Pipe & pipe length reccomendations

[Tim_Duggan]

Had my first real shakedown runs yesterday on the new boat and motor, and am getting ready to do some pipe & prop testing shortly. The motor is a new Picco.

I currently have a Mac's 45 pipe and an AB45 pipe to try, any other suggestions for this combo??

Thanks,

Tim

 

[Tim_Duggan]

Thanks Greg,

Length and stinger diameter?

Tim

 

[Slideblues]

Timbo,

According to AB's site, 9.5" center of cyl to weld

 

[Tim_Duggan]

Timbo,

You still running that FF21 rigger ?

Just wondering....

Gene

PM on the way Gener

 

[Slideblues]

10/4

Hit browser refresh got a pipe length for ya B)

 

[Slideblues]

Musta slipped when I clicked....Pic edit

Thank you Greg,

Gene

 

[Tim_Duggan]

Hey Timbo

sorry had to go measure it

9 1/2 from plug to centre of the weld

stinger drilled out to 9.5mm

:note for inexperinced boaters put the drill bit in the vise and turn the pipe by hand

its much safer on thin Aluminium pipes

Greg

slidy thats a parabolic pipe not an AB Nitro

great to see you back BTW

Thanks Greg! Well done on the SAW record too man! Any word yet on when you are headin' up to build that new place - I heard a rumour about where it's going to be located - it's 5 minutes walk from my place.

 

[shoboat]

Tim,

Irwin 67 nitro [email protected]"

 

[Tim_Duggan]

Tim,

Irwin 67 nitro [email protected]"

Thanks for the tip Mark B)

 

[Tim_Duggan]

Bat Street Tim as far as i Know

Looks like november at this stage it has pushed a little later than i had hoped

we also have another on in Liverpool that might be before that

Thanks Tim the SAW was really fun i spent most of the weekend running the timming

equipment with Tony Grinter so i didnt have much of a chance to adjust anything

it was just my oval setup with the strut lifted up and Aaron Cupped the prop while it was

on the boat. I did have to add a can muffler after saturday as it was reading 107 db lol

Greg

Yeah I'd heard it was @ Batt St too, near York Rd - used to be a Telstra depot there. It's 600m from my place based on aerial map. 1st weekend of August is Winter spec. Liverpool is only 30 minutes away if you are there at the time. Easy drive.

I wonder how much quicker you could have gone if you had the chance to spend time on it? 107dB - would never have thought that was possible on a 21 pipe! Thats really, really loud - especially for a CF pipe!!!!!!!!

 

[Joe Warren]

The new picco 45 will easly pull 9 1/4 pipe length from side of cooling head & center of piston to the weld of the pipe. Some riggers can go even shorter depending on the prop & the weight of the boat. Octura 1657 would be my Bench Mark Prop.

 

[Tim_Duggan]

Yep - I used a 1657 and pulled it no problem - the Mac's pipe was @ 10 1/2 and I was over running it easily - the boat was happier at half throttle and transitioning, than at full throttle. I forgot to pack the pipe cutter into the trailer so had to live with it for the shakedown runs.

Also, my rudder blade is too deep. Whats a good starting point for depth below the rear sponsons with a 1657 prop? transom pic

 

[dr gary turner]

I am running the new Picco in our version of the JAE with the AA parabolic pipe at 8.5-8.75 inches pulling a 1657 prop with 4.57 inches of pitch.

 

[John Knight]

I am running the new Picco in our version of the JAE with the AA parabolic pipe at 8.5-8.75 inches pulling a 1657 prop with 4.57 inches of pitch.

Now you are talking!!

 

[Tim_Duggan]

Thanks again Greg,

Looks like I have a little work to do making some longer pipe brackett to get the pipe shorter too.

 

[David Kingston]

Off topic here but ..

Greg if you are in townville in August let me know and maybe there might be a chance to head out with the boys up here.

Dave

 

[dwilfong]

I run a AB#2 same as the CMB HIGH NITRO and found that 9 1/2 is the sweet spot on that pipe. will pull tons of prop at that length at 27 to 28K. stinger stock size.

Lodged many runs with this pipe so I know what the RPMS are at this length. Will pull up from a idle crawl also.

If you want to go faster mess with the prop you might be surprised what it will pull at that length.

David

 

[Tim_Duggan]

Thanks David,

I have one of those pipes but I had already opened up the stinger as per Andy's suggestion. I'll set it up @ 9 1/2 to begin with. What exhaust timing is that 28K achieved with on that pipe, if you don't mind sharing?

Tim

 

[shoboat]

Tim,

I am sure David will tell you that it is the combination

of numbers that make it work very well. Just like propellers.

Have Fun Testing,

Mark Sholund

 

[dwilfong]

Thanks David,

I have one of those pipes but I had already opened up the stinger as per Andy's suggestion. I'll set it up @ 9 1/2 to begin with. What exhaust timing is that 28K achieved with on that pipe, if you don't mind sharing?

Tim

127 trans 130 boost 190ex; clearance at .009 at.41cc 9.2CR 1deg angle. strait sides and bottom on chamber.

This is in a mono running a AB 5077B/3 60 to 64 MPH. will also run a X457 with similar results.

This is a highly modded 45RS.

But from testing different pipes and eng setups have found pipes do have a sweet spot that mods and setups will work around. seams the pipe is the major controller of the power the rest is just to fine tune. This has just bin my limited experience with it so far.

David