Looking forward to seeing Raf's UB with the BF300!

The clocking is correct.
Starter fuel line at 12 o'clock, which brings the MPX plug close to 6 o'clock.
Sorry if I confused you with my explanations. I actually updated the manual on this matter to make it less confusing.

Great!
You'll enjoy this engine...

You'll need good eyes...

Hi Oli, What is the specification and the performance?

Have a look here:
http://www.ultimate-jets.net/collect...ducts/b-300-uf

I installed the B300F in my ultra's bypass. There is an extra mounting strap that helps keeps this beast at bay!

Hi Ravill.
A couple of observations here:

You absolutely need to test this configuration before the flight. The picture I see here raises two concerns to me:

1. The BVM brackets are very thin. I am not sure that 1 longitudinal bracket would be enough to hold the engine. You might need to put on a second one.
2. The bypass configuration as I see it might create some problems: the engine seems quite far back in the pipe and might generate an enormous amount of vacuum. This together with the thin FOD mesh and relatively small intake area might starve the compressor and create engine stall conditions.

Please check max EGT, max RPM and pump power at full thrust and write it down.
Also record idle EGT, and RPM and check RPM fluctuation.

Please test this in your plane extensively and call me on Skype when you are done.
I might be too pessimistic and it might work as is. But in any case please call me before the maiden with the above data.

P.S: your clocking is 100% correct, providing the bypass opening is facing up in the plane...

Hi Oli,

Thanks for the heads up as I was also thinking it was a bit "tight" looking in the bypass. But hey, describing the fit as "tight" is as far as my technical knowledge extends!

I have installed all the valves, pump, ecu last night. I was going to fire it up tonight after testing the fuel system by running it full throttle through the fuel pump through the ECU as a ground fuel system test.

What will I see with the temps and rpm? Higher temps and an idle that will not be stable?

And if this is the case, I will need BVM to make me a new bypass?

Fortunately, and unfortunately, BV's jets are designed intrinsically to run with a bypass. I think it would be too much of a hassle to try to make my ultra bandit run without one.

There is a gentleman, LAjetguy, that is running a P300 in his ultrabandit, apparently successfully. Would you happen to compare the dimensions of the B300F to the P300?

I will pm him as well.

This gentleman, Darryl Tarr, also in Dubai, PM'd regarding the 12 o'clock being the actual writing of B300F? And if you look at the video of ziggy's test here:

It is seen that his 12 O'clock is with the multiplex connector.

So confusing!

But if you say this is where the 12 O'clock is, I'll live with that!

Sorry for all the back and forth, I care alot about my model and my new engine and want to do it right Oli! I appreciate your help!

Raf

B300F specs:

Diameter: 133 mm
Length: 390mm

P300RX specs:

Outer diameter 132 mm
Length 365 mm

The B300F is 1 mm thicker and 2.5 cm longer than the P300RX.

I just pm'd LA Jetguy, and I'll see what he tells me regarding his perfomance of his 300N engine vs which ever bypass he is using.

Ravill.. I just replied to your PM. Im using the stock P200 bypass and straps but I had to curve a little to get the starter motor in. Also try to use 8mm (3/16) tubing all the way to the pump and then from pump 6mm to a few inches then step down to 4mm and then to turbine..

I currently have mine set ay 95K rpm which is 250N... its plenty enough and on a 6.2 L tank will get a good 7 min with 30% fuel left in saddle tanks.

Thanks for the quick reply LA Jetguy!

I actually went through GREAT pains to make sure my Ultra B fuel system has fantastic flow. I have JMP fittings through out and the biggest Tygon I could get my hands on!

I used a bigger header tank that gave me an additional 500cc's of fuel.

The behotec guys have a slightly different way of plumbing things up distal to the pump as the valves live outside the engine and thanks for the heads up.

I suppose, I'm just going to have to see how the whole jet holds up at full throttle on the ground.

Excellent... so it seems you are on the right track...

Let us know how you like it... will you be on full power 300N++ or will start lower and then increase power??

Can you say "Cape Canaveral Take off"?!

I don't want high top speed, I enjoy the transitions in speed. It was plenty fast with the P200, but power from take off is what I want.

Hi Oli (and Raf)

Pardon the interruption, but I have a question. I have often wondered about the dynamics of the engine and the bypass flow.

I thought that if you ended up with a high vacuum behind the turbine, this will manifest itself with a low EGT, and an associated lack of thrust (as the turbine is not "working"as hard). Since I have no idea what I am talking about, can you elaborate on what exactly is involved with the bypass and the interaction with the engine?

Thanks in advance

Matt,

I have no idea how to answer that. Maybe Oli will have more info?!

So, I started the beast. She started right up, she sounded and felt ready to move! I didn't get a chance to give it full throttle runs, as I didn't want to piss off the neighbors. However, the throttle response was fantastic.

You can see below, that I didn't have the pipe attached to the bypass, so it wasn't really a good test of the bypass system. I'm hoping to do that after fixing the problem I found testing the fuel system.



Oli, on your email, you said you thought the full throttle pump voltage was around 11v. As I wanted to make sure that my fuel system was up to the job for this engine, in my system, I could not get the pump to go over 6-6.5V. This is the screen that would pop up on the GSU when I tried to go over 6-6.5V:




Then press the check button on the GSU:




And nothing would happen. The pump wouldn't run and couldn't go back and reduce the voltage. I had to reboot the power to the turbine to start again.

I was able to run the system at 6V.

