I've got an I300 engine that I've modified with
Holley 390
Offenhauser manifold
260 comp cam
ceramic headers
msd ignition
1.94", 1.60" valves
9.5:1 ratio
How important is an aftermarket harmonic balancer? What kind does the stock engine have? internal or external balanced.
What weight is it? Can I use one for a V8?

Thanks

 

Someone correct me if this is wrong. The 300 I6 is internally balanced.

 

Yes I beleive the I6 is internally balanced, no counter weight on the flywhheel.

77f100, don't use a balancer off of a V8, they are externallaly balanced and different from an I6. The flywheels will fit but because they are balanced differently, they will vibrate bad.
Most dampers use a rubber compound between the hub and outer ring to handle vibrations and because an I6 is not a high revving motor, stock balancer is probably the best. There are fluid type balancers available for V8s that cover vibrations over a wide range of RPMs but I don't know if there is one made for I6s.

RCC

 

I am currently building a 300. My machine shop told me that an engine that is vertical needs very little balancing and the stock one will do just fine.

 

Hi Guys!

I've just started my 300 - 6 cyl. project and have done no small amount of research on our engine but don't have a finished product yet so I can't remark on practical issues...

Inline 6's and 8's suffer from a condition known as "torque wrap" or "flex" as a result of the long crankshaft. As you get more power from the engine, this condition gets worse, and can eat up the accessories that are run from the crank pulley, as well as cause internal failures.

Clifford offers a harmonic balancer for this engine but I think it is way expensive! I read somewhere that if you are NOT shooting for 300+ hp, the stock balancer is fine. I'd like 300 horses but will settle for around 200 if I get that far with the Clifford cam, intake and header, and some head work.

Best of Luck!

bigsixguy

 

It's true ... inline engines are naturally balanced. It's one of their many perks. I hadn't heard of the external balance needed for high HP engines, but I'd put my money on it if Clifford Performance recommends it ... after all, it IS all they do!

Chris in Canada
74 Gran Torino Brougham ... the toy ... older and wiser.
84 F150 2WD ... the truck ... wife says, "never trust a teenager."