Quieting Boats down

[Brian_Nelsen]

so Basically what brian is saying if I am correct is it can work to just glue the tube in with some type of silicone glue. That is interesting, in the case of a mono you have the v at the bottom to hold it straight. This is going in a good direction.

Allen

I am going to error on the side of caution here a bit and have you research some type of higher end silicone adhesive to use. So if you could please take a look to see whats out there.

I will try to draw up a few things to see how this works.

Brian

 

[AWaddle322]

so Basically what brian is saying if I am correct is it can work to just glue the tube in with some type of silicone glue. That is interesting, in the case of a mono you have the v at the bottom to hold it straight. This is going in a good direction.

Allen

I am going to error on the side of caution here a bit and have you research some type of higher end silicone adhesive to use. So if you could please take a look to see whats out there.

I will try to draw up a few things to see how this works.

Brian

brian, the basic thing is to stay away from any clear product. Brian used black rtv. the roblem with rtv is that is formulated in such a manner to cure and not destroy a cork gasket. RTV is an acid cure silicoln. it cures from the center outwards. It uses a combination of amonia and acetone mixed with in itself to cure (neither of which would I want on fiberglass ). I better choice would be a strucural silicoln like GE Silpruf or dow corning 795 and I am sure peccora makes one as well but pecora silicolns are not sold in this area. Both of these products are air cured (oxygen). Structural silicolns are very strong yet remain somewhat flexiable they are also intended to bond to differnent surfaces. Basically rtc silicolns are intended to bond two like surfaces together with cork gaskets between them which is a unusual carcteristic of any adhesive product because most are intended to only come in contact with 2 like or unlike surface (when you are bonded to three surface and contraction and expansion occur it destroys the sill because three surfaces will move differntly than two).

Allen

 

[Brian_Nelsen]

Allen

Thanks for the information. I will try to find those products locally. I am still working out exactly how I want to do this. I will share it once I do. The trick is going to be making the stuffing stay low in the bottom of the hull. There is another thread on this subject that just got started so I am looking at what they are saying as well.

Brian

 

[Shannon SC]

Here's something that I found while looking for a flexible adhesive that is gasoline and nitro fuel proof. I soaked one cured windshield adhesive sample in gasoline and another sample in 20% nitro for 3 months. The adhesive remained flexible and showed no signs of deteration. I got the adhesive from the local auto glass shop, what was left in the tube after a windshield replacement was free for the asking.

For the ISO pad type of securing the shaft log to a mono hull, I made my own, I put 2 small rubber 'O' rings on the tube to space it off of the hull surface, made sure that everything was aligned and then applied liberal amounts of the windshield sealant to bond the tube, rings, and hull together making the ISO pad the size that I wanted.

 

[Brian_Nelsen]

Well Today I am going to a local pond to do some testing. I plan to test mainly meter set ups today but have a new pipe on my rigger to try out. This is the one I welded the can type muffler on. Its a Muck pipe.

 

[Don Ferrette]

Well don if the speed is there , it consistant and it this quite that will be quite impressive.

Allen

Allen I'm excited about these pipes, they are incredibly quiet & have a wide torque curve. When I ran with 3 other boats the only time you really heard the twin was coming down the front chute, you had to be there it was amazing, people watching couldn't believe how quiet the boat was. I will say it is a very different pipe in terms of the powerband, very broad range. You go from a cruise to WOT without ever really feeling the typical "hit" of a pipe coming on. The transition though it's powerband is so smooth it's deceiving........... B)

Don, well the good part is if they are the quite and that fast they will not be hard to sell if they are consistant. We have all seen loud and quite pipes that were fast but not consistant. Find something that is fast and consistant and the masses will follow because if you cant beat them then join them. Until people are continually beat with quite pipes the masses will not follow. you are actaully on the correct tract to really quiten boats if you can show up at races and win over the louder (wehter muffled or not) pipes. Until then the masses will comply but also believe the old saying the more horses the more oats you have to feed them (fuel) the more oats you feed them the more they pop (exhaust).

Allen

Just thought I'd give an update on the pipe testing, today I found that these things seem to like big props. Was running a pair of 1667's @ 6.4" & it wasn't nearly enough prop, couldn't load up the engines without going too lean. Switched out to a pair of H50's that are pitched but I'm not sure how much & the boat was much better to hit a needle on. I'm going to measure the props & then go up a little more as it seems like they still want more. I'm really liking what I'm seeing so far, the boat is haulin' & doing it @ 82dB.

 

[mark voorhies]

Well don if the speed is there , it consistant and it this quite that will be quite impressive.

