Engine Mini-Series – Pontiac’s 326 Prt 2

[Guest timsweet]

Here is the link to Part 1 Engine Mini-Series – Pontiac’s 326 Prt 1 Average Guy's Car Restoration, Mods and Racing

The 326 was used as the base model for the Pontiac Tempest. That was going to be the extent of the division’s uses for this engine. For 1963 and 1964 production years that was the case.

But in the 1960’s GM had a rule that production A-body or intermediate-size car would carry no more than 330 cubic inches and none were to be sold. Pontiac had the idea that they would bring on the Tempest GTO would have the 389 as its base engine, but GM set the rules. So the best Pontiac could do was to offer the GTO with the base engine as the 326.

1964 Tempest GTO, Yes you'll find 'em with a 326

However, on the order form there was a check box to order the 389. This is how the 326 got in to one of the most famous iconic cars of the muscle car era.

1965 was the year and the 326 offered was with 250 and 285 hps in both automatic and manual transmissions.

That’s enough to make it a piece of historical automotive hardware. But there is one more noteworthy pair of shock towers this power plant was mounted between that was the 1967 Pontiac Firebird. Yup it powered up its second iconic car with a 250 hp version and a 285 hp version.

326 in a 1967 Firebird

67 F-bird

And that, fellow car crazies, was the short life of Pontiac’s 326.

Thanks for reading.

Tim

[Guest]

Before the 330 cubic inch limit was established the 1963, the 326 was actually 336;). all 1963 326 engines are 336 and all 1964 326 engines are 326. The 63 engine dimensions are 3.78 bore 3.75 stroke and the 1964 326 engine dimensions are 3.72 bore X 3.75 stroke. The Pontiac 350 (starting in 1968) dimensions are 3.88 bore and 3.75 stroke giving 354.71 or 355 cubic inches. All three of these engine are from the 389 engine ( 4.06 X 3.75 ). The 350 (355) has the new heads like the new for 1967 400 engine ( 4.12 X 3.75 ) which replaced the 389. All the crankshafts on the above engines use 3" main bearings and have the same stroke for interchangeability.

The larger Pontiac engines 421- 4.09 X 4.0, 428- 4.12 X 4.00 use the same crank, The 455 dimension of 4.1525 X 4.21 giving a real dimension of 456. All of these three engine use a 3.25 main bearing, and cranks interchange between the three sizes.

There is no big or small block Pontiac V-8 engine, ALL Pontiac engines from the 1955 287 to the 455 have the same external dimensions and the bore centers are the same, in fact all engines can use the same connecting rod as the rod length ( 6.625 ) is the same as well as the crank throw journal the same diameter. All Pontiac engines are known as a medium block.

Pontiac also made a 336 for GMC truck in the mid to late 50's. It has a different dimension than the 1963 Tempest V-8 though.

The exception to the above dimension would be the short deck 301

BTW, there is no such thing as a Tempest GTO. ALL 1964-1965 and 1972-1973 GTO's are called LeMans GTO's because it's a option on the LeMans. When you check off the LeMans GTO option you got the 389 for 64-65 and the 400 or 455 for the 72-73. In 1974 you checked off the GTO option on the X body Ventura 2 and you got a Pontiac 350 (really a 355 )

Here is my 455, notice how similar this engine is to the picture in the last post. This engine has heads from a 400" Pontiac. The beauty of interchangeability!

http://www.pismoderelicts.com/photogallery/new%20format%20937/images/p1020753.jpg

Don

Edited May 10, 2011 by helfen (see edit history)

[Guest timsweet]

According to the drive reports Tempest GTO is what they were call them in 1963 and 64.

[Guest]

According to the drive reports Tempest GTO is what they were call them in 1963 and 64.

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Unlike Olds 442 where you could order a F-85 442 or a Cutlass 442, the Pontiac order form says LeMans and check here for the GTO option @ $299.00. -- The Vin tag says LeMans . How many times have you heard someone call a 421, 428, or 455 a big block Pontiac?? It just isn't so. How many times did the factory call a 350 Pontiac engine a 350 when it was a 355 all along. or a 428 instead of a 427 or a 455 a 456 or back to the beginning a 1963 Tempest badged a 326 when all along it was a 336.

Remember the 421 Super duty's from 1961-1963, Factory rated at 373, 390, 405 and 410 horsepower. How does 410 horsepower propel a full size Catalina down the quarter mile at 125MPH?? They don't because that engine was making 500+ horsepower.

