Re: useing a Subaru DOHC Engine

Reg Clarke <airryder@...>

Hi ,Tony
I have always used the SDS ignition system on my Subarus and work great he has a web sight. Simple and cockpit adjustable. 

Best regards and cheers.  Reg Clarke

On Dec 12, 2013, at 13:27, jon@... wrote:


Hi Ron,

Whole bunch of stuff…

The DOHC is not the ideal engine for aircraft as it is heavier than the SOHC. The DOHC big benefit is better breathing at high rpm - not needed in an aircraft.

The answer sensor/computer issue varies by year - the newer/more recent, the more difficult.  However; my experience (and most others) has been that the auto computer is a very poor fit.  You are miles ahead to go with Tracy Crooks EC-2 or the SDS EFI system.  Both are pretty inexpensive but us auto-engine guys are cheap and don't like to spend that money. However; it is dough well spent as the alternative is to spend hundreds of hours trying to work around the OEM computer only to later spend the money for the aftermarket (assuming you haven't run out of steam or damaged your airplane).  However; if one were to REALLY want the OEM ECU, I would find the oldest engine possible (SOHC, EJ-22, about 1994 - maybe an early EJ-25 with SOHC or swap SOHC heads onto it) and get your hands on Don Parham's book that details the steps to making it work.  It will work, but it will never be ideal.  I flew mine with the OEM ECU for a hundred hours or so and was not happy with the inability to tune it.  Others have fought larger problems.


Join the guys over on the Yahoo FlySoob list - lots of knowledge there.

Hope that helps,


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