WVO/SVO preheat via exhaust coil

[BruceM]

I saw this fue preheat setup on Mr Lister's UK web page, and wondered if this is safe?  It sure is an easy way to preheat fuel- and should kick in much faster than using coolant fluid.

http://listerengine.com/coppermine/displayimage.php?pos=-3

Bruce
Snowflake

[kpgv]

I, personally, wouldn't do that.
Copper is funny about "work hardening".
If that was the only way to do it, think about maybe steel brake line...

Kevin

[kyradawg]

Dude Ill hit you off with a tasty tid bit, Get oil from seafood joints the oil doesnt have all the fat oil from other places do. Ive run filtered wvo from seafood places unheated down to 50*f with no problem and its still liquid @ 20*f.  For the long haul I wouldnt fuck with copper either!  BTW I did some viscosity testing a while ago and average wvo is the same viscosity @ 150*f as Diesel is @ 20*f. My f250 will run on any viscosity that the lift pump can throw at the injector pump! Pre-heating is waaaay over rated! Peace&Love, Darren

[n2toh]

Dude Ill hit you off with a tasty tid bit, Get oil from seafood joints the oil doesnt have all the fat oil from other places do. Ive run filtered wvo from seafood places unheated down to 50*f with no problem and its still liquid @ 20*f.  For the long haul I would fuck with copper either!  BTW I did some viscosity testing a while ago and average wvo is the same viscosity @ 150*f as Diesel is @ 20*f. My f250 will run on any viscosity that the lift pump can throw at the injector pump! Pre-heating is waaaay over rated! Peace&Love, Darren

Good tip about the WVO I'll check it out.

[Tom]

I had a liquid LP Onan generator that had steel fuel line wraped around the exhaust like that. Seems like it might be a good for wvo even if just some waste heat energy from the exhause is recaputred.

[Listeroidsusa]

I build thermostat housing assemblies that allow the coolant to thermo-siphon internally via a bypass line until the thermostat opens. The coolant is preheated in a few minutes instead of several hours as with a large tank cooled engine. The bypass line could easily be utilized to preheat VO, WVO, and WMO. The engine is allowed to come up to temperature and at an even temperature unlike some other thermostat configurations that deadhead the coolant, causing localized overheating and thermal shock when the thermostat does open.

Mike Montieth
Listeroids/USA

www.listeroids.com

[BruceM]

Thanks guys for the good ideas.  Even with steel brake line substituted for the easier to fabricate copper,  it looks like a very easy to build preheater.

Mike, your thermostat design with bypass sounds like a beauty.  Do you have a photo you could send me?

Bruce

[Listeroidsusa]

I'll post some photos of my 6/1 installation this evening. I'll include photos of the accessories I build as well.

Mike Montieth

[kyradawg]

Looking forward to it. Ive been browsing your site and would love to see more details. Im in the market for a quality 6/1. Peace&Love, Darren

[Mr Lister]

Hi List,

Thanks for someone posting up my picture of the fuel pre-heater coil around the exhaust.

This is on the low pressure side of the injector pump,  gravity fed from the fuel tank.

I use 8mm  (5/16")  OD    1/4" bore annealed copper tubing which is pressure rated to 81 bar.

Might someone explain to me why they think this is dangerous, and why steel brake line hose might be any better?   Work hardening of copper is a poor excuse.  If this was the case we would see central heating systems flooding homes on an hourly basis.

How hot do you think the copper  tube is getting?  I have measured the fuel temperature and rarely does it exceed 100 C or 212F.

Vegetable oil is 6 times the viscosity of diesel fuel at room temperature  (20 C  70F)  and any reduction of its viscosity by the addition of waste heat can only help to reduce the strain on the injector pump and give it a longer service life.

In addition, by pre-heating the oil you get an improved spray pattern from the injector and this makes starting much easier.

I will prove this one day by trying to photograph the spray from the injector when used with cold oil and pre-heated oil.

IMHO, the best way to improve the starting of a CS is to invest in one of Georges glow-plugs.  I am pleased to see that he now has this in production and look forward to trying one in the near future.

Although this diverts from the original mechanical simplicity of the Lister, in that a starter battery is now needed, I see this and the addition of an electric starter a very worthwhile upgrade to the original Lister design.

Lister were making Start - O -Matic generator sets since the 1950s, using an alternator with a built in starter motor.   They applied 24V dc to the house wiring, and if anything more than a 40W bulb was turned on, the current would trip a relay and the engine would be started.

Of course this was back in the 50's when there were very few electronic appliances.   It is no longer advisable or practical to use this method for detecting an appliance switch on  - and we all have much more than 40W plugged in at any one time.



Ken

[BruceM]

Thanks for your post, Ken.
I'm not sure how work hardening would affect the copper either; where is the working happening if it has rubber fuel line attached at both ends and is wound like a spring???

I"ve also just ordered George's glow plug.  Because the thin air up here at 6000 feet, it makes sence for me.  I had to have a battery anyway for auto shut down on over temp, low oil, or excess vibration.

Best Wishes,
Bruce

[kyradawg]

Ken I often run straight wvo in my f250 pickup. On the topic of viscosity I wonder how much the reduced friction that the wvo oil allows (better lubricity) offsets the wear do to increased ip pressure. Ive found 150*f oil temp to be the same vicosity as diesel  @ 20* timed using a orifice. I let my ip do the heating for me but Im using good quality wvo with little fat. Peace&Love, Darren

[Tom]

Hi Mr. Lister,

From your reply it seems your understanding is that work hardening is due to temp changes. Copper tube will work harden and crack from the vibration of the engine. Same concept as bending a piece of copper back and forth until it breaks. The process with vibrations in copper is just slower.

[Mr Lister]

Hi List,

By way of experiment  I removed the injector from my Lister 6/1 with the tank full of rapeseed oil.

Temperature today was around 45 F

By turning over the engine several times with the starting handle I was able to see a distinct squirt of oil from the injector.

I can confirm that straight veg oil does not form a mist, or a drizzle, but a highly energetic squirt that will shoot 3 feet before it even thinks of breaking up.

I will repeat this experiment with the oil and the injector prewarmed in a steam bath to 100C / 212F and see if the reduced viscosity helps the oil form a better spray mist.


Ken

[kyradawg]

Ken, good to know your tinkering. Cant wait to hear about you results. Be careful with that injector it could turn into just that. Peace&Love , Darren