SDPC Tech Tips: Internal vs External Balance

Not quite sure what the catalog means when it says "Externally" or "Internally Balanced?" Nick goes over the differences between the two and why it's important to not get them mixed up!

#SDPC #SDPCRaceshop #TechsualHealing #Cranky #ChevroletPerformance

[vSciroccoboi]

Neutral balance balancer is a harmonic damper then and not a balancer at all.

Calling it a balancer when it's a non counterweight damper I believe causes more confusion than anything.

[bigredracer]

2👍's up SD thanks again for having us all along with you for the rest of the story

[El]

Thanks for the clear explanation. I have a 1985 GM 4.3L V6 (2 piece rear main seal) in my garage that I want to mate up to a manual trans. The flex plate that came with the 4.3 has no weight on it. Now I know I can source a flywheel from a 1985 or older small block with a manual trans and go with it.

[mightyeagle]

Your very good at getting to the point thanks

[christopherkanuk]

Thank you so much not confused anymore

[ronpetrosky]

Would putting the pressure plate on in a different position cause a vibration ?? 4 speed AMC T-10 externally balanced. Thanks for your help

[frederickshipp]

I know someone who ran a 427 flywheel on a 454 and was going through main bearings all the time until he found out what was causing the problem. (Flywheel)

[MariusSalvetti]

Technically, there are no internally balanced 350's from the factory. the 2 piece crank 350's had an external "wing" that was part of the crankshaft. The 1 piece crank 350's could not use the external "wing" because of the 1 piece seal design. Chevrolet had no choice but to add the required weight to the flywheel or flexplate.

[stevesteve]

So if I need to swap flywheel from 1 piece to 2 piece crank, my 10.5 clutch will still bolt up ok? And starter should fine as well? Just the mounting to crank changed?

[TheComputerArmory]

Long story short, rebuilt 700r4 all new sonnax parts, replaced factory flexplate as two welds were cracked, have since put 3 flexplates and still have a vibration and have also replaced TQ convertor twice. Old flexplate "weight" best i can measure weighs 2.19lb, new flexplate weight weighs 2.32lb nearly a full 2oz or more over factory.
Can this be causing my vibration? Vibration occurs during all RPM and in Park, Neutral and all others, ranges from 600-6000rpm, very bad at 1200 and 4000.
How i measured was laying flexplate flat on a scale and a box that was simular hight and a 50/50 weight distribution on the scale and the box the best i could.

[timmygun]

Question are marine 383 vortec external engines. Internal or external? Please help

[joneich]

I have a 1 piece seal 350/5.7 chevy that I am rebuilding. Would it benefit me to internally balance this motor, then balance it again with the flexplate and harmonic balance?

[warrenlucier]

This question pertains to the SBF as they went from a 28 oz. to 50 oz. and why can't the assembly just be zero balanced? I realize you were explaining SBC for your customers, but all of this pertains to all 3 manufactures that have a similar design.

[adamgarcia]

Can I use a normal four-speed standard flywheel for a internal balance 400 small block

[Timmyboy]

Does the engine block set the internal versus external, one-piece versus two-piece application? I'm looking at a used 400 SBC block

[ussjbrolli]

To note - this is incorrect for the LT1 in a 95 Camaro, regarding the 383. For example, when making it a 383 using an eagle crank that is internally balanced, you need a zero balance flywheel.

[josephacevedo]

I have a 1973 400 sbc that’s in my 74 c10 I bought this from a friend but he dnt knw anything about the previous work on it. So I’m asking if you know or can point me in a directions if that year was internally or externally? It is a two piece rear main came with a 400 externally 168 flexplate but had a balancing plate? Is this needed or is it wrong and just needs a internally balanced flex plate?

[MauricioHernandez-stsu]

Hi. Good information. I have a question. I bought a 350 vortec one piece. The motor was on truck with std transmission, . Can i use flex plate for automatic transmission??? Thanks.

[ratgasgarage]

Can I take a early sbc flywheel /clutch and install it on a mark4 bbc

[sharons]

I’ve got a 350 one piece rear main marine engine, it’s got a flywheel on it I did notice it was drilled out when rebuilt, I did question engine builder when replacing balancer they said neutral or internal balancer will be fine ? I just don’t know whether to believe them
Help please