400CI Crank, balance weight amount?
Thread Starter
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
400CI Crank, balance weight amount?
I have 400 crank with a balance plate on it. I weighed the balance plate and it weighs 12.0 ounces total.
My question is this,,, is 12 ounces the standard weight to hang off of the 400 crank in lieu of using a 400 flywheel?
I want to get a 400 flywheel designed for the 400 crank and the ZF tranny so I can eliminate the balance plate. Centerforce makes one,, I will call them on Monday but figured someone on the site would know the answer.
Ultimately, I plan to sell my Centerforce 350 CI flywheel so I can ditch the balance plate.
TIA
My question is this,,, is 12 ounces the standard weight to hang off of the 400 crank in lieu of using a 400 flywheel?
I want to get a 400 flywheel designed for the 400 crank and the ZF tranny so I can eliminate the balance plate. Centerforce makes one,, I will call them on Monday but figured someone on the site would know the answer.
Ultimately, I plan to sell my Centerforce 350 CI flywheel so I can ditch the balance plate.
TIA
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by LD85
My question is this,,, is 12 ounces the standard weight to hang off of the 400 crank in lieu of using a 400 flywheel?
RACE ON!!!
Thread Starter
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
Originally Posted by CFI-EFI
There is not, and there can not, be a "standard" amount of weight to add to a flywheel to balance it. A lot depends on where you put the weight. The imbalance is measured in ounce/inches. An ounce added to the flywheel, one inch from the centerline of the crankshaft will be 1/12th as effective as one ounce placed at 12" from that same centerline.
RACE ON!!!
RACE ON!!!
I imagine that Centerforce is matching the factory balance nevertheless.
Thanks CFI-EFI!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by LD85
That makes sense, the Centerforce website says 24 In/Oz, so they are calculating the weight at a specific distance from the crank center
RACE ON!!!
Thread Starter
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
Originally Posted by CFI-EFI
Actually it is at a non-specific distance. It is just an appropriate combination of weight and distance. It could be 24 ounces at a distance of 1", or 2 ounces at a foot (12 inches). You mentioned 12 ounces. Is that what you have? How far from the crank centerline? Was the engine final balanced with that add on balance plate? If yes, and if it isn't real close to the 24 In/Oz CenterForce provides, you may be headed for trouble.
RACE ON!!!
RACE ON!!!
The crank was not balanced with any weight, it was left unbalanced the way a typcial 400 crank is on a typical 400.
The short block builder used the balance plate and then we put a nuetral balance FW and clutch package on ,,,,so I guess, the balance plate simulates the external balance weight that a 400 crank uses
I will call them in the morning and see what they say!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
The old, 12 ounces times 6 inches, 72 In/Oz, is a little scary, especially in light of Centerforce's 24 In/Ozs. Did the engine have any vibrations? Going from a stock balance, as built, to a stock weight flywheel SOUNDS like it ought to work.
RACE ON!!!
RACE ON!!!
