Thread: harmonic balancer

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I recently built a 350, when I bought the engine, it did not come with at damper. I have been looking at various dampers, but am not sure of the differences between the 6 3/4" and the 8". It is the early model 350. Does it matter which one I put on?

Use the one that will work with the timing tab pointer on the front timing cover.

350-2bolt uses small balancer
350-4bolt uses big balancer

Originally posted by tooltime
350-2bolt uses small balancer
350-4bolt uses big balancer

What,if it has two bolt mains or 4- bolt mains has nothing to do with the size of the balancer.Be carefull,the 400 also has a 8 in. dia. balancer which is an external balance.The 400 balancer has an extra weight on the inside of the balance.You will also notice that some of the smaller dia. balancers are much thinner found on 283 and 327 small journal and the balancer used on a 305 is much thicker.

Originally posted by erik erikson
What,if it has two bolt mains or 4- bolt mains has nothing to do with the size of the balancer.Be carefull,the 400 also has a 8 in. dia. balancer which is an external balance.The 400 balancer has an extra weight on the inside of the balance.You will also notice that some of the smaller dia. balancers are much thinner found on 283 and 327 small journal and the balancer used on a 305 is much thicker.

The extra weight is on the flexplate not on the dampener. The dampener has a machined groove/channel approx half of the circumference of the dampener. One other note, to my knowledge no 400sbc came with a standard transmission. To run a standard tranny behind a 400 sbc you will need a flywheel from a 454 bbc as they are also externally balanced.

[QUOTE]Originally posted by NTFDAY
[B]The extra weight is on the flexplate not on the dampener. The dampener has a machined groove/channel approx half of the circumference of the dampener. One other note, to my knowledge no 400sbc came with a standard transmission. To run a standard tranny behind a 400 sbc you will need a flywheel from a 454 bbc as they are also externally balanced. [/B If you look at the back of the balancer there is a section like you said a half moon but it sticks out maybe 3/8 of an inch.Yes there is the extra weight also weldedto the flex plate.A manual transmission was available with some of the trucks.

so which harmonic balncer woudl u recomend for a 350 sbc with 4 bolt mains then???

is there a big difference in a normal balancer and a performance balancer or what ever.. I am just wondering how many choices I will run into

Dave

I would buy any good aftermarket 350 balancer.That does not have the interia ring visable.I walked though the pits a couple of months ago at Sears Craftman Nationals looking at all different class's of cars.And I did not see any balancers that had the fluid in them.What does this mean?Does the fluids viscosity change with the temp?and how does this affect the balance?What happens if the fluid starts to leak out?Would it then affect the balance because the cavity is no longer filled completely?Does the fluid wear out after time spinning at what ever r.p.m.s. after so many years?Maybe I am overthinking this L.O.L.