Air Fuel Ratio Tuning of the 5 - 8KW Diesel Heater / Stage one using AFR gauge

[@andrewbartleman9169]

For anyone wanting to copy his numbers.. his numbers wont work for everyone. There is differences in the heaters ,burner tube construction, fuel pump, the combustion fan gap map be different, and exhaust intake and elevation all effect your clean burn settings. We see people trying to use others settings all the time and have high carbon monoxide so their heater soots up. Unfortunately you have to do your own for optimal burn.

[@DavidMcLuckie]

I've pinned this so people will see it better. Andrew is spot on, these numbers might not be ideal for your setup. I'm going to use a CO meter in the next video to see how this relates to the AFR, this is interesting.

[@andrewbartleman9169]

@@DavidMcLuckie thanks David. I am interested too

[@ericdee6802]

@@DavidMcLuckie What is your Altitude (feet above Sea level)? Just curious.✌️

[@coachk7674]

I missed how you got into the settings adjusting I am at 9400 feet

[@rhiantaylor3446]

It will also vary with fuel type so if you are blending used sump oil or vegetable oil with petrol/methanol/kerosene you should aim for consistent proportions and use this video's technique to calibrate the heater.

[@dm1126]

Finally tinkered with the controls... Been running my 5-8 kw heater for over a year on the factory settings but needed a better air flow to circulate around my caravan. Used a set from another youtube video ... and so far seems to have improved the heat output and smell from exhaust (outside the caravan) When it starts up Set range 1.0 to 3.0 hz And fan at 2050 to 4550 I use the lower settings and run the heater all night in my caravan Still cold here in NZ frosts this week Always enjoy the content Cheers Dave

[@andrewbartleman9169]

We usually keep the max fan speed under 4500 or around there. The fans don't last long over 4500. And we will tweak the fuel only. The problem with running rich or cold is they soot up. No one enjoys cleaning these heaters when they actually use them for heat for hours or months at a time. You want the case temperature to be over 150°c for low setting and over 180 up to 215°c for high. And yes you can tune it while it's running by the way..

[@barrydwernychuk3902]

Agreed: limit the fan rpm to 4500! I tweaked my unit to max settings of 5000 rpm and 6hz. Noticeably hotter output air temperature with no smoke so good guess on the combustion side. However, the fan motor self-destructed after an hour's total run time, over about 6 start cycles. Huge PITA getting this sorted with the vendor and Amazon and had to cancel a boat trip because of no heater, plus massive job getting dead heater out of the boat.

[@oojimmyflip]

have you any ideas on the ideal case temps for the 2kw heaters Please? im running mine at 2.0Hz with one red bar on the lcd controller screen but the core is only acheiving around 107 degrees C and the exhaust silencer seems cold to the touch even though the exhaust pipe itself is insulated.

[@v8snail]

Regarding pump capacities for those interested, the ml rating stamped on the pump body refers to how many millilitres are delivered per 1000 pump strokes. So ml per hour can be calculated using Pump Capacity (ml per 1000) x Hz x 3.6 (3600 secs per hour/1000 strokes per capacity) For example, a 22ml pump at 5Hz = 22 x 5 x 3.6 = *396 ml/hr* +/-5% accuracy.

[@nomadchad8243]

is that a microliter or a picoliter?

[@v8snail]

@@nomadchad8243 A 22ml (millilitre) capacity pump, a measurement in ml per 1000 strokes, will deliver 22μl (microlitres) per stroke.

[@lanceboudreau3630]

My diesel heater ( hcalory Hc-A01 has a setting that you could change the pump size does that mean I could make it burn more fuel making it put out more btu’s it ranges from 16 up to 65 I believe

[@v8snail]

@@lanceboudreau3630 The ratio of fuel and air needs to remain correct. If you jam in more fuel you need to increase the airflow accordingly. Your unit may not allow for that.

[@tonythorrington3740]

I have been fitting these of various quality for a couple of years and I have 2 myself ( loving your videos by the way ) I have the one in my work van set to 1.7hz low 5.2hz on high (pump)the fan speeds are 1900low and 4410 on high I have stripped the unit out once to have a look at the soot build up and was amazed at how little there was after a year and a half about half a teaspoon of that much !!! The workshop one i have set to 2.5hz low and 5hz high / fan on 1900 low and 4300high ( seems to run hotter but I need it as no insulation ) also both units are the 5/ 8 KW ones I hope this may be some kind of help or to build up some info keep up all the brilliant content

[@Nerd3927]

Thanks!

