306 vs 331

[Joes95GT]

A 347 has a longer stroke. Which means it travels further, up and down, in the cylinder. That means the rings are moving more and eventually wear out quicker. bearing and piston wear would be the same, unless you're running the bottle.

Put the wrench down and stop thinking immediately. If you run "the bottle" which I assume is nitrous, how is that going to help bearing life? Does it have some magical bearing potion in it or something?

If money isn't an option go with the 331. In general it will cost another $500 bucks for the shortblock over a 306 (a bit more actually). Figure in the added price of a 28 oz flywheel and matching balancer.

A 347 will "burn" more oil over a 331 over prolonged period of time in a controlled enviroment. Increased cubes equals increased oil burning potential. It is minimized much more than "yesteryear" but you can't change the engine dynamics.

There is a reason why they make a 331. If the 347 had the same pros as the 331 with no side effects the 331 would not be made. It just wouldn't be practical in the enthuisiast market.

If your going for a blower the sidewall pressure will be greater with the 347...but a dart block could cure that...but it will also "cure" your wallet

This is by far and away the most retarded thing I've ever heard you say....and you've said some pretty retarded stuff...

Joe

 

[5spd GT]

What about when the 331 is revved higher? Or when you have to put a higher gear in the 331 than the 347? Cruising speeds will have higher rpms.....


This argument is pointless. :Track:

Who said you had to rev it higher? Who said you have to put a steeper gear in it? Were talking about engine life, not track times.

We are keeping variables the same here

No changing...

Joes95Gt - Explain why that is so "off" (my statement).

He was referring that bearing life would suffer on the bottle. Reading comprehension my friend

 

[nmcgrawj]

Who said you had to rev it higher? Who said you have to put a steeper gear in it? Were talking about engine life, not track times.

We are keeping variables the same here

No changing...

OHHH I GOT IT! So we are building motors....spending HUGE amounts of cash to NOT build the car right? I dont know what you do with your car, but if i spend thousands upon thousands of dollars, believe me im going to build it right.

Take your little physics "imaginary" lab else where. You dont build engines to compare the life of them. You build engines and cars the way they need to be built. THEN compare the outcome. What good is it to me if u "keep all the variables the same" and then when i put the engine in my car, i have to get a steeper gear...or rev it higher than a comparable 347, your "claims" go out the window.


Its amazing how many times this argument can come up on these boards and just go on and on and on about this stupid physics lab "hold all variables the same" type of trash. What is the point of "holding the variables the same" if they WONT be the same in the car? They wont be the same when u drive the car every day? Will they? I think not. So what is your "experiment" proving?

 

[Joes95GT]

He was referring that bearing life would suffer on the bottle. Reading comprehension my friend

"A 347 has a longer stroke. Which means it travels further, up and down, in the cylinder. That means the rings are moving more and eventually wear out quicker. bearing and piston wear would be the same, unless you're running the bottle."

Bearing and piston wear would be the same......as what?

I'm sorry if I can't understand vague, incomplete sentences.

Joes95Gt - Explain why that is so "off" (my statement).

Sure!

A 347 will "burn" more oil over a 331 over prolonged period of time in a controlled enviroment. Increased cubes equals increased oil burning potential. It is minimized much more than "yesteryear" but you can't change the engine dynamics.

My first statement is this: Prove it. I have never, ever, heard of such bull****. So you tell me that a 460 is going to burn +28% than a 331 over a "prolonged period of time?"

Ring seal, piston design, and bad valve seals are the causes of oil consumption - not cubic inches. Where in the world are you coming up with this nonsense?

There is a reason why they make a 331. If the 347 had the same pros as the 331 with no side effects the 331 would not be made. It just wouldn't be practical in the enthuisiast market.

Simply put, there are idiots by the truck load who believe the rhetoric in your post that I've chopped all up, and because of that, 331 stroker kits sell.