Edited May 10, 2011 by helfen (see edit history)

[Guest timsweet]

Before the 330 cubic inch limit was established the

BTW, there is no such thing as a Tempest GTO. ALL 1964-1965 and 1972-1973 GTO's are called LeMans GTO's because it's a option on the LeMans. When you check off the LeMans GTO option you got the 389 for 64-65 and the 400 or 455 for the 72-73. In 1974 you checked off the GTO option on the X body Ventura 2 and you got a Pontiac 350 (really a 355 )

Here is my 455, notice how similar this engine is to the picture in the last post. This engine has heads from a 400" Pontiac. The beauty of interchangeability!

http://www.pismoderelicts.com/photogallery/new%20format%20937/images/p1020753.jpg

Don

Hey Don - Nice CAR didnt' see the link earlier.

One for reference for this topic. The Ultimate American V-8 Engine Data Book by Sessler, shows the 326 being used in the 1964 Tempest GTO this continued through 1970 and in 1971 it was the Le Mans, Tempest, GTO. Really it was just a package on the Tempest and then on the Le Mans. Tempest bodies were use for Old and Buick the first few years.

[Guest]

Hey Don - Nice CAR didnt' see the link earlier.

One for reference for this topic. The Ultimate American V-8 Engine Data Book by Sessler, shows the 326 being used in the 1964 Tempest GTO this continued through 1970 and in 1971 it was the Le Mans, Tempest, GTO. Really it was just a package on the Tempest and then on the Le Mans. Tempest bodies were use for Old and Buick the first few years.

My first "NEW" car, ordered in Nov of 68, delivered in Dec 68. Drove it last week end.. originally a 355 H-O 330HP, T-400, 3.23 posi.

http://www.pismoderelicts.com/photogallery/new%20format%20937/images/p1020752.jpg

[nzcarnerd]

Helfen, I agree with everything you say. People seem to need to define all V8 engines as big or small blocks and most aren't aware that all Pontiacs (at least from 1955 into the late 1970s) used the same lump. As you say they are 'medium' blocks; weight is between the small and big engines of their rivals. Interchangeability is a can of worms but is at least well-documented. I ran a 455 with #62 heads on my 1965 Bonneville. It ran 14.1/102 with its original TH400 and 2.56 rear. I did a 12,000 mile tour of the US in 1978 in a '67 LeMans with a 326. It got about 22mpg over the whole trip at a cost of 3c/mile - those were the days.

[Guest]

Helfen, I agree with everything you say. People seem to need to define all V8 engines as big or small blocks and most aren't aware that all Pontiacs (at least from 1955 into the late 1970s) used the same lump. As you say they are 'medium' blocks; weight is between the small and big engines of their rivals. Interchangeability is a can of worms but is at least well-documented. I ran a 455 with #62 heads on my 1965 Bonneville. It ran 14.1/102 with its original TH400 and 2.56 rear. I did a 12,000 mile tour of the US in 1978 in a '67 LeMans with a 326. It got about 22mpg over the whole trip at a cost of 3c/mile - those were the days.

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That is very impressive numbers on that Bonneville and I bet you ran the quarter as a two speed. I have three sets of gears in the LeMans and one of them is a 2.56. My LeMans weighs 4050lbs and with those gears I would do 105mph in second at 5,200rpm and get 24mpg, but with todays 10% ethanol I only get 20mpg. I remember seeing a article in HPP about a 66 Bonneville convertible with a 376hp tri-power 421 going 13.90 @ 100+.

My 59 Catalina, 389 Tri-Power 4speed hydro with 3.90's or 4.10's ran a consistent 13.90 @ 101-102mph.

Certainly the Gen 1 Olds engines are also considered a medium block and I think the Gen 2 short and tall decks are also considered a medium block, in fact the short deck 403 has the largest Olds cylinder bore.

D.

[nzcarnerd]

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That is very impressive numbers on that Bonneville and I bet you ran the quarter as a two speed. I have three sets of gears in the LeMans and one of them is a 2.56. My LeMans weighs 4050lbs and with those gears I would do 105mph in second at 5,200rpm and get 24mpg, but with todays 10% ethanol I only get 20mpg. I remember seeing a article in HPP about a 66 Bonneville convertible with a 376hp tri-power 421 going 13.90 @ 100+.

My 59 Catalina, 389 Tri-Power 4speed hydro with 3.90's or 4.10's ran a consistent 13.90 @ 101-102mph.

Certainly the Gen 1 Olds engines are also considered a medium block and I think the Gen 2 short and tall decks are also considered a medium block, in fact the short deck 403 has the largest Olds cylinder bore.

D.

Yes, the Bonneville had had a bit of head work and had a good cam, a 650 Holley double pump carb but stock exhaust manifolds. It terminalled the quarter at about 6000 in second - way too much for the stock rods but it really came alive at 5000.

