nncoolg Posted October 17, 2009 Share Posted October 17, 2009 Just wondering if someone has some background experience with the EA82 2 port heads, and knows why they all seem to crack between the valves? Are they ALL overheated? Or do they suffer from the valve seats being too tight in the casting or something? I know there is not much meat between the 2 runners, but surely FHI engineers made them good enough.... Also, is it better to buy brand new (including 2nd hand good ones, if they can be found), or repaired, like, once the heads have cracked & relaxed, then repaired are they better? Thanks. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 17, 2009 Share Posted October 17, 2009 (edited) They all crack. Overheated or not. Doesn't matter. That goes for EA81's, EA82's, and EA82 Turbo's - doesn't matter. Subaru put out a TSB years ago saying they don't matter, don't affect operation, and should be ignored unless the cracks extend down into the exhaust port water jacket - which does occasionally happen to turbo heads. You can repair them all you want - it's wasted money as they will just crack again. Ignore them - we all do. As for why they crack - that's anyone's guess. I would assume that if the FHI engineer's could have figured out an easy solution they wouldn't have made three sucessive generations of turbo heads to try and solve the problems with the cracking and the head gaskets. In the end they were only mildly sucessfull and it's a mute point as the engine is a dead design. The EJ's are much better. If I were to guess as to the cause, I would say it's poor coolant flow through the head/block interface. Being a closed-deck, sand cast block, the coolant ports are small and there's not a lot of cooling area around the valve's. GD Edited October 17, 2009 by GeneralDisorder Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 17, 2009 Share Posted October 17, 2009 yep, it's a benign issue so don't worry about it. leave the cracks alone, they don't affect anything. "cracked head" is a very ambiguous term. in the case of Subaru's they can be "cracked", as in the valve seat cracks you're talking about, and it doesn't matter at all. they can also be cracked in the typical "bad" way too, with cracks into the exhaust/coolant ports. Those are bad and will be found with a pressure test. They are rare in non-turbo heads. have them tested to make sure there aren't "bad" cracks. machine shops can use "stitch pins" to repair them if you're bent that way and can find a shop familiar with aluminum heads. they can be found by finding out who supplies the rebuilt aluminum heads for the local stores, NAPA, Dealerships, etc. the guys i used were actually called "Aluminum Head Specialists" and were very familiar with the valve seat cracking of 20 year old Subaru heads. Quote Link to comment Share on other sites More sharing options...
nncoolg Posted October 18, 2009 Author Share Posted October 18, 2009 But wont the bridge cracks extend to port cracks? I mean, isn't that how they start? It's gotta be a heat issue, pehaps fitting an oil cooler would help, by cooling the head where the water doesn't get? Im puzzled as to why the triangle shaped water jacket at the top of the block, in between the bores is blocked off, I think I will drill a hole in the heads there and wad-punch a hole in the gasket, to promote a bit of extra coolant flow. Thoughts? Quote Link to comment Share on other sites More sharing options...
Ricearu Posted October 18, 2009 Share Posted October 18, 2009 just make sure there is not an interfering oil galley Quote Link to comment Share on other sites More sharing options...
torxxx Posted October 18, 2009 Share Posted October 18, 2009 I've NEVER had a N/A set of heads crack down into the coolant or oil galleries. (done 100's of headgaskets on these in the past 10 years) Only had that problem on turbos. It cracks because of the lack of metal there, and its a low grade metal. I dont think I've ever seen a EA82 head that didnt have the hairline crack between the valves Trying to remember what the rule of thumb was that subaru said in the TSB. Something to the point of if the edge of a dime will fit in the crack, it needs to be addressed. If it was smaller than that it was fine. It was something like that (read it a long time ago when I first did HG's on my EA82) Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 18, 2009 Share Posted October 18, 2009 But wont the bridge cracks extend to port cracks? I mean, isn't that how they start? It's gotta be a heat issue, no. the hair line cracks between valve seats are NOMINAL. what happens beyond that - yes can be caused by excessive heat, poor maintenance. keep your cooling and oiling system in check and you'll be fine. much harder to do with turbo's where those cracks are most likely to become fatal. have you been to the northwest, colorado, mountains in the east...there are thousands of 20+ year old Subaru's. Most of them have had those hair line cracks for a decade or more, they are benign if you keep the system running and maintained properly. Quote Link to comment Share on other sites More sharing options...
jono Posted August 11, 2018 Share Posted August 11, 2018 someone once managed to reproduce the TSB for this online out of curiosity, does anyone have a copy to stick up here please? It does matter to some of us that really need to stick with EA's for road transport requirements or have an engineer$ report Quote Link to comment Share on other sites More sharing options...
ausubaru92 Posted August 11, 2018 Share Posted August 11, 2018 I was talking to Nncoolg's dad yesterday and he said he got gen3 heads from the US years ago. Are these still available and how much? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted August 13, 2018 Share Posted August 13, 2018 No. Long discontinued.... thankfully. GD 1 Quote Link to comment Share on other sites More sharing options...
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