50 is worse, there is more counterweight on the flywheel and balancer, 28oz is less "effectively" moving this weight into the crankshaft. Anytime you can move the weight from the outboard ends of the crank the better.

 

the two crankshafts have different shapes and weights of the counterweights....
so none of the dampeners or flywheels will interchange.

the less weight the better.

the overall best is a "internal balance", this is when all of the weight is inside the engine thus on the counterweight... and the flywheel and dampener have NO offset weight on/ in them....

this is overall the best when there is a heavy acessory load such as a belt driven blower / turbo /
or just making lots of power Normally aspirated.

 

The SBF pushrod Windsor came with 28 inbalance and then adopted the 351W’s 50 ounce. You can neutrally balance your engine (0 ounce imbalance), a costly endeavor using expensive Mallory metal

I had this question when I was starting to build an engine; a 5.0 with 289 crank and rods (this would require 28 inbalance); Jay Steel of Taylor engines told me that the money is better spent on a good balance and high quality dampener than trying to 0 imbalance. That with quality parts lets you rev as high as anyone.
He did mention that he thought 351/5.0 firing order was superior to 289/302 but thats another debate. Basically what I came away from the conversation with is that its better rev-wise to get better valvetrain parts or better strength-wise to get an aftermarket block than spend money turning 28 to 0 imbalance

this is overall the best when there is a heavy acessory load such as a ... turbo

Good one Kunto

 

How can a turbo create an accessory load? I have heard that this 0/28/50 balance is more critical if the rpm's are over 6000 regardless of horse power.Is this true? Steve

 

50 oz just means the internal components are heavier than the 28 oz stuff, thus requiring a heavier balance weight. Now, the lighter the engine parts are OVERALL is better, as the reduction in recip and rotating mass is beneficial, period, regardless of chosen balance.

Now, some builders have told me they don't like to 0 balance a 289/302 because the front crank throw isn't well served by this and can snap from torsional stress. IDK, I've never seen it happen, save in ridiculous stress situations like ultra-wrenched blower belts and such.

P51C

 

in a high rpm setup, what would be better....

cast crank, i beam rods, forged pistons, balanced to 28oz

or

forged crank, h beam rods, frged pistons, banlance internaly?

 

Depends a LOT on the use. For N/A I'd go with option 1. Use a Mahle or SRP piston because they are nice and light also, reciprocating weight will be very low with a 331 or 347 and that setup. Would be just as strong as a stock 302 block assuming quality pieces were used.

For forced induction of Any kind I'd go option 2 with some kind of stronger block, at a MINIMUM a studded early (D1 or C8) block..

 

you do understand that there are also things called "belt drive turbos"....


I know jay @ taylor quite well....

 

Never heard of one.Why would you want to belt drive a power adder that was driven by exhaust gasses? Seems a little counter productive to me.That's the whole advantage of a turbo,efficiency.Please provide more info(pics,etc.) Steve

 

the great crankshaft debate as to if and when a O balance isbetter than a 28 0unce setup is still a little more than just doing the balance.

the PROPER mannor to do a O balance is to start with a crank that is designed to be ZERO.

the specific cranks that are designed to be, usually have thicker areas where needed and also most have center counterweights....
this makes the crank overall stronger.

it is a whole 'nother thing to try and "convert" a common ford production car 50 ounce crank into a zero unit..just because the material is not there...the material is just not there to even be able to drill and add tungsten / mallory metal / heavy metal to be able to then remove the comenserate amount of weight from dampener and flywheel.
the counterweights on a production crank are "skinny"....

allthough quite a few aftermarket cranks can be "converted"...
only because they are made "heavy" in comparison..

it is quite common to be able to "make" many cranks that were originally a 28 ounce / inch into a zero unit with the addition of heavy metal....

And then there is the factor nowdays that installing heavy tungsten metal to counteract the loss of the counterweight on dampener and flywheel will COST $$ you as much as just BUYING A PURPOSE BUILT CRANK, and not having to "add" material.......
most of the occasions that I have to add mallory / heavy metal to a crank, the material itself is 200 dollars... and when you factor in the original cost of the bare crankshaft, without or with any added cost such as case hardening-nitride work / grinding / polishing / ETC... it could EASILY be MORE than a "puropose built crank" that you can buy like a EAGLE....


not all agree that the change in CAMSHAFT firing order is a benefit to lower the front main bearing loading.
having built and competed / set records with BOTH..and even using "other" firing orders.....
...using individual port injection and carbs ...and EFI ...there is not allways any difference untill there is DETIONATION......

overall bathroom scale related weight is not the factor here...
because there are many under 40 pound scale weight cranks that are ZERO / internally balanced.
super good / superior grade material / heat treating and designs will achieve this...
many oem production cranks are over 37
pounds....and "look" skinny".....

