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hey guys i have a 1992 lx hatch back mustang with a few mods done to it and was concidering building my self a stroker. now from what i hear the 347 is eather a great motor or its a poor motor.. my car is mainly a daily driver but it will be hitting up the 1320 everyonce in a while so should i concider the 331 or the 347... thanks for your help
 

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A 347 built to correct tolerances will work very well & last in a street/strip car. I wish I had built one instead of my 331. I'd like to have those 16 extra cubes. Torque is what makes it fun to drive. Just remember, you get what you pay for in parts & machine work.
 

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A 331 has a better Rod-to-Stroke ratio than a 347 (the higher the ratio, the better). The lower the ratio, the more side loads and the more wear on the rings.

331 = 5.4 / 3.25 = 1.662:1

347 = 5.4 / 3.4 = 1.588:1

A stock 302 = 5.09 / 3.0 = 1.696:1

Some believe that the power lost from giving up 16 cubes can be gained back from the better rod-to-stroke ratio.

I have NO complaints about my 331. It has a lot of torque and really pulls hard!
 

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I have a carburated 347 with a CC 280HR cam and it's a torque monster. I love it! Bruce
 

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I think you'll get tons of people that love both. Read the article here about the 331 build up:

http://www.fordmuscle.com/archives/2002/04/331/

Maybe that will help you decide.

If I could do it all over again (since I built my engine from scratch after acquiring a 302 block), I would have found a 351 block and built a 383 stroker.
 

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On 2006-09-04 13:53, 89Trooper wrote:
A 331 has a better Rod-to-Stroke ratio than a 347 (the higher the ratio, the better). The lower the ratio, the more side loads and the more wear on the rings.

331 = 5.4 / 3.25 = 1.662:1

347 = 5.4 / 3.4 = 1.588:1

A stock 302 = 5.09 / 3.0 = 1.696:1

Some believe that the power lost from giving up 16 cubes can be gained back from the better rod-to-stroke ratio.

I have NO complaints about my 331. It has a lot of torque and really pulls hard!
There are several stroke ratios for 342/347's. The one you mention (wrist-pin, below the oil ring land) is currently more popular for the "Streeter" engines. Using the same rod length and greater pin height, you give nothing away to rod ratio.

Quite a few years back, Jim Allen, was running a 302 based 355 cu. engine.

The only point I am making, is where there is a will, there IS a way.

My observation is and has been ...if its going to be a problem with the guy spending the money, then its a problem. If you do your homework, are willing to live with the possible conequences and are willing to get away from the herd - then its not a problem.

As far as them being "more or less equal" ... I kinda' wonder about that. You spin one higher, the other puts our more torque. Seems to me, the application is more of a factor than making a blanket decision as to which is better or even if they really are equal.
 

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Just to put things in perspective.

Not that long ago, stokers were almost 100% thought of as something to be avoided. Guys loved the 289, hated the 302.

Guys then decided that the the 302 was always better than the 351, it was thought to be a "dog". As better heads have come ont he market, better cam designs and better compenents (ignition, cheaper forged pistons, cheaper high quality rods and cheaper crank kits) the whole game plan has started to change.

The 429 was the winner, the 460 was a "dog", same engine - the 460 is just a factory "stroker" of the 429. Now, most guys don't even think about running a 429 (even though it will usually rpm better, very few are ready to walk away from the extra 31 cubes...matter of fact, most guys are shooting for 500 cubes or better.

It's just real hard to dismiss those "free" cubes. Same with 351 vs, 393/408, if you are going to spend the money and the time - seems kind of weird to leave power on the table. Very few rodders are trying to build 100K mile engines, personally - at 50K miles, I'm usually ready to rebuild my street engines.
 

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Thanks to My427stang, I get the timing almost perfect and now the car is even better... never thought the timing off by only a little could make such a huge difference!
 

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Build a 393 or a 408 and then you will have something when you are done for almost the same money. I would not build a 347 because of the poor rod ratio. I have seen several of them split themseles in two down the ceter of the block because the internal side load on the bore.
 

