The different V6- Buick 3.8
This Motor is close to my heart and for a long time I have
wondered on how I could write about it, without sounding like a
self-Advertisement. What the Heck- A few Horse Power figures follow:
|
RPM |
Ford XR6 |
Stock 3.8 |
3.8 HO |
|
2000 |
53 |
87 |
91 |
|
2500 |
71 |
108 |
121 |
|
3000 |
91 |
130 |
151 |
|
3500 |
110 |
144 |
180 |
|
4000 |
127 |
150 |
209 |
|
4500 |
142 |
148 |
233 |
|
5000 |
151 |
136 |
249 |
|
5500 |
154 |
113 |
254 |
|
6000 |
149 |
84 |
248 |
|
6500 |
137 |
52 |
235 |
|
7000 |
121 |
16 |
214 |
This Motor was developed in
1961 to meet the new compact car market in the USA. It is a Cast Iron version
of their 3.5 L V8 (Rover) Alloy motor, though only being 50 Pounds heavier (362
Lbs.). By 1979 it had progressed to its present size and Even Fire Crank with
Smokey Yunick having developed its new heads. From ’78 onwards it was also
available as a Turbo Version. In 1967 Kaiser Jeep bought the Tooling and some
came here in the form of the Jeepster. In 75 Buick bought it back and in 80
went to 4.1L. We even had a derivative of that Motor here in the Opel 380i.
The figures above show the
Amazing Potential of these Motors. Their strength has become Legendary in
racing Circles, far surpassing that of the Small Block Chevy and its derivative
the 90deg. V6. Look at the 3.4L Turbocharged Indy Motor producing 800 Hp at
8400 Rpm while having a flat 530 Lbs. Torque Curve from 5200 to 7400 Rpm. I
have built some Twin Turbo Versions of these Motors for Kit Cars that hover
around the 400 HP mark, while remaining Reliable. On a 1HP per cubic inch Motor
you can get 20MPG on bad fuel, what other motors can claim the same?
The big downside of this
Motor is its hefty Torque at Low RPM- there are very few gearboxes that can
take the Punch. Hilux 4*4 is to weak, but can survive if you don’t lug the
Motor. Cressida 5 speed is another Candidate as that also ran in the Celica
Turbo, while we use the Audi 5 speed Turbo box in the VW Bus. Again in the Bus
it can do 160 Kph with the Motor loafing around 3000 RPM.
In stock form the Motor has
a Compression ratio of 8:1 which can guarantee you no Pinging ever! The High
Output version runs a 4 Bbl carb, (or EFI) single Plane Intake, different
Valves, Ported heads, Decent cam, 9.5:1 Hypereutectic Pistons, Big bore
Headers. On the twin Turbo versions we used an Intercooler and Electronic Fuel
injection. I have customers who have run this motor for over 300 000 K’s
without any problem. Maintenance is Restricted to oil and Plug Change, as the
valves are Hydraulic and the Spark is Electronic. The Motor is more compact and
lighter than the V6 offerings from Ford and Nissan.
For those people wanting
beat- this thing sounds totally different. It has a split Journal crank and a
"weird" firing Order. If you remember the old Maserati V6 sound- this
thing has it and at 7000 RPM it sends shivers down your spine. It has a
bellhousing pattern similar to a Chevy V8 and therefore a lot of Adapter kits
are available for this Motor. A customer recently built a Courier bakkie with
this Motor and a Cressida Box- he claims that there are few things on the Road
able to catch him. His reasoning goes that weight is the be all and end all-
Light Motor and Loads of Glassfibre parts.
A Carefully Built Motor
should make 200 Hp without spending big Moolah. Basically go for a 600 4Bbl
Holley (its far to big but cheap and can be made to work). A cheap 4BBl
manifold such as an Edelbrock, standard Rebuild Parts and Headwork plus a free
flowing exhaust. Plus you will make over 300 Nm torque from 1800 Rpm onwards.
