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Volvo Turbo Engine Project |
This purpose of this
project was to produce a bored and stroked B23FT with
2630cc of turbocharged, Volvo
torque!
Update: A dyno session in 2005 produced a rear wheel torque
measurement of 323 ft lbs at 3200 RPM (18 PSI boost with 100
octane fuel)
This project began with the purchase of a used B23FT junkyard motor way back in January 1999.
The custom engine was finally completed and installed in April of 2001. At this time I have logged more than 25k miles.
When I started this, I had originally planned to use the stock K-Jetronic fuel injection since I did not think at the time I could afford (or figure out how to install) a decent aftermarket EFI system. I considered a stock EFI system from another Volvo but dropped it because of it's inflexibility. This was many years before less expensive EFI alternatives were born, like Megasquirt. But... since I eventually decided to go to the trouble to fit an EFI, I wanted it to be something more programmable. What I ended up with was a complete and fully programmable aftermarket EFI system from Racetech - SDS (Simple Digital Systems). They have a web site that fully explains this system.
Fuel injectors are 550cc Lucas units from RC Engineering in Torrance, California.
Also, I have had a custom all-aluminum intercooler fabricated for use in this project. It was made to my specs by Spearco Intercoolers. It's really massive. This intercooler was basically made to OEM 240 Turbo intercooler dimensions, except that it's 3 1/2 inches thick. Click here for a pic of this thing. The reason for this was my desire NOT to be too limited in boost. I figured that the enhanced intercooling would give me a wider margin since the new motor had an elevated compression ratio.
Turbocharger was a Turbonetics
"Super 60" (T-3
based) bolted to a later style turbo exhaust manifold. It had a
60
trim compressor wheel and .63 A/R turbine housing. Performance
was pretty good, but the exhaust turbine came apart after about 2,000
miles.
Here are some pics
of the damaged exhaust turbine and the pieces I found in my exhaust
pipe.
After that mishap, I moved to a standard T-3 turbo from a 240 Turbo, because I had one laying around.
Specifications for this Project:
Block: 1984 B23FT, bored from 96 to 97 mm (3.818").
Click
here for "BEFORE" picture
Click
here for "AFTER" picture
Deck Height: (Crank CL to
deck) 231.685 mm (9.121")
Why bore the block to 97 mm?
The stroker parts supplier (no
longer in business)
sold me 97 mm pistons and claimed to be highly knowledgeable in Volvo
race
motors. He insisted that boring a B23 to 97 mm was never a
problem for him. I have since discovered that boring a B23 block
past the 96.6 mm second bore spec
is NOT recommended. The reason for this is because of a design
problem common
in many Volvo B23 blocks where the core had shifted slightly during the
casting
stage.
This made the cylinder wall thicknesses uneven and thin in some spots
(sometimes...
not always). If one of these thin-walled blocks is bored too
much,
the
cylinder wall becomes dangerously thin and would be prone to
cracking.
This has happened several times
to fellow Volvo enthusiasts who have tried a 97 mm bore. I
consider
myself very lucky that my block hasn't cracked. If you are
unsure about your B23 block, you should have a Sonic Test done
by your machinist
to determine cylinder wall thickness before boring. I have been
told that a minimum thickness of 0.100" (2.5 mm) is recommended for a
turbocharged engine.
Pistons: WISECO forged, Click here
for a photo of my pistons
Bore: 97 mm (3.818")
Compression Height: 30.785
mm (1.212")
Wrist Pin Diameter: 22 mm
(.866") full floating
Reverse Dome: 12cc dishes
(reverse
domes) with 4 mm radius at bottom. 10 mm (.400") "squish band"
retained around edge. This dome was done for me by Wiseco after I
bought
the pistons. Sounds kind of backwards, I know. I had no
choice
as the pistons sold to me were the wrong configuration and needed to be
re-configured
for the stroker design.
Assembled Deck Height:
0.40
mm (.016") below deck.
Click
here to view the piston to deck dimension view
Squish Height: 0.056"
using Cutting Edge head gasket of 1.0 mm (.040") compressed.
Update on
Squish Height: This squish
height
dimension has turned out to be excessive. It was used at the
strong recommendation of Pauter Machine, who supplied the connecting
rods. They didn't know better and neither did I back in 2000 when
this was done. A better squish height would have been to set the
pistons to be at or just above the deck at TDC, to a max height of
0.012" above the deck. My next motor will use this configuration.
Piston Source: WISECO PISTONS, INC. , 7201
Industrial Park Blvd., Mentor, Ohio 44060, (440) 951-6600, http://www.wiseco.com/
Piston Side Clearance
Issues:
When my engine was being
completed, I had the machine shop set the piston clearance to the
supplier's
recommended figure of .004" (four thousandths).
Consequently, the pistons make a clatter noise when cold (piston-slap)
and
still some noise when warm.
I have since learned that .004 inch is a bit much. Mike
Aaro of Unitek in Sweden recommended the side clearance for
a forged street-driven piston of .0018 to .0020 inch (eighteen to
twenty
ten-thousandths). For your project, you should consult the piston
designers for these specs..
Connecting Rods:
PAUTER "X" beam, made from E4340 Chrome-Moly steel
billet.
Click
here for photos
Length (Center to Center):
6.140" (156 mm)... 11 mm longer than stock "M" rods, which are 145
mm.
