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Guest Message by DevFuse

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EA81 performance build essay *HI-RES PIC WARNING*

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24 replies to this topic

#1 backwoodsboy



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Posted 09 May 2009 - 10:33 AM

Well folks, for those that dont know... its time to come clean with what Ive been doing all winter.

Can we say performance build?


Original EA81 out of my BRAT... YUCK!


Tearin' it down...

More teardown...

Now for the hand-cleaning/POR15-ing of the steel parts. :rolleyes:

Case halves off to the machine shop...

...while I round up some EA82 SPFI pistons.


Heads back from Jerry DeMoss... decked .030, ported and polished with a match-port intake. :headbang:



Crankshaft machined 10/10 with new ACL main and rod bearings.

Case halves are back!

Camshaft is back, with a DeltaCam torque-grind!


Case halves back together.

Install pistons. *Note the clearance, this is TDC*

Heads on! Installing rockers and pushrods.

Wheel 'er from the shed to the barn...
(sweet, the engine gets to go wheeling before the brat!)


Up in the air... install oil pump and filter, fill with oil... and drop er in. :headbang:

MAJOR thanks to Jerry DeMoss and Ken at DeltaCam for the help and great service!

More pics to come... stay tuned.

Edited by backwoodsboy, 09 May 2009 - 11:41 AM.

#2 darlingchip


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Posted 09 May 2009 - 11:16 AM

Nice pictures! I am glad we got your brat going again. :banana:

#3 Greybeard


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Posted 09 May 2009 - 11:26 AM

What kind of carburetor are you going to run, or is it going to be SPFI? Exhaust? Can't wait for a report on it's performance.

#4 backwoodsboy



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Posted 09 May 2009 - 11:32 AM

Currently Im going with the 'ol Weber 32/36 DFAV, which is doing a fine job.

Ive actually had it running for 3 days now. Put almost 300 miles on yesterday. :headbang:

Exhaust is 2 & 1/4" from the factory Y pipe cat(less) back. :rolleyes:

From 1700 - 3000 rpm there is a DEFINITE heavy power band where there previously was, um... nothing.

Its a torque-y little sucker, lemme tell ya.

Edited by backwoodsboy, 09 May 2009 - 11:39 AM.

#5 Pooparu


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Posted 09 May 2009 - 11:40 AM

Nice job on the build. :banana:

#6 Bucky92


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Posted 09 May 2009 - 12:16 PM

Congrats John!! Will be nice seeing that Brat again. So when are you going to take this POS coupe off my hands?? :) ( seems all my cars go to John)

#7 backwoodsboy



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Posted 09 May 2009 - 12:41 PM

So when are you going to take this POS coupe off my hands?? :)

Thanks Connie!

Jess and I have been talking about doing a hatch as the next project, actually.

You dont want that Coupe going to my garage.

Id throw in an EJ22T, the XT6 5spd AWD with diff lock, 5 lug swap it, and lower it.

Sounds great you say? ....well, then youd be getting it BACK! Dont make me do it. :grin:

#8 Bucky92


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Posted 09 May 2009 - 12:52 PM

Ha the way I feel about that coupe ....it could be sitting out in your field up on its side just like Rocky. And once its gone..I dont even want to see it again....unless it is in the shape of a small cube.

So you planning on running the Brat over foofy haired Datsun lady this year?

Edited by Bucky92, 09 May 2009 - 07:20 PM.

#9 hatchsub


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Posted 09 May 2009 - 01:06 PM

pics no worky for me :( stupid mac

BTW john let me know how big of a difference you feel in that cam swap. Im thinking i might do that later this summer when i go to redo my valve seals.

Edited by hatchsub, 09 May 2009 - 01:13 PM.

#10 bratman18



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Posted 09 May 2009 - 07:16 PM

Awesome!! My Brat had shaved heads like that before I bought it, it had somewhere around 120 horse just from that!!! I wanted to do it but I just haven't. I bet there is a big difference. Nice job!! I want some more pics of your Brat!!

#11 erik litchy

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Posted 09 May 2009 - 07:56 PM

what do the ea82 pistons give you? that looks so simple to work on compared to the ea82.