While I am no expert (and I'm sure you'll agree ), it's my opinion that the 331 kits came about because an industry "standard" way of making a stroker kit is to add a quarter inch of stroke to the crank. A good idea, and one that I would look into if I wanted to put a serious 347, would be to use the 3.25" crank with a 4.125" bore. A 3.25" crank on a 4.000" bore simply isn't cost effective.

If your going for a blower the sidewall pressure will be greater with the 347...but a dart block could cure that...but it will also "cure" your wallet

First, the differences in rod angles between the 347 and 331 are less than 4*. Secondly, please explain to me what sidewall pressure is and why it's bad.

Joe

 

[5spd GT]

OHHH I GOT IT! So we are building motors....spending HUGE amounts of cash to NOT build the car right? I dont know what you do with your car, but if i spend thousands upon thousands of dollars, believe me im going to build it right.

So what is building it right mean? Getting it down the quarter mile the fastest? Burning less oil than the faster car? Or a mix of both? Answer me that first. What is building it right mean?

Take your little physics "imaginary" lab else where. You dont build engines to compare the life of them. You build engines and cars the way they need to be built. THEN compare the outcome. What good is it to me if u "keep all the variables the same" and then when i put the engine in my car, i have to get a steeper gear...or rev it higher than a comparable 347, your "claims" go out the window.

You don't build all engines to compare power either. What about back to back factory engines? Do they dyno each own to see which one made more power. Nope, they provide a nice balance of longevity and get he power and reliability to meet the market they are trying to acheive.

Who said you need to add a steeper gear? Who said you had to rev it higher?

Your changing the outcome, so why can't I?

Its amazing how many times this argument can come up on these boards and just go on and on and on about this stupid physics lab "hold all variables the same" type of trash. What is the point of "holding the variables the same" if they WONT be the same in the car? They wont be the same when u drive the car every day? Will they? I think not. So what is your "experiment" proving?

An argument is between two or more. It takes two too argue.

My experiment (a bit bold there) is showing that under equal circumstances that the slightly less tolerable 347 has a harsher rod ratio to it and will cause more wear over time. Very easy. Why argue with that?

 

[5spd GT]

"A 347 has a longer stroke. Which means it travels further, up and down, in the cylinder. That means the rings are moving more and eventually wear out quicker. bearing and piston wear would be the same, unless you're running the bottle."

Bearing and piston wear would be the same......as what?

Same revolutions of the crankshaft is what he is referring to.

I'm sorry if I can't understand vague, incomplete sentences.
Sure!My first statement is this: Prove it. I have never, ever, heard of such bull****. So you tell me that a 460 is going to burn +28% than a 331 over a "prolonged period of time?"

Well reading context also helps.

Where did I ever say that oil burning is directly related to cubic inches alone?

The rod ratio my friend is the deeper of the enemies.

Ring seal, piston design, and bad valve seals are the causes of oil consumption - not cubic inches. Where in the world are you coming up with this nonsense?Simply put, there are idiots by the truck load who believe the rhetoric in your post that I've chopped all up, and because of that, 331 stroker kits sell.

Yep about the oil consumption reasons.

You are so wrong, the 331 has it pros. Ask Rick91GT.

You have to be kidding. Their is a reason they sell it. Just like their is a reason they sell anything that last. Wow, I'm shocked you stated that...

While I am no expert (and I'm sure you'll agree ), it's my opinion that the 331 kits came about because an industry "standard" way of making a stroker kit is to add a quarter inch of stroke to the crank. A good idea, and one that I would look into if I wanted to put a serious 347, would be to use the 3.25" crank with a 4.125" bore. A 3.25" crank on a 4.000" bore simply isn't cost effective.

That is a possibility...but I believe (as I'm sure you won't agree) that there are other reasons for that.

First, the differences in rod angles between the 347 and 331 are less than 4*. Secondly, please explain to me what sidewall pressure is and why it's bad.

Yep, but every little bit adds up. Like in a cam for example.

