Professional products balancer: which weight for magnum

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snailpower

snailpower

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I have searched a bunch, even reached out to professional products and couldn’t get an answer. I am using an LA front cover and v belts, 99 5.9 mag, this is the #80012 balancer recommended on magnumswap.com but the only section in the instructions for using it on a 360 says this:

360 externally balanced 1993-97 engines with cast crank. Use supplied counterweight #91013. Will not work with 1993-97 Magnum 5.9L engine.

Seems like people have used this on their magnums but with which weight of the 3? Isn’t the only 360 engine 93-97 a mag?

The rest of the instructions are as follows:

Powerforce Street Dampers

  • Chrysler/Mopar


    Note: Professional Products offers one damper model that can be used without a counterweight for internally balanced engines. Or, use one of three supplied counterweights for other engines. Dampers #80012 and #90012 will fit the following applications:
  • All internally balanced 318 V8 standard and Magnum, all internally balanced 273 and 340 engines with forged cranks. No counterweight is used with any of the above applications.
  • 340 externally balanced 1972-73 engines with cast crank. Use supplied counterweight #91014.
  • 360 externally balanced 1993-97 engines with cast crank. Use supplied counterweight #91013. Will not work with 1993-97 Magnum 5.9L engine.
  • 360 externally balanced 1971-92 engines with cast crank. Use supplied counterweight #91012.
 
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I think the instructions are messed up. 1993-03 360s are magnum, with a 14.0 in.-oz. counterweight. 1971-1992 360s are 19.8 in.-oz. counterweight. maybe contact pro products again, I love it when a company guy is clueless
 
Marcohotrod said:
I think the instructions are messed up. 1993-03 360s are magnum, with a 14.0 in.-oz. counterweight. 1971-1992 360s are 19.8 in.-oz. counterweight. maybe contact pro products again, I love it when a company guy is clueless
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Yeah my thinking exactly. I think if it’s not SBC a lot of these guys are lost.

He basically said “not up on Mopars, get in touch with your Mopar expert”. For me that’s fabo haha

But definitive answer for using “91013” on a 5.9 mag from someone here would be conclusive. After a lot of searching that’s one thing I couldn’t find anywhere.
 
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fshd4it said:
A lot of times things get lost in translation from Chinese to English.
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Ironically posted this while in china for work (the reason for 4am post haha) Now just need to find their factory while I’m here and get some answers.

:lol:
 
There should only be three different LA and Magnum engine balancer weights needed, and two are already outlined in those instructions for LA 360s (all except Magnums) and for cast crank 340s. That leaves 91013 for Magnum 360s regardless of year, from 92 on. I suspect they either intended to say except 5.2 Magnum, which is neutral balance, or intended to exclude the NON magnums. This happens all time with parts from overseas and details lost in translation. Put on the 91013 and see how it feels. You'll know right away if it's wrong, but it won't be bad enough to cause damage during testing. Also, it probably only goes up to 1997 because they never updated there instructions or because they don't know when the factory changed to an integrated pulley/damper setup.
 
Here's an idea, weight the three weights and see if the differences in them are close to what they should be for the balances since they are known.
 
360 externally balanced 1993-97 engines with cast crank. Use supplied counterweight #91013....

the newer magnums harmonic balancer was incorporated with the front pulley....hence the professional product balancer will not work in a OEM situation.
 
I bought a PP balancer and the keyway was to small for the key on my Magnum 5.9 with a 408 stroker.
Having the keyway machined to fit. Not cheap to have done.
Just wanted people to know surprises are waiting with magnums.
 
triumphman said:
I bought a PP balancer and the keyway was to small for the key on my Magnum 5.9 with a 408 stroker.
Having the keyway machined to fit. Not cheap to have done.
Just wanted people to know surprises are waiting with magnums.
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Oddly for me, I didn't have that problem. The balancer went on smoothly with a balancer install tool. I took it off once too and it was fine going back on again. Unrelated but I realized the oil slinger wouldn't work with the cloyes chain and mag timing tensioner (reason for removing the balancer).