#12 Durania


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Posted 09 May 2009 - 11:25 PM

I found myself covering up the laptop from the wife. Felt like I was looking at porn with her in the same room as me. I want to see a video of that thing running.

#13 Jerry DeMoss

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Posted 09 May 2009 - 11:33 PM

Nice pictures man. Thanks for the nice words on the heads I did up for you. Glad you like them.

Now lets see the pretty engine get muddy!:brow:

#14 rat fink

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Posted 10 May 2009 - 03:14 PM

That's a nice build! I love it someone does the neccessary modifications to make an engine more efficient rather than writing it off because it's not the most powerful engine of the the line. Being a swap junkie I wouldn't know anything about that, but it's nice all the same. :lol:

#15 hatchsub


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Posted 10 May 2009 - 09:01 PM

Yea i think i may go this route too but not sure when ill have the time to do it. I would love a bit more kick with this car.

#16 cockroach


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Posted 11 May 2009 - 12:58 AM

nice to see an EA81 getting a rebuild and not swapped out for another subaru motor. are the EA82 pistons the same size as the EA81's or did you have to get the engine bored out a bit? what was the cost of the rebuild if you dont mind me asking? my engine went bang today (think it broke a connecting rod) so now im looking at the cost of a rebuild or swapping the engine if my one has too much internal damage.


#17 idosubaru


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Posted 11 May 2009 - 06:54 AM

are the EA82 pistons the same size as the EA81's

same - interchangeable.

#18 backinbrat


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Posted 11 May 2009 - 08:32 AM

ah yes, very nice, good work man, i admire your skills,nice clean parts, love it!

i am thinking of doing the same with mine, but have you had any trouble with skimming the heads? i.e valve timing and all that, as i only get one chance with mine if i do it, theres no go out and get some more!

i am going to rebuilding mine soon when the funds come together, ive got a power cam, dualport heads and all that, which i want to transfer over, and ive got a pair of 40 IDF webbers on there way as well very soon as well as wanting to use the 12.5:1 compression pistons avalible from ramengines, what do you reakon power wise and torque yours is now good for, 130hp? 160lbs?

im aiming for around 170 hp and whatever torque that produes with it, should be fun, especially in RWD! hahaha

#19 gray wrx

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Posted 11 May 2009 - 12:09 PM

nice jod ya me to what was the cost of the rebuild if you dont mind me asking? I need to know so I can start hooking for extra $$$ or sumthing I love the look of that clean motor mine has so much oil on it it is as big as a V8

#20 glh1975


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Posted 26 May 2009 - 07:06 AM

Looks like a great build.With the Delta cam in it,how's the fuel mileage on it now?That's something I've always been curious about before trying it.

#21 gwilson87


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Posted 03 June 2009 - 08:40 PM

Inspiring, truly inspiring. Makes it look possibly for joe shmoe to accomplish... I am tossing around the ideas of rebuilding my EA81 or being all trendy and going with the EJ22 like most people. Thanks for the write up.

#22 riverranger


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Posted 14 March 2010 - 03:01 AM

Engine looks fantastic. What did your fuel mileage turn out to be? I just bought a 1981 Brat and believe it or not, it;'s actually in good shape. I'm not sure exactly what I'm going to do with it yet, but I do know I want to do what you did to the engine. I have located a car with a SPFI EA82 that I am going to comvert the SPFI unit over onto mine. After reading your performance build I guess I can use the pistons also. Did you use the original rods with the EA81? What did you have done to the case halves? I would like every detail of your build so I can do it. Also, do you think I should leave the stock 4 spd tranny in mine, or should I go with the 5 spd?

#23 apintonut


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Posted 15 August 2013 - 01:42 AM

the pics are not working for me :-(

#24 Bantum


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Posted 15 August 2013 - 09:16 AM

Same here - getting this error message : "Invalid Conversion ID"

Ciao, Bantum ...

#25 kirzick


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Posted 20 July 2014 - 06:04 PM

Please fix the pictures, i could really use it. Thanks!

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