Mine is this way. You make the rotating assembly lighter.
Internally or externally ballanced 383
Thread Starter
Instructor
Joined: Apr 2004
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From: Norfolk VA
Internally or externally ballanced 383
I have just received word from my local machine shop that the engine I wanted to use as a foundation for a 383 is in good shape and the project can move forward. So, the question I have is how much of a difference is there between an internally and externally balanced engine and where would the diffference show? I see that on average the price diff is 5-7 hundred dollars. What does the extra cash get you and is it worth it? Anyone out there have experience with both diffefent types?
Thanks
Todd
Thanks
Todd
Race Director
Joined: Sep 2004
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
no first hand experience on 383 ..... but the interanlly balanced sure sounds like the right way to go....in other words fix the balancing issue at the problem spot instead of haging a counter weight at the end of the crank....
Burning Brakes
Joined: Feb 2004
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From: shawnee ks
Actually makes no diff.It is a way for big stroke engine combinations to balance with mallory metal versus a flexplate counter balancer.No real performance advantage either way but mallory metal is very expensive.Ext balanced can work fine.balanced is balanced.
Last edited by big632; Dec 29, 2004 at 11:39 AM.
Team Owner
Joined: Jul 2001
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From: Lakeland, FL
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Originally Posted by big632
Actually makes no diff.It is a way for big stroke engine combinations to balance with mallory metal versus a flexplate counter balancer.No real performance advantage either way but mallory metal is very expensive.Ext balanced can work fine.balanced is balanced.
Team Owner
Joined: Feb 2003
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From: Lake Norman NC
my 383 was internally balanced....My engine builder said it would most likely help in longevity of the engine. I don't know if this has to do with being at 6000+rpms on several occassions or what...but it couldn't hurt. Although i do agree with the others...balanced is balanced.
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Just put it together as external balanced. It will be fine. Use the money for something that will make you go faster. Just for reference my 540 is externally balanced and it has spent LOTS of time WAY over 7000 rpm. No problem.
When internally balancing one, the mallory metal is added to the counterweights at each end of crank. That means you are basically talking about the difference in having the weight on one side of the front and rear main caps or the other.Not a big deal. Many engines are done externally....454-502's, 400,s, big block Fords etc...no big deal.
*IF* you can easily balance it internally go ahead, but usually there isn't enough counterweight available especially when using stronger rods etc. Liteweight pistons etc can help by getting bob weight down.
One of the big benefits of internally balancing stuff is when you are switching flywheels etc often and they had to be drilled to external balance it. No big deal if you just use std. 400 weights on flywheel and balancer and have them do all drilling on crank to final balance. Try to have them NOTtake any metal off balancer or flywheel so they can easily be replaced as needed.
JIM
When internally balancing one, the mallory metal is added to the counterweights at each end of crank. That means you are basically talking about the difference in having the weight on one side of the front and rear main caps or the other.Not a big deal. Many engines are done externally....454-502's, 400,s, big block Fords etc...no big deal.
*IF* you can easily balance it internally go ahead, but usually there isn't enough counterweight available especially when using stronger rods etc. Liteweight pistons etc can help by getting bob weight down.
One of the big benefits of internally balancing stuff is when you are switching flywheels etc often and they had to be drilled to external balance it. No big deal if you just use std. 400 weights on flywheel and balancer and have them do all drilling on crank to final balance. Try to have them NOTtake any metal off balancer or flywheel so they can easily be replaced as needed.
JIM
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Melting Slicks
Joined: Apr 1999
Posts: 2,010
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From: Moon Twp. PA USA
Originally Posted by lps&vettes
I have just received word from my local machine shop that the engine I wanted to use as a foundation for a 383 is in good shape and the project can move forward. So, the question I have is how much of a difference is there between an internally and externally balanced engine and where would the diffference show? I see that on average the price diff is 5-7 hundred dollars. What does the extra cash get you and is it worth it? Anyone out there have experience with both diffefent types?
Thanks
Todd
Thanks
Todd
Instructor
Joined: Oct 2001
Posts: 184
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From: Stronghurst Il
Im not a big fan of having all of your balancing weight hanging off of the end of the crank. Small block fords are a good example why. I would spend the extra money, do it right, and have a little extra strength where it counts, and not hanging off of the end of your crank.
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Not sure where the money differece is coming from Scat makes intermally balanced 383 cast crank, same price as externallly balanced or pretty close. You son't need to buy or find a 400 flywheel and balancer, heil you don't really have to balance it if you are buying weight matched pistons and rods, shuold be cheaper in the long run to go internally balanced if you already have a 350 with all the parts. 
Melting Slicks
Joined: Dec 2000
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From: Union Ontario
My 383 is going internally balanced for the simple reason the cost of modifying current parts/ or purchasing the proper parts will consume a significant portion that you saved on the rotating assembly.
Plus you are balancing out closer to the source of imbalace which will stress your parts out less.
Plus you are balancing out closer to the source of imbalace which will stress your parts out less.