I am going to do a rotary to vw swap but do not have any 83 rear counter weight and they do not make them any more. What I do not under stand is if I have a 80 counter weight and can make it weigh the same why it would not work and what are the weights of the counter weights by year.

 

you'd probably need to have the rotating assembly out of the engine to "correctly" balance your '80 counterweight with your '83 assembly.

try check the classifieds and vendor sites (craigslist, ebay, etc.). you might get lucky.

 

You cannot modify the weight of a counterweight to match another one and expect it to be equal in terms of balancing, A counterweight has a weight that is offset, you can change the weight, but you won't be able to get the exact amount of offset right. So, really look for a 83' counterweight, or have your rotating assembly balanced with the 80' counterweight, but that will require engine disassembly.

 

So what you are saying is the weight is off set for different years and by adding or taking away weight from the counter weight it would have to be added or taking away in the right spot on the counter weight to maybe work if it could be done.A lot of words to get no were.

 

1. i'm not saying anything with regard to specifics. engine balancing is well beyond my scope and knowledge/experience. what I can say is if you don't find a proper counterweight, you're probably in for rough time getting one "made".

2. speaking only for myself, other than disassembly and giving the full rotating assembly to someone that knows what they are doing, I don't know of another way to get your '80 counterweight balanced to your '83 assembly.

 

post a wanted to buy, someone's gotta have one lying around.

 

I am talking to someone now about buying one but I just don't under stand the concept were you just can't adapt one from another year by changing the weight of it .. Thank you to the ones who replied.

 

well, it's kind of crude, but would you trust balancing a wheel on your car by plucking a weight from another one and affixing it to yours just because it came off the same kind of car? it's rotational and therefore the balance that matters is dynamic. similar concept.