Holset HX50 Supermoto Jetbike

[BFTO]

Can be some problems with cavitation with one prefilter and splitting to two pumps, depends on what size you use on the lines/filter.

Filter to the afterburner i would say is overkill.

[slittlewing]

It should be 15mm OD Tubing from the tank to splitter (Then 15mm to each pump), which is pretty huge!

So just wondering what the point of the post filters would be in this case (surely the pumps don't output any debris... unless they fail dramatically)!

Cheers

Scott

[slittlewing]

Been working hard for a few weeks on CAD, doing all heatshields, bracketry etc and going through an iterative process of plotting the designs (at exact scale) on paper and checking them on the bike, then modding if required.

Got everything finished finally and last week sent off 50+ files to be laser cut, which should arrive next week!

Today I pulled the engine out, removed swingarm and forks and spent many hours grinding back previous welds etc ready for the next phase of welding.

My combustor has got quite a lot of surface rust since running it and parking it up, presumably all surface oil etc would have burnt off not sure whether to sandblast it before painting or not!?



Also saw this interesting bike on the web, an old turbine bike with Garrett GTP30

[racket]

Yeh , that bike was made back in the 1990s , the single shaft engine meant it needed a gearbox and wasn't the easiest bike to ride, it was probably the first turbine bike that actually worked , it preceded my bike by a couple of years , though he had the luxury of a ready made APU engine, I was still developing my TV84 turbo based engine ............theres video of him riding it as well

[Johansson]

[slittlewing]

So I thought I best update this thread after a year 

I have been working on the bike sporadically since spring, after busy winter at work. It's one of those where you can't see much visual progress given the hours that have gone in!

-I have had two batches of laser cutting done (some items from the first batch didn't fit). 
-The heatshielding is finally completed. There is very minimal clearance to fuel tank.. will have to see how it goes.
-All ancillaries (Battery, pumps, filter, radiator, fuel filters post pumps) are mounted. 
-I made a "split cowling" for the oil radiator which goes across the downtube, complete with two 4.5A 12v PC fans that turned out pretty good.
-I have added a drilling to the compressor housing to impinge on the blades for starting with scuba tank (fingers crossed I did it correctly!)
-The last top cap got distorted (from heat) during the propane running which melted the danfoss kero injector. I made a new stainless 5mm top cap, and changed the propane injector.
I know that its "frowned upon" to use axial propane injection, but the radial injection just blowtorched the end of my combustor. So I have had a new propane injector machined that has one axial hole (2.5mm dia) pointing towards the spark plug, and 3 holes at 45 degree angle that point directly through the cone path of the kerosene. No holes radially.
-I plan to try starting the engine on kerosene rather than propane, using the scuba tank to get to ~1bar P2, and instead of a spark plug to use a glow plug. I have purchased one that fits in my existing M14 spark plug boss, but it has an exposed coil. Apart from the risk of this breaking and going through the turbo, the other option of a "hot spark" route seems like alot of extra hassle, cost and weight. 

Next step is dry fitting all the fuel and oil lines (ordered AN from ebay, ludicrously expensive but wanted to do it properly!)

Images to follow..

Cheers,

Scott

[slittlewing]

--

[slittlewing]

Another small update.. pictures of the new flame tube, propane injector and impingement tube. I angled the impingement pipe to try and hit the compressor wheel at the largest diameter possible, thinking this would give the most “leverage” to turn the compressor wheel. It spins to a low speed with a 7 bar airline blowgun, although it also spins faster with the same airgun just pointed straight into the front of the turbo  
Hopefully it’ll be better with 200bar behind it?

[slittlewing]

Not the healthiest but... if you have to spray when it’s 6 degC, might aswell do it inside the garage with a fan heater haha 

[slittlewing]

Tonight I finished painting the oil tank. You can see the 16mm feed port (from turbo at diagonal), filler/breather also at diagonal, 8AN drain port and suction line to connect to pump.

Previously I used some eBay blue “high temperature gasket paper” to seal the top cap. With the blowtorching of the cap from radial propane injection, this got overheated. It still sealed but looked terrible when I removed the cap. I have therefore instead had a huge copper “crush washer” laser cut to try as a seal with more temperature resistance.

Cheers

Scott

[slittlewing]

Job for the weekend... to dry fit the fuel and oil lines after refitting engine to chassis.
All the AN fittings and hose arrived (mostly Chinese ebay) along with two new fuel pumps. One is a Sytec 044 that should be capable of 10 bar for the main combustor. One is a cheaper 380lph 5 bar pump for the afterburner which is much more free flowing and will therefore need less pressure. The Marelli pump I used previously is consigned to uselessness after just one hours use!

[slittlewing]

Had a great day today and finally feel like all the little bits of work and planning have come together! The dry hose runs went well, all that’s left is the fuel tank to pumps (silver soldered 15mm hardline), fuel filters to combustor and AB, and one oil feed for turbo (waiting for m14 banjo).
The fuel filters are tucked at the back of the engine. There are NPT bosses on the fuel lines post filters and on the oil line pre turbo for pressures and oil temp (for Arduino control)
The oil pump is tucked in front of the engine a few mm clearance from the combustor.

I think I am feeling confident enough now to send the frame for powder coat in a couple of weeks!

Cheers

Scott

[slittlewing]

A brief update.. the chassis is now powder coated and reassembled. The bike is now starting to look more like a finished product! I have silver soldered the tank to pumps fuel line too. I also had to rebuild the forks with new seals whilst the chassis was away because they were leaking.

The heatshields I have coated in 3M gold foil film to try and reflect the heat from the tailpipe. Will see if it stands up to it or not! 










Next job is wiring and arduino programming, which will be a new one for me! Thankfully I managed to time it as an indoor job in the coldest months 

Cheers

Scott

[slittlewing]

A little update - I have managed to make good progress with the arduino based ECU and dash in the last week or so. 

I have it working based on simulated pressure sensor inputs (matching the voltage response of the pressure sensors I bought) and thermocouples for oil and TOT. The program performs a check that all sensors are close to zero before the dash comes up. It also kills fuel pressure if oil pressure drops below boost pressure.
There are 4 PI controllers for fuel pressure, afterburner pressure, oil pressure and oil temp via the radiator fans.
the ecu has an auto start sequence (pre heat glow plug, wait for boost rise, wait for TOT rise To confirm running) and a cool down sequence (keeps oil circulating and aims for 25 deg oil temp after shutdown).
Two other buttons that will be on handlebar do afterburn or fogging.
A variable potentiometer (E bike twist throttle) gives throttle demand.

A couple of pictures:



Cheers,

Scott

[turboron]

Scott, very impressive ECU work. Can you publish the Arduino code?

Thanks, Ron