Irwin 7.5 pipe length

[EatMyShortsRacing]

OK now I am just about to install my Rossi 45 on the Lawless unit and need to work out how to measure the length and what is a good starting length.

The pipe is a muffled Irwin pipe spun alloy with a dome on the muffler and the exhaust exiting off centre. It seems to have about 1/2" flat section before the reversing cone is welded on.

The questions are: Do I measure to the start of the flat section, mid-point or to the weld? And what length is a good startign length for the Rossi?

EMS Raving Someone swapped my heart pills!!!!!

 

[RIGGERMORTISE]

Hi Craig

The new SPP 45 pipe we have been testing is giving best results at 245mm on the KB and 230mm on a rossi.

They have a small center band of 3/4" and i tell people to measure to the center of the flat section. The pipe can run down to 220mm but prop size needs to come down as well. I wonder if anyone has converted a MAC45 to an outboard it would be interesting.

seeya

DAve

 

[EatMyShortsRacing]

Hi Craig

The new SPP 45 pipe we have been testing is giving best results at 245mm on the KB and 230mm on a rossi.

They have a small center band of 3/4" and i tell people to measure to the center of the flat section. The pipe can run down to 220mm but prop size needs to come down as well. I wonder if anyone has converted a MAC45 to an outboard it would be interesting.

seeya

DAve

Dave,

want to try this pipe first (prolly coz I already have it) so need a starting point for it. Will look at a SPP once I get a decent hull!!!

Craig

 

[james irwin]

Hi Craig

The new SPP 45 pipe we have been testing is giving best results at 245mm on the KB and 230mm on a rossi.

They have a small center band of 3/4" and i tell people to measure to the center of the flat section. The pipe can run down to 220mm but prop size needs to come down as well. I wonder if anyone has converted a MAC45 to an outboard it would be interesting.

seeya

DAve

Dave,

want to try this pipe first (prolly coz I already have it) so need a starting point for it. Will look at a SPP once I get a decent hull!!!

Craig

[ HEY CRAIG . REGARDLESS OF WHAT YOU HEAR , YOU HAVE THE BEST NOW . MABY I CAN HELP YOU ? THE ROSSI ENGINE IS A BIG BORE SHORT STROK ENGINE , IT NEEDS A LOT OF RPM ,PROPS 447/445 WORKS GREAT MUFF. LENGHT? TRY THIS , SHORTEN THE H3EADER ON THE ENGINE FIRST. THEN TRY THE HEADER ON THE PIPE , WE HAVE FOUND YOU CANNOT GET THIS COMBO TO SHORT , GOD BLESS, O YA , DO NOT USE A FUEL IN THIS ENGINE THAT DOES NOT HAVE A COMBO MIX . OF CASTER OIL AND SYNTHETIC FOR THE LUB.

 

[EatMyShortsRacing]

Hi Craig

The new SPP 45 pipe we have been testing is giving best results at 245mm on the KB and 230mm on a rossi.

They have a small center band of 3/4" and i tell people to measure to the center of the flat section. The pipe can run down to 220mm but prop size needs to come down as well. I wonder if anyone has converted a MAC45 to an outboard it would be interesting.

seeya

DAve

Dave,

want to try this pipe first (prolly coz I already have it) so need a starting point for it. Will look at a SPP once I get a decent hull!!!

Craig

[ HEY CRAIG . REGARDLESS OF WHAT YOU HEAR , YOU HAVE THE BEST NOW . MABY I CAN HELP YOU ? THE ROSSI ENGINE IS A BIG BORE SHORT STROK ENGINE , IT NEEDS A LOT OF RPM ,PROPS 447/445 WORKS GREAT MUFF. LENGHT? TRY THIS , SHORTEN THE H3EADER ON THE ENGINE FIRST. THEN TRY THE HEADER ON THE PIPE , WE HAVE FOUND YOU CANNOT GET THIS COMBO TO SHORT , GOD BLESS, O YA , DO NOT USE A FUEL IN THIS ENGINE THAT DOES NOT HAVE A COMBO MIX . OF CASTER OIL AND SYNTHETIC FOR THE LUB.

James,

I think I have it at around 10.5" for starters. It has #1 engraved on it if that helps identifying the pipe... Will be running 60% nitro with Neo/Castor oil blend

Craig