my latest pipe project... NEW PICTURES ADDED

[topfuel443]

Ive cut down a few good .21 and .45 nitro size straight pipes over the years and then had them welded in a J-Configuration for an outboard. Here is my latest attempt at the perfect .21 OB pipe. It is the rare Irwin .21 nitro pipe, Now I just have to find a good tig welder who wants to tackle the job of sewing it together.... any takers??

~James

OvalExpress Irwin .21 S/J Outboard Pipe Picture...

 

[dave roach]

James

You have PM.

Dave Roach

 

[Wally Marsh]

Hey James,

Looks good, certainly worth trying, I've been thinking the same for another "hard to beat" .21 nitro pipe. Just haven't gotten past the "thinking" stage. In my own set-up and experience, I still use my Rossi outboard pipe as a good consistent benchmark.

Wallster

 

[cooperpipes]

James

Looks Good might work great I have welded a few pipes if you want me to I can weld it

Lynn cooperpipes@aol let me know

 

[Rules]

Ive cut down a few good .21 and .45 nitro size straight pipes over the years and then had them welded in a J-Configuration for an outboard. Here is my latest attempt at the perfect .21 OB pipe. It is the rare Irwin .21 nitro pipe, Now I just have to find a good tig welder who wants to tackle the job of sewing it together.... any takers??

~James

OvalExpress Irwin .21 S/J Outboard Pipe Picture...

Hello, That design is almost the same dimensions as

the Equalizer "S" shaped pipe sold by Bob Kensill.

Rules

 

[kilr95ss]

If you still need one, TIG welding aluminum is what I do for a living. Where I work we make the aluminum radiators for Northern Racing, Jegs and Summit. I've been TIG welding for 9yrs. No charge, let me know.

I believe we still have some of the Aerotech pipes laying around in our Prototype lab where the maker of Aerotech tunnels and pipes used to work.

 

[topfuel443]

Wow...! Thanks to everyone who replied! I will let Dave roach have a try at it, as he sent me a pm first. Thanks again Guys!

~James

 

[Richard Dahlheimer]

Wow...! Thanks to everyone who replied! I will let Dave roach have a try at it, as he sent me a pm first. Thanks again Guys!

~James

James, great idea for a out board pipe. Pease let us know how it works. Richard D

 

[topfuel443]

Hey Richard, ive had few pipes welded up like this actually, this is my fifth one, they all work about as good as any other pipe, but of course we are always looking for that "special" one...The cool thing about it is you can adjust the volume/shape/taper as desired.

~James

 

[Richard Dahlheimer]

Hey Richard, ive had few pipes welded up like this actually, this is my fifth one, they all work about as good as any other pipe, but of course we are always looking for that "special" one...The cool thing about it is you can adjust the volume/shape/taper as desired.

~James

James, i have a AB .21 nitro pipe that i thought might be a good bet for a out board pipe. Did you ever try one? Richard D

 

[Lar'Dog]

:blink: James,have You got that pipe back yet? I'd like to see a picture of it finished. B)

 

[topfuel443]

not yet, I actually just sent it out to Dave. He probably hasnt gotten it yet. I had some pictures of the other pipes I had, will have to look for them.

~James

 

[topfuel443]

OK guys, a little late on the update, but Ive had alot of family in town recently so ive been busy. Got the pipe back from Dave Roach and it looks great. I would like to thank Dave for doing a tremendous job with such a tedious task.

I got it all mounted up to my liking, fabbed up a nice carbon fiber bracket that is strong, light and will allow me to use many pipes, at different lengths without changing the bracket.

here you go...

Left side view:

Right side view of pipe, muffler, oil bottle, and bracket.

