A new nitro engine coming soon (some say I am mad for doing this!)

[Steve White]

Ricky, it all makes sense. Where does that leave things in the overall performance continuum? Smaller props and wind 'em up tighter and tighter.

I'm a big NHRA fan, and know just a little about tuning the nitro cars and drag boats. They have advanced things to a very fine line as evidenced by the performance. This hobby has taken a similar path as one would expect - after all, we race the boats.

I may try one of these engines out for fun, as I am currently building 90 class only outriggers.

Pondering scavenging lately, and being an audio engineer I got to thinking how fast are things occurring in then little power plants. 24,000 RPM = 400 HZ, which means the engine is turning 400 revolutions per second at 24K. Things are happening pretty rapidly. The control line guys on methanol are turning upwards of 40K now I believe?

 

[LohringMiller]

Two strokes and four strokes are very different. A four stroke's valves are in the head so the more head area the better for breathing. This leads to engines with short strokes and big bores. A two stroke's ports are in the cylinder wall. To get the most wall area for a given displacement you need a long stroke. However, other factors than breathing tend to give engines with equal to slightly long stroke to bore ratios for best power. Piston speeds are a better measure than rpm. Our little engines run fairly low piston speeds compared to larger race engines. I think friction plays a bigger part as engines get smaller.

Lohring Miller

 

[Steve White]

Two strokes and four strokes are very different. A four stroke's valves are in the head so the more head area the better for breathing. This leads to engines with short strokes and big bores. A two stroke's ports are in the cylinder wall. To get the most wall area for a given displacement you need a long stroke. However, other factors than breathing tend to give engines with equal to slightly long stroke to bore ratios for best power. Piston speeds are a better measure than rpm. Our little engines run fairly low piston speeds compared to larger race engines. I think friction plays a bigger part as engines get smaller.

Lohring Miller

My post must not be crafted well Lohring. The meaning is that our model race boats are very highly tuned racing vehicles as are the NHRA cars.

The engineering and science involved in the engine design for our models is phenomenal.

"Piston speeds are a better measure than rpm " - very interesting.

 

[LohringMiller]

No worries. Everyone reads so much about automobile racing engines that they forget we run two strokes, a different beast.

Lohring Miller

 

[Steve White]

^^^ Yes, they are very different. The pipe plays a major role in the performance and operation - to a much greater extent for the 2 stroke.

 

[Ricky Neal]

Ricky, it all makes sense. Where does that leave things in the overall performance continuum? Smaller props and wind 'em up tighter and tighter.

I'm a big NHRA fan, and know just a little about tuning the nitro cars and drag boats. They have advanced things to a very fine line as evidenced by the performance. This hobby has taken a similar path as one would expect - after all, we race the boats.

I may try one of these engines out for fun, as I am currently building 90 class only outriggers.

Pondering scavenging lately, and being an audio engineer I got to thinking how fast are things occurring in then little power plants. 24,000 RPM = 400 HZ, which means the engine is turning 400 revolutions per second at 24K. Things are happening pretty rapidly. The control line guys on methanol are turning upwards of 40K now I believe?

With regard to the performance continuum, I think the engines produced will become more and more performance-focused based on market forces. The only people that will be buying engines will be the purists that want to run in specific classes of competition.

This already happens with the tethered hydroplanes that I run, it's the same for the tethered cars and the same for F3D pylon racing, and as you mentioned the F2A control line, speed models.

This is where the innovation is happening and where small-scale production is taking place. For example the MB40 engine for F3D or Profi speed engines for F2A. Fora have just released a new F2A engine.

This part of the market is smaller but is populated by people who know what they are doing and have a relentless pursuit for performance and I think that model boats will likely follow the same route.

The methanol-fueled, control line speed, F2A models you mentioned are now beyond 45K I believe. We use the same engines in a tethered hydroplane class. See the link below.



