Lockwood Hiller won't start.

[ozykev]

Hi everyone,
I had this crazy idea in my head to make a large Lockwood Hiller valve-less using LPG for fuel.
I am now up to the stage where I am trying to start it but it won't start. It will give a constant faint drone when controlling the right amount of gas but that is as far as it goes- it doesn't produce any thrust.

I have tried making different types of gas injectors eg.

1)these type of injectors was fitted at the inlet end of the expansion chamber spraying back toward the 'U' bend. They were made using about 5/16 o.d copper pipe & blocking off the end & then drilling 13x 1/8 holes in it. - This type didn't do anything but produce intense heat from exhaust and inlet.

2)the second injector I tried was 5/16 o.d pipe going in the expansion chamber with a 90 degree bend the spraying the gas directly into the centre of the chamber toward the 'U' bend. This way seemed to work but only a faint drone is produced. The engine just won't produce thrust. - I tried making the same type but with 3/8 o.d copper pipe.
o.d copper pipe.
The approx sizes are as follows: *Expansion chamber is about 500mm long. The dimensions given start at end where it joins to the 'U' bend then runs toward the opening of the inlet.- 125mm stepped up to 255mm then tapered down to 230mm then stepped down to 150mm which tapers down to about 140mm at the start of the inlet,
*the 'U' bend is 125mm right the way round.
*the exhaust tapers from 125mm up to 220mm and is 2340mm long from opening end to the 'u' bend.
going off these sizes i thought it would have went a little better than an quite drone.

Does anyone have any suggestions- any help appreciated.

Maybe I have just gone overboard and made a "White Elephant".- I guess it will make a good heater in winter.........

Thankyou
Kev

[Mike Everman]

hey Kev. Welcome. There was a thread here recently that said it all for another large lockwood that was having starting probs, but I can't find it. Within the last month, though not as big as this fella.
in short:
Leaf blower required.
Certainly some experimentation on fuel location.
Flare the intake opening.
You'll probably need two propane tanks to start this monster on gas, then be able to flip one tank to get liquid going in.
Got a good ignition system?

[metiz]

You'll probably need two propane tanks to start this monster on gas

Nah. Just hook up a single tank flipped upside down. Use a Rosscojector (when you cut off a piece of pipe with plyers, you're left with a squashed end on both pipes, that's a Rossco). open the resulting slit slightly and saw a V shape in the slit. place injector not a whole lot further then 50% in the intake and fire it up (again, if you do not have a decent ignition system, throw a sparkler in the cc. Works quite well for big engines)

*edit* updated drawing. other was wrong

[GRIM]

Hi Kev

This is a BIG engine 5"dia u bend, It will need lots of fuel, one bbq cylinder may not be sufficient, vapor or liquid,

Sparklers , if you can get them are very good , a leaf blower will almost certainly be needed,

Try what Metiz says , if that dont work for you ,
you might take a look at this , download/file.php?id=10047, these have worked very well for me, especially with linear engines ,

For this size engine I would go with something like 2"TO 3" diameter washers and 1/2" to 3/4"" bore tube, with a 0.5 TO 1MM mm gap between the washers , The idea is that the liquid gas can change into gaseous gas in the large dimeter tube and come out of the slit as high velocity vapor, these work best JUST INSIDE the cc , they dont work at all in the inlet ,
Do yourself a favor and weld some tags onto the tube to keep it centred,

Tie the mother down real good , and take care , be sure to video everything ,

[ozykev]

Hello again everyone,
First thankyou everyone who has given me feedback & tips on how to get my "monster"up & running- it is most appreciated.
I have made the changes suggested eg: made flared end for the intake, fitting a Rosscojector, tipping the bottle up-side down for liquid & using sparklers as ignition & using air compressor to give it extra air.
These changes certainly changed the note of the faint drone too a louder drone that is starting to make the tiny hairs on the back of my neck stand-up as she shakes the box trailer I have it mounted on.
She's getting very close but not quiet starting to produce substantial thrust.
I am currently expermenting with the location of the fuel delivery & the amount of liquid gas going in. Sometimes when I connect it to a 45Kg house LPG bottle the outside of the gas copper line freezes up almost instantly indicating the high draw of liquid going through- also at this time it is puts the sparkler out (maybe too much) so I will work on that one.
My next step will be to attempt the setup that GRIM suggested, I have attached a photo of the Rosscojector & the flared intake I made & fitted.
I will also catch it all on video for you guys to see.
Once again thankyou for you assistance, I'll keep-in-touch

Cheers
Kev

[Dang911]

First post in several years, woohoo. Now with a career at the Advanced Aero Combustor Lab at GE Aviation, I recommend a simple radial nozzle injector. Take a look at the attached picture. It runs my lockwood nice. Also you will want to find your engines injection sweetspot, BUT it should be somewhere in the middle of your intake to combustor transition frustum. If you are a good machinist, you can drill the holes at 15 degree angle forward toward the combustor for increased efficiency.

[metiz]

hey Ozykev,

Getting there I think you made the injector wrong but that was my mistake :S I uploaded the wrong picture but hey sounds like you are almost there. If you have the materials to play with, change the cuts in that injector to the updated pic in my first reply and cut them about twice as deep as you have now and try to keep them as narrow as possible. the idea is that the gasses smash into each other when they exit the nozzle providing some sort of atomizing. Worked just fine on the Dreadnought engine. Any chance you could upload a sound or video clip of you trying to start 'er up?

[loco]

sorry to hijack, but where did you get the U-pipe? I'm really struggling to find any locally...

[poelmanski]

hi,

i have made one my self, I used some what called in dutch ,las bochten, i think the translation is something like weld bends.
correct me if I'm wrong.

I can send you some photo's just send my a personal message.

greetings,

Rutger

[ozykev]

Hi Loco, yeah the U bend came from 2x 90 degree bends I welded together. I was just luck that the distance between centres that I needed was spot on for it to turn out as a clean U bend.

I have a video clip I would like to attach howeverI can't seem to find the link where I do this- does any one know the best way to do this??
It is now starting to pulse with the longer injector & the air blower of a Jumping Castle. I found the blower to be more effective than the air compressor as I think it deliveres a greater quantity of air.

[loco]

Probably best to upload it to youtube, then post a link to the video on this forum.

Where did you source the 90 degree bends? i've found some stainless ones from a marine fabrication company, but they are seriously expensive...

[ozykev]

I sourced the bends from an exhaust shop here in Oz. It costed about AU$130.

[Mike Everman]

Hi Loco, yeah the U bend came from 2x 90 degree bends I welded together. I was just luck that the distance between centres that I needed was spot on for it to turn out as a clean U bend.

I have a video clip I would like to attach howeverI can't seem to find the link where I do this- does any one know the best way to do this??
It is now starting to pulse with the longer injector & the air blower of a Jumping Castle. I found the blower to be more effective than the air compressor as I think it deliveres a greater quantity of air.

Look down to "upload attachment" tab, then browse to the file and press "Add the file", then submit. Movies must be under 2mb.
If it is a large file and you have MS Movie Maker, then you can compress it to under 2mb using "save movie file" to your hard drive.