WJM Posted March 1, 2006 Share Posted March 1, 2006 I was at the SouthEast Regional HQ's for Technical training.... ofcourse, I got to see the warehouse again...got to touch the last ten 10103AA240's in the country (EA82T shortblocks)...and etc etc... In the traing area, they had an ER27 disty side head and cam case assy...and an EA82T head. It was cracked something horrible....and they had cut the head right down the middle of the combustion chamber so you could see all the coolant passages and where the exhaust port went. Its no wonder there are cooling issues and head cracking issues with these things. The port walls are no thicker than 5MM~6MM, and there's a TON of surface area that the coolant runs right against that port. High boost? more heat...super heating the coolant....CRACK. BOOM. Obviously, anyone who ports the exhaust side will make that wall even THINNER...resulting in faster cracking, faster super heating of the coolant. Solution? Well...NONE that are cost effective asides from getting an EJ engine....unless you want to spend some serious R&D on the stuff. So here is my solution... EGT sensors AND AFF sensors AT EACH of the exhaust ports to monitor temps and AFR's AT the port at ALL times. That way...you can tune it properly for reliability...and eventually figure out how to get the power w/out extreme temps and AFR's....make it safe, make it fast. that takes the whole 'cheap' part out of the equation. You gotta pay for speed somehow....either blowing stuff up, or spending the right money on the right stuff to make it go fast and be reliable. 1. Fast 2. Cheap 3. Reliable Pick two. I wish I would have had my digi cam with me, i would have taken some detailed pics...I do have a head here that is cracked and warped pretty bad...I might just snap a shot of that one if/when I cut it open like that one i had my hands on. So there's another flaw for you guys to work around/work with.... No, I'm not really done with the EA82...I'm just...playing...more...extreme-ish...with...all things SUBARU. Quote Link to comment Share on other sites More sharing options...
Subarian Posted March 1, 2006 Share Posted March 1, 2006 That's good stuff to know. I've had EA82t heads welded up before, and it just seemed there wasn't a lot of material there. Since i got my "new" Subaru, a 94 Legacy with the EJ22, I've decided that's the way I'm going to go on building my next GL wagon. Plenty of power and far fewer issues than with the turbo, and since I'd have to swap the wiring harness and plumb the turbo anyway, it seems like no more and maybe even less work. Still, I think what some of the people on this board have done with EA82Ts is impressive. Quote Link to comment Share on other sites More sharing options...
operose Posted March 1, 2006 Share Posted March 1, 2006 the er27 head was the same way? Quote Link to comment Share on other sites More sharing options...
WJM Posted March 1, 2006 Author Share Posted March 1, 2006 I would imagine so since its the same basic head design...but the ER27 head was not cut open. It was assembled with the cam case/cam/HVLA/etc all on it assembled. Quote Link to comment Share on other sites More sharing options...
Subarutex Posted March 1, 2006 Share Posted March 1, 2006 Thanks for info Will. Too bad you didn't get pictures... But its ok... EJ FTW eh!? Quote Link to comment Share on other sites More sharing options...
WJM Posted March 1, 2006 Author Share Posted March 1, 2006 Yeah...well...since I had several EJ's that I could peice together and make run...it only made sense...seeing as I had 0 EA82's i could peice together and make run. *shrug* I'll be back with an EA82 at some point. Quote Link to comment Share on other sites More sharing options...
Loyale 2.7 Turbo Posted March 1, 2006 Share Posted March 1, 2006 the er27 head was the same way? ...Yes... well... Almost, there might be some sort of variation due to use / abuse (I Mean Overheatin´ the Engine, and the Wear) but is the same design, Basically. Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted March 1, 2006 Share Posted March 1, 2006 Anyone have any idea about the coolant passages on the EA81/EA81T heads and if they have the same design? Quote Link to comment Share on other sites More sharing options...
WJM Posted March 1, 2006 Author Share Posted March 1, 2006 Not a clue...if the T and n/a heads are the same...I have a set of N/A's. Quote Link to comment Share on other sites More sharing options...
avatar382 Posted March 1, 2006 Share Posted March 1, 2006 So you're saying a water temp gauge cannot be relied upon? I have an EGT gauge 3 inches from the passenger side head and a mechanical water temp gauge. I never see the coolent higher than about 195 F, and that's on a hot day in Miami. The highest EGT I've ever seen is about 820 C (1510 F) in 4th gear, 4500 RPM's, WOT. Both of these numbers seemed safe, to me - but then again, I've never had the chance to pull my heads and look Quote Link to comment Share on other sites More sharing options...
WJM Posted March 1, 2006 Author Share Posted March 1, 2006 Well, i was on track (road course) for a good 8 hours one weekend running stock boost....water temps never got past stock operating temp....and I never had to use the elec. fans either.... However...I do not have a way to monitor EGT's yet. Seems that 1600*F is the max high peak....and the 1500~1550 range is fine for constant WOT on WRX's and STi's on track.... So....green light for you avatar.... HOWEVER...with these heads being the way they are....i dont think anyone *REALLY* knows what the max safe temp is.... Quote Link to comment Share on other sites More sharing options...
