Starting problems (Lockwood)

[JetSet]

Hey.

Firstly I am going to say sorry for yet another one of these posts, but I have read up and cant find any problems that match mine. I am almost certain that it is a fueling issue, however, the tank is full and on its side, which is confusing me.

The fuel is delivered through a copper pipe in the intake, with holes in radially about 1 inch into the combustion chamber.

When the tank is on its side the copper pipe and regulator dont take long to freeze. It doesnt seem to want to go on vapour.

The best I can achieve is a rumbling sound, and occasionally a pop or two. (with liquid and vapour)

I have attached a video of it, but the whining sound of the leaf blower drowns out the deep rumbling which is strange seeing as this wasnt the case from where I was! If you listen carefully you may be able to make it out. There were a few times when I thought it was nearly there, but a bit quiet.

If this is a fuel problem, how could I best solve it? It didnt even work using liquid (i guess it froze?). I have seen people with larger engines using vapour, and mine didnt start. The copper pipe (8mm) is freezing with liquid, so I could wrap that around the engine, however the regulator and hose will still have the same problem.

Unless it could be something else?

Thank you for your time. I hope you can help.
JS.

[Mike Spike]

try a different angel of the leaf blower and/or having it closer to the intake.

[JetSet]

I did try different positions, but the most I could manage was a 'medium loud' rumble.

[mk]

I cannot see you trying different fuel flow settings, i.e. altering the fuel valve's degree of being open.

Furthermore, there are no flames appearing at any port. Even if you would get ignitions once in a while, some flame should at least come out of the exhaust port.

So, are you sure actually liquid propane is getting delivered into the duct continously?
E.g. did you smell unburned propane? Or is there just a very small flame appearing at the injector tip in the combustion chamber?

In either case you would deliver too less fuel.
Thus I hope you already did get rid of the pressure regulator put to the propane bottle and any internal flow restrictors. Then a start-up on vapour must be possible.
Additionally, how many holes of which size are you using for your injector? Once, with regard to the M-SP 14c Hiller-Lockwood-shaped pulse-jet, I found the reactions on such a simple radial injector somwhat disappointing. The fuel-rail - also called (perpendicular) swizzle-stick - injectors did perform much metter though, as far as getting the duct up running decenty (at first).

Finally, I would try the following:

(a) Fix your sarting-air source in some similar position, as demonstrated in the video, and alter the fuel flow.

(b) Get a compressor and alter fuel flow, air-volume and injection angle. Do not be afraid of sticking the air pistol into the inlet duct. This will give you some "choke effect", which I experienced, makes starting somewhat easier.

Either case of the above might be tried with having the main bottle valve as single throttling device in line. A ball valve might be used for immediate shut-off reasons only. At lest for now.

[JetSet]

Thanks for the reply.

The pressure regulator (37bar) is in place, I will get a replacement for that (I have seen just a threaded hose connection somewhere (a regulator without the regulating bit!) I cant remember what it is called but will have a look for one. With regards to a flow restrictor, I am not sure how I would go about removing this, and would probably be best if I didnt seeing as it is a rented tank.

I noticed the lack of flames too. After I ceated a bunch more holes in the fuel injector they started coming out when the leaf blower was not blowing, but as soon as that started all sign of the flames disapeared. If it wasnt for the rumbling I wouldnt have known it was still alight.

We did try changing the fuel flow, starting with little and working up. It is not seen in the video as the cameraman was also watching it, so the majority of film is of his feet.

I took the injector out of the engine and saw what it was like when lit outside. There was no noticeable increase in flame size when the bottle was turned upside down, but the copper did freeze up quickly.

The injector has about 10 1.5mm holes in, and a number of other holes (i cant remember size... mainly slots).

I will go hunting for a regulator replacement and try again tomorrow.
Thanks for your help.

[mk]

Well, I would not be comfotable with the idea drilling around at the propane bottle. However, I've heard that in Northern America there are used some restrictors just downstream the main valve. It was said that they could be drilled out of the way easily. Okay, that supply system "over there" seems somewhat different to Europe.

What the above looks like in the UK, I do not know. Maybe ask Nick Ibbitson, or Graham C. Williams, or Steve Wallington though. In Germany, I have never seen any further restrictors that were put in place additionally to a pressure regulator. Of course, the bottle outlet "straw" only is something like 4 mm in ID, which is some kind of restriction, too, but by no way as much as an extra restrictor would be up to.

Are you sure it was a 37 bar regulator?
I know of the small mbar ones. Maybe there are some larger ones available allowing up to or something over 1 bar, but I doubt there arwe any doing so for much more.

I for one would suggest now:

(a) Leave the bottle as it is. Or try contacting one of the above people.

(b.1)* If the pressure regulator can be taken appart - older designs used screws, newer ones are pressed together - do so and watch how it works. Then put out the essential part - most probably a small seesaw acting on a small hole - and drill all ports and holes to the size of your bottle outlet straw ID or somewhat larger.

(b.2)* Build yourself a bottle-hose adapter, so that the pressure regulator is entirely out of the line. An old pressure regulator might be used to get the threads and nuts.

(c)* Rebuild your injector. You may want to use holes only, so that the area can be controlled easily. Start with some 6 x 1.5 mm holes or so. At least, keep the sum beyond the fuel line's cross-sectional area or do not exceed it.
Building several exchange-able injectors could help you, too.
The easiest would be a "fuel probe design", consisting of some 1...3 mm ID tubing sizes, which spray just dowstream the duct. You might want to take care of exact in-line parallel center line placment. Search for this term. The idea was provided once by M. A rather crude - but in some ways working - adaption is the "Rosscojector".

(d) Always check, that the spark unit is working properly. Adjust the spark plug's sparking distance to some 2...3 mm or so.


*) Make sure you do not have any leaks at the tubing joints!