These custom rods give the motor a rod
to
stroke ratio of 1.75:1, which is a little less than stock (OEM is 1.81:1
ratio).
Small End dia. (wrist pin):
.866" (22
mm)
Big End dia.: 1.8897" (48
mm)
Small End width: 1.120"
(28.448 mm)
Big End width: 1.164"
(29.565 mm)
Big End weight: 485 grams
Overall weight: 696 grams
Rod Bearing: (Listed
below
with crankshaft specs)
Source: PAUTER MACHINE CO., INC.
367 Zenith St., Chula Vista, CA
91911
(619) 422-5384
FAX (619) 422-1924
http://www.pauter.com/
Crankshaft: OEM B23 forged steel crank. Click to see it. Rod journals have
been offset ground for increased stroke from 80 mm to 89 mm (3.503")
stroke. The journals were reduced from 54 mm to 45 mm. The
main crank journals are original size (63+ mm).
Rod bearings used for this
project are as follows:
Clevite CB-1120P (full
specifications below)
Shaft diameter (crank/rod
journal): 1.7710-1.7717" (44.9834-45.0011 mm)
Oil clearance: .0006-.003"
(.0152-.0762 mm)
Bearing wall thickness:
.0588" (1.4935 mm)
Housing diameter (rod
big-end): 1.8897-1.8905" (47.9983-48.0187 mm)
Some OEM Crank Main Journal/Wrist Pin Dimensions Courtesy of
Mike Aaro
First generation "red" engine (B18/20/21/23/230,
1961-1984/85) main bearing size is 63.454 mm nominal (integrated axial
bearing). Wrist Pin
is 22 mm (1961-1972) and 24 mm (1973-1984/85).
The second generation main bearing (1985-1988/89)
is 55.000 mm nominal (separate axial bearing). Wrist Pin is 23 mm.
The third generation and final (1988/89-1998) design was
63.000 mm nominal (integrated axial bearing). Wrist Pin is 23 mm.
Head Used for this
Project: "1000398" casting with
3/85 date code (small coolant passage) (Click for Photos). Combustion chambers opened from
OEM 51.7 cc to 59 cc. Chambers were re-shaped slightly and valves
unshrounded. Click here to see the
actual template used by my machinist (Measurements
in this photo are in centimeters). Or click
here to see an actual scanned image of the #4
combustion
chamber (Measurements for this photo are in 10ths of an inch).
OEM turbo (Stellite faced, sodium
filled) valves and the later style OEM valve springs are used.
The next photo shows a comparison
between the OEM combustion chambers (51.7 cc) and the modified ones (59
cc). Also, it's easy to see the difference between the big
coolant
passage (BCP) head and the more desireable small coolant
passage
(SCP) head. Click here for the
photo.
Why is
the
Small Coolant Passage head better? It is considered to
be a stronger design that is less prone to cracking.
When did
this change occur? One Turbobricks subscriber wrote: "I have a 398 head that is BCP dated 3/3/84... and a
398
head that is SCP dated 4/12/84." I also have a SCP 398
head
I pulled from a Pick-A-Part that is dated 4/4/84. Obviously
the
change occured between March 3 and April 4, 1984.
Where can you find the date code?
It's
molded into the aluminum on the exhaust port side very close to the
back
of the head. The numbers are vertical, i.e.: for my 4/4/84 head,
you
can see a "4", then below that a "4", then below that an "84".
Head Gasket:
The head gasket I'm using is the "cutting
edge"
type, which actually has a hardened steel fire ring that cuts into the
soft
aluminum and seals the head. It's designed for very high
combustion
chamber pressures and is 0.040" (1 mm) thick when compressed (a stock
head gasket usually runs about 0.060" (1.5 mm) compressed).
Here are some close up photos:
"Cutting
Edge" Gasket
"Cutting
Edge" Gasket Close Up#1
"Cutting
Edge" Gasket Close Up #2
Comp. Ratio: The above combination (assuming a head gasket with 1.0 mm/.040" compressed thickness), has a 9.4 to 1 Compression Ratio.
Camshaft: The camshaft I used for this motor is the Unitek Phase One. It is an aftermarket cam that works very well with a turbocharged engine. It has almost 12 mm of lift and very short duration. It completely blows away other cams I have experienced. It may be ordered from Unitek in Sweden.
Machine work done by:
Greg Landes
Millenium Motorsports, Temecula, CA
http://millenniummotorsports.net/
951-699-1889
For a cool on-line COMPRESSION RATIO java applet calculator and more... CLICK HERE
Remote Oil Filter Setup
I chose to install a remote oil
filter because it's a pain in the butt to get to the filter on a 240
Turbo motor. As you will see in the photos, I chose AN aircraft
style aluminum fittings and braided stainless hose from Earl's
Performance Products.
The remote lines begin at the engine block with a standard spin-on type adapter.... Photo 1, Photo 2.
Then I mounted an Amsoil dual oil filter block in the right front fender area just ahead of the wheel, behind the bumper. I used an OEM Volvo (740 Turbo) sandwich oil cooler adapter between the filter block and filter, which is thermostatically controlled to keep oil at the proper temperature. Photo of Amsoil Dual Oil Filter Block. The oil cooler lines then come from the Volvo sandwich adapter to the oil cooler, which is mounted in the original location near the intercooler. The oil cooler is a Setrab (made in Sweden).... Photo of Oil Cooler.
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