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:


Ford XR6

Stock 3.8

3.8 HO













































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 í78 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 donít 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 Kís 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 donít 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):


Factory HP


Single plane Manifold


Holley 390 carb




9.25 Compression ratio


Oil Pan Mods


Head Porting


Needle Roller Rockers



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 ľ mile in 15 sec and 92.3 mph. Ok it is a re-developed version, from the 90ís, 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 V8ís (so has everybodyís 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!