I just bought a 1995 Camaro with the LT1 and 6 speed. The engine threw a rod through the pan so am working on rebuilding it. I was looking into buying a new balanced rotating assembly and noticed that all of the externally balanced assemblies come with a new flexplate. My question is when companies sell these rotating assemblies and say that they are externally balanced does the counterbalance weight that comes on the new flexplate match the stock counterbalance of my flywheel? Do they externally balance them to match the stock spes? Thanks.

 

The LT1 is internally balanced, so the flex plate or flywheel will be neutral balanced and will not have large counterweights. Externally balanced engines use counterweights on the flywheel or flex plate, and these must be balanced to the individual engine. Flex plates and flywheels for internally balanced engines may show balancing work done to them, but this is only to balance the flywheel or flex plate itself, and they can be used with any internally balanced engine, as long as they fit.

 

pete the lt1 is a late model engine and is extrenally balanced and you have to have the rotating assembly blanced with your flywheel i know this cause im running into the same problem and this is what my machinist told me

 

Sorry about the bad info, too many beers for lunch. The LT1 is externally balanced. You can get an externally balanced flywheel and you machinist can touch up balance it to match the crank. Also, if the factory found the engine out of balance after assembly, they corrected the unbalance by drilling into the front damper. This means you will have to include the front damper when balancing the assembly. This poses a problem, because the front damper is not keyed and can go back on the crank any old way. This means the damper position on the crank needs to be marked before dis-assembly, and placed it back on the same spot when the crank is balanced, and when the engine is assembled. You also have the option getting the crank internally balanced, especially if you are gong to build a high revver and want to lessen the stress on the crank.

 

I kind of thought I would still have to get it balanced up with the flywheel, but didnt know for sure. I was also thinking about going with an internal balanced assembly and getting a neutral balanced flywheel like you said. The only one I found was the SPEC SC85S. It has removable weights but the company is not responding to my emails to find out if the flywheel is neutrally balanced when the weights are removed. I was just assuming it would be. Does anyone know?

 

the fly whell is balanced alot like a wheel you would assume the wheel is balanced but you thorw a tire on it and you have to add weight to make it so and it is the same consept with a flywheel