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The Rod Ratio of some factory Ford engines is "worse" that a 347 stroker
2.0L ZETEC 1.547 : 1
2.0L OHC 1.499 : 1
300 I-6 1.56 : 1

...and the newer Triton V8 and V10?
5.4L V-8 1.598
6.8L V-10 1.598

and lastly let's not forget about the most popular stroker of all time. The Chebby 383 with a rod ratio of 5.2 : 1

All I'm saying is don't get caried away with the whole rod ratio thing.
Get a 347!
 

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You guys still beating this horse?

It ought to be steak tartar by now. Cheap as stroker kits are now, unless you have a fetish for accuracy or running some class that has originality/displacment restrictions; its hard to pass up all the engine you make for a street car. Torque rules (on the street)...and cubes make torque down low where it does some good.

At some point you have to get off the dime and build something.

Taking a line from Nike...Just Do it!
 

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On 2006-10-10 10:54, lovemyHO wrote:
The Rod Ratio of some factory Ford engines is "worse" that a 347 stroker
2.0L ZETEC 1.547 : 1
2.0L OHC 1.499 : 1
300 I-6 1.56 : 1

...and the newer Triton V8 and V10?
5.4L V-8 1.598
6.8L V-10 1.598

and lastly let's not forget about the most popular stroker of all time. The Chebby 383 with a rod ratio of 5.2 : 1

All I'm saying is don't get caried away with the whole rod ratio thing.
Get a 347!
And none of those motors is based on a 289/302 block. I do agree, 347's have their place. Right now I'm debating a 347 or 393 for my 84 hatch. But my point is, the 289/302 stock block is a WEAK design when you start loading the cylinder walls. Some split as early as 350rwhp, although on average it seems 500fwhp is a typical sign off number. Comparing rod ratio's between various engine families and citing their successes vs. a small block ford is apples to oranges. They don't use the same blocks, end of story. That would be like comparing oiling between a 351C and a 351W, and saying 'Don't get carried away with the whole oiling issue!' =).

They're different! End of story =p.

Cris
 

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Rod/stroke ratio is over-rated...especially when talking street cars.

Go with a 347 with the shorter 5.315" rod. This will allow you to run the same piston as used in the 331 preventing the wrist-pin/ring issues related to the 5.4" rod combo.

5.0 motors run strong because they make good torque, and the 347 combo capitalizes on that idea.
 

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On 2006-09-12 19:31, gbbmustang wrote:
Build a 393 or a 408 and then you will have something when you are done for almost the same money. I would not build a 347 because of the poor rod ratio. I have seen several of them split themseles in two down the ceter of the block because the internal side load on the bore.
I any high HP (over Approx 500Hp) application the Stock Blocks will eventually Split !! In a 350-400 hp street motor it won't be an issue. All the BS ablut rod ratios is a load too, the small differences we are talking about don't matter for a mild street application. But when building a motor and using all new parts it is better to use the longer rods, but its an extreamly small gain.
_________________
1991 LX Mustang 347 C4 combo 11's with the AC on.
1984 Mustang GT 460, Powerglide "Its alive !!!" 10's out of the box, 9's on the way N/A !!
1929 T-Altered "In the works" Easy 8's are on the horizon

<font size=-1>[ This Message was edited by: dfree383 on 11/9/06 8:57pm ]</font>

<font size=-1>[ This Message was edited by: dfree383 on 11/9/06 8:58pm ]</font>
 

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Here's a novel idea. If you are going for the high dollar, Ultra build - cough up the 1-2 grand for a good 4-bolt block? It's not like it'll be wasted money...the peace of mind by itself is a good enough reason. Then you add in dimensional stability, better deck sealing (besides the web cracking issue, you also have a very thin deck on the late model 5.0 liter blocks, even if you drill and tap for 1/2 in. head bolts they are still anchored by the "Flexi-flyer" thin deck).

The issue really isn't that the block is weak - the problem is trying to pull max horsepower (even worse; when you add in power adders - like superchargers, heavy N02, or Turbos) out of factory equipment, then blaming the stock part for not holding up. The solution has been found and widely known for years. Either get a decent aftermarket block or be prepared to re-build the engine with a replacement factory block when it lets go - and hope your high dollar parts can be salvaged and reused in the new build. The flaw in this solution is; it cost a lot in block prep everytime you get a new block. Any savings in starting out with a cheap block is eaten up at least by the 2nd block.