[@snottanz]

Awesome Video, Mine was pumping out clouds of smoke, pulled it apart - major coking - cleaned out, then reprogrammed (5kw unit - my new pump is a 28ml) and my settings ended up being P 1.2 @ 1450 for low (didn't adjust) and P 4.4 @ 4500 for high (was pushing black smoke @ P 5.0) - absolutely awesome now - thank you for a great video

[@ingresoprepararte]

HI Snotta.,I,m frfom Argentina,my inglish is very bad....sorry.I have a 5KW and my new pump its a 28ml .its in a litle sailboat,any recomendations ?

[@ingresoprepararte]

sorry!!!its a webasto 9012868 c !!!

[@barrydwernychuk3902]

Thanks for this, David! Others here have requested EGT and CO/CO2 readings. On a more practical note, measuring output air temperature as a function of AFR changes would be easy and useful. On my 5Kw unit, increasing max pump Hz from 5.0 to 6.0 produced noticeably hotter discharge air. I have no way of measuring AFR but I think I'd hesitate going above 6.0 hz (I tested as high as 6.3, in .1 hz steps) because the discharge air temp was hot enough to potentially soften/melt the (cheap) discharge vent and possibly damage the synthetic carpet abutting my floor-level discharge.

[@Simon_Rafferty]

I went through a similar process, using a wide band Lambda sensor, connected to the Arduino (ESP32) that was controlling the heater - trying to make it run closed loop (auto adjusting the AF Ratio). What I found however was that immediately after a fuel pulse is injected into the heater, it runs rich, leaning off towards the next pulse. Somewhere in the middle it (should) get to 14.7. You can kind of see this on your meter with the value dancing around. I assumed that if I averaged the O2 reading over the time between fuel pump pulses, and drove the average towards 14.7 it would be about right. Unfortunately, this resulted in gouts of smoke from the exhaust. The profile of the burn (from the O2 readings) was non linear. It also varied with - well, everything! Fuel pump speed, fan speed, heater temperature, ambient air temperature, day of the week..... Using a simple average didn't work. Nor did any of the other algorithms I tried. After a week or so of experimentation, I found the results were no better than tuning it by eye for minimum smoke! I gave up on the Lambda sensor idea!

[@DavidMcLuckie]

The only other though I had was to make the exhaust gas fill a larger volume to try and average out the spikes. I was trying to imagine how a car ECU would do it. Would we also need to add a MAF to measure the air intake volume and have it do the maths based off of air quantity coming in, fuel required to burn stoichiometrically, and then use the lambda sensor for error correction? I can see this becoming a very complicated way of controlling a simple heater. But boy you could get it to be efficient. :) Stage one would be getting a useful and reliable reading from the lambda sensor.

[@Simon_Rafferty]

@@DavidMcLuckie There has got to be a solution! Not sure a MAF would give you much more than the fan speed, though I guess it would account for air pressure & temperature. I think I was concentrating too hard on getting a perfect 14.7 ratio, rather than looking at what average value coresponds to it running nicely. I like your approach of using a CO meter (in a different video). I wonder if that might be a better metric to tune it by, automatically?

[@reubenk7331]

Great video! I really enjoy going through all of the tunning even with all of the effort to turn it off every, single, time. Your videos are always entertaining, and educational! I am really interesting in watching the CO video as well 🙂

[@corvairkid17]

2hz sounded like a grandfather clock next to a roaring wood stove. I liked it.

[@mark6205]

that noise is from the flame going out then restarting...(small contained explosions[the pops] - not good for the seals)

[@wouldliketosleep.2845]

Hellooooooo . I bought the 5 kw all in one . It is the taller one and hope it works as well as what they say . I havn't tried it as of yet . I am hooking it up to a Deep cycle marine battery . Battery was actully more then the heater . Thanks for sharing the knowledge with them . Take care . Cheers .

[@coldtrader4737]

Those gauges are expensive ! Thanks for saving us the cost of buying one . Brilliant stuff

[@rednecktek2873]

Please do the smaller unit too, I really need to tune mine. :/

[@derektodd4126]

Safety say you are the UK expert on this subject now. Best wishes from Northern Ireland.

