whipple belt size question

aarons04cobra

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I know this question is beat to death but there is no belt chart that gives me the information I need.
Cobrabob and malcolm where both very helpful but we still can not determine an exact size.

Running a whipple 2.9 with 3.5 upper, stock cobra tensioner, "3" 90mm idlers and "1" 100mm idler. Stock size alternator pulley and stock lower pulley.

Can anyone help me with a belt size?

Hoping to start the new motor for the first time this weekend and wanted to have a belt in hand.

Thanks - Aaron




For anyone needing the info in the future, the needed belt size is 78". Dayco part number "5080780" works perfectly
 
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03' White Snake

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Run a string on the pullies the way the belt would, max out the tensioner, Mark the string and measure it. I subtract 0.5-1" for stretch and it's worked everyone for me so far.
 

can04cobra

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I'll check mine in the morning it has the 3.25 pulley on right now with the rest is pretty close to same setup
 

aarons04cobra

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Run a string on the pullies the way the belt would, max out the tensioner, Mark the string and measure it. I subtract 0.5-1" for stretch and it's worked everyone for me so far.
I will if i have to but i was just hoping to have the belt with me when i finish putting the car together this weekend.
 

CobraBob

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For anyone needing the info in the future, the needed belt size is 78" Dayco part number "5080780" works perfectly
Awesome! That's great that you figured out the size, Aaron.
1c66e646b4492b821fd0f5ac0746a915.png
 

MG0h3

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Are you running a stock lower? Im just curious if this is going to work on my 3.0 pulley
affirm.

You gotta remember the belt only sees the change in radius, not diameter as half the diameter goes below the bolt (in reference to the upper). So even going from a 3.5 down to 3.0 you see 1/4" change.
 

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