Ross Posted March 1, 2006 Share Posted March 1, 2006 Anyone have any idea about the coolant passages on the EA81/EA81T heads and if they have the same design? I've got a spare thats had a broken valve beat it up, i should cut it up..... Quote Link to comment Share on other sites More sharing options...
MSSLGECKO Posted March 1, 2006 Share Posted March 1, 2006 I've got a spare thats had a broken valve beat it up, i should cut it up..... Do it! This is some good info for reference of EA turbo heads! Does anyone know much about the design differences between the n/a EA81s & '2s? Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted March 1, 2006 Share Posted March 1, 2006 Not a clue...if the T and n/a heads are the same...I have a set of N/A's. They should be identical except for the FI bosses in the head and the oil return fitting on the passenger's side head. Quote Link to comment Share on other sites More sharing options...
MilesFox Posted March 2, 2006 Share Posted March 2, 2006 speaking of porting and thin walls in the passages, i was porting a pair opf carb heads when i went through the exhaust wall to the dead space around the port casting where it would be above the motor mount. i craed jb weld putty in this cavity to block the hole, but i alsi figured it woule reinforce the head around the exhaust port, and act as a heat sink to keep any one particular spot fro being too hot. filled in the other head too for the sake of reinforcement and heat transfer i would consider doing this again to any other heads while they are apart. i would consider this a modification Quote Link to comment Share on other sites More sharing options...
Phizinza Posted March 2, 2006 Share Posted March 2, 2006 I didn't read all the posts and I'm not sure if anyone has said it, but. What about more radiator fans (and maybe bigger radiator) and a very low temp thermostat? Do you think it would be possible to keep the coolent cool enough to keep the heads cool? Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted March 2, 2006 Share Posted March 2, 2006 Sounds feasable, don't see why it wouldn't work. Also consider using Redline Water Wetter or a similar product to keep hot spots down in the head. Quote Link to comment Share on other sites More sharing options...
iluvdrt Posted March 2, 2006 Share Posted March 2, 2006 Couldnt you bypass the turbo outlet cooling hose so it went somewhere else? That way hot coolant from the tirbo wouldnt be dumping into the head. Quote Link to comment Share on other sites More sharing options...
Phizinza Posted March 2, 2006 Share Posted March 2, 2006 Couldnt you bypass the turbo outlet cooling hose so it went somewhere else? That way hot coolant from the tirbo wouldnt be dumping into the head. A little seperate radiator for the turbo? Quote Link to comment Share on other sites More sharing options...
calebz Posted March 2, 2006 Share Posted March 2, 2006 A little seperate radiator for the turbo? Hell.. a number of the EJ guys I know are running oil cooled only. Have even seen the stock TD04 run oil only. I imagin this reduces longevity, but I would also imagine it keeps overall coolant temps down. Quote Link to comment Share on other sites More sharing options...
WJM Posted March 2, 2006 Author Share Posted March 2, 2006 Couldnt you bypass the turbo outlet cooling hose so it went somewhere else? That way hot coolant from the tirbo wouldnt be dumping into the head. A little seperate radiator for the turbo? The turbo coolant outlet does not dump into the head. The turbo coolant outlet dumps into the Thermostat housing. Quote Link to comment Share on other sites More sharing options...
DasWaff Posted March 2, 2006 Share Posted March 2, 2006 I was thinking... (or not...) Seems to me, changing the difference in temperature of the coolant, with lower theromstats, bigger fans, etc. Is less important than the total volume of coolant flow. Coolant at too low a temp entering the heads only makes the thin walled problems worse. Since hotter coolant carries away less waste heat per unit we need lots more units. So what options are there for upping the flow through the heads? Maybe polishing some of the water channels? Better hoses? Water pump changes? Just brainstorming here, DasWaff Quote Link to comment Share on other sites More sharing options...
monstaru Posted March 2, 2006 Share Posted March 2, 2006 ,then what about a forced coolant system Quote Link to comment Share on other sites More sharing options...
Caboobaroo Posted March 2, 2006 Share Posted March 2, 2006 well from what I understand, besides trying to keep the coolant temp down, you also need to keep the oil temp down which will also help keep the temp of the engine down overall. I got a nice sized oil cooler but I don't have the sandwich for it yet. Hopefully, I can get one and start doing some testing on the engine I currently have. Since my RX finally runs now:banana: Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted March 2, 2006 Share Posted March 2, 2006 To tell you the truth, oil temps are what we should be worrying about, like Caboobaroo says, as it actually does more of the cooling for the engine than the coolant does on its own. Now, I have noticed that extended freeway driving will bring my oil temp up to about 225*F, which is HOT!!! (Don't know what an EA82T runs) Almost to the end of the gradents on the autometer gauge I'm using. My car does have the factory oil cooler, but its pretty small. I have a big fat one sitting in my basement, but the high temps make me wonder if my oil thermostat in the cooler sandwhich isnt opening all the way or opening at all. At some point I would like to have the oil and coolant passages extrude honed (Polishing will decrease surface area, thus cooling potential) when I can track down a decent spare engine. Quote Link to comment Share on other sites More sharing options...
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