Yeah, I understand it hurts to let go of $1000+, for a block! There is a lot of temptation to skirt the edge of durablity...plus there is a lot of satifaction in displaying your "war trophies", cracked and split, stock blocks...at least the first time. Once you know it can be done, and you keep on doing it - well, the defintion of insanity comes to mind. The popular definition of insanity is "after trying something and finding it doesn't work, you continue to do the same things, the same way - expecting a different outcome". Doesn't that sound eerily familiar?

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Of all the rest..."There are three faithful friends, an old wife, an old dog, and ready money..."-- Benjamin Franklin, 1738 --

<font size=-1>[ This Message was edited by: Beoweolf on 11/9/06 10:46pm ]</font>
 

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On 2006-10-10 10:54, lovemyHO wrote:
The Rod Ratio of some factory Ford engines is "worse" that a 347 stroker
2.0L ZETEC 1.547 : 1
2.0L OHC 1.499 : 1
300 I-6 1.56 : 1

...and the newer Triton V8 and V10?
5.4L V-8 1.598
6.8L V-10 1.598

and lastly let's not forget about the most popular stroker of all time. The Chebby 383 with a rod ratio of 5.2 : 1

All I'm saying is don't get caried away with the whole rod ratio thing.
Get a 347!
Thank you for posting that as I've tried to make this point before. You mean with all that side load the rings and bores last!?! All those problems you hear about 383 chevys and premature wear. Oh wait! I haven't heard about any! Yes, I'm being sarcastic and having a little fun.
Funny how my chevy buddy doesn't give a darn about rod ratio on his stroked sbc.

A bigger engine will be more rpm limited than a smaller one with the same heads and induction. The same cam also will most likely run out of steam sooner as well. So what's the real reason 347's get a rep for being low rpm motors? I would guess it' not the rod stroke ratio. Joe Sherman is one guy that can make those 347's scream up high.

Some of you guys start to sound like you believe only 347's split blocks. That may be the next bad rep the 347 gets! You can find plenty of cases where 302's split blocks at the same power levels. It seems to me the blocks split at a certain power level and not because of a certain stroke. Sure the extra stroke will get you to that power level easier!

I think when someone builds a 289-331 and it burns oil or splits a block they say that it was because of poor assembly and/or too much power. The same happens with a 347 and it all of a sudden is due to the rod ratio. Just an observation.
 

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On 2006-11-09 07:38, Beoweolf wrote:
Here's a novel idea. If you are going for the high dollar, Ultra build - cough up the 1-2 grand for a good 4-bolt block? It's not like it'll be wasted money...the peace of mind by itself is a good enough reason. Then you add in dimensional stability, better deck sealing (besides the web cracking issue, you also have a very thin deck on the late model 5.0 liter blocks, even if you drill and tap for 1/2 in. head bolts they are still anchored by the "Flexi-flyer" thin deck).

The issue really isn't that the block is weak - the problem is trying to pull max horsepower (even worse; when you add in power adders - like superchargers, heavy N02, or Turbos) out of factory equipment, then blaming the stock part for not holding up. The solution has been found and widely known for years. Either get a decent aftermarket block or be prepared to re-build the engine with a replacement factory block when it lets go - and hope your high dollar parts can be salvaged and reused in the new build. The flaw in this solution is; it cost a lot in block prep everytime you get a new block. Any savings in starting out with a cheap block is eaten up at least by the 2nd block.

Yeah, I understand it hurts to let go of $1000+, for a block! There is a lot of temptation to skirt the edge of durablity...plus there is a lot of satifaction in displaying your "war trophies", cracked and split, stock blocks...at least the first time. Once you know it can be done, and you keep on doing it - well, the defintion of insanity comes to mind. The popular definition of insanity is "after trying something and finding it doesn't work, you continue to do the same things, the same way - expecting a different outcome". Doesn't that sound eerily familiar?

_________________
Of all the rest..."There are three faithful friends, an old wife, an old dog, and ready money..."-- Benjamin Franklin, 1738 --

<font size=-1>[ This Message was edited by: Beoweolf on 11/9/06 10:46pm ]</font>
Post of the year.
 
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