I've done plenty of searches and while I have found advice (chances are you don't need to rebuild the bottom end) and tricks (port heads, use EA71 or 82 pistons etc), I have not found and actual build thread.

 

I have built 4 EJ25 race engines and the Haynes manual for the ea81 looks pretty straight forward but I want to see if anyone has actually composed pics and a walk through to address any "tricks" and "shortcuts".

 

Thanks for your help!

Edited October 28, 201114 yr by tundrabrat

I don't have any real "tips & tricks" but I documented my engine build with pictures. I just followed the Haynes manual for Subaru 1980-1989. I never added them to my brat build thread, so I was planning on putting them there.

I've done plenty of searches and while I have found advice (chances are you don't need to rebuild the bottom end) and tricks (port heads, use EA71 or 82 pistons etc), I have not found and actual build thread.

 

I have built 4 EJ25 race engines and the manuals look pretty straight forward but I want to see if anyone has actually composed pics and a walk through to address any "tricks" and "shortcuts".

 

Thanks for your help!

 

Hope this helps, just some thoughts. Lifters and rocker arms are heavy, tho you have aluminum pushrods? and you only have a single valve spring stock. So it's rev limited.

 

If you use the EA 71 pistons, you can if you want "destroke" and take a bit off the tops of the pistons.

 

If you don't have excellent compression, why bother in the first place?

 

Doug

 

P.S. Just ran across this again:

 

Camshaft Identification On

Subaru 1.6 & 1.8L Engines

 

The AERA Technical Committee offers the following information to assist technicians in camshaft identification and possible reuse limits on Subaru engines. Although the camshafts from different engines look similar, substitutions are not permitted.

 

Subaru has marked their camshafts with numbers for identification purposes. Refer to the chart for easy reference and reuse limits.

 

Cam & ID Lobe Lift Push Rod

Engine Lifter Type Mark (Int & Exh) Length

 

1.6L OHV Solid 51 1.2693-1.2732 8.620-8.624

1.8L OHV Solid 72 1.2693-1.2732 9.080-9.100

1.8L OHV Hydraulic 76 1.4134-1.4173 9.120-9.140

 

The wear limit for cam lobes on all camshafts is .059 (.15 mm) less than the listed specification. The maximum camshaft end play is .008 (.20 mm) and is controlled by a replaceable thrust plate.

 

The AERA Technical Committee

 

Just some numbers for you, hth. A stock flatop N/A EA 81 piston I have weighs 415g. New EA 82T piston comes in at 365g. I'll weigh a SPFI piston, which is more than the T piston. Edit: 396 grams for SPFI piston.

Edited October 30, 201114 yr by Quidam

Is this what you were looking for?

 

EA81 performance build essay

^^^ Great... Thanks... Keep them coming!!! :clap:

Here's a E 81 N/A piston installed in E 82 #4 cylinder. The -.036" is how far down in the bore it sits.