Allen

Allen I'm excited about these pipes, they are incredibly quiet & have a wide torque curve. When I ran with 3 other boats the only time you really heard the twin was coming down the front chute, you had to be there it was amazing, people watching couldn't believe how quiet the boat was. I will say it is a very different pipe in terms of the powerband, very broad range. You go from a cruise to WOT without ever really feeling the typical "hit" of a pipe coming on. The transition though it's powerband is so smooth it's deceiving........... B)

Don, well the good part is if they are the quite and that fast they will not be hard to sell if they are consistant. We have all seen loud and quite pipes that were fast but not consistant. Find something that is fast and consistant and the masses will follow because if you cant beat them then join them. Until people are continually beat with quite pipes the masses will not follow. you are actaully on the correct tract to really quiten boats if you can show up at races and win over the louder (wehter muffled or not) pipes. Until then the masses will comply but also believe the old saying the more horses the more oats you have to feed them (fuel) the more oats you feed them the more they pop (exhaust).

Allen

Just thought I'd give an update on the pipe testing, today I found that these things seem to like big props. Was running a pair of 1667's @ 6.4" & it wasn't nearly enough prop, couldn't load up the engines without going too lean. Switched out to a pair of H50's that are pitched but I'm not sure how much & the boat was much better to hit a needle on. I'm going to measure the props & then go up a little more as it seems like they still want more. I'm really liking what I'm seeing so far, the boat is haulin' & doing it @ 82dB.

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

 

[Don Ferrette]

Just thought I'd give an update on the pipe testing, today I found that these things seem to like big props. Was running a pair of 1667's @ 6.4" & it wasn't nearly enough prop, couldn't load up the engines without going too lean. Switched out to a pair of H50's that are pitched but I'm not sure how much & the boat was much better to hit a needle on. I'm going to measure the props & then go up a little more as it seems like they still want more. I'm really liking what I'm seeing so far, the boat is haulin' & doing it @ 82dB.

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

Yes Mark they are a pair of modded Evo 2002's. I will post a pic of the pipes tonight. B)

 

[Brian_Nelsen]

Ok here are my week end details.

I went to a new test pond this week end (first time I have ever used it) the pond is long and kinda narrow so get the boat out onto what we usually see as a normal course was hard but I made due. The boat I tested was a 90 rigger. This is an older avenger boat that has been lightend and trimmed down some from the origanal boat. It usually runs very well with the old nitro pipes I have. The pipe I usually use is a muck nitro pipe. it usually runs about 96 db with no addons, with an internal stinger 92 was the best reading I ever got. I welded on an add on can that muck made me years ago. it worked pretty good, got the db's down to 88.

So here are the test results (sorry no speeds as the radar gun failed to work)

stock muck nitro pipe 95 to 96 db (set up as the rule book states with the angle board added)

Inverted stinger muck nitro pipe 92 to 93 db (not a surprise)

welded on can muffler (which is kinda ugly) 87 to 88 db

The result is good and the boats needle changed only slightly. With out the radar gun it was hard to get the fine speed details but I have run this boat enough to say it did not loose any speed. I do not recommend that people go ahead and add this muffler to thier pipes as it is kinda ugly and a bit heavy. There is likely a better method out there.

I did a ton of other db reading testing and believe I have found a decently consistant result between the two ponds I use but that is for another thread.

Stated finalising the ideas for mounting the stuffing tubes in the mono's and will report and that soon. I am also looking to try some things on the rigger becasue that installation has some specific issues as far as being water tight.

Brian

 

[Terry Keeley]

Hey Brian:

Did you use the add-on muffler with the internal stinger or just on it's own to get 87-88dB? What motor are you running?

I get 91-92 on my CMB 67 with "Big Belly" pipe and internal stinger, if I add the little Muck double cone muffler to the end it drops to 89-90.

 

[SayMikey]

Hey Brian:

Did you use the add-on muffler with the internal stinger or just on it's own to get 87-88dB? What motor are you running?

I get 91-92 on my CMB 67 with "Big Belly" pipe and internal stinger, if I add the little Muck double cone muffler to the end it drops to 89-90.

Brian you might go to a ford dealer and get some diesel rtv its not acid and it hardens good.Its durable enough not to breakdown like the others grey in color.....Mike

 

[Brian_Nelsen]

Hey Brian:

Did you use the add-on muffler with the internal stinger or just on it's own to get 87-88dB? What motor are you running?

I get 91-92 on my CMB 67 with "Big Belly" pipe and internal stinger, if I add the little Muck double cone muffler to the end it drops to 89-90.

Engine is a CMB evo 90. Pipe is a muck with no internal stinger just a can type device that covers the entire back end of the pipe. it would be like taking a soup can and putting a stinger in it and put it over the whole back of the pipe.

I did make the stinger in the can longer kind of like an internal stinger but it does not enter the nitro pipe in any way. It is also offset to the bottom of the can.

Brian

 

[SayMikey]

Hey Brian:

Did you use the add-on muffler with the internal stinger or just on it's own to get 87-88dB? What motor are you running?