[@andrewbartleman9169]

You actually have a lot of experts over there who actually know a lot more about heater tuning that David Mcluckie. Join the chinese diesel heaters on Facebook. Theres a lot of us over there :). I am canadian not from the UK but there is definitely some people in the UK who know more than myself

[@hillonwheels8838]

This video is just perfect timing. I just got a brand new 5kw heater and it keeps over temping e-05 code and has a constant little bit of white smoke coming out of exhaust. I have checked the intake and exhaust for combustion for anything being stuck and same with the vent. Now I have a better idea of how to adjust the settings to get mine to work.

[@TheSdheights]

I've collect imperfect data from various sources, including the comments from this video and my setup, which works fine. The average tuning parameters show a general trend of LOW: 1Hz @ 1000 rpm. HIGH: 5Hz @ 5000 rpm. Draw a line on graph paper and then chose your desired upper and lower points based on the limits of your specific heater. My setup is 1.4Hz @ 1500rpm and 3.5Hz @ 3500 rpm. So far so good as it's oversized for the space and I've turned the upper limits down.

[@oojimmyflip]

at which Hz setting do you tick over at when up to temperature and what is the core temperature at full chat with your lower settings please? Im asking for shutdown and startup temperature reasons, thanks. your revised high setting is similar to that of a 2kw heater so im wondering if the burn chamber reaches a similar core temperature to that of the 2kw heater, if the ecu's are the same and the controllers are the same im guessing it must be around 120 degrees C at full chat I am also wondering if the sixe of the burn chamber makes a marked difference in the core temperature. if the highest setting on the 2kw is 3.1 Hz and the electronics are the same it is fairly reasonable to assume that the 5kw will stay clean shutting down at only 3.5 Hz if the core temperature is high enough, this could greatly reduce wear and tear on the internal componants like the motor and bearings. I am about to install a 5kw outside a caravan heating outside air and these settings you use may be very helpful to reduce fuel consumption and over heating inside the caravan. I shall test run it tommorrow with your settings.

[@ultravoxa]

I twisted a ball of 5m 0.25mm nichrome wire and placed it in the combustion chamber to expand the heat zone. Fuel vapor burns better as it passes through the high temperature zone. The effect was staggering. The fuel supply had to be restricted as it started to fail due to overheating. An aquarium metal tap had to be installed to limit fuel supply by 50%. Then the output has a 143c airflow at 1.6Hz and with 5l running in 27h in my variant. The fuel burns so well that there is almost no smoke from the exhaust pipe, only weak steam. I suggest you give it a try.

[@Yankeeprepperasshat]

Would heating element wire from dead heaters or toasters work? Or what about super coarse stainless scouring pads? Would help resist airflow, which is what you want anyways. But maybe the stainless will break down after a few months and the nichrome wire won’t. Could I use slightly thicker or thinner wire? I was thinking 28 gauge is just a bit thicker and would hold the heat a tiny bit longer. Might help prevent flameouts or interruptions if the air mixture isn’t perfect. Might even be worth replacing the glow plug screen with a homemade sleeve made from ni chrome, since the screen seems to clog up easily

[@ultravoxa]

@@Yankeeprepperasshat Nothing critical here. The wire can be both thicker and thinner just to keep the high temperature. You can do it differently. It is necessary to cut 9-11 notches about 1.5 cm deep at the exit of the combustion chamber and bend them inward while forming the jet vector. A good, stable fuel pump is essential. Then play with the fuel delivery amount using a small tap. Aquarium metallic tap is well. In my case, the exhaust port of the combustion chamber is reduced by about a third. On 2.4 hz 5L for 25h Fuel tap open 45%. No smoke, just steam.

[@Yankeeprepperasshat]

@@ultravoxa I don’t understand the instructions about cutting notches. I really wish I could talk to you somehow or see a picture. How deep in the combustion chamber do you shove the wire? Throughout the entire depth of the chamber? Or at the deep end only, where the fuel ignites? Or are you only capping the open end of the combustion chamber and leaving the rest open, to swirl gasses uninhibited, and the wires are acting like the gas lamp element on the combustion chamber exit? Please be more specific. I’m VERY interested in your mod. Also, why restrict the air when you can just turn your fan speed down? Didn’t you say you were restricting both your fuel and your air? Why not just turn them both down on the controller?

[@Yankeeprepperasshat]

@@ultravoxa I ended up pulling a bunch of coiled up nichrome wire out of a dead mini-hair dryer, and stretched it out so it’s still a coil, but a lot longer. Probably 25 feet long. I wound it up into a ball and pulled it apart into an elongated but equally dispersed mess and shoved it into the combustion chamber. The back of it is touching the deep end where the glow plug is. The other end is sticking out of the combustion chamber an inch, so it will actually touch the heat sink where the gasses roll around and back towards the exhaust pipe. Is that going to work?

