2.8L/3.1L AND 3.8L FWD same bellhousing pattern?

[Frederic Breitwieser]

>I am going to swap either a 3.8L Buick or a 5.0/5.7L TPI in "one" of my
>Citation X-11's. I'll pause for a moment......

Into a citation, you probably want to stick with Olds or Chevy, since the
original car is Chevy, unless you swap out the transaxle as well.  The
Fiero drivetrain is very similar to the Citation, therefore, maybe a Getrag
from a Fiero might allow you to bring the 3.8L or 3800cc later version of
the same Buick engine into the Citation.

That and a turbo - wheeeeee!

Remember that ALL of the 3.8L FWD vehicles in the late 80's were automatic
only... so if you are putting a stick in, you absolutely MUST create a
flywheel.  But it can be done - a gent by the name of "Fieroman" slammed a
3800 Gen II Buick FWD block into his fiero, making the appropriate flywheel
(instead of a flexplate).  Its absolutely doable.  Here is his URL with all
the purty pics, drawings, diagrams, and snags:

	http://www.ipass.net/~fieroman/index.htm

Now, in my situation, I am mating a BUick 3.8L to an Audi transaxle, which
is a manual 5-speed great for mid-engine use, however I had the same
flywheel problem Fieroman did - none exist, at least not exactly.  So, at a
suggestion from George Dailey, I cut out an aluminum disc slightly smaller
than the existing flex plate, balanced it at a machine shop, and drilled
the same three holes that the flexplate has to bolt directly to the torque
converter.   Then, I drilled the crank - mount holes, getting them off the
flexplate as well.  Put in the torque converter bolts, then put in longer
ARP grade 8 bolts into the flywheel/flexplate/crank, and wala, a perfectly
acceptable solution to the problem.  Remember, that the existing flexplate
has the imbalance necessary to match the imbalance of the engine internals,
off 180 degrees, so a balanced "add-on" flywheel will work, if you get it
balanced.  This also allows the OEM starter to work, since the flexplate is
there and retains its teeth.

>Ok, are your eyes clear?

Very clear :)

>though. The 5.x will need an adapter plate. From the feedback, it looks
>like the FWD Buicks use the same pattern as the 2.8/3.1. I think a 3.4
>would not be enough of a change (again, rare). So......

Buick and Pontiac are the same, and Chevy and Olds are the same as far as
FWD blocks go.  I've done a lot of research in this for my mid-engine
madness, so you might want to stick with the same family as the car, or
change the entire powertrain.

Another neat thing about the late 80's 3.8L FWD block - mine, from a 1986
LeSabre, as the same underhood wiring harness and ECM as the infamous Buick
Grand National.  Fast car, aye?  So, a FWD block with better rings, a GN or
replacement turbo, and a GN or aftermarket chip, could easily bring you
into the 250-290 HP mark without too much aggrevation.  If you are mounting
the engine transverse in your Citation, the 3.8L (at least in the late
80's) comes with headers, not manifolds, and the appropriate crossover
towards the firewall - sawzall off the exhaust pipe coupling, and weld on a
turbo flange - bolt the turbo - and wala, you are 1/2 way there to more power.

Since my mid-engine car is not mounting the engine transverse, I started
making my own headers and they will go to seperate turbos, feeding back to
the intake manifold, which in the longitudinal position, has the air intake
towards the rear of the car, right where the turbo's will be.  Talk about a
good thing :)

>are too, but I lose to torque above 60 MPH. Runs great, but I need more
>torque.

You will have more torque with a 3.8L than a quad 4, if you compare them
bone stock or equally modified.  Just look at the GN's, there was a recent
magazine that showed a street legal GN with 400 something HP and 550 ft/lbs
of torque.  Since the GN block is "nothing special" compared to the
naturally aspirated 3.8L, you can upgrade easily.  The FWD is a little
funky, the crank from the GN fits, but doesn't sling oil around the engine,
but a neat factoid is the FWD 3.8L has a fillet high-strength crank, which
is supposively a "better" crank than the first year or two of GNs.  Later
GNs had the fillet crank.

George Dailey convinced me to consider the 3.8L FWD Buick - over the 4.6L
Modular Mustang engine I had here... its a great compromise between power
and performance, and there's absolutely nothing to sneeze at if the little
V6 can make 400+ HP and 500+ ft/lbs of torque.

Works for me :)


Frederic Breitwieser
Homebrew Automotive
Bridgeport, CT 06606

Portable Web-Site: http://www.geocities.com/MotorCity/Downs/4605/index.html

Vehicles:
   1989 AG Hummer 4-Door
   1993 Supercharged Lincoln Continental
   2000 Mid-Engine Sports Car <smile>

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