I am surprised the LeMans is that heavy. I had the Bonneville on the weighbridge and it was 1970kg which is about 4300lb.

[Guest]

Yes, the Bonneville had had a bit of head work and had a good cam, a 650 Holley double pump carb but stock exhaust manifolds. It terminalled the quarter at about 6000 in second - way too much for the stock rods but it really came alive at 5000.

I am surprised the LeMans is that heavy. I had the Bonneville on the weighbridge and it was 1970kg which is about 4300lb.

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I was surprised as well. My 59 Catalina weighed 3900lbs and my current 62 Catalina comes in at 3709. A friend has a 66 GTO and his car comes in at 4100lbs. The factory shipping weight for my LeMans says 3,300lbs, but it's a stripped model- six cylinder, no A/C, no A/T ect.

Wow, 6,000rpm with cast rods? Gotta have a very good balance job on that one-dead nuts! The 59 Cat shifted at 5,800 and I used the tried and true factory Mac # 7 solid cam. The LeMans uses one of the best Pontiac street cams, the 068 with a 800cfm Q-Jet and I shift at a safe 5,200. Take a closer look at the picture of my intake on the LeMans and tell me what you think it is.

D.

[PONTIAC1953]

i think mr. timsweet needs to know that magazines article's like drive report, and book writers often make make mistakes, or end up printing wrong information. in 38 years of seeing 1964 lemans GTO's, i have never seen, heard, felt, or smelled one with a 326 engine, unless it was a clone. charles coker, 1953 pontiac tech advisor.

[Guest timsweet]

Charles – Thanks for dropping by and giving us some of your insight.

Here is what he provided:

Hi, i’ve never heard of the Chevy reaction in 38 years of studying

GM’s

history. Pontiac was violating GM’s rule of limiting cubic inches of cars smaller than

full-size

to one cubic to every ten pounds of

car

’s weight, so cars like Pontiac’s Tempest/Le Mans, Buick’s Special/Skylark, Old’s Cutlass/F85, and Chevy’s Chevelle/Malibu were limited to 330

cubic inch displacement

. Pontiac marketed the 336 as a 326, and after some time, someone in GM figured out the actual bore and stroke made 336 cid. Pontiac had to change the 336 down to the 326. Then for 1964, Pontiac (Thank You – John DeLorean) created an option for the Le Mans, the

GTO

option, since the standard Le Mans engine obeyed the limit rule, there was nothing in the rule saying you couldn’t offer an optional extra cost, bigger engine. Can you say 389 cid, 348 horsepower ?, OH YES, turn it on, wind it up, blow it out, GTO.

1964 LeMans GTO Convertible

Thanks for reading.

Tim

Edited May 14, 2011 by timsweet (see edit history)

[PONTIAC1953]

post #12 is mine, not timsweet's, charles coker, 1953 pontiac tech advisor.

[Guest timsweet]

Sorry..this got cut off from my post.

Charles – Thanks for dropping by and giving us some of your insight.

Here is what he provided:

Edited May 14, 2011 by timsweet (see edit history)

[Guest]

post #12 is mine, not timsweet's, charles coker, 1953 pontiac tech advisor.

Well Charles, you have part of the story right. First, the standard engine for the Tempest and Tempest LeMans was the straight 215" six. Yes the Idea of the GTO came from DeLorean and also from two Pontiac staff engineers, Bill collins and Russ Gee, and happened at the GM proving grounds in DeLorean's Saturday what if sessions. These three guys created the concept, but it was Pontiac's general manager Pete Estes who actually stuck his career on the line and allowed the option on the LeMans to happen without 14th floor approval.

Building a great car is one thing and selling one is another. Jim Wangers was the guy that was behind some of the most creative marketing of a product that I have ever seen. From Wide-Track to Tigers, Great Ones, to Pontiac Breakaway excitement, Jim was the man who let everyone SEE what Pontiac was doing.

Inspiration from a former Pontiac engineer and general manager was the model that these men looked up to and rose Pontiac from a division that was going to be terminated to a mid-level brand to the number three sale success. This was mostly done by turning a grandpa's car into a hot rodders car starting in 1957 and this mans name was Bunkie Knudsen.

All Pontiac heroes to me.

Don;)

[PONTIAC1953]

hi don, yes you're right about the 215 chevy six, we were talking just about the V8's only. charles coker, 1953 pontiac tech advisor.

[Guest]

hi don, yes you're right about the 215 chevy six, we were talking just about the V8's only. charles coker, 1953 pontiac tech advisor.

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I agree, however the 326 was not a standard engine for the Tempest or the LeMans as you said it was. 326 2bbl or 4bbl was a option just like GTO was a option. Sorry to be so pedantic................Phew, I think I feel better.