Harmonic Balancer Question

['71buickg.s.]

I'm trying to replace a cracked balancer off of my 4.1 motor. I got a replacement balancer and have now discovered that it is not the same as the one off my car. Difference being that my cracked one has a reluctor ring and the replacement is aparently a pre-reluctor ring balancer. I guess the question is did 4.1 blocks come with a reluctor ring? Is the balancer off my 4.1 actually a balancer for a 3.8? Or what??? I had the replacement at a performance shop who was going to balance the new one to match the old one. Any ideas from those who know?

 

[pacecarta]

without a pic i cant say what your 4.1 had but odds are if its a cast crank its off a 3.8turbo

4.1 were all NA so no reluctor ring on any factory 4.1 balancer

except for slight balance difference for the weight of the larger piston
the crank is the same as the 3.8
because the cast factory cranks were external balanced the balancers are unique balance for each crank but should be close enough , the flywheels are also a little different as theres one for the 4.1 , one for the 3.8turbo and one for the 3.8 NA (you can tell by the D shaped hole in it which is which ) and those flexplates are fine tuned with the crank

what you probably got to replace yours was a 3.8 NA balancer , they wouldnt have a reluctor ring and 3.8 NA is balanced a little differnet for the lighter NA piston but should be close enough for your machinist to balance, and though ive never swapped a reluctor to a NA balancer i dont see why it would be straight forward press off press on

easiest is use the 3.8 turbo balancer

 

[bison]

$85 shipped for a 3.8 balancer with the reluctor on it.

 

['71buickg.s.]

Thanks for the offer Bison. I believe I have one coming from a friend. If it doesn't get here by next week I will contact you for yours.

 

[turbofabricator]

4.1 balancers have a LARGER counter weight. A 3.8 balancer will NOT work unless the engine is re-balanced. As stated previously the flywheel/flexplate is also different on a 4.1 engine. You CAN install a interruptor ring on a 4.1 balancer, though.
Was your 4.1 engine balanced with the 3.8 balancer on it, or was it thrown together with misc. parts?

 

['71buickg.s.]

In speaking with the guy who built it, the cracked balancer is from a 3.8. I am not sure as to what was thrown or not thrown together. I was told that I would need to replace it with what was on it. I know this motor ran fine before I got it and it sat for years in my garage.

 

[turbofabricator]

Sounds like it was balanced with the 3.8 balancer. Buy one used and slap it on.:smile:

 

['71buickg.s.]

I sure as heck hope so. As money allows I have tried desperately to get ths car running so I can be a more active part of the buick community. It sucks going to Norwalk or whereever with out a car. I even drove to Noble in 2009 without a car to run. It was a 1500 mile round trip. Those Texas guys are a great group to hang with. Hoping to hang with the midwest group this summer!