a half inch or more long. That sounds bad, i'm not encouraged to use this head. Does that sound right? Sounds about right. I've seen lot's of them with vavles out, and they ussually go an inch to an inch and a half. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 12, 2008 Share Posted July 12, 2008 Yeah - the crack's are usually pretty deep like that. As long as they don't extend into the water jacket you are fine. The cracking has little to do with mileage - it's a design fault. It only takes a few heating/cooling cycles for them to crack down through there. That, and being they are deep as you see is the primary reason all attempts to fix the cracks by peening them shut or stiching them with pins invariably fails. It's also one of the big reasons the stock EA82T heads will never make big power. GD Link to comment Share on other sites More sharing options...
McDave Posted July 12, 2008 Share Posted July 12, 2008 Subaru doesn't seem too concerned about them... Cylinder Head Crack Between the Valve Seats Service Bulletin # 02-88-93 Pages: 1 Bulletin Description: Some cylinder heads may exhibit cracks between the intake and exhaust valve seats. These "Bridge cracks" do not cause coolant leaks or result in valve seat movement. "Bridge cracks" are cosmetic in nature and do not justify replacement of the Cylinder Head. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 12, 2008 Share Posted July 12, 2008 Subaru doesn't seem too concerned about them... And that's exactly what we keep telling people but some folks won't listen. On the EA82T's though, the cracks can extend down to the cooling jackets in extreme cases resulting in coolant leaking from the exhaust port. The service bulletin is only a CYA on Subaru's part for *stock* engines. When you start to modify things (as in the case of some of the heavily built EA82T's that have come and gone in the past) you quickly find that these cracks become a problem. Subaru redesigned the heads twice in an attempt to overcome this problem but never did solve it. GD Link to comment Share on other sites More sharing options...
McDave Posted July 12, 2008 Share Posted July 12, 2008 And that's exactly what we keep telling people but some folks won't listen. On the EA82T's though, the cracks can extend down to the cooling jackets in extreme cases resulting in coolant leaking from the exhaust port. The service bulletin is only a CYA on Subaru's part for *stock* engines. When you start to modify things (as in the case of some of the heavily built EA82T's that have come and gone in the past) you quickly find that these cracks become a problem. Subaru redesigned the heads twice in an attempt to overcome this problem but never did solve it. GD I was just looking through the Genuine Subaru Remanufactured Parts brochure at endwrench.com and noticed they didn't offer any reman heads. I guess it's hard to sell them with cracks. On a similar note, do you guys see many dropped valve guides on the ej22 heads? The technicians network seems to be full of references to the guides dropping and causing misfires by hanging the valves open. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 12, 2008 Share Posted July 12, 2008 On a similar note, do you guys see many dropped valve guides on the ej22 heads? The technicians network seems to be full of references to the guides dropping and causing misfires by hanging the valves open. Never heard of it. EJ22's are absolutely bulletproof engines. All the dealer tech's I've talked with have said they don't see EJ22's with mechanical failures of any kind before 300k. And there hasn't been any talk of that on this board that I'm aware of. The EJ22, along with the EA81, are considered the most reliable engines Subaru has made to date. The EA82T, and the EJ25 phase I are the least reliable. Neither are particularly bad save for some specific defects that are quite common. GD Link to comment Share on other sites More sharing options...
McDave Posted July 13, 2008 Share Posted July 13, 2008 I went back and checked the dates. Almost all were for the '96 2.2s and they occurred with mileage between 35k and 80k with one around 108k, and most were fixed before 2004. Sounds like the few that were going to go bad already have. Still, on misfires it wouldn't hurt to drop the exhaust pipes and have a look-see... particularly if a vacuum gauge is bouncing around (does anybody use those anymore?). Link to comment Share on other sites More sharing options...
