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Dissection of a Very Modified EA71 - Please View


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I've tinkered with motorcycles a bit, rebuilt one engine. But I am a novice mechanic compared to others on the board. And still very new to the world of subaru. So, apologies in advance for any dumb questions! :-\

 

I have begun a tear-down of what I'm hoping is a very special engine. I've attached lots of pics to this thread. Please take a close look at your leisure and let me know what you know. This is the first time I've looked inside an EA71, so I'm not sure what's normal and what's not.

 

Firstly some history: I was sold this engine on the premise that it was an E71 with modifed heads (obviously), dual valve springs with stainless valves, modifed rocker arms, deep sump oil pan (obviously), possibly custom pistons, and possibly that it had been left out in weather and held water at one point in its life.

 

Now for what I have learned so far: By measuring the placement of the mounting studs on the intake manifolds I have determined that the heads have been set up for dual VW Weber 48 IDAs. This is a gigantic racing carburetor that is typically on engines larger than 2L. I have a hard time imagining that these would run well on a 1600 engine. I am wondering if the engine has been bored out, but I am not sure how to tell.

 

Furthermore, I am fairly sure that the heads began life as EA63 dual exhaust port heads. From what I have read, this would mean that the engine must also have an EA63 cam. I have not split the case yet, but because of the monstrous carbs that were on this thing, I have my fingers crossed that there is some sort of high performance cam in there. Else again, I just couldn't see the engine running properly with those gigantic carbs.

 

And finally, since the tear down, I can see an obvious water line on the valves, indicating that the engine has definitely held water at one point in its life. I'm not sure how to tell if this has done a lot of damage.

 

So please correct me if I am wrong on any of the above points, and now here are several pictures from the tear down. Is it junk? Is it useable? Is it awesome? Let me know. The collective advice from the USMB knowledge pool will weight heavily my decision on what to do with the engine.

 

The engine as it got home

100_4121.jpg

 

Top-down view

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Rocker arm - Modified?

100_4123.jpg

 

Intake manifold close-up

100_4119.jpg

 

Valve spring close up

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Engine front

100_4136.jpg

 

First head - Notice water line

100_4137.jpg

 

Second head

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First bank of pistons - Are these custom?

100_4138.jpg

 

Second piston bank

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Serial No.

100_4135.jpg

 

What it looks like now

100_4146.jpg

 

I guess that's it. I'm very excited to hear your comments. Also guess I want to mention the distibutor looks great. Shaft had no wobble, which to me indicates not a while lot of running time. If you guys need more picture to figure anything out, just let me know. I plan on opening the case soon.

 

Thanks in advance!

Crabman.

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From what I see right away:

 

Larger valves with aftermarket spring caps

Custom pistons for HIGHER compression (note the recessed area for the valves)

Bore size is stock

Possibly aftermarket studs

Possibly custom pushrods

 

Got any good pics of the exhaust ports? Get those valves out so we can see in there better :grin:

 

From what I see so far, those custom pistons alone make this engine worth having... But it definitely had some water in it at some point! Look at the rust in there :-\

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looks like a sweet engine!

 

does it turn over still? can you get a look at the cylinder walls? they are most likely pitted due to all that water being in there however it looks like the block is the only part that was left untouched so swapping everything over to a new(er) block shouldn't be a huge issue.

 

get those heads cleaned to make sure the valve seats aren't ruined and order up a engine rebuild kit and get those heads rebuilt and throw a complete engine together. :D

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Thanks Kostamojen and Zefy. Engine does turn over. So what I'm hearing so far:

 

1. Heads may need to be rebuilt, valve seats might be poor due to rust.

2. May need new shortblock because of rust in cylinders

 

I'll try to take some pics of the pushrods and exhaust ports. I'll also try to finish up the tear down in the next couple of days too. Still a couple of question marks left about what's in the case.

 

The webers that those heads are set up for are insanely expensive, and may be flat out cost prohibitive, or at least make this a very long term project.

http://www.webercarbsdirect.com/product_p/wk328.htm

 

They sure look mean on an engine though. Here's a pic of what they look like on an old bug.

30120360.jpg

 

I may look into some kind of adapter for the intake manifolds, so I can run a cheaper VW dual carb set up. Money is tight right now!

