Discussion on lowering nitro %

[Norm Doerr]

Now shall I start the muffled pipe/noise regulations thread?

I dare ya!

 

[derek owen]

Now shall I start the muffled pipe/noise regulations thread?

welcome to our world here in the uk! noise nitro and lack of water to use all well restricted

 

[Buckshot]

I dare ya!

One can of worms at a time.

 

[gilbert galli]

welcome to our world here in the uk! noise nitro and lack of water to use all well restricted

in France it's the same and maybe even worse

 

[SayMikey]

Well we all can agree or disagree,in the end no Org. is going to mandate any fuel restrictions. Our main concern is parts and pieces,plugs are at the forefront for now we have a few suppliers. We have had struggles with fuel<NITRO before and survived. Very few races can bring 100 boats to an event without the help of Gas and Fe. To keep going we must support these suppliers who ever they are.

 

[Charles Perdue]

The primary problem of the noise issue in the past was not being able to measure the sound level of each boat separately when they were running on the water, like in a heat race, to see who was and who wasn't in compliance with the DB rule.

When using the anechoic chamber WITH the DB meter this problem was eliminated.

Charles

 

[Buckshot]

This thread is supposed to be about low % nitro R/C fuel.
Lets try this, If going from 60% to 40% in a 15cc what did you need to change? I had to retune the needle slightly and took about 1/4" cup out of the prop, pipe stayed at 11.5".
Now I need to go from 40% down to 16%, thinking I might need to open the spray bar a little, reduce cup some more and maybe 1mm diameter on the prop. Reduce stinger I.D.?
Thoughts?

 

[Charles Perdue]

No need to open the spray bar as you will be using LESS fuel........

Charles

 

[ALLAN YUEN]

The primary problem of the noise issue in the past was not being able to measure the sound level of each boat separately when they were running on the water, like in a heat race, to see who was and who wasn't in compliance with the DB rule.

When using the anechoic chamber WITH the DB meter this problem was eliminated.

Charles

I see notice IMPBA and NAMBA for SAW dont use muffled pipe and tuned pipe without muffler I dont understand that make on book rule follow less DB but said Bulls..t That’s why

 

[ChrisHerzog]

No need to open the spray bar as you will be using LESS fuel........

Charles

I agree with this. You will be leaning the needle down so getting fuel with what you have now will work with no problem. You might consider going to a smaller head button tho. There was a huge difference between the head button that came on the stock OPS engines and the head buttons for FAI fuel.

 

[David Ashcroft]

welcome to our world here in the uk! noise nitro and lack of water to use all well restricted

Shhhh

 

[Buckshot]

I agree with this. You will be leaning the needle down so getting fuel with what you have now will work with no problem. You might consider going to a smaller head button tho. There was a huge difference between the head button that came on the stock OPS engines and the head buttons for FAI fuel.

I have thought about reducing the bowl volume along with reducing the stinger of the pipe.

 

[ChrisHerzog]

I have thought about reducing the bowl volume along with reducing the stinger of the pipe.

I wish I had the two heads side by side to show you. The FAI looked the same, same angles same shape of the bowl just much smaller.
I don’t know of any difference in any of the pipes however in Europe where FAI fuel was more popular at the time, they also all ran muffled pipes witch may have some of the same effects on the engine as a smaller stinger would on a tuned pipe.
It’s possible I guess that a smaller bore in a carb running the lower nitro may also be better all around. You will be very surprised at how drastically your fuel mileage will also go up simply by running less nitro. Ideal and midrange should also improve especially if your use to running 60% nitro and a huge bore carb.

 

[Ray Sametz]

Now shall I start the muffled pipe/noise regulations thread?

Let the buckshot fly.

 

[Charles Perdue]

Ray, how much time do you spend on your computer looking for these funny little videos?????????????????

Not complaining mind you, I like them.

Charles

 

[Norm Doerr]

One can of worms at a time.

One can of worms at a time.

Next Up.... Hit a Boat automatic drivers test, while be heckled by a group of obnoxios

I have thought about reducing the bowl volume along with reducing the stinger of the pipe.

That makes sense. Some folks used to open up stoch bowls to run high Nitro with a tight headspace.

 

[John Beardslee]

I agree with this. You will be leaning the needle down so getting fuel with what you have now will work with no problem. You might consider going to a smaller head button tho. There was a huge difference between the head button that came on the stock OPS engines and the head buttons for FAI fuel.

As you reduce nitro % the viscosity will go down and you’ll turn in the needle. Ron Logghe did some experimenting with FAI fuel back in the early 90’s when Angus petroleum had a fire and the Chinese nitro was pretty bad. We had to increase the compression ratio in order to get it to run and to get it to run consistent we when so high we had to loosen the plug to start even with 24V dynatron.

 

[Norm Doerr]

As you reduce nitro % the viscosity will go down and you’ll turn in the needle. Ron Logghe did some experimenting with FAI fuel back in the early 90’s when Angus petroleum had a fire and the Chinese nitro was pretty bad. We had to increase the compression ratio in order to get it to run and to get it to run consistent we when so high we had to loosen the plug to start even with 24V dynatron.

That makes sense.. using the same set up for nitro, (bowl volume) just tighter headspace?

 

[Timbo Whalen]

Can I add something else?

When a newby comes along with some hurtin' POS they picked up at a yard sale or whatever try to get them on the water with what they have for the least amount of dough possible.

Telling someone they're wasting their time and money on their new pride and joy is the quickest way to lose them. If they get the bug they'll figure it out quick enough if they wants to race, many guys just want to go around in circles and have fun.

AMEN, Terry!...reminds me of how it was in the 70's and 80's!

 

[Timbo Whalen]

As you reduce nitro % the viscosity will go down and you’ll turn in the needle. Ron Logghe did some experimenting with FAI fuel back in the early 90’s when Angus petroleum had a fire and the Chinese nitro was pretty bad. We had to increase the compression ratio in order to get it to run and to get it to run consistent we when so high we had to loosen the plug to start even with 24V dynatron.

There's even more power to be had, John, in doing a whole new button config- bowl shape, volume, AND!.... squish band/angle...

Reducing the volume while optimizing the squish clearance for good propagation and velocity- usually, the squish clearance

will be more, rather than tight and less- but there's relativity going on in the whole scheme. One needs to consider not only the

flame velocity, but the dwell, as well.

I remember Jim Wilson used to try and get the 'center of the sun' as close to the bowl's spherical radius point of origin-

dropping the plug through machining trickery and pulling plug elements are a couple of schemes that come to mind.


John, I know exactly what you mean about decompressing with a 24v Dynatron!...lol!.... that scenario is right on the edge of a

hydrostatic state..... we even wadded a K&B rod, or two, before the Richardson Precision Machining pieces were available.


Since you brought up Logghe's Pro Power fuel, to this day, that was my all time favorite- especially the stuff with UCON LB-625

Tom was selling at the Prop Shop.

Thanks always, John-

tim