idosubaru Posted July 13, 2008 Author Share Posted July 13, 2008 As long as they don't extend into the water jacket you are fine. how can i verify they don't extend into the water jacket before installing it? this is a JDM engine with a fabulous 30,000 mile unknown history. i installed it and it had head gasket symptoms on start up. replaced intake gaskets, no dice. pulled heads. since the crack goes from combustion chamber to exhaust port, essentially bypassing the valve doesn't that cause a loss of compression? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 13, 2008 Share Posted July 13, 2008 how can i verify they don't extend into the water jacket before installing it? this is a JDM engine with a fabulous 30,000 mile unknown history. i installed it and it had head gasket symptoms on start up. replaced intake gaskets, no dice. pulled heads. Only way is to either remove the valves and visually inspect it, or have them pressure tested. Pressure testing and then surfaceing if they pass might be the way to go in leiu of removing otherwise properly functioning low-mileage valves. since the crack goes from combustion chamber to exhaust port, essentially bypassing the valve doesn't that cause a loss of compression? Absolutely. But in practice this is a very tiny hole for it to leak through. Even at idle RPM's this size leak is negligable. And as the engine revs to higher RPM it becomes even less of an issue. Engines all leak some compression - past the rings, past the valve seats, etc. One of the reasons you compare compression test numbers to each other and not to other engines (even of the same model) is that, within reason, the differences you see on a gauge aren't going to make a whole lot of difference in the way it will run. Given two engines of the same model with one testing at 125 psi on all cylinders, and the other testing at 175 psi on all cylinder.... you wouldn't be able to tell which was which with them idling. Because at the speeds the engine runs at the differences become almost non-existant. Cylinder pressures are high for such a short time that the a hole of that size doesn't have the flow capacity to adversely affect the runability. GD Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 13, 2008 Share Posted July 13, 2008 I went back and checked the dates. Almost all were for the '96 2.2s and they occurred with mileage between 35k and 80k with one around 108k, and most were fixed before 2004. Sounds like the few that were going to go bad already have. The 96 and up EJ22's were a redesign pushing more HP (147 IIRC) with solid lifters as part of a larger performance upgrade - the valve train was redesigned for the solid lifters as hydro's cause drag on the cam lobes and thus decrease performance . The EJ22 was phased a few short years later. When people around here talk of the bulletproof EJ22 they are mostly refering to the 90 - 94 EJ22e and EJ22g (turbo). Still, on misfires it wouldn't hurt to drop the exhaust pipes and have a look-see... I get what you are saying, but you have to remember that this post is about the EA82 and the EJ22 is a completely different animal altogether. EJ's are to EA's what small-blocks are to big-blocks. particularly if a vacuum gauge is bouncing around (does anybody use those anymore?). Funny you should mention that. I use vacuum gauges everday. Digital ones even! A lot of the pumps I work on are rated in Torr. I work on some that can pull 0.5 Torr. And I have a 1940's combi gauge that reads 24 inches of vacuum clockwise and 12 psi (fuel) pressure counter-clockwise. It's got a special hook for hanging it under the hood. Pretty neato actually. GD Link to comment Share on other sites More sharing options...
idosubaru Posted July 13, 2008 Author Share Posted July 13, 2008 okay thanks GD. you think it's likely this head will hold just fine? one inch crack sounds about right? *no warranty expressed or implied* haha!! i avoided picture because i'm on dial up - maybe i could post one tomorrow. i'm completely used to the cracks between the seats - i've yet to pull an EA82 or ER27 that didn't have at least one - but you think 1" is normal? thanks i'll reuse this head...except this little added tidbit now: realizing this isn't perfect - i already pulled the valve out - am i okay to just reinstall the valve, springs, and keepers? Link to comment Share on other sites More sharing options...
McDave Posted July 13, 2008 Share Posted July 13, 2008 I get what you are saying, but you have to remember that this post is about the EA82 and the EJ22 is a completely different animal altogether. EJ's are to EA's what small-blocks are to big-blocks. Sorry, I didn't mean to drag the thread off topic. And I have a 1940's combi gauge that reads 24 inches of vacuum clockwise and 12 psi (fuel) pressure counter-clockwise. It's got a special hook for hanging it under the hood. Pretty neato actually. GD Mine's only about 35 years old. (My apologies again Gary) Link to comment Share on other sites More sharing options...
idosubaru Posted July 13, 2008 Author Share Posted July 13, 2008 (My apologies again Gary)yeah for real, my *head* is hurting. for real, i don't care, that wasn't even on the "this off topic is getting annoying" radar screen. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 13, 2008 Share Posted July 13, 2008 okay thanks GD. you think it's likely this head will hold just fine? one inch crack sounds about right? *no warranty expressed or implied* haha!! i avoided picture because i'm on dial up - maybe i could post one tomorrow. i'm completely used to the cracks between the seats - i've yet to pull an EA82 or ER27 that didn't have at least one - but you think 1" is normal? thanks i'll reuse this head...except this little added tidbit now: realizing this isn't perfect - i already pulled the valve out - am i okay to just reinstall the valve, springs, and keepers? I would run it. Twice on Sundays even. I have yet to meet the non-turbo head that has cracked badly enough to be a problem. As long as I don't suspect coolant leakage I will run them. Generally you can tell - carbonized coolant, green gook, etc. I would put it back together and run it. Might want to lap the valves just because you already have one out. Probably not necessary though. GD Link to comment Share on other sites More sharing options...
Andy FitzGibbon Posted July 13, 2008 Share Posted July 13, 2008 My' '89 GL has a head cracked bad enough that coolant seeps out and collects on the ends of the exhaust studs. This is with the radiator/WP/thermostat removed, so there's not much coolant and no pressure in the system. I was surprised when I noticed the coolant drips on the end of each stud. It can be wiped off, and will collect again in a day or so. Andy Link to comment Share on other sites More sharing options...
McDave Posted July 16, 2008 Share Posted July 16, 2008 Has anyone thought about or tried to use the Subaru Slime on these older engines to help prevent or even cure small seepage type coolant leaks? For many years, Cadillac used the Bars Leak powdered tabs in their engines for this purpose. They even recommended retreating with every coolant flush. Of course they may have been having porosity issues with their engines. Just wondering if anyone else thought it might be worth a try, even as a preventative measure?. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now