Origins of the 3.8 question

[Lord_Verminaard]

I know the 3.8 has a long history, but more specifically, is it designed after another engine, like Chevy's 4.3 being a 350 minus two cylinders? Was the 3.8 based off any Olds or Buick V-8's? Thanks for the history lesson. [img]smile.gif[/img]

Brendan
2000 Camaro L36 M49

[navyblue2000]

Hmm, i'm not totally sure if it's actually BASED off a V8, but 231 cubic inches is 75 percent of 305 (approx) cubic inches. I don't know if it's an identical bore/stroke, of if connecting rods/pistons are interchangeable (they're NOT), but the series two is based off the series 1 engine, with a few enhancements and vice versa.

[Lord_Verminaard]

Interesting. I may have to do some more research then. Especially on the Gen. 1 engine. I'd like to know what (if any) engine they patterned the 3.8 off of.

Thanks!

Brendan
2000 Camaro L36 M49

[toast]

The 3.8 orginally is a based off an older Buick designed V6 (4.1) in which that engine was based off a Buick V8 in the late 60s. The early 4.1 was sold to AMC back in the early 70s and then GM bought back the design in the late 70s and then modifided to the 3.8. The 3.8 then became Gm's benchmark engine in the 80s by showing that a smaller engine can produce as much power as the compitions V8s but get better gas milage. Gm did many enhancements to the 3.8 over the year and proving that the little V6 had the power they stuck a turbo on it in the mid 80s hence the Grand National. The series 2 came out in 95 and was the 1st major revision the engine has seen since the late 70s. The series 2 is very differnt than the old 3.8 it was based off of but yet shares basic things like bore and stroke, firing order, crank design, OHV layout, etc...

[Ex-5.0]

For 1961 Buick Skylark GM develops a 215 CI (3.5 liter) aluminum block and heads V8. This V8 was in production from 1961-1963. Essentially same engine with slightly modified heads used on Olds F-85 from 1961-1963. From 1964 through early 1980's this same basic design in cast iron was the Buick 300, 340 and 350 CI V8's. (Supposedly the 215 V8 was based on a prototype 215 CI supercharged aluminum V8 used in the 1953 Buick LeSabre show car that Harley Earl developed for the GM Motoramas)

In 1962, Buick introduces an iron block and heads 198 CI V6, having the same architecture as the aluminum V8 with two cylinders removed. This was a 90 degree uneven firing engine. The V6 was then enlarged to 225 CI (Bore and Stroke of 3.75" x 3.4") in 1964 and used in Buick Skylarks until 1967. GM then sells the tooling to build this engine to the Kaiser Jeep Co. American Motors bought out Kaiser Jeep Co. shortly thereafter and continued production of the 225 V6 for use in Jeep products through 1971.

After the gas crisis of 1973, GM needed more capacity to build small engines so they bought back the tooling for the V6 from AMC. They put the engine back into production for the 1975 model year. At that time it received a slight increase in bore to 3.80" to bring the engine size to 231 CI (3.8L). I believe it was rated at 110 Net HP @ 3600 rpm. This engine was still a 90 degree design and un-even firing because it did not use split crank pins.

In 1977 GM phased in the use of an even firing version of the engine by using split crank pins.

The 4.1L (252CI) version is just an overbored 3.8 and was offered in the early 1980's full size cars like the Buick Electra and Cadillac Deville. It make 125HP and used a 4-barrel carburator.

In the mid 1980's the 231 V6 was quite thoroughly re-engineered to become the 3800 V6. The basic architecture of the engine remained the same but the cylinders were relocated to be centered on the crank pins, balance shafts added, etc. to make it very nearly a new engine.

This 3800 became known as Series I when the Series II version appeared in 1995 for the L36 and 1996 for the L67 (supercharged). Series II is an evolution of the Series I. It has a shorter deck height, cross bolt bearing caps, better breathing, etc.

So yes, our V6 is based on a V8 design, but it is more ancestrial compared to the Chevy 4.3 V6 and 350 V8 that are much closer related.

[FirebirdGT]

Next time you might try researching www.firebirdv6.com :

http://engine.firebirdv6.com/3800history.html