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what makes a fat case ea71 a fat case ea71?


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as I recall, in the late 80's when Subaru started to phase the EA71 out, they started using a similar block to the EA81, so that an EA81 intake manifold and Y-pipe will fit, but a standard EA71 will not - I may be wrong, but I think they also started using an EA81 bellhousing

 

bottom line, the engine is wider

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Mmmmm, I thought they just fed it a high calorie diet?

 

Seriously, I don't think the engine is wider as much as it is a little taller. I have both and intakes, y-pipes, and bellhousing adapters are all interchangeable. The biggest difference is the water crossover that is right beneath the intake manifold. The early style has an external water crossover that bolts onto the crank case. The later style has this same coolant crossover cast right into the crank case. The water pumps are also different between the two. I believe the heads and valve covers are slightly different too but I'd have to look again to be sure.

 

The style of coolant crossover is the quick tell-all.

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Swiftt, I believe there is a minor type-0 in your post

 

please forgive and correct me if I am wrong but you state

 

"The early style has an external water crossover that bolts onto the crank case. The later style has this same coolant crossover cast right into the crank case."

 

Don't you mean "intake manifold"?

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Skip, please correct me if I am wrong, as I dont mess much with EA71's but I thought there were three variations -

 

The first one was the 1970's version - it had removeable piston liners, and tended to blow head gaskets. It has a top-center mounted starter.

 

The second one was the late 1970's/early 1980's one that had a top-center mount starter, but cast-in-block liners. A much more solid design. Same characteristics (for the most part) as the other EA71.

 

The third one was made in the late 1980's, mainly for the JDM and European markets, that had the same starter mounting position as the EA81, and it was used in the EA82 style body - it had hydraulic lifters, and was very different from the normal EA71's in other ways (higher compression ratio). It is very rare in the US, but will mate to EA81 or EA82 transaxles. (I don't know if it was even imported here as factory equipment.) - this is what I think is being refered to as a "fat case" EA71

 

I may be confusing the EA71 with the 1400 engine for the first two examples, but I do remember a board member having trouble getting a JDM EA71 engine he bought to fit in his car due to the different intake/exhaust setup, and managing to get a EA81 intake to fit.

 

Please do correct me if I am wrong tho......

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He's refering to the coolant passage that runs through the block on top the EA81... the later EA71 had it cast into the block as well The early engines had a bolt on flat cross-over pipe under the manifold that bolted to each half of the block. Coolant still runs through the manifold as well on both.

 

As for the EA71 with the side-mount starter, it was in the STD model hatchback (4 spd, FWD, Dual Round headlights) from 80-89. The 81+ ones had the side-mount starter. No on the hydro lifters (for the STD hatch), but the JDM engines did have them. Only place to find the bell-housing for the side-mount from a US car is the STD hatch.... as far as I know. No other model was equipped with the EA71 after 1981. Even the DL had the EA81.

 

GD

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its more or less a 1600 ea81, as far as using the same starter position, intake manifold diensions, and water pump

 

the older ea71 had a water pump where the backside was exposed to the outside.

 

the fat ea71 has the sae starter and bolt up to the tranny for the bell housing, but the but where the bell housing bolts onto the bolock, the pattern is saller than the ea81

 

but the fat case ea71 bell housing will bolt onto the old ea71 to put later trannies in oldersoobs

 

i am not sure if the heads are swappable, but they should have the same valves as ea81. maybe fat ea71 heads will bolt onto old ea71?

 

the fat ea71 is found in hatchbacks, especially after 85 with the dl or std hatch, gl's got ea81

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ok here's a bit more info regarding the earlier style EA71s...

 

The external water passage engines had68hp roughly, depending on the year. Also, the waterpump is totally different then the other EA71s. The passage runs under the intake manifold and bolts to the back of the waterpump, in the same area where the newer style EA71s have the coolant line that runs back to the heater hose. Also, the early EA71s have a plate which bolts to the back of the waterpump as well, except where the coolant passage bolts to. Next, is the top mount starter EA71. The waterpassage is now integrated into the intake manifold like the later side mounted EA71s and the EA81s but the case is still smaller then the later EA71s and EA81s. The waterpump is also the same waterpump as what is on the EA81s. The top mount EA71s with the EA81 waterpump was more of a JDM engine since the older style EA71 went right up to the bodystyle change (EA81). It was also a factory replacement as well. I've had both of these styles of EA71s and the top mount with the EA81 waterpump has quite a bit more power then the original EA71. Now I don't now much about the fatcase EA71 but I'll take a swing since I've seen one before. Has the same case as a EA81, same exhaust, intake, bellhousing, waterpump, but the bore is smaller then the EA81, thus giving it a 1.6 literage instead of the 1.8 literage. Thats a total guess but maybe I'm right?

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The waterpump is also the same waterpump as what is on the EA81s. The top mount EA71s with the EA81 waterpump was more of a JDM engine since the older style EA71 went right up to the bodystyle change (EA81)

 

That's not quite right. If you were to take a look at the water pumps sold through the dealer, you would notice that they pulley for an EA71 pump is smaller then an ea81 water pump. Also when subaru went to the EA81 body style the EA81 engine was only available in subarus with an automatic transmission, for the 1980 model year. Subaru continued to use that middle version of the EA71 in bargain basement 2wd models. During my time scrapping out subars for a living I don't remember seeing any EA71s with the side mount starter until about the 84/85 model year.

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Skip, please correct me if I am wrong, as I dont mess much with EA71's but I thought there were three variations -

 

The first one was the 1970's version - it had removeable piston liners, and tended to blow head gaskets. It has a top-center mounted starter.

All EA71s had "dry" liners. Unlike the removable iron "jugs" used in previous engines, these were thin sleeves cast inside aluminum cylinders.

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