This is a video I took at the tethered hydroplane world champs in 2017. (calling them hydroplanes when they have aircraft engines and propellors is a bit of a stretch but that's how they are classified)

 

[Ricky Neal]

Two strokes and four strokes are very different. A four stroke's valves are in the head so the more head area the better for breathing. This leads to engines with short strokes and big bores. A two stroke's ports are in the cylinder wall. To get the most wall area for a given displacement you need a long stroke. However, other factors than breathing tend to give engines with equal to slightly long stroke to bore ratios for best power. Piston speeds are a better measure than rpm. Our little engines run fairly low piston speeds compared to larger race engines. I think friction plays a bigger part as engines get smaller.

Lohring Miller

With regard to 4 strokes and bore/stroke - one way to benefit from a small combustion chamber and still maintain enough flow past the valves for high power is to have many cylinders, like the old V12/V10 F1 engines.

 

[Wasted wages]

or,,, less cylinders and lots of booooosstt !!!!

 

[dwilfong]

Yes high nitro is all but dead RIP........
But some of use heathens will still try and dump all we can in a small eng.

 

[Steve White]

With regard to the performance continuum, I think the engines produced will become more and more performance-focused based on market forces. The only people that will be buying engines will be the purists that want to run in specific classes of competition.

This already happens with the tethered hydroplanes that I run, it's the same for the tethered cars and the same for F3D pylon racing, and as you mentioned the F2A control line, speed models.

This is where the innovation is happening and where small-scale production is taking place. For example the MB40 engine for F3D or Profi speed engines for F2A. Fora have just released a new F2A engine.

This part of the market is smaller but is populated by people who know what they are doing and have a relentless pursuit for performance and I think that model boats will likely follow the same route.

The methanol-fueled, control line speed, F2A models you mentioned are now beyond 45K I believe. We use the same engines in a tethered hydroplane class. See the link below.



This is a video I took at the tethered hydroplane world champs in 2017. (calling them hydroplanes when they have aircraft engines and propellors is a bit of a stretch but that's how they are classified)

Well they launch off of the water and run in ground effect with the water as the boundary layer.

 

[dwilfong]

Well they launch off of the water and run in ground effect with the water as the boundary layer.

But thy load the eng total different. Sick your hand out the window of a car at 80 mph then stick your hand in the water in a boat going 80 mph. You will under stand why there is no substitute for nitro. Then again you may not understand how nitro needs load to burn.

 

[Steve White]

.................................This is a video I took at the tethered hydroplane world champs in 2017. (calling them hydroplanes when they have aircraft engines and propellors is a bit of a stretch but that's how they are classified)

Well they launch off of the water and run in ground effect with the water as the boundary layer.

But thy load the eng total different. Sick your hand out the window of a car at 80 mph then stick your hand in the water in a boat going 80 mph. You will under stand why there is no substitute for nitro. Then again you may not understand how nitro needs load to burn.

My comment was with regard to the tether boats, with airplane propellers leaving the water completely when they enter resonance and still being classified as boats.

"No substitute for nitro" fact. "Then again you may not understand how nitro needs load to burn" Got the basic concept a while back. (watching a crew chief tune a blown fuel 5/8" stroked 354 Chrysler in a drag boat by counting the blue threads on the spark plugs)

I've actually gone 100+ on the water in the passenger seat of a blown gas lake boat and it wasn't fun at all - glad to have that one checked off the bucket list - ain't gonna put nothing in the water at that speed - ain't never gonna do that again.

I like your current pipe project.

 

[JRXHydros]

Hi All

I have been working on a project for a while now and didn't want to say anything until I had more of the fine detail completed and was closer to something that I could present to the community but as we are pretty much now finalised on the CAD drawings I wanted to share what we have.

We are building a new 3.5cc nitro engine to be used in RC boats as well as tethered hydro's and tethered cars. The need for this came from tethered models primarily but to make a venture like this viable I needed to expand the market to RC boats as well. This means there will be variants of this engine available for RC and tethered use with some differences, an obvious difference, for example, would be the tethered variant will have a venturi and the RC version will have a carb but there will be more subtle differences as well.