 

My 325 stroker is 50oz balanced just for input

 

You can also use a 28oz balancer, drill a 50oz manual flywheel, and drill the s**t out of a very expensive neutral balanced crankshaft to balance the motor to 28oz. I coudn't believe my eyes when I tore down an engine built by a well known shop to find this.

 

Hamutoff's quote is way off

The SBF pushrod Windsor came with 28 inbalance and then adopted the 351W’s 50 ounce


351w where never 50 the are 28oz from 69 until end of production,however 302 changed from 28 to 50 sometime during 1982. From experience you can tell a big difference in the way a car revs from 50 to 28 and 0 even makes more of a difference. The motor will rev faster and be smoother with 28 oz and again even more so with internal balance. It is not cost effective to change the balance of a crank but if you plan on buying new parts spend the money and go internal everything will hold up better. The older 28 0z stock 302 cranks much like the older blocks will hold up to more then the newer thin wall stock blocks and 50 oz cranks.

 

hamit off,

yup.

351 W was allways a 28 ounce.

 

hamit off,

great, three people are now waiting for explainiation of your belt driven exhaust driven supercharging device you mentioned - but instead of answreing that you simply reiterated something someone else already said without adding anything to it; using that as a vehicle to yet again mock my name. Your decision to mock my name instead of clearing up your statements is interesting insight into your decision making process.

 

OK,
From what Ive read here:

28 is better than 50
0 is better than 28

Fine.

Now I know the engineers at Ford's powertrain group are not stupid. If 28 is better than 50 why did they change to 50? Was it just a cost issue?

If I stroke my 5.0L to 347 with 28 oz balance Ill need an new balancer and flywheel (vs my stock 5.0L parts) correct? If I have it balanced to 50 oz I can use my existing/stock balancer/flywheel, correct?

Thanks,
T

 

if you are buying a stroker kit, and your motor is a stock 50 balance, you are going to HAVE to buy a balancer/flywheel anyways, so just go right to a 0 balance..

its better than 28, and the cost will be the same for the extra parts

 

you should buy a new dampener anyways...because the stock type with rubber insiode wears out and the outer ring slippss and then the engine is out of balance...and you cant "shoot" the timing marker...

 

To get technical, any supercharger/turbo falls into a turbo category. Mainly, any centrifugal supercharger is basically a belt driven turbo.

 

that was obvious to some of us.............

 

YUP...


all the HYPE with each companies advertising just is to cloud the issue..

...nothing is really new.

...IT all has been done before....

 

why buy a cast stroker crank...???

cost...

 

why buy a cast stroker crank...???



cost...

A cast crank in a stock 302 block is all you will ever need, the block will split before the crank gives out. Why spend an additional $400 on a forged crank when a $300 crank will handle everything the block will take. Balance it to 28 and spend the money elsewhere...



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Can u mix a 50oz balancer in front and use a 28oz fly wheel in the back?
My engine builder said he balanced my stuff with that set up, i don't think its right.

 

if HE balanced it, you can start with whatever you want, they would add/remove material from the flywheel to get it to the desired balance.. but once in a running motor.. they would be the same, as the motor cant have a 50 oz weight on one end, and a 28 on the other

 

Cool thread is cool

So, balancing is more critical for rpms and not horsepower then? I'm trying to budget my new motor. If I can save $500 bux and use my stock damper and flywheel for a motor on the stock 6250 rev limit, then that would work for me.

What do you think?

 

Cool thread is cool



So, balancing is more critical for rpms and not horsepower then? I'm trying to budget my new motor. If I can save $500 bux and use my stock damper and flywheel for a motor on the stock 6250 rev limit, then that would work for me.



What do you think?

With the stock crank you are limited to 306-308ci, so it just depends on what you want to spend. You can get a nice cast crank based 347 stroker kit for under $1000 and it will out last the stock block. Or you can spend $300 on aftermarket pistons and reuse stock crank and rods, and make less power.

The real question is, how much do you want to spend and how much power do you want? Never start with a cubic inch goal, that is a dumb game to play. Figure out a budget, and stick to it. If you go with a cubic inch goal in mind, your budget doesn't exist anymore.


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How in the world did this thread from 2009 get dug up? I never pay any attention to thread dates...


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