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

[Steve White]

Crankcase volume is the ticket for aspiration. FI could work well in an aircraft application, for boats rear. Back in the day, I put an ST .40 rod in an OPS 40. If memory serves me correctly it was .150" shorter than the stock OPS rod. The performance increase was huge and across the entire power band.

 

[Terry Keeley]

Model engines have seriously lagged behind the designs of larger two strokes. That Profi design came from a collaboration with one of the world's best two stroke designers. Modern porting and transfer shapes combined with a modern tuned pipe lead to that engines domination of world pylon championships. Thay also started with a rear rotary valve, but now run a front rotary valve. The front bearing design allows a large intake with lower friction than rear rotary designs. See below as well as the core patterns Terry posted above.

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Lohring Miller

I was wondering if Fritz had a hand in this, now I see he had both!

Imagine if we had a boat motor with porting like that...

 

[Buckshot]

I also had to consider the new nitro fuel regulations and limitations in Europe, I would expect that in the near future most competitive running will have a mandate for lower fuel percentages so as to not alienate competition from Europe. with this in mind, it may well bring the differences much closer

It looks like this year was going to be the last year I would have been able to use high nitro when racing in Europe. Since the 2021 WC in Italy has been canceled I will now have to start testing w/15-16% nitro to be ready for Poland 2022. Not looking forward to it but it is inevitable.

 

[Ricky Neal]

Apart from an aspiring engine producer, I am also an obscure and rare engine addict, particularly high-performance ones. As I am working with Profi on the development of this engine I thought I would show you all one of their engines just because I think it looks beautiful

Below is a Profi .21 control line engine, machine from bar stock. Notice the AAC liner and the way the crank has been modified to aid with the balance

 

[Ricky Neal]

It looks like this year was going to be the last year I would have been able to use high nitro when racing in Europe. Since the 2021 WC in Italy has been canceled I will now have to start testing w/15-16% nitro to be ready for Poland 2022. Not looking forward to it but it is inevitable.

Change is a pain in the ass but in this case, it will likely help with the development of our engine so I have to look at that as an advantage.

 

[RaceMechaniX]

Keep the pictures coming Ricky.

 

[johnmills]

I like the way the head button comes off.

 

[Buckshot]

Absolutely Stunning!

Apart from an aspiring engine producer, I am also an obscure and rare engine addict, particularly high-performance ones. As I am working with Profi on the development of this engine I thought I would show you all one of their engines just because I think it looks beautiful

Below is a Profi .21 control line engine, machine from bar stock. Notice the AAC liner and the way the crank has been modified to aid with the balance

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[Charles Perdue]

Apart from an aspiring engine producer, I am also an obscure and rare engine addict, particularly high-performance ones. As I am working with Profi on the development of this engine I thought I would show you all one of their engines just because I think it looks beautiful

Below is a Profi .21 control line engine, machine from bar stock. Notice the AAC liner and the way the crank has been modified to aid with the balance

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Beautiful engineering and workmanship!!!!!!

Charles

 

[Wasted wages]

Love the fact that the cylinder comes off of the crankcase... so much potential to try different porting variations..

any more details about the way the crank and bearings are setup in the crankcase... is the front bearing a roller or sleeve bushing ?
( spinner end )

 

[dwilfong]

Here is one I have IR .21 boat eng.




The jug has no sleeve it is ceramic coated.
The case is STUFFED as much as you can with ports cast in to it.
The drum valve has HUGE times area and is punched from on piece to make as light as possible.
Has a water cooled head also.
It was a good running eng would rev to the moon on a small prop but it could not flow enough fuel when running 65% nitro.
This kind of high velocity port is great if run no or low nitro to get every last bit of power from the eng.
Big ports is the only thing that will FLOW high NITRO.
You can make all the fancy ports you want but it will not make up for NITRO.
All I am saying is it would be a shame to design a new eng from scratch and not have the ability to run high nitro.
The rest of the world is go the rout of low or no nitro but here in the USA NITRO is KING.............................................

 

[Ricky Neal]

Here is one I have IR .21 boat eng.
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The jug has no sleeve it is ceramic coated.
The case is STUFFED as much as you can with ports cast in to it.
The drum valve has HUGE times area and is punched from on piece to make as light as possible.
Has a water cooled head also.
It was a good running eng would rev to the moon on a small prop but it could not flow enough fuel when running 65% nitro.
This kind of high velocity port is great if run no or low nitro to get every last bit of power from the eng.
Big ports is the only thing that will FLOW high NITRO.
You can make all the fancy ports you want but it will not make up for NITRO.
All I am saying is it would be a shame to design a new eng from scratch and not have the ability to run high nitro.
The rest of the world is go the rout of low or no nitro but here in the USA NITRO is KING.............................................