 

Looking forward to more comments. Thanks guys! Crabman

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Looks like aftermarket springs and retainers. High compression pistons. They cut down the top center 2 head studs for the modified heads. It has stock pushrods, you'd have to measure the lift to see if it has a bigger cam. Kind of funny if it has a bigger cam with the stock pushrods. The EA63 I just took apart with a cam in it had custom solid pushrods and they ground the rockers smooth, but standard valve springs and retainers. I don't think that oil pan would fit any subie frame. I'm guessing this was in some kind of sand rail or something. The cylinders don't look so good. You might be able to hone it and put new rings in it, or you might need new block halves. Oh and that is an older EA71 block, I'm working on an 80 EA71 and the block is different.

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Guessing that "M" on the end of the ID number means Modified ??

 

Has anyone seen an "M" on an EA engine serial number before? Were some engines modified at the factory?

 

New question: Cylinders appear to be 'sleeved'. Is this normal? Possible to resleeve the case?

 

Subaru360 - Agreed, this was probably on a sand rail at one point. And although some work into that deep oil pan, It will definitely won't work in my Brat due to the position of the cross member. Love to see some pics of those pushrods and rockers you mentioned.

 

Well if the cylinders are shot and can't be repaired (reasonably), I also have another EA71 in my garage. It's a JDM fat case. Less than 40,000 on it. Still in the crate. Was planning to keep it as a spare, but now I am thinking I should take the best from both of these engines, and build something really super.

 

Going to be very busy through the weekend, but hope to find some time in the week to get into the case. I love tearing down an engine. Each one has a story.

 

Keep those comments coming fellas. I'll put up pictures of the open case when I've got them.

Cheers,

Crabman

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If you swap those pistons into another block, I'd keep the pistons matched up with the heads. It dose'nt look like there is much room for things to be off in those compression chambers.

 

I suspect those heads are shaved to bump up the compression because they clearanced for the spark plug. When you get it running again, only use premium gas to avoid detonation.

 

While you have the heads off, you might want to find a spark plug that wont stick too far into the cylinder.

 

good luck, thats a sweet find.

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If you swap those pistons into another block, I'd keep the pistons matched up with the heads. It dose'nt look like there is much room for things to be off in those compression chambers.

 

I suspect those heads are shaved to bump up the compression because they clearanced for the spark plug. When you get it running again, only use premium gas to avoid detonation.

 

These are great suggestions, thank you. Planning on opening the case tonight, will post more pics if anything interesting.

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I suspect those heads are shaved to bump up the compression because they clearanced for the spark plug. When you get it running again, only use premium gas to avoid detonation.

 

While you have the heads off, you might want to find a spark plug that wont stick too far into the cylinder.

 

That engine will not run on pump gas. You'd have to measure the cc's of the head and know the volume of the piston dome to be sure, but I would estimate 11:1 or 12:1 compression. You'd need to run it on race gas. Even more so if it has a stock cam in it. A bigger cam will bleed off some cylinder pressure at lower speed and you might get away with less octane.

 

The standard thread length spark plug should work. When assembling just put a bit of modeling clay on the top of the piston. Install the head and spark plug. Spin the engine over and pull the head back off. Measure the thickness of the clay and you will know how much clearance there is. You may need to index the spark plug. To do that you use different thickness washers to line the electode up so it is in the notch in the piston.

 

It will however need a colder heat range spark plug.

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That engine will not run on pump gas. You'd have to measure the cc's of the head and know the volume of the piston dome to be sure, but I would estimate 11:1 or 12:1 compression. You'd need to run it on race gas. Even more so if it has a stock cam in it. A bigger cam will bleed off some cylinder pressure at lower speed and you might get away with less octane

 

Uh, OK, I am definitely getting outside my comfort zone here. :-\ There's no way I am going to build an engine that will only run on race gas. Can anyone tell me how to measure the "ccs of the head and volume of the piston dome", or otherwise, can anyone tell me how to accurately estimate the compression. And furthermore, what's ratio's take it into the race gas only zone?

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Uh, OK, I am definitely getting outside my comfort zone here. :-\ There's no way I am going to build an engine that will only run on race gas.?

Just use the shortblock from the other EA71 then, and use the cam from the "super" block.

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It looks to me like you bought a parts engine.

 

Split the case.

 

Inspect the crank and cam. If the cam is special you might use it in your other block.