I get 91-92 on my CMB 67 with "Big Belly" pipe and internal stinger, if I add the little Muck double cone muffler to the end it drops to 89-90.

Engine is a CMB evo 90. Pipe is a muck with no internal stinger just a can type device that covers the entire back end of the pipe. it would be like taking a soup can and putting a stinger in it and put it over the whole back of the pipe.

I did make the stinger in the can longer kind of like an internal stinger but it does not enter the nitro pipe in any way. It is also offset to the bottom of the can.

Brian

Terry can you show a pic of your stinger setup? And has anyone tried a DOUBLE one in the pipe and one in the muffler.....Mike

 

[Don Ferrette]

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

Here's a shot of the pipes. 2" inch diameter, .500" stinger i.d., 1" lead ins that will go over a CMB 90 header with .020" machined off the o.d.

 

[Terry Keeley]

Hey Brian:

Did you use the add-on muffler with the internal stinger or just on it's own to get 87-88dB? What motor are you running?

I get 91-92 on my CMB 67 with "Big Belly" pipe and internal stinger, if I add the little Muck double cone muffler to the end it drops to 89-90.

Engine is a CMB evo 90. Pipe is a muck with no internal stinger just a can type device that covers the entire back end of the pipe. it would be like taking a soup can and putting a stinger in it and put it over the whole back of the pipe.

I did make the stinger in the can longer kind of like an internal stinger but it does not enter the nitro pipe in any way. It is also offset to the bottom of the can.

Brian

Terry can you show a pic of your stinger setup? And has anyone tried a DOUBLE one in the pipe and one in the muffler.....Mike

Hey Mikey:

A picture really doesn't show much 'cause the stinger is inside the pipe. Just run the stinger in to the mid section of the pipe and you'll be amazed at how quiet it is.

 

[AWaddle322]

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

Here's a shot of the pipes. 2" inch diameter, .500" stinger i.d., 1" lead ins that will go over a CMB 90 header with .020" machined off the o.d.

Don,

what is different about those pipes over the mac 15 cc muffled pipe? And what is this about 1" lead ins that will go over a cmb 90 header?

Alllen

 

[Don Ferrette]

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

Here's a shot of the pipes. 2" inch diameter, .500" stinger i.d., 1" lead ins that will go over a CMB 90 header with .020" machined off the o.d.

Don,

what is different about those pipes over the mac 15 cc muffled pipe? And what is this about 1" lead ins that will go over a cmb 90 header?

Alllen

Allen-

These pipes do not have a second cone rather a series of progressive baffles. The first baffle is 2" behind where the first cone ends (2" band as some would call it). This baffle's opening is only slightly smaller than the pipe i.d. Then an inch down from that is the next baffle which has a slightly smaller hole in it & so on. If you were to lay a straight edge along the holes of these baffles you'd see it follows the taper line that the secondary cone would normally make. The last internal baffle is flat with 2 offset .500" stingers 180 degrees apart from each other then exits the pipe thru a .500" stinger. The front lead in section from the header has a 1" diameter as opposed to the 7/8" diameter of the typical 15cc pipe. (it will be available with either 7/8" or 1" lead in) I chucked up a pair of new CMB 90 headers in the lathe & turned them down .020" (.040" off total diameter) so the pipes will telescope over the header. These pipes seem to be just like the gas version, they are happy at a particular length. I have tried longer & shorter (the power drops noticeably when even a little too long) & have found they are best at 10" from engine cylinder centerline to where the primary cone ends (this would be 12" to where the first baffle is). The big thing I found is they make lots of torque to turn up big blades, H50's @ 7.0" went well. I think this will be a pipe that you set at a given measurement & prop to that pipe length. I want to test with a set of H50's with more, about 7.2" next.

 

[AWaddle322]

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

Here's a shot of the pipes. 2" inch diameter, .500" stinger i.d., 1" lead ins that will go over a CMB 90 header with .020" machined off the o.d.

Don,

what is different about those pipes over the mac 15 cc muffled pipe? And what is this about 1" lead ins that will go over a cmb 90 header?

Alllen

Allen-

These pipes do not have a second cone rather a series of progressive baffles. The first baffle is 2" behind where the first cone ends (2" band as some would call it). This baffle's opening is only slightly smaller than the pipe i.d. Then an inch down from that is the next baffle which has a slightly smaller hole in it & so on. If you were to lay a straight edge along the holes of these baffles you'd see it follows the taper line that the secondary cone would normally make. The last internal baffle is flat with 2 offset .500" stingers 180 degrees apart from each other then exits the pipe thru a .500" stinger. The front lead in section from the header has a 1" diameter as opposed to the 7/8" diameter of the typical 15cc pipe. (it will be available with either 7/8" or 1" lead in) I chucked up a pair of new CMB 90 headers in the lathe & turned them down .020" (.040" off total diameter) so the pipes will telescope over the header. These pipes seem to be just like the gas version, they are happy at a particular length. I have tried longer & shorter (the power drops noticeably when even a little too long) & have found they are best at 10" from engine cylinder centerline to where the primary cone ends (this would be 12" to where the first baffle is). The big thing I found is they make lots of torque to turn up big blades, H50's @ 7.0" went well. I think this will be a pipe that you set at a given measurement & prop to that pipe length. I want to test with a set of H50's with more, about 7.2" next.

