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....

[TonyAKAVW]

I like the engine mounting idea. The engine mounts on the subaru engine are as I recall, about 2/3 of the way back or more anyway, so its not like you are moving the stress point back a whole lot. However, you now have a big stress at the joint of that L shape. the weight of the whole engine is going to be pushing down right there. Also, at the point where you meet the stock engine bar, you'll have to fabricate something pretty rigid, because there will be a tendency to push that bar out at an angle. Even if all of that is rigid, you may get some wierd oscillations or resonances in the structure. But what you could do is go straight up from the adapter plate and weld in a large heavy plate into the trunk and bolt it to that. You'd have to see what kind of stuff in the vicinity you'd be stressing..

As far as the flywheel goes.. I have both at home and I will take a picture tonight of them and post it here. Its possible this would work, though the tricky part will be cutting new teeth for the starter. As it is normally the subaru flywheel is basically a flat flywheel, versus the 914 design where the pressure plate and so forth sit almost inside the flywheel's perimeter ring. I'm not sure how things would work for the clutch, especially using a porsche design which is made to have that raised outer ring.

Maybe there's some other manufacturer that uses the flat-plate design and you could use their components???

Also I think you'll have to move the flywheel out on a hub which will need to be welded to the flywheel in all likelyhood.

Anyway, that adapter plate/engine mount is a good idea, and if you get it to work you would probably be able to sell them, especially if it was compatible with Kennedy flywheels.

-Tony