February 26, 200620 yr This is for a EA81 motor I have been reading through a few post and using the search fuction and have got mixed results so I figured I would just ask. How much have you shaved (decked) off your heads? And why did you pick that amount? I know if you take off too much you can not get your itake to fit. Soo lets hear it.
February 27, 200620 yr This is for a EA81 motor I have been reading through a few post and using the search fuction and have got mixed results so I figured I would just ask. How much have you shaved (decked) off your heads? And why did you pick that amount? I know if you take off too much you can not get your itake to fit. Soo lets hear it. Subaru max states .015" off the heads. That's what I took off mine. I've heard .020" is possible and the intake will still bolt on. Any more than that, and you *could* make the holes in the manifold a little bigger and get it to work, but you are decreasing the sealing area between the intake runner and the coolant passage. Even stock this is a weak point, so I wouldn't make it any smaller than it has to be. If you want more comp. then you can install SPFI pistons, or EA71 pistons for a little bit. I calculated it out once, and with the heads decked .015", and EA71 pistons you should be around 9.3:1 - 9.5:1 or so. SPFI pistons would give you 9.5:1 with NO decking of the heads, probably close to 9.8:1 with the heads decked. GD
February 27, 200620 yr I personally have built two EA81's in the lsat couple of years. Both run 1600 pistons, webers, large Delta cams and one was shaved .015 and the other .020. I have had no issues with either. Both generate good power and torque through out the power band.
February 27, 200620 yr Author Well then this may sound nuts.. I got off the phone with stratuss (Mykal) today. I was talking to him about the dual carb setup he wants to offer me as well as info about the cam. Any who.. He deckes his at .05 to get a 9:1 comp roughly he does not how ever use any thing but the ea81 pistons. He said I would have to redrill the intake. He also said if I wanted to I could mail them to him (my heads) and for $250.00pr a head he would deck them and give them a three angle job. I asked him is .05 alot and he said no.. that it works fine as long as you have a good coolant setup and that he builds these all the time.
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