Balance factor LA 360 VS 5.9 Magnum

[Kern Dog]

Hello,
I did do a search on this but saw nothing.
As I understand it, the 360s are all externally balanced just like the 5.9 Magnum. I’m having trouble finding the amount of balance that each engine has. I thought that they had a different amount of balance to them.
I have a 5.9 Magnum harmonic balancer and manual transmission flywheel. They both look really similar to the same parts from a 360.

 

[sam69sat]

The balance is different between 360 and 5.9 magnum although they're both externally balanced. I have a mcleod 464102 flywheel that can take balance weights. The instructions with the weights says to use the large weight for 360 and extra large weight for 5.9 magnum. Sorry i can't help with actual weight difference.

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American powertrain also sells flywheels balanced for 5.9 magnum that are a little cheaper. I think they have two different flywheels for the 5.9. One has provisions for some kind of sensor i believe if you're running with the 5.9 computer or something like that.

 

[4mulas]

They do have different balance between them.

Pretty sure it’s the same balancer just different flexplate (if you want to run neutral converter) or same flex plate but different convertor for auto/s.

And for the manual crowd I’m pretty sure there are different flywheel’s for each application. I don’t know the actual weight measurements/amounts but have seen the figures before.

 

[Kern Dog]

I knew this would be a tough one to pin down.
I’ve heard for years that the amounts were different between the two engines but never have read the exact amounts. I’m just learning about the differences between these engines because a friend is rebuilding his engine here.
Thanks to those that have tried to help!

 

[MopaR&D]

I don't know exact numbers either just that it's less in a Magnum than an LA due to the lighter pistons, I want to say the rods are lighter too but not sure.

 

[Kern Dog]

Thank you. I thought that too.
If that were the case, could a 5.9 flywheel be drilled more to get to the specs of a 360?
That is part of my curiosity.

 

[Bobzilla]

The balancer is different for both AND the flex plate is different for both. Once you have the correct balancer on the front, the flex plate is around 5 ounce-inches lighter for a 5.9 Magnum than for an LA 360. But those numbers don't really help since none of them were perfect and you cannot change pistons and just change the amount of weight without knowing where it goes.

 

[Kern Dog]

Is it possible to weigh both balancers and tell by that OR is the difference in the amount of weight removed (Or simply NOT added) to the harmonic balancer?
Thank you Bob for chiming in.

 

[Bobzilla]

I am not sure I understand that last balancer question. You can tell the difference in the balancers by looking at them. You cannot figure out how to balance a modified engine by weighing the balancers. They are offset weighted.

 

[Max1196]

Some info. from a different post, but related.

Cast crank 383, 400 and 440 . 12.9 inch/ ounce balance required.
"Heavy" rod or "6 bbl" rod . 6.5 inch/ ounce balance required.
340 Cast crank. 4.22 inch/ ounce balance required.
360 Cast crank 19.79 inch/ ounce balance required.
5.9 Magnum 12.825 inch/ ounce balance required.
So that would be a NO, 340 and 360 LA do not use the same weight.

 

[RustyRatRod]

I knew this would be a tough one to pin down.

.....and it damn well shouldn't be, but leave it to Mopar. It's ALL over the internet and ALL the Ford guys know and anyone whose ever worked on them know that there are only TWO balances for most all Ford V8 engines. The 50 ounce imbalance and the 28 ounce imbalance. Good luck finding that info for Mopar.

 

[Kern Dog]

I am not sure I understand that last balancer question. You can tell the difference in the balancers by looking at them. You cannot figure out how to balance a modified engine by weighing the balancers. They are offset weighted.

Maybe we are thinking different things.
My thoughts are if the 5.9 uses less mass removal to balance, can more mass removal be done to use the 5.9 parts on a 360?
It is my usual theme...I try to repurpose what I can to save money and time.
If a Magnum spec manual flywheel had XX amount of weight drilled out of it from those 3 holes and a 360 needs more weight removed, can the flywheel be drilled MORE to get it to work in a 360?
It may be a pointless endeavor but it has me curious.

 

[RustyRatRod]

Maybe we are thinking different things.
My thoughts are if the 5.9 uses less mass removal to balance, can more mass removal be done to use the 5.9 parts on a 360?
It is my usual theme...I try to repurpose what I can to save money and time.
If a Magnum spec manual flywheel had XX amount of weight drilled out of it from those 3 holes and a 360 needs more weight removed, can the flywheel be drilled MORE to get it to work in a 360?
It may be a pointless endeavor but it has me curious.

That's something most likely only your machinist can answer. A good machinist. With a balancer. That knows how to use it. Rather than some guys on the internet. No offense to any of the guys on the internet.

