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Does anybody do this??? (long)


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OK, I've got an 85 GL hatch with an EA81 that I've been working on lately. When I first got the car (from StormTrooper, Thanks Don!) it had oil leaking into the coolant. So I dropped a motor from an 82 I had sitting around into it and started driving it. The 82 motor was never planned to live in the car very long, just till I could do a reseal on the original motor.

 

NOW, many moons later, I've got the original motor all torn down and the problems are mounting up. First thing I noticed was that the heads have the infamous little cracks between the exhaust and intake valves on cylinders 3 and 4. No big deal, $150 for a new set from AHR. Next, the gaskets looked so bad, I couldn't believe that the motor wasn't pooring water and oil all over the ground, needless to say, I wasn't able to isolate the spot where water was getting into the oil. With 234k on the bottom end, I fugured it probably needed bearings and rings, but when I tore is apart, I noticed some pretty heavy carbonization on the piston skirts. Uh Oh. Soooo, I take the block halves to the local engine rebuilder to have them hot tanked and bored over, but they tell me that their boring machine doesn't do flat motors :-\ Meanwhile, I'm still having trouble finding all the seals I need to get the motor back together (but hopefully the NAPA distribution center can end that saga today).

 

So right now I'm in search of a shop that will bore a subaru motor. Immediately after that I'm going to have pistons made, probly do 9.5/1 comp. At the same place I do the overbore, I'm going to have them do a cam grind and balance, because I figure if I'm this far into it, I might as well do it up :D

 

So my question is. . . Does anyone do this to EA81's or am I just nuts?

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Yeah - Qman has a couple EA81's that are built up. Lots of folk have changed out the cam's in them and what not. Even CCR will put in high compressions pistons for you if you like (EA71 pistons fit, and will raise the compression). EA82 SPFI pistons should works as well for this. I wouldn't go to the expense of having custom pistons made. Decking the heads to match the reground cam profile will further raise the compression, but don't go over .020, as the intake won't line up anymore if you do. Make sure the heads you got are the big valve heads that came on the hydro lifter engines like you have.....

 

Delta cam up in WA does good cams for lots of board members - I think it's around $80 for a cam for the EA81, and they have several profiles availible.

 

GD

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If you really feel it needs to be bored make sure you get the over sized pistons first. they can be done by a creative machine shop but almost none will have a torque plate to fit that motor.

I had one done once (no torque plate) and it did not last long at all 54 miles:banghead: the machine shop I took it to later said that it was bored too tight.

 

if the taper and out of round is not bad I would just hone and reassemble with new rings and bearings.

 

I wasted a LOT of $$$$ trying to do the bad arse rebuild only to have it fail.

 

could just be my bad luck but be aware of the situation.

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Thanks for the advice guys. I'm having trouble finding a shop that will bore a sube motor as it is. Maybe I will just drop that part of the plan. The pistons that are in the car have got to go though, they are carbonized and have some scratches and whatnot on them. The cylinder walls themselves are just smooth, no crosshatching what-so-ever. I'm taking the block over to a machine shop right now to have it hot tanked and I'll have them mic it out at that time.

I'll keep you all updated

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Find another block if you need to bore it. The blocks aren't too expensive, and as has been pointed out, no one knows how to do it, and mostly the results are bad when people try. Just put in some SPFI pistons, or EA71 pistons, and call it good. Bore failure on EA81's is almost unheard of anyway - the bottom end's get sloppy, or you throw a rod (usually out the top of the block!) LONG before the rings fail.

 

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I know the probelm with finding anybody to rebuild Suby engines. There's nobody that will touch em here. I'll prolly end up going to Phoenix just to get a used one out of a junkyard. 200 miles just for an engine? Is that legal??!?!!?:banghead:

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Wow, this topic realy sparked some interest. Well, I went to NAPA and ordered the cam and crank seals as well as an oil pump reseal kit, total cost $42.31. They will be in on Monday.

 

NAPA also had the bearings but they were $48.99 for the mains and $64.99 for the journals, and I dont even know what the situation is with the crank is yet. They could also get Piston rings in any size I want for $71.49. Since I don't know if I'll need any of those parts oversize or if I can get a better deal somewhere else, I'm holding off for now.

 

The only thing I just couldn't find is that water jacket O-Ring that goes between the block halves. No one even knew what it would be called.

 

The block is still in the hot tank (actually they just put in this morning), but I should be able to pick it up tomorrow. At that time they are going to mic the cyliner walls and let me know what the verdict is there. They will also spec out the crank and cam, total cost $37.50

 

Well thats where I am right now, I'll keep you updated

Later

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  • 2 weeks later...

OK, Sorry for the delay, I've been busy getting the rest of my parts together for the rebuild. Just got the Block back from being hot tanked and honed. The block looks mostly OK, there are some areas of cylinder wall wear that did not totally dissapear with the honing. I'll try to take some pics and post them so you guys can tell me what you think.

 

Right now the machine shop has the crank, cam, and connecting rods to do a regrind and spec out new bearings. $45 to turn the crank and resize the connecting rods, $35 for the cam regrind, and $48.50 for bearings in whatever size I need. As for the other parts, so far I've got the crank and cam seals, an oil pump rebuild kit, and the whole top end rebuild kit (head gaskets, intake gaskets, exhaust gaskets, etc. . .). I've also got a set of rebuilt heads coming from AHR in Oregon that should be here by Friday / Monday.

 

Unfortunately I'm still missing that pesky block seal and the flattened out O-Ring that goes behind the oil pump, in front of the cam. I'm also trying to get a new set of pistons, but they are proving hard to track down. Rings wont be cheap either, but at least I know where I can get a complete set in just about any size I want to order.

 

Heres a question for all the others who have tried this before, what is a good way to remove external corrosion from the aluminum block? Its not real bad, but there is some visible tarnish and "scarring" on the external surface of the block that I would like to polish out, but I cant think of any way to do it without causing futher damage (i.e. wire wheel). If I can get it cleaned up pretty good, I was thinking about painting it too and was wondering if anyone had any tips for what type of paint to use and what steps I should take for prep?

 

Thanks for all the great comments. I'll keep you posted and hopefully get some pics up soon.

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