We are just finalising component productions costs and timelines then we will be able to start testing pre-production engines and I felt that this process would be something that the community would enjoy watching unfold and see the results of our labour.

I am new to this forum but I have been part of the modelling community for a long time and worked in it directly for a number of years as well. In general, I would consider myself a knowledgable person when it came to model engines but when I started to explore the possibilities of producing a new engine, designed completely from the ground up, I realised just how complex and difficult an undertaking like this really is.

I'm not too proud to admit that to make something like this competitive and even partially viable I needed to enlist some help. For this help, I turned to what many would consider being the best in absolute performance model engines, Profi engines.

Many probably do not know who Profi engines are but they are a Ukraine based model engine manufacturer, They mainly make engines for the extreme speed models like F2A (Control line speed) or F3D (Pylon racing) - Their F2A 2.5cc engines has some very interesting innovations, like doing away with the inner race of the main bearing and using the crankshaft as the inner race, this enabled a larger bore crankshaft and a more efficient bearing.

They also produce the Metkemeijer MB40 Pylon race engine, if you know these engines then you know why I am working with Profi on the development of this new 3.5cc engine, if you don't, then I suggest you do some searching on the internet for information, you won't be disappointed.

Here is a picture of our engine to whet some appetites...

View attachment 287583

As I said, this is a ground-up design of a new engine, we have incorporated a Zimmerman disk drive induction as we believe this is the best for overall performance. As we start testing I will share more information, pictures and videos.

Some of my friends accused me of being mad for financing the development and production of a new model engine to what they believe is an ever-shrinking market. The only way I can explain this is that while the overall numbers of nitro users may be shrinking, those that stay or indeed start with nitro models are serious about the hobby and are committed to performance and want to push the hobby forward. I'm the same and really love this hobby.

The issue is, engine manufacturers will focus on the biggest markets to survive, that's why Picco stopped making marine engines and also why there are so few options when it comes to marine nitro engines.

I decided to put my money where my mouth is and this is where I am at. (let's hope I don't lose too much money!)

Hopefully, the community will be as excited about a new engine option as I am to be bringing it to market but I am not naive, I know that we need to make this engine competitive to a be a commercially viable venture.

If we can make a success of this engine we will look at producing more engines for different classes but before we attempt that we need to make this a success first.

Sorry for the essay!

Ricky

Hello Ricky,Are you going to make glow plugs for your glow engine?

 

[Ricky Neal]

I've actually gone 100+ on the water in the passenger seat of a blown gas lake boat and it wasn't fun at all - glad to have that one checked off the bucket list - ain't gonna put nothing in the water at that speed - ain't never gonna do that again.

Braver man than me, you would catch me getting in one. They look scary

 

[Ricky Neal]

Hello Ricky,Are you going to make glow plugs for your glow engine?

Hi, No not likely. We will probably get some manufactured so they can be supplied with the engines though. I have worked with Cipola before and I liked the quality of the plugs they made for us.

 

[Niklas Edlund]

I dont think Cipolla makes any glowplugs nowadays. Think TCA took over that quite a few years ago (10+?)

https://www.tca-srl.it/tca-racing/en/

 

[Ricky Neal]

I dont think Cipolla makes any glowplugs nowadays. Think TCA took over that quite a few years ago (10+?)

https://www.tca-srl.it/tca-racing/en/

Thanks Niklas, I didn't know this. The last time I dealt with Cipola was back in 2002/2003 I think so It makes sense that things have changed since then

 

[David Bryant]

I have a brass chrome plated sleeve and a billet piston coming for my RCMK/Tiger King rear ex Nitro eng project.

I recently received a custom Anatoly billet piston, for CMB 27cc Alpha EVO. A thing of beauty

 

[Wasted wages]

How is that ring pin held in ?

 

[Steve White]

How is that ring pin held in ?

Venturing a guess, splined and pressed in.