Subaru Conversion, CSOB style... Options

[jsteele22]

I've been thinking about what it would take to do a Subaru install
into my 914, and making it as inexpensive (and as home-brew) as
possible. I have a friend who is a machinist with a lot of enthusiasm
for the project, and a nice shop. He's done a couple of adapter plates
before, so I'm confident in that part. What I'm more curious about is
the flywheel. My idea for this is to take the stock Subaru flywheel
and machine it down to a radius of 4-5-ish inches, and then bolt a
stock Porsche (okay, VW) flywheel to it. So the Subaru FW becomes
just an adapter hub. Then, the thickness of the adapter plate is
chosen to get the input shaft to reach the proper position in the
friction plate/pilot bearing.

What do all you hybrid gurus out there think of this ? Am I
overlooking anything glaringly obvious ? (I haven't seen the pieces
in person, just in Haynes & on EBay.) Sure, the assembly will have to
be balanced carefully, but I think we (he) can handle that. The
engine I'm looking at is an EJ25 (165-ish HP) or, more realistically,
an EJ22 (130-ish), so it won't be an axle-snapper like some of you SBC
folks are driving.


Another issue is the engine mount. I've seen pics of Scott's, and
another one (tube steel) that I think Friid had made up, but not the
ultra-secret Renegade design. One idea I had on this is to not use
the stock Suby engine mount points, but instead make the adapter plate
several inches wider than the bell housing. Then each side of the
adapter plate could have an "L" shaped bracket bolted (sideways) onto
it; the bottom of the L would bolt vertically onto the plate at two
points, and the back of the L would point (horizontally) forward to
hang from a cross bar, either in the conventional (lower) position, or
up high across the top of the engine bay. This would take essentially
all of the torque off of the mounting bar bolts, and would leave an
open path for the shift linkage. In practice, I'm sure there would
need to be a little cross-bracing to prevent side-to-side motion, and
also to keep the L from straightening. Again, oh learned ones, what are
your opinions on this setup ? I *think* that suspending an engine
from the adapter plate is essentially what all the Subaru airplane
folks do.


I'm really pretty excited about the idea of putting a Suby in my car.
And it would be even more cool if it turns out to be affordable.

Please let me know what you think....

[jsteele22]

Okay, so at least it sounds like the ideas aren't totally crazy.

About the mounting, it sounds like a plan : Leave some ears on the
adapter plate, and hang the engine from a reinforcement of the
trunk/engine compartment wall. Will the stock shift linkage now work
as-is, or is the Suby oil pan in the way ?


About the flywheel, I like Mueller's idea about welding in a new
center section to the stock 914 flywheel. I wasn't sure if welding a
flywheel was kosher from the point of view of warpage, but I'll ask
about it. Also, if I go with the bolt-together approach, I like
Brian's idea about the locating pins. Might make for more balancing,
but probably woth it.

Tony, I'm not sure if we're on the same page. The way I'm picturing
it, the 914 flywheel remains basically intact, and it is held in the
exact same position with respect to the 914 transaxle bell housing and
starter, so there are no teeth to cut. The whole challenge is *how*
to hold the flywheel in that position. I haven't done any homework on
this yet, so I'm not sure how much axial distance needs to be made
up. But the differences in Suby vs 914 design and the thickness of the
adapter plate combine to make one critical distance : the distance
from the mounting surface on the end of the Suby crankshaft, and the
plane that the rear (tranny-side) surface of the 914 flywheel needs to
be held in. If the distance is about the same as for a stock 914
flywheel, the "weld-in" approach of Mueller looks more appealing; if
the distance is rather large, then the "bolt-on" approach looks
better. I also don't know quite where the friction plate presses on
the flywheel, but "common" sense would say its mostly out near the
edges. Hopefully there's room closer to the center for the weld-in or
bolt-on solution.


audioculture : that sounds like a cool project. I'm actually planning
to stick to a "mere" 165 HP (or maybe just 130) non-turbo engine. I
just wanna be able to get up to 30 or 65 MPH quickly. There's no way
I could have a 275 HP 914 and not get into trouble......

And a little note : I'm just tossing the ideas around right now
(and hoping my 2.0 L doesn't turn into chunks). This may or may
not turn into an actual project. If it does, you'll definitely
know.