Don, you are not turning big props. We have been over 7.0 inches with 80 size motors for a couple of years now. If your 90 will not turn more like 8.0 something is wrong.

Allen

 

[Don Ferrette]

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

Here's a shot of the pipes. 2" inch diameter, .500" stinger i.d., 1" lead ins that will go over a CMB 90 header with .020" machined off the o.d.

Don,

what is different about those pipes over the mac 15 cc muffled pipe? And what is this about 1" lead ins that will go over a cmb 90 header?

Alllen

Allen-

These pipes do not have a second cone rather a series of progressive baffles. The first baffle is 2" behind where the first cone ends (2" band as some would call it). This baffle's opening is only slightly smaller than the pipe i.d. Then an inch down from that is the next baffle which has a slightly smaller hole in it & so on. If you were to lay a straight edge along the holes of these baffles you'd see it follows the taper line that the secondary cone would normally make. The last internal baffle is flat with 2 offset .500" stingers 180 degrees apart from each other then exits the pipe thru a .500" stinger. The front lead in section from the header has a 1" diameter as opposed to the 7/8" diameter of the typical 15cc pipe. (it will be available with either 7/8" or 1" lead in) I chucked up a pair of new CMB 90 headers in the lathe & turned them down .020" (.040" off total diameter) so the pipes will telescope over the header. These pipes seem to be just like the gas version, they are happy at a particular length. I have tried longer & shorter (the power drops noticeably when even a little too long) & have found they are best at 10" from engine cylinder centerline to where the primary cone ends (this would be 12" to where the first baffle is). The big thing I found is they make lots of torque to turn up big blades, H50's @ 7.0" went well. I think this will be a pipe that you set at a given measurement & prop to that pipe length. I want to test with a set of H50's with more, about 7.2" next.

Don, you are not turning big props. We have been over 7.0 inches with 80 size motors for a couple of years now. If your 90 will not turn more like 8.0 something is wrong.

Allen

Well there Allen 7.0" on an H50 profile is a stout prop not to mention I've seen plenty of supposed 7.0" props that weren't even close to that. Guess it depends on whose doin' the measuring.............

 

[AndyBrown]

Don, sounds like a dream come true, 82 db pipe that wants more prop, don't keep

us in the dark tooo long. 90 Evo 2002s , right?

Here's a shot of the pipes. 2" inch diameter, .500" stinger i.d., 1" lead ins that will go over a CMB 90 header with .020" machined off the o.d.

Don,

what is different about those pipes over the mac 15 cc muffled pipe? And what is this about 1" lead ins that will go over a cmb 90 header?

Alllen

Allen-

These pipes do not have a second cone rather a series of progressive baffles. The first baffle is 2" behind where the first cone ends (2" band as some would call it). This baffle's opening is only slightly smaller than the pipe i.d. Then an inch down from that is the next baffle which has a slightly smaller hole in it & so on. If you were to lay a straight edge along the holes of these baffles you'd see it follows the taper line that the secondary cone would normally make. The last internal baffle is flat with 2 offset .500" stingers 180 degrees apart from each other then exits the pipe thru a .500" stinger. The front lead in section from the header has a 1" diameter as opposed to the 7/8" diameter of the typical 15cc pipe. (it will be available with either 7/8" or 1" lead in) I chucked up a pair of new CMB 90 headers in the lathe & turned them down .020" (.040" off total diameter) so the pipes will telescope over the header. These pipes seem to be just like the gas version, they are happy at a particular length. I have tried longer & shorter (the power drops noticeably when even a little too long) & have found they are best at 10" from engine cylinder centerline to where the primary cone ends (this would be 12" to where the first baffle is). The big thing I found is they make lots of torque to turn up big blades, H50's @ 7.0" went well. I think this will be a pipe that you set at a given measurement & prop to that pipe length. I want to test with a set of H50's with more, about 7.2" next.

Don, you are not turning big props. We have been over 7.0 inches with 80 size motors for a couple of years now. If your 90 will not turn more like 8.0 something is wrong.

Allen

:lol: :lol: Ahh yes the ole bigger's got to be better sydrome! :lol: :lol:

Fast oval time at the Internats in twin hydro was mac 67's turning 4.8" of cup. So what's with that? :lol: Placed a close 2nd it SAW too!

I know Iknow....just wait till next year........