Sidewall pressure is the pressure exerted by the piston during its rotational movement against the sidewall of the cylinder wall. The increased (steeper rod ratio) causes more loading and in turn puts more stress on the block and makes it want to split in the lifter valley even more so.

 

[Michael Yount]

Slow5.0 - You're gonna spend a pretty significant amount on this beast, so it's best to get it right the first time. If you're serious about boosting a 331, you really should go with an upgraded block. The stock-block based stuff from DSS or CHP won't cut it -- and any sort of lifter valley or main girdles won't help a bit -- unless you count having something that helps keep all the broken parts in the same general vicinity as a 'help'. When you start to stray into the 450 rwhp level and above, the stock block is at risk. As others said -- every now and then someone gets a good one and it holds together, but MANY have broken up stock blocks at that power level. As to the fellow that broke his crank -- and thinks that took out the block -- almost always, it's the other way around. The block lets go, and when it does, it takes the crank with it. The stock block is MUCH weaker than the crank.

If you go with a Dart block in the 8.2" deck height, you can build up to a 374" motor -- 4.125" bore X 3.5" stroke. Don't pay any attention to the worries/concerns over rod/stroke ratios, rod angles, side loading and oil burning -- if the engine is machined properly and competently assembled with quality components, it should last for about as long as you want it to. As someone else said, there have been literally millions of OEM blocks built with worse rod angles and more side loading than a 347. No need to worry about it any more than a 331.

5 spd -- You asked "Where did I ever say that oil burning is directly related to cubic inches alone?" In your first post you said "Increased cubes equals increased oil burning potential." That's likely what the other poster was referring to.

 

[Michael Yount]

OOPS - double post...

 

[nmcgrawj]

The increased (steeper rod ratio) causes more loading and in turn puts more stress on the block and makes it want to split in the lifter valley even more so.

Can u explain why then so many professionals say rod ratio doesnt matter? I guess you should be doing their job And can you prove that it will split the lifter valley sooner? Or is this just more guessing based off your physics book?

I think people would recommend a 331 over a 347 in some applications not so that it lasts longer....but maybe for a supercharger to have higher rev's or something of that nature.

 

[nmcgrawj]

If you go with a Dart block in the 8.2" deck height, you can build up to a 374" motor -- 4.125" bore X 3.5" stroke. Don't pay any attention to the worries/concerns over rod/stroke ratios, rod angles, side loading and oil burning -- if the engine is machined properly and competently assembled with quality components, it should last for about as long as you want it to. As someone else said, there have been literally millions of OEM blocks built with worse rod angles and more side loading than a 347. No need to worry about it any more than a 331.

5 spd -- You asked "Where did I ever say that oil burning is directly related to cubic inches alone?" In your first post you said "Increased cubes equals increased oil burning potential." That's likely what the other poster was referring to.

:Word:

 

[Grn92LX]

Heres 2 327/331 threads from corral where Ed Curtis chimed in. Both times he said "Build a 347, why give away the inches." Gee, wonder why he said that

http://www.corral.net/forums/showthread.php?t=714755

http://www.corral.net/forums/showthread.php?t=717327

I have one question for the stroker expert (you know who you are ) What happens when you build a 3.40 stroke 347 using a 331 piston with a 1.175" CH instead of the typical 1.09" CH?

I think i'm gonna go outside and hug my 347 right now

 

[Joes95GT]

Slow5.0 - You're gonna spend a pretty significant amount on this beast, so it's best to get it right the first time. If you're serious about boosting a 331, you really should go with an upgraded block. The stock-block based stuff from DSS or CHP won't cut it -- and any sort of lifter valley or main girdles won't help a bit -- unless you count having something that helps keep all the broken parts in the same general vicinity as a 'help'. When you start to stray into the 450 rwhp level and above, the stock block is at risk. As others said -- every now and then someone gets a good one and it holds together, but MANY have broken up stock blocks at that power level. As to the fellow that broke his crank -- and thinks that took out the block -- almost always, it's the other way around. The block lets go, and when it does, it takes the crank with it. The stock block is MUCH weaker than the crank.