Thats a super interesting engine, i need to find one for my collection now lol

 

[Ricky Neal]

Love the fact that the cylinder comes off of the crankcase... so much potential to try different porting variations..

any more details about the way the crank and bearings are setup in the crankcase... is the front bearing a roller or sleeve bushing ?
( spinner end )

This engine has traditional bearing at both ends. Their small F2A engines use the crankshaft as the inner race so they can run a larger bore down the crankshaft. Pretty clever design but not easy to rebuild

 

[AlexValishev]

This engine has traditional bearing at both ends. Their small F2A engines use the crankshaft as the inner race so they can run a larger bore down the crankshaft. Pretty clever design but not easy to rebuild

Hey Ricky,

An F2A flyer here. The story behind the integral main bearing is actually rather silly: high quality small size bearings were hard/impossible to find in the Soviet Union, hence the engine makers developed this technology. You are correct that the assembly and proper alignment of such a unit is terribly difficult. Whether the integral race bearing offers any advantage in an F2A engine is arguable. At least my best F2A Profi that holds the unofficial World record at 308.4 kph is equipped with a standard slide-in main bearing.

 

[Ricky Neal]

Hey Ricky,

An F2A flyer here. The story behind the integral main bearing is actually rather silly: high quality small size bearings were hard/impossible to find in the Soviet Union, hence the engine makers developed this technology. You are correct that the assembly and proper alignment of such a unit is terribly difficult. Whether the integral race bearing offers any advantage in an F2A engine is arguable. At least my best F2A Profi that holds the unofficial World record at 308.4 kph is equipped with a standard slide-in main bearing.

Thanks for the clarification Alex. I have also had slightly better luck with the junior profi than i have with the highest spec Profi but I use them in tethered hydroplanes.

I have never run an F2A model myself but years ago i worked at Ripmax for about 5 years with Pete Halman and Ken Morrisey and have spent far too much time at events with people who do use them.

A lot of the people running tethered cars and F2A are also people that run tethered hydros. Its a small group

 

[Steve White]

Hey Ricky,

An F2A flyer here. The story behind the integral main bearing is actually rather silly: high quality small size bearings were hard/impossible to find in the Soviet Union, hence the engine makers developed this technology. You are correct that the assembly and proper alignment of such a unit is terribly difficult. Whether the integral race bearing offers any advantage in an F2A engine is arguable. At least my best F2A Profi that holds the unofficial World record at 308.4 kph is equipped with a standard slide-in main bearing.

Holy moly!!!!

Way back in the day a buddy of mine flew a little hobby control line aircraft. So, we both built Ringmasters - his had a FOX 36X and mine had a K&B Torpedo 40 rear intake side port with ring. Of course it was full tilt the first flight for me. Somehow, I managed to get through the first tank of fuel. Second tank, never really catching up to the airplane in flight, I unsuccessfully attempted a wing-over - it exploded when it hit the ground. I can't imagine the learning curve to fly one of those single wing monsters.

 

[Wasted wages]

That's insane!

Man....when that thing jumps on the
pipe...

 

[AlexValishev]

Thanks for the clarification Alex. I have also had slightly better luck with the junior profi than i have with the highest spec Profi but I use them in tethered hydroplanes.

I have never run an F2A model myself but years ago i worked at Ripmax for about 5 years with Pete Halman and Ken Morrisey and have spent far too much time at events with people who do use them.

A lot of the people running tethered cars and F2A are also people that run tethered hydros. Its a small group

It's a small world indeed - I've been using Peter's Irvine Specials for a very long time and still have a number of them. Strangely enough I only saw a tethered hydroplane once when the F2A World Champs were in Bulgaria where the two circles are next to each other.

 

[AlexValishev]

That's insane!

Man....when that thing jumps on the
pipe...

Yes! It's a really cool feeling when the model accelerates from 100 to 300 kph in less than one lap. And the best part is that you have to hold on to it

 

[Tony Ball]

Hi Ricky
Will there be an option for reverse rotation for gearbox use in endurance boats in Europe.