Rear view:

Another bracket view: (kinda had a brain fart when I cut up the pipe, I didnt pay any attention to where the pressure tap was facing... oh well. )

~James

 

[Lar'Dog]

James,looks good! Is that a home made muff,and where is the exit? Have You had a chance to test it out yet? Later,Lary B)

 

[topfuel443]

Yep, they are mufflers that we have been running for a number of years, the exit is on the end, on the bottom, basically the exhaust hits the top of the water. Havent tried it yet. Ran it on the bench a little, got a 100 mph out of it on the table! should be good for atleast 200mph on the water after it breaks in.

I will let you guys know when it gets wet, I have big hopes for this little motor, especially after all of the work that went in to it.

~James

 

[Jerry Wyss]

Ran it on the bench a little, got a 100 mph out of it on the table! ~James

:lol: !!!,,, :lol: !!!! Hahahaha!!,,, Now I REALLY Want One! :lol: Good One!

EDIT: Ok Top I wanna know, so I'll tell ya what I did to my Rossi,

(1) Opened crank window to 215 degrees, 30deg ABDC(open) and 65 ATDC(close

(2) Lathe cut head button- 50/50 squish/bubble ratio , .18cc volume @ .008" H/S (clearance)

(3) .015" sleeve shim the brought the transfer ports to .130deg

(4) Cut exhaust port to 181deg (had to dremel case Exhaust port roof area to clear sleeve Ex port)

(5) Installed O.S. 20J carb

(6) Sealed oil hole in case going forward to front bearing.

(7) Aircooled head (RB 728) cut to nearly no fins! some like it HOT

going to make a effort to film allota the testing for once.

 

[Ronald van Essen]

James

Good looking on that pipe. Hope it runs like hell.

Ronald.

 

[topfuel443]

Jerry... Ive done three motors since the Rossi's and dont remember exactly as I didnt write down what all I did to them, and dont want to take them apart to get exact numbers....but heres what I do remember.

The exhaust got moved up to around 176 or 178 degrees, not sure which...( I also cut a .020 "top hat" configuration into 1/3 of the top of the exhaust port, obviously had to match the case to that.

After raising the exhaust, I had to hog the **** out of the case exhaust outlet area... it was way to small and choking in that area. removed a LOT of material from inside that exhaust spigot.

Matched the sleeve tranfer tops to the top of the case passages without moving the timing.... it was horibble. Almost .035 thous. hanging down below the case passage.

cut a little here and there on the sleeve at the intake window and tranfer window to help things move along with the proper amount of "swirl"

Turbo cut the crank, cleaned up the opening side of the crank window, about 0.012 thous worth.

clearanced the big end of the rod.

got the piston to actually "fit" the sleeve, also releived where the sleeve sits on top of the case with a little deburring tool.

Got the head clearance down to 0.007 with a 0.004 headshim installed.

.18cc bubble volume with 1/3 squish band at 1.5 degree angle. Its got a couple more cuts in the head, but nothing we havent seen before. I modified a stock CMB TT head button to make all of this happen.

Using the stock water jacket for now, will see how she heats up or deosnt and go from there. Im not big on air cooling a motor as its to easy to overheat one, but will if I have to.

Thats about all I can remember... ~James

PS, oh yeah... I got Rod G. to do his magic on one of his carbs for me and make an adapter to the rossi.

 

[Jerry Wyss]

Well that's a perdy good memory,,, I did the Thunder Tiger buggy engine (long stroke 21) and the

Mac on a REK lower after the Rossi too,, so we're on a similar pace.

I've really got a hankerin' to do another Mac, only this one will get the Mac buggy crank in it and

spin'er the other direction to use the TT geared lower. The Mac needs a little leverage (I think)

to take advantage of it's "screaming self".

The buggy crank will get cut to the same specs as the O/B crank so I can see if the gearing is an actual

improvement over it's normal direct drive.

Gawd, I'll be settin' up boats till spring, easy :blink:

 

[Tim_Duggan]

Turbo cut the crank, cleaned up the opening side of the crank window, about 0.012 thous worth.

Hey James,

What weight % did you set the crank balance to after cutting the turbo port?

Tim