If you do all work yourself it will cost you below 12 Grand including the
Motor. You can also spend time modifying the stock 2BBl manifold and fitting an
Autolite carb with good Results. Just be careful of one thing; different Years
had different Blocks, Heads, Cranks, Rods, and although they will interchange,
they will not work together.
Many people consider the
Oiling system to be the weak link on this Motor and many mods have been done,
All I do is sandwich a Plate between Pump and body- Voila. On a stock and
regularly serviced Motor I don’t believe any Mods are necessary. NO High Volume
Oil Pump should ever be used, but please take it easy on a cold Motor. I always
baffle the Oil Pan to keep oil of the crank and in the Pump (especially for 4
Wheeling). The Bottom end is Rock solid, should you pick up problems it will be
on Number 3 mains. The turbo Crank is stronger as well as a few other
components from that Motor, so I tend to lean towards using that as my base,
otherwise both Motors tend to be the same including compression ratio. Thoughts
differ on head studs and I guess you should use them from 200 Hp onwards. The
stock Rocker assembly is fine for most street Engines and Rollers are
Available.
Boring the Motor needs deck
plates as do all modern thin wall cast Motors. I am a believer in Balancing and
this little Motor will thank you for it, also there are quite a few theories to
the proportioning here. The even Fire heads only need a bowl and blend job,
while Aftermarket valves only become necessary if you want to go beyond 250 HP,
or if you can not port. The Intake can easily flow 200 CFM at 28" H2O and
the Exhaust 80 % of that, which is more than enough. The combustion Chamber is
very small and running an efficient flat top Piston sends the CR to14:1, most
other Motors have a problem with the converse. Camshafts are a weird one here,
unless you have a grinder who has experience on this Motor, go for a Reputable
Aftermarket unit. What works on a V8 or Nissan V6 does NOT work here! High RPM
and stiff springs mean you have to go to a Double roller chain and its
associated problems. You only need a single plane manifold for this motor as
there is virtually no charge Robbing taking place, but good ones are not cheap.
Overall Timing Advance should be set at 32 degrees due to the very Efficient
Combustion Chamber.
A few years ago I spent
considerable time Experimenting on this Engine and got the following
Improvements (note HP is not corrected):
|
125 |
Factory HP |
|
25 |
Single plane Manifold |
|
10 |
Holley 390 carb |
|
22-32 |
Camshaft |
|
12 |
9.25 Compression ratio |
|
6 |
Oil Pan Mods |
|
30 |
Head Porting |
|
5 |
Needle Roller Rockers |
|
5 |
Headers |
This Totals to 240 HP being
a 92% Improvement while being Legal and Reliable- The Most I could squeeze from
this Engine without going to Stage 2 Parts was 400 HP without Turbo.
Now if you think that this
motor is dead, look at the 97 Pontiac grand prix GTP that has a Blown version
(7 psi) of this 3.8. Making 240 Hp @ 5200 and 280 lbs. at 4400 while already
giving 250 lbs. just off idle. The testers were getting 25 mpg on the Highway
in a 3400 lbs. Vehicle, while 0-60 mph is achieved in 6.6 seconds with a slush
box while doing the ¼ mile in 15 sec and 92.3 mph. Ok it is a re-developed
version, from the 90’s, but if I may quote Hot rod magazine " The torque
curve is hairy and abundant- a big, fat ball of it is always there, always
eager to sling you down the road." Oh yeah the base price is USD 19,739.00
= less than 100 000 N$ for a real sports car, so eat your hearts out.
I have done a lot of work
on Chevy V8’s (so has everybody’s dog) and on Fords (here Jack Roush rules)
plus on a whole variety of weird and wonderful Motors, but even at the risk of
sounding Pompous, I do not think many People have spent as much time as myself
on this Little Motor and I think it is the best affordable V6 around- Period.
So if you wish to play with it, give me a call and let us see what we can do!