 

[Bobzilla]

Maybe we are thinking different things.
My thoughts are if the 5.9 uses less mass removal to balance, can more mass removal be done to use the 5.9 parts on a 360?
It is my usual theme...I try to repurpose what I can to save money and time.
If a Magnum spec manual flywheel had XX amount of weight drilled out of it from those 3 holes and a 360 needs more weight removed, can the flywheel be drilled MORE to get it to work in a 360?
It may be a pointless endeavor but it has me curious.

I see. Basically yes, sort of. Any combination of parts that fits the platform can usually be balanced. Sometimes weight is removed if lighter components are used. Sometimes weight is added (mallory metal in the crank throws) if heavier components are used.
Really you just need to keep it as simple as possible and just have a good crank guy balance whatever combination is being used, within reason. And it can get confusing when doing weird stuff.

 

[Kern Dog]

That's something most likely only your machinist can answer. A good machinist. With a balancer. That knows how to use it. Rather than some guys on the internet. No offense to any of the guys on the internet.

Maybe so.
It is my nature to wonder IF something can be done. I often wonder WHY when other people just accept that it does....

 

[Bobzilla]

That's something most likely only your machinist can answer. A good machinist. With a balancer. That knows how to use it. Rather than some guys on the internet. No offense to any of the guys on the internet.

I agree with this 100%. We can guess all we want and get close enough that it feels ok, but how far off is it still going to be. Ultimately, just get the parts you want to use and get it balanced.

 

[Kern Dog]

The friend of mine has this 5.9 Magnum stuff that will be be replaced ( The new heads and intake will have the LA pattern ....Along with a stroker assembly) but it helps to know what it would take to make it worthwhile to a guy with a 360.
This is NOT a sales ad, I'm just trying to learn the compatibility of the parts.

 

[RustyRatRod]

Maybe so.
It is my nature to wonder IF something can be done. I often wonder WHY when other people just accept that it does....

You can do anything with a fat enough wallet.

 

[fshd4it]

Since I don't know how to attatch a link, I'll just type this out and hope I get it right. Some weights, some math, and some theories.
moparchat.com/forums/performance-talk/71263-flywheel-360-magnum.html Best of luck...

 

[Bobzilla]

The friend of mine has this 5.9 Magnum stuff that will be be replaced ( The new heads and intake will have the LA pattern ....Along with a stroker assembly) but it helps to know what it would take to make it worthwhile to a guy with a 360.
This is NOT a sales ad, I'm just trying to learn the compatibility of the parts.

There is a bunch of compatibility between those parts when used correctly, but the differences in weight will always require a balance job.

 

[mderoy340]

If your friend is going forged stroker kit then the engine will be internal balance.

 

[MV8]

If you have the right weight flex plate or flywheel, it can be bolted and indexed to the wrong weight flywheel, put on a balancer jig for a motorcycle wheel (a horizontal shaft and two, tapered cones to center the wheel, and a two level, 1/8x3" strips, knife edged on top to roll on). Can't just line them up. The right weight must be 180 from where it needs to be, then the wrong wheel is modded until it rotates without pulling one side down from gravity. Could also do it with a dynamic tire balancer (hand spin). Better just to buy the right parts.

 

[Kern Dog]

If your friend is going forged stroker kit then the engine will be internal balance.

Thank you. We both agree and are aware but he wants to sell off some of the stuff he won't need to help offset the costs of the rebuild. I was trying to help with determining what can be worth trying to sell. Sometimes, used stuff is so specific to it's original application, it has limited value for other builds.
Neither of us wants to falsely advertise something as being a direct fit.

 

[autopar3000]

I just came across this page:

Sorting Out: Chrysler’s 238, 318, 360 Engines, Doug Anderson, Automotive Rebuilder, April 2000

It mentions the following: "The non-Magnum engines required 19.79 in.oz. and the Magnums need 14.65 in.oz. in order to be properly balanced."

Not sure how accurate that is, but the webpage is older than Yoda.

 

[RBConvert]

If your friend is going forged stroker kit then the engine will be internal balance.

Yep, that's me. We tore down my 5.9 magnum in @Kern Dog's shop. I ordered the stroker kit from Hughes Engines. It's a cast crank, forged Icon pistons and internally balanced by Hughes. I also ordered their crankshaft damper.

The flywheel still requires some thought. It's backed by a Keisler Engineering (circa 2006) 5 spd. The clutch disc still had a lot of meat on it, even after almost 19 years. Regardless, I will order a new clutch and pressure plate from SST and talk to them about the flywheel.
From what I'm reading, the current flywheel can't just be refaced and thrown back in. Either the flywheel is re-balanced or I get a neutral balance from SST.