If you go with a Dart block in the 8.2" deck height, you can build up to a 374" motor -- 4.125" bore X 3.5" stroke. Don't pay any attention to the worries/concerns over rod/stroke ratios, rod angles, side loading and oil burning -- if the engine is machined properly and competently assembled with quality components, it should last for about as long as you want it to. As someone else said, there have been literally millions of OEM blocks built with worse rod angles and more side loading than a 347. No need to worry about it any more than a 331.

You da man, Mike! You said it all.

5 spd -- You asked "Where did I ever say that oil burning is directly related to cubic inches alone?" In your first post you said "Increased cubes equals increased oil burning potential." That's likely what the other poster was referring to.

LOL. We should have known that he meant something other than what he said.

You are so wrong, the 331 has it pros. Ask Rick91GT.

If you are in persuit of a "pro" that is "getting beat at the track by a 347," then be my guest.

Joe

 

[5spd GT]

5 spd -- You asked "Where did I ever say that oil burning is directly related to cubic inches alone?" In your first post you said "Increased cubes equals increased oil burning potential." That's likely what the other poster was referring to.

Yeah I did put that and I didn't say "automatically" a bigger engine will burn more oil like Joe95gt tried to infer. I knew what he was talking about

 

[5spd GT]

Can u explain why then so many professionals say rod ratio doesnt matter? I guess you should be doing their job And can you prove that it will split the lifter valley sooner? Or is this just more guessing based off your physics book?

Because they build it for the track...not driving it for long periods of time (mileage). Easy answer to an easy question.

Nope I shouldn't be doing their job. They sell products.

I think people would recommend a 331 over a 347 in some applications not so that it lasts longer....but maybe for a supercharger to have higher rev's or something of that nature.

That would be known as another reason (pro) for a 331 and why they offer it on the market.

 

[5spd GT]

Heres 2 327/331 threads from corral where Ed Curtis chimed in. Both times he said "Build a 347, why give away the inches." Gee, wonder why he said that

http://www.corral.net/forums/showthread.php?t=714755

http://www.corral.net/forums/showthread.php?t=717327

I have one question for the stroker expert (you know who you are ) What happens when you build a 3.40 stroke 347 using a 331 piston with a 1.175" CH instead of the typical 1.09" CH?

I think i'm gonna go outside and hug my 347 right now

He said it because in those references (and you forget we are talking about Ed "take it to the track" Curtis) he was referring to being faster. It isn't Ed "daily driver" Curtis

You get you 347 with a 331 rod ratio

 

[5spd GT]

We should have known that he meant something other than what he said.

Finally getting the picture, atleast your understanding

If you are in persuit of a "pro" that is "getting beat at the track by a 347," then be my guest.

Just because you have a 347 doesn't mean you will beat a 331 nor does it mean you will beat a 302.

I'll be that guest.

 

[Joes95GT]

Just because you have a 347 doesn't mean you will beat a 331 nor does it mean you will beat a 302.

I'll be that guest.

I was just about to not say anything because I knew that was coming. In some cases, and this being one of them, your rebuttals are ridiculous.

Ok, here goes. Use the 331 because of extreme block-splitting, side loading power of the 347. The 331 utilizes a better rod ratio and is much better than a 347 because it will burn less oil over a prolonged period of time in a controlled environment, since, as we all know, we all operate our engines in controlled environments.

The 331 is for you.

All hail 5spd GT, for he is the one who knows it all, yet is the one who can't convey it all clearly so he tells everyone that they take his words out of context to make himself feel better.

Joe

 

[94GTLaserRC]

 

[Slow5.0]

Wow guys, stop fighting

I decide to go with 306 stock block and keep HP # around 450HP
I'm on budget

 

[Michael Yount]

You can still break it at that level....

And by the way guys -- it's a 332...