Why would someone want to internally balance a 1peice rms engine and use a flexplate such as this?

http://store.summitracing.com/partde...3&autoview=sku



Ring Gear Tooth Quantity: 153-tooth
Rear Main Seal Style: 1-piece
Engine Balance: Internal
Balance Style: Neutral
Notes: These are not stock replacements. For special internal 0 balance applications.

 

That's an SFI certified flexplate required for vehicles running 9.99 and quicker in the 1/4 mile.

My 540 is an internally balanced engine mainly because the 4340 stroker crank I needed wasn't available as an externally balanced crankshaft.

 

The point i was trying to make is that its for a one peice engine without the batwing counterweight. Can you explain this benifit?

 

I thought I did. Some race cranks are only available as internally balanced so a neutrally balanced flexplate is required.

 

OK I think I understand now, thats why my machine shop ground the counterweight off my flexplate.

 

stock L98's are internally balanced but also have the flexplate wieght so its kinda both external and internally balanced

not sure if most 1 piece rear main blocks should be the same way or not

 

An internally balanced engine will be a longer laster better running engine. The reason to balance internally is to keep the crank from causing a bending harmonic that is hard on bearings etc. It its done externally you only have the front and rear of the hole assembly balanced by the small weights on the balancer and flywheel. If it is done internally you will have an even balance thought the entire rotating assembly and there for a smoother running more efficiant engine.