Some links:
- "Berry's" Hiller-Lockwood
- "Grado's" Hiller-Lockwood propane vapour injector


EDIT: Spelling.

[El-Kablooey]

Lose the regulator! This has been discussed a few hundred times here. I doubt you'll ever get it to start with a regulator in place. You can buy adapters for propane tanks without the regulator. I don't know where you are, but here there are stores called Tractor Supply Co. They have them for around $5.00.

[JetSet]

Thanks. I have known about the regulator issues, but couldnt find a fitting without, so didnt really have a choice... however... today I found on fited to a hose to go to a bottle changeover system - I cut off the tube and connected up the fitting (only 6.3mm) to my hose (8mm). The improvement is spectacular!

I didnt get a video, nor did I get it to start, but was SOOOO close!!

I can now manage to get it to pop and bang, occasionally rattle on the mounts. It has been at what I believe is operating sound, however it wont run without the forced air (leaf blower).

It was hard trying to determine how much fuel was too much, but it made a lot more noise once it was warm.

One noticeable noise was when it started to go 'fwwhhum fwwhuum fwwhuum' (starting deeper then getting higher during each beat, like 'whhhuuuuUUUmm' about once a second, maybe slightly faster. What was this about? Is it close to what I need?

I am almost certain it was about to start, it was rattling windows about 150 yards away, and I could feel it.

Due to the heat and flames I attached the leafblower to some drainpipe, so I'm didnt have much control over the airflow, I did try the full range of throttle though, but not quite there. I have an elbo joint for the leaf blower now that I will try tomorrow hopefully it will give me more control as I will be closer to it.

I do not have access to compressed air at the moment. Do you think this is necessary?

Thanks for the help guys, really appreciate it!
What do you think is the next step? Should I keep trying more of the same, or do you have any other suggestions?

Thanks again.
JS.

[Dang911]

You are almost there!!!.... I'm getting into this a little late, but I had your problem with my first lockwood.....

First thing you need, FUEL FUEL FUEL... One you can get big flames shooting out of the front with no forced air, you know you are giving it a good amount of propane.

That wining noise in the video is only 1/100 of how loud it gets when it catches.... From the sound of it your fuel nozzle is not correctly adjusted. If you have a radial fuel injector into the intake, it needs to be anywhere from the spot where when intake meets the expansion cone to the combustion chamber, to 2 inches down into the intake tube. It is also important the injector be centered radialy! As you move the injector in that range, you should notice large performance jumps. That was the factor retarding my engine from starting. And once I had it running further tweaking of the injector position gave me super easy starting!!!!

Your leaf blower looks good, maybe back it out a bit so it is like 8-10 inches away and crank that sucker up. I start my engine with my leaf blower on full blast. If the blower is too close to the intake when it is getting ready to start it will start and stop start and stop because the forced air messes with the timing of the engine. You will know when your engine is started because the leaf blower will blow back almost out of your hands!! Good luck....

[El-Kablooey]

It sounds like you need to give it a little more fuel, and keep playing with the air. It can be difficult starting your first engine. I know I had a hard time with my first, but after that first start it becomes really easy. I didn't have much luck with a leafblower, but with my compressor it started right up. Lots of other people use leafblowers though, I just found it difficult to control, and the noise from the blower was annoying. If you start getting flames from the tailpipe, turn off the fuel, but keep blowing air, then pop the valve back open quickly.

Listen for it to sound like a foghorn. Ususally pops and machinegun sounds mean you need a little more fuel.

Good luck! I'm sure you'll have it running in no time.

[JetSet]

Thanks!

I am almost certain that there is enough fuel available now, when I had it cranked right up and the leafblower on full it was just a big scary flamethrower (looked like it needed more air!). Turning it down to about half way gave me some nice little pops. To spare some other details, I singed some hair too

I have just put the engine to bed and noticed that the fuel line was a couple of inches into the CC, further than I realised. I think I will re-make that tomorrow and experiment like you say, but it obviously wasn't in the correct place, so looks like you (hopefully!) may be right!

The leaf blower is ex-council, so nice and powerful, ebay quality, £14.10 - bargain! (altho i was robbed with P&P, haha).

I will take all of your advise and have another go tomorrow.
Thank you, much appreciated!
JS.

[JetSet]

WWHHHHHOOOOOO!!!!
Its alive!

Thanks everyone, you're geniuses (geneii? lol). Re-making the fuel injector (now has 8x1.5mm holes around the tube on the same plane) and positioning it inside the intake/CC cone worked wonders. It started within a couple of seconds of the fuel igniting, I couldnt believe it! I filmed the second run, which was harder to start than the first, and didnt seem to run so well. Apparently I knocked the fuel line with my foot, moving the injector about an inch, which is probably the reason. The bit of film I have is at the end of the run where I am experimenting with max throttle, hence the flameout. If you look carefuly, the stand falls back into position an inch or two once the engine stops.

I have uploaded the filehere and am documenting by build (not much detail) here

I think after this project is out of the way I will make something smaller and quieter so I can run it closer to home, seeing as I live in the town.

Thanks for the help!!
JS.

[Dang911]

congrads!!! Running off of vapor also..... When you do run it off of LPG you only need to open the valve a crack because the fuel rate will be much higher. I see a greater thrust potential if you run liquid, looks like your only running it at 30% right now. A bit louder now than before!!!

[El-Kablooey]

Congratulations!!! Quite a rush isn't it?

After my first startup my father and I spent at least 30 minutes in his yard laughing like hyenas. We were forced to quit laughing when my mother came outside and discovered we blew down her ornamental japanese maple tree with the exhaust.

[JetSet]

haha, yes. I'm still smiling. The boards on the floor in the second vid are there because the heat had runied the grass on the first, and there was soot all over the washing