Name this pipe

[anthony_marquart]

first time running 45s in a long time. not revs like a .21 for sure.. I've seen this on a .21 also.. I tried to run a S pipe at the same length I ran a AB Parobolic,.. it would launch.. but not go real fast. It was on the pipe,.. just not really winding up. Got better when I redid the setup and put the pipe longer.. but I couldn't confirm that the pipe length actually caused the problem cause a few things changed.. but it did launch..

 

[Norm Doerr]

will running pipe too short reduce speed? or will it increase until you cannot launch? I was running it at 8.875,.. to the front edge of the seam on the AA,.. and dog slow.. prop was questionable also..

Irwin nitro pipes have a longer divergent cone than most pipes.. 8" anything is too short for most timing numbers on a .45 engine with the Irwin pipe.

 

[anthony_marquart]

that was with the AA pipe.. Norm,, thread kind of derailed. sounds like I need to lengthen the pipe though for sure.. just wondering now if too short of a pipe would cause my poor performance problems..

 

[DickJones]

So, if I had the boat running like 67 mph, and was able to launch ok,.. it's not slow do too a pipe being too short?

More info would help, what boat, what prop, nitro amount, strut height, head clearance, engine, strut height, was it blowing plugs when U reached max speed or just kept running, with this U should get a lot of answers.JM2CW

dick

 

[HOTWATER]

So, if I had the boat running like 67 mph, and was able to launch ok,.. it's not slow do too a pipe being too short?

More info would help, what boat, what prop, nitro amount, strut height, head clearance, engine, strut height, was it blowing plugs when U reached max speed or just kept running, with this U should get a lot of answers.JM2CWdick

As far as answers go...this is the first bit of common sense to lead to any answers (other than "what pipe is this") that I have seen on this thread....
JM2+CW

 

[JimZaremski]

Name this pipe

Bill.

 

[Mike Betke]

It is an Irwin .67 pipe. The strait section being almost 3 inches long indicates it is a .67. These pipes were early 90's era. Back then the .67 pipe was only about 1/16 larger in diameter than the .45. The .45 pipe only has a 2 inch strait section and a narrower divergent cone.

I never had much luck running the .67 pipe on a .45. The long strait section creates to much volume and I never could make any rpm with it.

 

[Brian Sorgente]

It is an Irwin .67 pipe. The strait section being almost 3 inches long indicates it is a .67. These pipes were early 90's era. Back then the .67 pipe was only about 1/16 larger in diameter than the .45. The .45 pipe only has a 2 inch strait section and a narrower divergent cone.

I never had much luck running the .67 pipe on a .45. The long strait section creates to much volume and I never could make any rpm with it.

Yep, I just measured mine and the straight section is also 2" long. The divergent cone looks to be at a sharper angle as well.

Brian

 

[anthony_marquart]

Well so much for having an extra 40 pipe.. I guess I have a pipe for sale. I don't run any 67's.

On the extra topic,.

AA45, 66% nitro, AA pipe @8.875 to front of seam, H22 modified, JAE style boat, strut on the ski bottom. Head clearance 0.009. Stock motor. Dog slow, 67 MPH.. Hull not running wet, not hopping, seems well balanced at least at this speed. I can't really judge the RPM at this point.

 

[Chris Wood]

just from what you have posted above i would say the prop is alot of it.. does the boat seam to GLUED DOWN???

try a 1457 pitched up and if the motor will pull it a 1657.. that seams to be the two choices for props.

the pipe you have is fine.. a little short though.. i don't think the 1657 will work on that short of pipe.. more like 9 1/4 maybe?

try the 1457 1st see how that goes..

chris

 

[anthony_marquart]

No,.. not glued down.. seems pretty good on the water. I will be testing new props as soon as they arrive. Trying to get 3 decent props to test.. 57mm seems to be a highly recommended diameter,..

The flex shaft is very free, engine is not mounted horizontal to the shaft has less bend,.. thanks for all your input guys..

 

[DickJones]

Well so much for having an extra 40 pipe.. I guess I have a pipe for sale. I don't run any 67's.

On the extra topic,.

AA45, 66% nitro, AA pipe @8.875 to front of seam, H22 modified, JAE style boat, strut on the ski bottom. Head clearance 0.009. Stock motor. Dog slow, 67 MPH.. Hull not running wet, not hopping, seems well balanced at least at this speed. I can't really judge the RPM at this point.

Anthony, U might want to try raising the strut .080 thousand's with the H 22 just to see if the engine can pull the RPM's for more speed before U try a different prop, I would agree the pipe is a little short to pull the bigger props, I think a good starting prop would be the 1457 pitched or a 1655 pitched, the 1657 may work **** because of the ski type boat U have.

JM2CW

dick

 

[Ron Zaker Jr]

Well so much for having an extra 40 pipe.. I guess I have a pipe for sale. I don't run any 67's.

On the extra topic,.

AA45, 66% nitro, AA pipe @8.875 to front of seam, H22 modified, JAE style boat, strut on the ski bottom. Head clearance 0.009. Stock motor. Dog slow, 67 MPH.. Hull not running wet, not hopping, seems well balanced at least at this speed. I can't really judge the RPM at this point.

67 MPH may seem "dog slow" until you get in a heat with others boats in traffic.Just a thought.

 

[Tom Kelly]

Name this pipe

Bill.

I was waiting for that, Jim. LOL