The Fireball V6

[MolaKule]

GM introduced the V6 in about 1962 with 198 cu. in. or 3.2L displacement for their Buick line. Basically, it was a V8 block with two cylinders lopped off. This engine later morphed into the 3.8L V6.

This early engine had a characteristic that was reduced by an engine component.

Q1: What was this characteristic?

Q2: What engine component was used to reduce, but not eliminate, this characteristic?

 

[SwampSurvivor]

These were the "dauntless" v6 in the Jeeps right? They were pretty unbalanced and had an awkward firing order.

There was a different firing order on some of the buick engines to make them a bit more smooth. The jeep dauntless always sounds like it has a misfire.

 

[PontiacHO]

Vibration.

Counterbalance shaft

 

[supton]

I've going with, "odd fire". I don't understand it, but I recall reading it about (and simply going off and googling it is probably not demonstrating my knowledge). Want to say, because of the 90 degree banks, it's hard to get a smooth firing V6, so instead of firing every 120 degrees, it's like 90-160.

To go to even fire, the crankshaft needs to use split pins, where the rod journals go, if a 90 degree bank is to be used. This weakens the crank a bit, as the two journals don't overlap; I'm guessing this also hurts because the rods are no longer quite as close as before? maybe they are, just seems like a problem area to me.

Better fix is to go 60 degree on the banks, then 120 degree firing order works well.

IIRC, GM did their big block V6's as 60 degree banks. But when the Torroflow diesels didn't do so well, they felt a need to introduce a 637 cubic inch V8--but using a 60 degree block. Sneaking a peak at google on this one, it sounds like they elected to use a balance shaft for this. Anyhow...

 

[wag123]

Q1: vibration and rough idle due to uneven firing.
Q2: 1. A heavy counterbalanced flywheel was used by Jeep after they purchased the engine in 1965. 2. After GM repurchased the engine, crankshafts with offset crank pins were employed in 1977 to make it even firing. 3. A balance shaft was added beginning in 1988.

 

[TheLastWord]

GM introduced the V6 in about 1962 with 198 cu. in. or 3.2L displacement for their Buick line. Basically, it was a V8 block with two cylinders lopped off. This engine later morphed into the 3.8L V6.

This early engine had a characteristic that was reduced by an engine component.

Q1: What was this characteristic?

Q2: What engine component was used to reduce, but not eliminate, this characteristic?

This 1961 was a better engine. Sadly it didn't survive, the bean counters won:

https://www.teambuick.com/reference/library/215-300-lightweight.php

Remember Roger Huntington the author 1964?

The aluminum V-8 215 is very sought after for light weight apps.

I drove one belonging to friend in college 1967.

Check out the Olds supercharged version and the Mickey Thompson 1962 Indy car.

 

[Chris142]

Q1: vibration and rough idle due to uneven firing.
Q2: 1. A heavy counterbalanced flywheel was used by Jeep after they purchased the engine in 1965. 2. After GM repurchased the engine, crankshafts with offset crank pins were employed in 1977 to make it even firing. 3. A balance shaft was added beginning in 1988.

That flywheel weighed 80 lbs and made for great torque. The heads were thin around the valve seats. A friend had a set of heads rebuilt and when the machine shop tried to put new seats in they hit a water passage.... Ruining the heads

 

[MolaKule]

This engine was interesting, and we had one in a downsized (don't remember the model) Buick Station Wagon back in the late 70's as our family was growing at the time, but it was the 231 cu. in. version. It was still a shaker at the stop light but ran smooth on the highway and with sufficient power. The 90 degree engine had a firing order that caused the shaking.

The shaking was reduced by a massive flywheel, as @wag123 mentioned.

After we arrived home from the dealer, I noticed a puddle of fluid as the transmission was leaking. While on the lift and after the transmission was removed, I saw this massive flywheel. A few days later the dealer installed a new transmission and we never had any other transmission problems.

On one trip between St. Louis and Iowa we had a fan blade brake and luckily found a gas station who ordered one quickly and replaced it. Once the fan blade broke we had a whole lotta shakin' goin' on.

It was after that we moved to a full-size Chevy Van which had the smog air pump and other interesting amenities.

 

[urrlord]

A girlfriend in the late 80's had a GM(olds or buick) car with a v6 .Blue with a white vinyl roof.Nice. but way too heavy for that engine. Accel was slow and passing was nerve wracking and top end was not very high. But she was not a great driver so it was a good car for her.

 

[MolaKule]

Our Station Wagon was Blue as well.

Jim's Automotive Machine Shop Inc (JAMSI on YouTube, Jeep Dauntless V6 episode) has a good explanation on the wierd firing order and its relationship to crank angle. They also show this massive 80 lb flywheel.

 

[ms21043]

Swapped an odd fire 231 V6 into Vega many years ago. It was I think a 75 model, it had an HEI distributor.
At first I had a Saginaw 4 speed behind it and yes, that flywheel was heavy, around 50lbs. It had headers, a Kenne Bell cam, an aluminum intake, Edelbrock I think, and a Holley 450 4 bbl. It was my daily driver and it got about the same gas mileage as the original engine. Added a NOS cheater system and with the nitrous, the power felt about the same as if it had a stock chevy 350 in it.
Was a fun car to drive.

 

[bullwinkle]

Had a ‘76 Olds Starfire (like a Monza) with the 231/Turbo 350 combo-that car was pretty quick, fastest I ever (young & crazy) drove-buried the 120 MPH speedo, guessing 125-130. Lucky those old radials held up!

 

[Exhaustgases]

Offset crank pins?

 

[MolaKule]

Swapped an odd fire 231 V6 into Vega many years ago. It was I think a 75 model, it had an HEI distributor.
At first I had a Saginaw 4 speed behind it and yes, that flywheel was heavy, around 50lbs. It had headers, a Kenne Bell cam, an aluminum intake, Edelbrock I think, and a Holley 450 4 bbl. It was my daily driver and it got about the same gas mileage as the original engine. Added a NOS cheater system and with the nitrous, the power felt about the same as if it had a stock chevy 350 in it.
Was a fun car to drive.

When I lived in Kansas I had a friend who built his own airplane and the engine he was using was the Buick V6, but it was mounted in an "inverted" position with a special oiling system and dry sump of course. He had enough space behind his property for a landing strip and I witnessed many takeoffs and landings, and he said the engine performed flawlessly. I formulated and supplied a 40 grade SL oil for the engine.

 

[hank2]

As I am remembering, when GM went to even fire on the 231, (1978?) it reduced the horizontal shake 50% and increased the vertical shake 50%.

Very long ago I had a '67 Kaiser Jeep C-101 Commando with the Dauntless 225. That was surely a heavy flywheel engine. I didn't think the shake was too terrible on that, but it was there.