Harmonic Balancer, Crank, and Flexpalte matching help!

spirockp

5 Year Member

Mar 26, 2004

465

12

39

NJ

Dec 29, 2006

#1

• Dec 29, 2006

• #1

I'm currently running a 1990 Ford 302 truck motor (non-roller) in my 66 Mustang. I am also using a 28 Oz flexplate and an orginal Harmonic balancer.

My question is on balancing the motor. Do I just match the Flexplate and the Harmonic Balancer? Or does the crank also have to be considered?

I'm getting a little virbration and was thinking this may be the issue?

Thanks for the help!

Peter S.

 

xoxbxfx

Founding Member

May 9, 2001

3,959

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0

Southlake, TX

Dec 29, 2006

#2

• Dec 29, 2006

• #2

crank needs to be considered...

 

spirockp

5 Year Member

Mar 26, 2004

465

12

39

NJ

Dec 29, 2006

#3

• Dec 29, 2006

• #3

After searching here again, I have read that the crank dictates the size of the weights. If I'm running a 1990 302 I should have 50 Oz weights, but I'm running 28 Oz weights.

Am I understanding this correctly?

Peter S.

 

xoxbxfx

Founding Member

May 9, 2001

3,959

0

0

Southlake, TX

Dec 29, 2006

#4

• Dec 29, 2006

• #4

that is correct

 

spirockp

5 Year Member

Mar 26, 2004

465

12

39

NJ

Dec 30, 2006

#5

• Dec 30, 2006

• #5

Great! Time to drop the trans again........

Thnaks for the help.

 

D

D.Hearne

New Member

Sep 29, 2000

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south louisiana

Dec 30, 2006

#6

• Dec 30, 2006

• #6

With a 1990 5.0 you need a 50 oz/in flexplate and balancer. You cannot mix and match. It doesn't work that way. Measure the 1990 balancer from the back side of the crank hole to the front where the pulley sits, and ditto for the 3 bolt unit you're trying to use. If that measurement is the same, simply drill the crank pulley to match the 4 bolt balancer. The 50 oz flexplate you need is available new thru Summit racing. It's a B&M part, 50 oz, 147 tooth flex. Think it's about $50.