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Pontiac 347 V8 Engine

The Pontiac 347 V8 was introduced for the 1957 model year and did quite a bit to change the future for the muscle car era. The 347 was simply a bored out version of the Pontiac 316 V8 with a longer stroke. Most notably is that the 347 had the honor of being the first engine from Pontiac to use the famous tri-power carburetor setup which consisted of 3 two barrel carburetors. The idea behind tri-power was that the middle of the three carburetors would feed the engine at cruising speeds and at idle but when more power was needed the other two carbs would open up and supply the engine with a greater amount of fuel. This idea became very popular with Pontiac and would be used up until the mid 1960s on the famous Pontiac 389.

The 347 was available in a large number of options that produced a large variety of horsepower ratings. One of the rarest 347 models every produced was a fuel injected version that was used in the Pontiac Bonneville and produced 315 horsepower. There were only 630 of these fuel injected Bonnevilles ever produced and they were all convertibles. There was also a special 347 NASCAR model built that included the tri power option as well and put out a respectable 317 horsepower. For the 1958 model year the 347 would be replaced by the Pontiac 370 V8.

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Hi
I hope you can help me.I have a 57 Pontiac Super Chef and i stay in germany and need a 4 barrel intake manifould for my car,but i dont no from where i can get them,you can help me or you sell them?
Thank you and greatings from germany
Jens
#1 - Jens - 02/09/2010 - 22:27
57 pontiac intake manifold
Hi Jens,
We checked four different part's sources for that intake manifold and unfortunately found nothing available. We checked ebay as well just in case but there was nothing. If we find one we will let you know. Thanks for visiting the site.
#2 - Engine Facts Admin - 02/10/2010 - 09:22
55-64 Intakes Interchange?
Will all the intakes ineterchange from 1955-64?
#3 - Marco - 05/10/2010 - 20:10
information on parts availability for fuel pump cam drive on 347 pontiac 4 barrell engine. Also, lower front crank seal retainer.
#4 - Mark - 10/13/2010 - 19:30
I have a 1957 gmc withe the 347 Stromberg 2 bbl.

why is exhaust gas ported cente4r engine up to carb connection plate through intake casting? Are the 2 holes suppossed to be sealed? Maybe I have an incorrect gasket?

please help
#5 - matt brown - 05/12/2011 - 22:08
i have 1957 gmc truck. i believe the motor is the original. 347? how can i verify the model and locate parts to rebuild the entire engine?

thank you very much,
chris
#6 - christopher fisher - 01/28/2012 - 20:38
Pontiac Bonneville
The 1957 Bonneville engine was 370 CI with Fuel Injection and a special high performance camshaft. This cam used hydraulic lifters to comply with Pontiacs no warrantee policy for solid lifter engines. Fuel Injection badges were applied to the front fenders of thes cars. The 1957 Pontiac was also the first year for their Super Duty engine program. In this year it was the 347 CI with the Isky E-2 cam as in 1956 along with the 2 x 4 barrel intake manifold. The 347 engines were also offered with Tri-Power as an RPO and came with TriPower emblems on the front fenders.
#7 - Seamus McGowan - 02/04/2012 - 02:21
Pontiac Intake Manifolds and such
Tri-power was an option from 1957 thru 1966 and mixing parts can be confusing. Three different manifolds were used and 3 different sets of carburators as well. Initially 3 small carbs were used, then the end carbs were changed to a larger size and finallt all 3 were the larger size. The basic shape of the intake manifold did not change but water passages and bolt hole location did. If anyone wants the exact years send me an email and I will reply and post it here.

The Pontiac engines in GMC trucks were only used in the GMC. These were long stroke engines although many parts will interchange with the same year car engines.
#8 - Seamus McGowan - 02/04/2012 - 02:32
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Engine Specifications

1957 with 2 Barrel Carb
(Lower Compression)
Max Brake Horsepower - 227 @ 4600 rpm
Max Torque - 333 @ 2300 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 8.5
Firing Order - 18436572

1957 with 2 Barrel Carb
(Higher Compression)
Max Brake Horsepower - 252 @ 4600 rpm
Max Torque - 354 @ 2400 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 10.0
Firing Order - 18436572

1957 with 4 Barrel Carb
(Lower Compression)
Max Brake Horsepower - 244 @ 4800 rpm
Max Torque - 350 @ 2600 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 8.5
Firing Order - 18436572

1957 with 4 Barrel Carb
(Higher Compression)
Max Brake Horsepower - 270 @ 4600 rpm
Max Torque - 359 @ 2800 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 10.0
Firing Order - 18436572

1957 with 4 Barrel Carb
(Even Higher Compression)
Max Brake Horsepower - 314 @ 4800 rpm
Max Torque - 375 @ 2800 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 10.25
Firing Order - 18436572

1957 with 3 X 2 Barrel Carbs
(Tri Power)
Max Brake Horsepower - 290 @ 5000 rpm
Max Torque - 375 @ 2800 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 10.0
Firing Order - 18436572

1957 with 3 X 2 Barrel Carbs
(Tri Power NASCAR)
Max Brake Horsepower - 317 @ 5200 rpm
Max Torque - 375 @ 2800 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 10.0
Firing Order - 18436572

1957 with Fuel Injection
(Bonneville Convertible)
Max Brake Horsepower - 315 @ 5000 rpm
Max Torque - 375 @ 2800 rpm
Stroke - 3.5625
Bore - 3.9375
Compression - 10.0
Firing Order - 18436572