Speedmaster 21 pipe length ??

[Albert Marroquin]

Hi i have a 21 speedmaster with a 21 Rb c5 with a 180 degree header macs pipe what would be a good pipe length ? When measuring do i start from center of plug or start from rear exhaust port to thickest part of pipe ?

Would a 440x3 or a 437x3 work good for a good speed ?

Help would be appreciated THANKS

 

[Walt Barney]

Hi i have a 21 speedmaster with a 21 Rb c5 with a 180 degree header macs pipe what would be a good pipe length ? When measuring do i start from center of plug or start from rear exhaust port to thickest part of pipe ?Would a 440x3 or a 437x3 work good for a good speed ?

Help would be appreciated THANKS

Either X prop that you suggested will work

. You just have to test to see what prop works best , as far as the pipe start @ 8" and work you way closer to 7". I run 7 1/8" with a N/R.long stroke, measured arround the full length.

Walt Barney

 

[Preston_Hall]

I don't know the total length, but 4.5" from the plug to weld of the pipe. I run a 440. Some run the 437.

 

[M@MRacing]

measure from middle of the casiing of engine to the weeld should be 8 inches also try the 1614 prop

 

[Joe Warren]

Hi i have a 21 speedmaster with a 21 Rb c5 with a 180 degree header macs pipe what would be a good pipe length ? When measuring do i start from center of plug or start from rear exhaust port to thickest part of pipe ?Would a 440x3 or a 437x3 work good for a good speed ?

Help would be appreciated THANKS

mono - plug to weld on pipe. 3 3/4length. ops 3280 pipe... 440/3 octura. Have ran 3 1/2 after the boat is dialed in.

 

[M@MRacing]

If you have rear exhaust measure 8 inches if you have side exhaust measure 4 inches

 

[Rick Cesati]

I don't know the total length, but 4.5" from the plug to weld of the pipe. I run a 440. Some run the 437.

Preston...isn't that a bit long? ( 9.5 in. total) or did you mean to say 3.5"? Just curious

R-