Liquid fueling a big lockwood

[Dan72]

I have been reading the forum for a few weeks now but have a few questions about some stuff I can't seem to find. Most of the questions are probably pretty stupid but I could really use the help.

I’m planning on building a big lockwood engine like the 55lb thrust plans for a shop class project, the first part of the project you need everything drafted up before you start building anything. The drafting wouldn’t be a big deal if I was just building a welding table or pickup truck tool box like everyone else, but the teach wants the fuel system and ignition system drawn up before I start :( !!!

I'll have plenty of time to learn all the details on how to run the engine and get money together for parts but the drawings are due way too soon for me to research everything on my own!

I really want liquid fuel for the engine because I want to use it on a gokart eventually, and upside down propane tanks scare me, especially with the bumpy roads we have!


I searched the forum and found some diagrams and basic descriptions for liquid fuel systems, the only one that I found that had a decent layout picture was one by Bill Hinote, but it looked like it had all kinds of measuring and extra stuff that I wouldn’t need, aka way too complicated for a gokart!

My main question is the fuel bypass thing that is right after the fuel pump, what kind of valve is there that lets the fuel flow back to the tank if the line gets blocked, but not let any fuel flow back when its not blocked? Am I understanding this correctly or is it just some kind of valve to drain what’s in the fuel line when you’re done?

Also do I really need a fuel filter if its just going into an engine with no moving parts that wouldn’t be bothered by dirty fuel?

I’m going to attach a very crappy paint drawing of what I am thinking of for the fuel system, I tried to simplify the layout, if there is something horribly wrong that wont work or explode please tell me!


Can anyone recommend a fuel pump that works with a 55 lb lockwood?

Im thinking I will use a model T coil for igniting the engine since its simple and would make the drafting deadline easier.

Thanks in advance!

[hinote]

I really want liquid fuel for the engine because I want to use it on a gokart eventually, and upside down propane tanks scare me, especially with the bumpy roads we have!


I searched the forum and found some diagrams and basic descriptions for liquid fuel systems, the only one that I found that had a decent layout picture was one by Bill Hinote, but it looked like it had all kinds of measuring and extra stuff that I wouldn’t need, aka way too complicated for a gokart!

My main question is the fuel bypass thing that is right after the fuel pump, what kind of valve is there that lets the fuel flow back to the tank if the line gets blocked, but not let any fuel flow back when its not blocked? Am I understanding this correctly or is it just some kind of valve to drain what’s in the fuel line when you’re done?

Also do I really need a fuel filter if its just going into an engine with no moving parts that wouldn’t be bothered by dirty fuel?

I’m going to attach a very crappy paint drawing of what I am thinking of for the fuel system, I tried to simplify the layout, if there is something horribly wrong that wont work or explode please tell me!


Can anyone recommend a fuel pump that works with a 55 lb lockwood?

Im thinking I will use a model T coil for igniting the engine since its simple and would make the drafting deadline easier.

Just use an auto fuel pump from a fuel injection system; they're pretty much positive displacement--so you have to create the right pressure by bypassing the excess, or the pump will stall. Also, the excess fuel pumped is used as a cooling and lubricating medium for the pump. I use and recommend the Moroso #2225, commonly available at hot rod supply sources (Summit, etc.).

The right way to set it up is to use a bypassing-type regulator. I'll be using my AEM unit, when I really get up-and-running; for the time being I'm using a manual valve and watching the pressure in the line to the injector.

The throttle valve should be a good needle valve, for accuracy; also, put a quick shutoff valve in the supply to the motor (a ball valve is probably the best choice). Use at least one check valve.

The filter keeps the big junk out of the needle valve, and the small orifice in the injector. Cheap insurance.

What kind of injector are you proposing to use?

Frankly, the issue of liquid fueling is huge--and probably beyond the scope of your project; things like fueling rates, injector locations, pressures, etc., --all need to be optimized for your particular motor.

Why don't you buy one of Eric Beck's CD's and get a motor that uses less than 1/2 the fuel of the 55 lbf Lockwood? You'll also get (as I understand it) tips for proper fueling.

This would also make propane a viable fuel source, without the need for turning the tank over.

[NickC]

Bill, why the need for a check valve? do you recommend a spring laoded one? and should it be placed before or after the bypass valve?