Max(ie full throttle) pump voltage for the P200 was 5V. I figured since 300N is 50% more thrust, the 300N engine would need 50% more pump voltage. That would mean the new, higher, full throttle pump voltage would be 7.5V.

As in my previous post, I was not able to test out the system at this voltage. I had to settle for 6V. With the understanding that when I was able to give my engine full throttle, I would note the pump voltage and then come back and test the integrity of my system.

The problem I ran into, testing my fuel system at 6v, is about 2 minutes in, I thought I was seeing bubbles coming out of the center nipple out of my large CAT air trap.



And indeed, there were bubbles.



Not acceptable.

Either

A: The system is cavitating (there was NO air in the CAT)

B: This new center fuel tubing I placed is leaking and allowing air to be sucked in. I must admit that I'm not to happy about the way I placed my safety wire. I will redo that and revaluate.

An air bubble in this line will likely cause a flameout, is something that can never be tolerated and immediately grounds an airplane.

I will find the source of the bubble before continuing.

Oli, as you wanted to know the idle values, I was able to get them, BEFORE putting on my pipe, and hence having the complete and assembled bypass, for comparison.

They were as follows:

Idle RPM: 34,700-35,200

Idle pump voltage: 0.8 V

Idle Temp: 533-538 degrees Celcius.

These all seemed reasonable to me and will give me a good baseline for comparison.

Hi Ravill. This is cavitation.
Your idle values are OK, just a bit of fluctuation on RPM. You might want to increase min RPM by 1000.
You cannot compare the pump value between Jetcat and Behotec as they use completely different gearing/ motor and thus give a totally different flow value.
The B-300F will run at full thrust around 50 to 55 W on the pump.
Testing at 60 W seems reasonable to me as you want a bit of buffer from cavitation.

How smooth was your start in the bypass with the engine clocked as I told you?

The vacuum would migrate to the front of the engine and starve the compressor. This will create a drop of pressure in the compression chamber that will get out of its sustainability domain. In other word, the engine will flame out. The combustion chamber is only able to sustain the flame within a certain range of air pressures and velocity.
The bypass is ducting vacuum from the back of the engine to the front. if it is too loose and the venturi effect is set too high, the phenomenon described above will occur.
Having a very tight bypass is actually good on that respect.
Regarding venturi effect, if the engine is placed back into the thrust tube, the venturi effect will increase. If the engine is placed forward, the venturi effect will decrease.

Full throttle is to be checked in terms of pump power. Here about 50 to 55 W. That is because different batteries/ cable combo will give different current to the pump. The power is voltage regulated.
What I was meaning is that in the worst case senario, max power would not go beyond 11 V. That would be in case of a battery/ battery lead combo that cannot give more than 5 amps continuous ( typically, puffed battery or dry soldering on the powwer plug ).

The test menu was designed to work with a fully functional battery, and would return an error with pump power over about 70W. This is to protect the pump from over power/ over heating during test sessions.

Yup, cavitation has reared it's ugly head again.

I ended up disassembling my entire fuel system to try to isolate which tank and/or pick up was causing the cavitation and all three tanks hooked up individually all 'caused cavitation.

Also, in my possession were two brand new JMP accumulators that I tried out as well and they had more cavitation than that CAT, just like my previous tests a few years ago.

This makes me believe that the CAT is just not quite up to the job of feeding this beast. Even with my tanks (all individually tested) at a much higher level with the CAT (to help with gravity feed) at 50W, cavitation was occurring.

Before I even try to go further with this engine, this cavitation needs to be figured out. I will completely rebuild my fuel system and will buy that new Large 450 cc CAT.

And Oli, the engine started silky smooth in that orientation. Also, the fuel pump doesn't even get warm after repeated tests! I'll post some pics with my infrared thermometer before and after for some real numbers.

Rafl...

Give BV's Hi flow fuel system a try.. I noticed the same thing when using the 6MM system with my P300 and then when I switched over to the the Hi Flow (8mm) the problem was solved... You got to make the "pickup line" and "vent line" in each tank 8MM with huge brass clunk and use 8mm festo tee's.. the UAT is also 8mm...

Using the old 6mm lines from your P200 is not sufficient for this beast...

good luck..

David

You know David, I was just on BV's website and JUST saw that he has a whole new system for the Ultra B! All I saw before was his new bigger UAT.

My Ultra B has had more fuel combinations (UAT, JMP, CAT's) different clunks, pickups etc...Some even custom made by me and I've never been satisfied with the fuel delivery performance.

It has been my opinion that the fuel system was just barely able to supply the P200. Any "special need" situation would cause cavitation and hence a flame out.

I've had more "Low RPM" flame outs in this Ultra B than all of my jet flying career combined. I've gotten lucky every time, even on short fields.

BV's new system isn't cheap at $600, but I was going to spend $450-$500 with the bigger CAT, pleated clunk and bigger fittings. Yeah, I hate building those BV tanks, but they are the best in the business.

Time to give my favorite person, Patty Generali, another call! LOL!

Raf... They have a special conversation for existing BV tanks so you don't need to change your saddle tanks.. the only tank you got to change is the center tank and the aluminum pieces in the saddle tanks... When you talk to Patty ask for the "special Conversation of existing" like for mine...

Call me to discuss if you need too.. PM me..

Rav the CAT-U has run AMT Titans (circa 392N thrust) without any issues, extensively tested by NASA and Boeing on the X-48 project so your B300 will be well within its limits just as long as the feeds are all big bore too.

marcs