 

Sell the pistons to somebody. They are the same bore as an ea81 and ea82 and theres a lot more people willing to run those motors in a race or non stock setting. Probably get your $ back out of the whole engine on just pistons alone if the rings are still like new.

 

Dont forget aluminum is pretty high value right now and dont get discouraged. Much interest in what you find splitting the block. You will need a wrist pin puller to get the pistons out or you have to split the case, tilt the center halves up at weird angles, use thin wobble sockets and wrenches to take the rods apart and slowly but surely you can get all the rod caps split and then take it apart that way.

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:confused: Oh man now I'm really confused. I got into the case tonight and got the cam out. It's got a number '51' stamped on the side. And according to my Chilton's book, this is a very normal EA71 cam. I also saw stamped, the letter G on the cam, but I could not find out whether or not this meant anything.

 

But here is the kicker. This EA71 block (and cam) is running the EA63 dual exhaust port heads. This goes contrary to everything I've read. EA71 heads have exhaust valves on the inside of the head (as well as the exhaust port). EA63 dual exhaust port heads have exhaust valves on the outside of the head (just like the exhaust ports). MEANING, if you are going to use EA63 dual exhaiust port heads on an EA71 shortblock, you have to run an EA63 cam from and engine that had the dual exhaust port heads of course, because the lobs will be in completely different places.

 

I really need to see some pictures to be sure of all this. Does anyone have pictures of any of the different EA63 cams? Does anybody know any of the identifying features of those cams? Does anyone have pictures of the piston side of the different EA63 heads?

 

I'll try to post some pictures of everything I found tomorrow, but we are getting ready to go out of town soon, so this thread may be on temporary hiatus.

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  • 2 weeks later...

Finished the tear down a while ago. Some good, mostly bad.

 

First off - This case is definitely garbage. Correct me if I'm wrong, but the dark spot is probably some sort of JB weld repair?

 

100_4337.jpg

Other side

100_4338.jpg

 

The deep oil pan is kind of neat. But probably only compatible with sand rails and what not. Any idea what those little hinged doors are for?

 

100_4339.jpg

100_4340.jpg

 

All four pistons are in decent shape, but the rings were totally shot. The manufacturer is "ARIAS", and I think the model is 353. I found a website for Arias pistons and emailed them looking for compression info, but they got back to me saying that they didn't have any info on this model because it was too old.

 

100_4345.jpg

100_4344.jpg

 

Finally the cam. And this is where the real mystery is. Because according to my book this cam is from an EA71. The EA71 has exhaust valves on the inside of the heads. These EA63 heads have exhaust valves on the outside. Which indicates to me, that this engine probably never actually ran in this configuration. Perhaps this explains that JB weld repair, and whatever catastrophic event happened to the case?

 

100_4349.jpg

 

I'd really like to hear what you guys think. If you see something I don't. I am looking for an EA63 cam (from a 4 exhaust port engine) right now. But at this point, I'm not even sure that you can put an EA63 cam in an EA71 case. So it's still totally a question mark, what I can use from this engine and what I can't.

 

Let me know what you think.

Cheers,

Crabman

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What makes you think that the cam has different lobs because of the different locations of the intake valves?

 

Thanks for the pics! I could make this engine run if I had your new cam!

 

It's not that the lobes are in different spots, is that the high spots on the lobes are at different places. I'll try to explain better. If you orient either one of your cams to point the same direction as the cam in my picture, try turning your cam so that all of the high spots in the lobes line up with all of the high spots in the lobes on my cam. You wont be able to. This is because those lobes open and close the intake and exhaust valves at very specific times. And since this cam is from an engine that originally had exhaust valves in the center of the head, you couldn't expect that this cam would be compatible with an engine that had exhaust valves on the outside of the head, because the specific times that those valves should be opening and closing would be completely different.

 

Having said all that, some information from you would really help me out. Do you have a part number for that new cam? Is there a number on that cam, between the first and second lobes like in my picture? Do you know where to find another one?

 

Thanks in advance!

Crabman

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Having said all that, some information from you would really help me out. Do you have a part number for that new cam? Is there a number on that cam, between the first and second lobes like in my picture?

Its a REPCO camshaft, part number 056-4000. There is a 3 on the camshaft, and a S-01 (possibly 8-01, hard to make it out). On the other side, there is a 3 digit number I can't read, looks like G13, but it could be 813 or S13 or 313.

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