As for the other suggestions, I am going to go with my gut and the suggestions here to use 91013 and see what happens. Its really the only one that makes sense to use.
 
For anyone reading this in the future, I used the 91013 and everything seems ok after running it for a bit. No weird harmonics or vibrations as expected.
 
Mine slid on with 2 fingers. I knew it was way too loose but I used it anyway. It wound up coming loose and sounded like a rod knock which is why I am building a 416 right now.
 
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If anything about the PP balancers. We are learning... After installing on my 408... Smoooooth.
 
superchargeddrt said:
Mine slid on with 2 fingers. I knew it was way too loose but I used it anyway. It wound up coming loose and sounded like a rod knock which is why I am building a 416 right now.
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Interesting, mine went on tight, needed to use a balancer installer to get it all the way on.
 
A note for anyone planning on using this balancer:

I've been speaking with Jim at Performance Products over the past couple of days, and this issue was brought up by him. He incidentally is the guy that developed this product. I was contacting him about my fitment situation, and shortly after I got the balancer installed onto the crank, he sent me a message saying something to the effect of:

This product was never intended to be used with 5.9 magnum engines. It was developed before the magnum engine came out, and does not take into account the lighter weight of the magnum pistons. Therefore there is not a counterweight for the 5.9 magnum.

Now that's not to say that the counterweight we've all been using wouldn't work fine, but this is pretty concerning. I'm talking with him about where do we go from here, and he has mentioned developing the right counterweight, but said it will take some time.

I referred him to this thread and pointed out the fallacy in the instructions that say "for use on 93-97 360s, but not 360 magnums". He reiterated that the magnum was not around when the 80012 was developed. Caveat Emptor I suppose. I'm at a loss as to just running it as is, or switching to a much more expensive one, having wasted time and money on this one already.
 
Then you should ask him for clarification on what the different weight applications are. If he designed it, what are the correct applications?
If the later LA 360s have a lighter roatating weight than earlier LA 360s, then that puts them right in line with Magnum 360s, or at least close enough that it works fine for street apllications.
When in doubt, have the rotating assembly balanced.
 
Bobzilla said:
Then you should ask him for clarification on what the different weight applications are. If he designed, what are the correct applications?
If the later LA 360s have a lighter roatating weight than earlier LA 360s, then that puts them right in line with Magnum 360s, or at least close enough that it works fine for street apllications.
When in doubt, have the rotating assembly balanced.
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That’s whats next, I’m waiting for a response to what the weight actually weighs, and I’ll get clarification on the applications
 
Also, I have never seen any Dodge vehicle newer than 1992 with an LA version of the 360. Not saying it doesn't exist, but never seen one. Highly doubt they designed a weight for an engine that may not exist.
 
Bobzilla said:
Also, I have never seen any Dodge vehicle newer than 1992 with an LA version of the 360. Not saying it doesn't exist, but never seen one. Highly doubt they designed a weight for an engine that may not exist.
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That’s exactly what my thought was...I’m guessing if he’s right then the documentation about what years it works with is wrong
 
someone step up and have their stock motor balanced with the supplied PP weight and have the guy take the balance material out of the PP weight and get back with us and PP. I know the Magnum rods have a thinner little end as I had to clearance magnum stroker pistons to fit bushed 340 rods so there is a little reciprocating weight savings there.
 
pishta said:
someone step up and have their stock motor balanced with the supplied PP weight and have the guy take the balance material out of the PP weight and get back with us and PP. I know the Magnum rods have a thinner little end as I had to clearance magnum stroker pistons to fit bushed 340 rods so there is a little reciprocating weight savings there.
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I would do it but I doubt I have the cash. My motor isn’t installed so I’ll chexk around on prices
 
You just have to look back into older information, while it's still available, when working on Magnum engines, since Mopar abandoned them years ago.
There used to be a kit available available, part number P5249930AB, that had an LA sryle timimg cover and water pump, along with the 80012 balancer. Even that kit said to use the 91013 weight on the 80012 balancer, because back then it was tested and verified to be correct weight for 360 Magnums.
Details of this part number kit can still be viewed on Jegs website, even though the kit is long ago discontinued.
 
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