Cmb 45 hr pipe

[Drew St. Amant]

I have a red head 45 hr in a eagle sgx just wondering what pipe you guys have been running on that engine. I've been running what I believe is a cooper pipe at 9.5in to the weld. Here is a pic of the pipe, maybe someone can tell me what it actually is or if I'm right.

 

[Danny King]

Irwin. Edited to avoid confusion. Lol

 

[Lay26]

Looks like a Irwin 45 pipe....don't remember Cooper having such a pronounced weld....pipes that worked well on that motor in my past experience was the Andy brown parabolic 45 and the ops 60 pipe worked really well

 

[Drew St. Amant]

I do have a parabolic I could try what length is a good starting point?

 

[Danny King]

Looks like a Irwin 45 pipe....don't remember Cooper having such a pronounced weld....pipes that worked well on that motor in my past experience was the Andy brown parabolic 45 and the ops 60 pipe worked really well

That is what I meant to write. It is Irwin. Geez I’m seeing one thing and writing another.
They can be good pipes. As is the parabolic. The Cmb 45 pipe as well. The length will vary from set up to set up.

 

[Drew St. Amant]

Ok so with the irwin pipe I'm running a 1462 that has been cut down and back cut in the sgx I mentioned. Does 9.5 in sound too short? I would obviously just lengthen it and try it but my header has been cut so short that 9.5 is about as far as it will go. I may have to get a new header if it needs to be longer and for that same boat and prop what is a good starting length for a parabolic pipe? The only reason I ask any of this is the boat is extremely sensitive to tune and I have a feeling it's due to the pipe.

 

[Lay26]

When I was running nitro there was a saying "lean is mean but fat is where it's at!"....this applies to the pipe as well...u have a good pipe on my nitro riggers I find 10 1/8 was good to go

 

[Lay26]

On a light rigger u probably could get away with that 9.5" pipe but u also may have to turn a smaller prop
If u want to run bigger props especially with more pitch in them u may have to go longer on the pipe
..it's all a balancing act and what u doing...heat racing boat needs to be able to rev and crawl straight away Rev as high a it's safe to

 

[Drew St. Amant]

Yeah so I definitely need a new header so I try longer. thanks for the help guys I'll give it a try and report back with what I find

 

[Buckshot]

That’s definitely an Irwin pipe.
I prefer the CMB nitro pipe (or the muffled AB version) as it hits harder.
9.5” or so, as short as you can get away with while launching and milling.

 

[SayMikey]

That’s definitely an Irwin pipe.
I prefer the CMB nitro pipe (or the muffled AB version) as it hits harder.
9.5” or so, as short as you can get away with while launching and milling.

Buck have you tried both open 45 cmb nitro pipes?

 

[Norm Doerr]

Irwin, 10.125" to 10.375" was the happy range on those with most .45 engines.

 

[Buckshot]

Buck have you tried both open 45 cmb nitro pipes?

Mikey, I only know of one open pipe didn't know there was 2.

 

[tnrcboatracer]

Andy had a 45 muffled pipe that needed the stinger opened up. It was a good pipe shape, just had a stinger that was too small. The mfg of the pipe apparently mixed up the ID vs OD when putting on the stinger. Too much back pressure.

 

[SayMikey]

Buck here are both

 

[Buckshot]

Buck here are both

I have not seen or tried the black pipe.

 

[Drew St. Amant]

Ran the boat this weekend with the cmb nitro pipe at 10 1/8 ran much better thanks for all the help guys