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331 vs 347

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Old Jun 16, 2009 | 08:28 AM
  #1  
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Default 331 vs 347

Well, as the name implies, which is better for high rpm autoX situations? I've heard that the 347 has issues with the stroke?

It's getting an aftermarket block and I assume some are capable of high revving 347s? I'm not too experienced with engine parts, as the the only thing stock on the car now is the engine, save an exhaust and pulleys.

Where do you suggest I start building the power? I want to buy parts that will remain when the 347 is in there. Fuel and ignition system first? Cooling system first?

BTW I plan on supercharging. Would that make the 331 a better idea?
Old Jun 16, 2009 | 09:22 AM
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Go with the cubes.
Old Jun 16, 2009 | 09:38 AM
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this topic has been covered many times, the 347 is what you want no replacement for displacement
Old Jun 16, 2009 | 12:00 PM
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high rev 347 in a aftermarket block with boost sounds like a boat load of fun!
Old Jun 16, 2009 | 12:30 PM
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in a stock block, I like the 331 over 347.
It has been several years since I have looked into one though.
In a light car it isn't worth 20lbs of torque to lose 30 or 40 horsepower. Also the the 331 will last longer.

If I was going to build a race car, I would go with a 351 and spray the shizz out of it before I would build a 347.

Even with aftermarket blocks for both, I would go with the 351 over the 347.

Last edited by TrimDrip; Jun 16, 2009 at 12:35 PM.
Old Jun 16, 2009 | 12:52 PM
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Aftermarket block, 3.4" 347 crank, 4.125 bore, 363 inches of very light small block quick revving love. Just make sure you have a good suspension setup so you can controlt he torque.

http://www.youtube.com/watch?v=OIKz2M0Uao8 This is a 67 with a 363 on a road course, it obviously has no revving problems!!
Old Jun 16, 2009 | 02:20 PM
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Originally Posted by TrimDrip
in a stock block, I like the 331 over 347.
It has been several years since I have looked into one though.
In a light car it isn't worth 20lbs of torque to lose 30 or 40 horsepower. Also the the 331 will last longer.
This is how myths are kept alive.

331 = 347 in a stock block...... why would you choose the 331?..... mythological hearsay?

Why would the 347 loose horsepower and gain torque? Or is the 347 horsepower production limited?

A 347 has the same lifespan as a 331. Why wouldn't it?
Old Jun 16, 2009 | 02:26 PM
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Originally Posted by TrimDrip
I would go with the 351 over the 347.
Why??????? a well chosen combo for a 347 as well for the 351...... the 347 will win.
Old Jun 16, 2009 | 02:48 PM
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Originally Posted by Joel5.0
This is how myths are kept alive.

331 = 347 in a stock block...... why would you choose the 331?..... mythological hearsay?

Why would the 347 loose horsepower and gain torque? Or is the 347 horsepower production limited?

A 347 has the same lifespan as a 331. Why wouldn't it?
see this is where I am out of the loop. They must of done something to reduce friction of the 347. I have read many tech articles and heard from many mechanics how a 347 side loads the block and reduces horsepower.

I would go for a 351 over a 347 anyday. Rebuilding purposes for one. I may be fine with a 500 horse motor this time but, next time I may want more.
Might as well already have the block.
Old Jun 16, 2009 | 03:19 PM
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Originally Posted by TrimDrip
see this is where I am out of the loop. They must of done something to reduce friction of the 347. I have read many tech articles and heard from many mechanics how a 347 side loads the block and reduces horsepower.
More hearsay........ what you hear is based on the infamous Rod:Stroke "excuse" for poor engine building techniques ..... added to the piston pin intersecting the oil rings land in the first configuration of the 347. Friction in a 347, due to the aforementioned R:S myth, is less than a 1980 Toyota 1.8L 3-TC engine, a 454 chevy, a 300 I-6 Ford engine... all OEM setups........ and I've worked on customer cars/trucks + owned one..... that provided, and continued to provide service, past the 250k miles mark under REAL service/abusive conditions.

FYI.... 351w based stroker setups are "worse" than a 347 in that R:S department.

Originally Posted by TrimDrip
I would go for a 351 over a 347 anyday. Rebuilding purposes for one. I may be fine with a 500 horse motor this time but, next time I may want more.
Might as well already have the block.
Like MJR said.... a 347 will be faster than a 351w setup, stroke that 351w to 408, and you've evened the ground for comparison sakes....... unless you go with a lighter than OEM rotating assy for the 351w setup.



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