[hinote]

Bill, why the need for a check valve? do you recommend a spring laoded one? and should it be placed before or after the bypass valve?

Without the check valve the whole fuel system can inadvertently become a resonant entity, excited by the pulsejet.

All kinds of things can result, from loss of fuel delivery to partial or complete destruction of fuel systems/components.

I'd place the check valve pretty close to the injector.

[Dan72]

Awesome! Thanks Ben & Bill that really helped a lot, I'm good at science and building things but haven’t taken a power tek class or worked on cars so I'm totally a noob with that stuff.

I'll make sure to have a check valve, I saw in your fuel system topic that you have 2 check valves, is that really necessary or is it just a backup?

I think I'll skip the fuel filter for now, a large part of the grade is how well you stick to the plans you draft up, and it sounds like its probably just going to be easier to make sure the gas is clean. I don’t want to have to spend a lot of time tuning the fuel system to work right, so simple is good.

Is there any kind of injector that would work the best, like some kind of car injector, or can it just be made from a tube with lots of small holes? I read that the large lockwoods can start themselves without any air, is that only with propane?

I just emailed Beck Technology to see if I can download the plans, I didn't see anything on the home page about downloading. The project is kind of a rush, I knew it was going to be way more intense than what most people are doing, I convinced the teacher to give us a few more days before we start into it.

The only other project that’s pretty complicated is a roll cage and grill guard for a pickup, lots of tight tube bending.

I was looking for a project that I could build in shop class and then later use as part of my physics project to kill 2 birds with one stone, I was thinking of building a medium sized trebuchet originally, then my friend sent me a link of a pulsejet powered dragster and I thought YES! I MUST HAVE ONE! :D

As long as I can get the thing running that will be great, and then ill have plenty of time to play around with everything and get it running perfectly.

Thanks!

[leo]

Is there any kind of injector that would work the best, like some kind of car injector, or can it just be made from a tube with lots of small holes? I read that the large lockwoods can start themselves without any air, is that only with propane?

I just posted a link in a other post for a fuel injector.
Self starting probably requires propane.
fuel injector for lockwood

[hinote]

I'll make sure to have a check valve, I saw in your fuel system topic that you have 2 check valves, is that really necessary or is it just a backup?

I think I'll skip the fuel filter for now, a large part of the grade is how well you stick to the plans you draft up, and it sounds like its probably just going to be easier to make sure the gas is clean.

Is there any kind of injector that would work the best, like some kind of car injector, or can it just be made from a tube with lots of small holes? I read that the large lockwoods can start themselves without any air, is that only with propane?

I just emailed Beck Technology to see if I can download the plans, I didn't see anything on the home page about downloading. The project is kind of a rush, I knew it was going to be way more intense than what most people are doing, I convinced the teacher to give us a few more days before we start into it.

First--I admire your enthusiasm--but I hope you're not going to let some failures get you down.

An in-line fuel filter is so cheap it's ridiculous to forego it. Reconsider.

2 check valves is a throwback to my steam car days; why put one 2-bit part in, when 2 of them could avoid disaster?

Your question about the injector is probably the best reason why you shouldn't be trying to fuel this project on liquid fuels. The answer lies in a lot of research--are you prepared for many failures, to reach this goal?

[NickC]

so just regular un-sprung check valves found in the plumbing section will do?


I recommend you get Eric's CD as it will provide details on adjustable injectors. Whenever you are unsure of your injector run a fuel with the highest possible Hydrogen:Carbon ratio. These would be low octane fuels, or if you can get some E85 use it. The best fuel would be methanol, you can get it for racing applications like go karts and formula 1 uses it and there are other things that use it. I'm not sure how much it is, you don't need any kind of high grade of it. I buy race gas for my 125 and the most I've paid for the really good stuff was like $12-$13 a gallon, but my bike actually likes the $5 a gallon stuff better. I'd expect methanol to be available for as low as $5 a gallon. just google racing fuels, VP is supposedly the best and definitely one the most well known and they sell methanol http://www.vpracingfuels.com/vp_01_fuels.html#specialty there should be a dealer list somewhere on that site with phone numbers. They tend to be expensive though. Maybe check a go kart forum