[@Yankeeprepperasshat]

Oooooh. When you said “cut notches 1.5vm deep and bend them” I thought we were taking about nichrome wire and I couldn’t figure it out. I read your message a hundred times. But I just now resides I think you were describing turning the end of the combustion chamber into a nozzle. Right? Had nothing to do with the nichrome wire. Next time I take it apart to inspect or clean, ill try that. But I’m now getting excellent results with my nichrome and regular settings at H3, as long as I preheat my waste oil. I’m actually pretty happy with my system. Getting as much free hydraulic fluid as I want. Stocking up tomorrow. They have 14 barrels of clean oil waiting for me. Can’t wait to snatch that up. All I’ve been burning was dirty synthetic oil and it’s working great. And I’m told that the hardest stuff to burn..

[@yajawstin]

Love your video 🤣 I've been tuning by my fuel air mix with a little needle valve and bypass fuel pipe 😆 did the job!!! I used the farty noise as audible tuning limit and runs great now! I've got completely different display with round pin connector and rf remote but no instructions!

[@DavidMcLuckie]

If it works, it works. :)

[@scotnorth]

Great videos on the Diesel heaters David keep them coming Would really like to see a video for a 2kw Fan speeds and fuel feed rates Regards Ronnie

[@timp8711]

"Focus, you fuck!" Love the AvE reference.

[@brianhalliwell2628]

i would note that the default setting getting you a a/f ratio of that 16 .1 would actually be preferred if it was automotive, a small amount of unburned oxygen and much reduced chance of co and coking

[@dr_jaymz]

I found this very interesting, its an oldish video but here are many tinkering this year. I think though that the unit should be run much leaner than the Oxygen sensor would suggest. If you were injecting into a cylinder you want all the fuel to burn with all the air then 15:1 is what we're after. But if its a flame in a wind tunnel then there is going to be a lot of excess oxygen and so you'll struggle to get near 15:1, and the only way you will is by burning it downstream like in the exhaust. I am not surprised it smokes. On a more recent video you cut the combustion chamber open, and that showed a Bunsen burner blue flame which shows its pretty close to ideal, too lean and it will struggle to stay lit or will be in patches and if its yellow its too rich and that will deposit soot. So for reasons I can't really back up, I think that it will work best much leaner

[@philcross7315]

For what it's worth, when I was truck driving, that noise it's making is the same as the thousands of them I heard running sweet. Go to any truck park in the winter, you'll hear them ticking over the same.

[@andrewbartleman9169]

That low speed resonance was not a good burn. When you hear that sound the mixture is off or the heater is sooting up inside. But I think he was too lean

[@andrewbartleman9169]

Most everyone tunes a diese heaterl by the carbon monoxide.

[@philcross7315]

Just an observation really. Obviously, with the correct test gear, it could be set up perfectly, but that noise wasn't unusual. I should say though, that it wasn't a pulsing noise.

[@andrewbartleman9169]

@@philcross7315 it's not unusual.. but you will hear a perfect burn. Think of it as a torch. If it's doing the pulsating it's not burning proper

[@troutstag]

Change your password. The last function in the setting is change password. I did mine to 6 - - - so I only had to enter the first digit then hit ok three more times. Works great and saves some swearing. The newer screen allows changes on the fly.

[@DavidMcLuckie]

Brilliant suggestion.

[@GatorOverland]

@troutstag This is fantastic!! ive read a few CDH owners manuals (as best as i could) and haven't come across the procedure for resetting the Admin PIN.. is there a series of buttons to press to reset it? Assuming you type in the 1688 or 9009 code first to access the admin settings and then prompt it to reset some how? @David McLuckie have you figured out the procedure for reset?

[@coachk7674]

I’ve purchased 6 diesel heaters from 4 different sellers 5 of them have failed within 30 days. Trying to read and comprehend the Chinese manual might as well listen to the coyotes howl thank you for your video

[@Estabanwatersaz]

Very informative and educational. Thank you 🙏 sir.

[@mattg5924]

I've tried to set mine before with a oil burner gauge think it has a profile built-in, temperature and humidity will change the profile. Setting's are for temperature running like a PLC. Best results at 3.4 hz or lower nothing under 2.

[@caseyrayman2364]

I didn’t hear you mention it in the video but those gauges actually measure lambda and convert that to AFR. So if that gauge is setup for gasoline(most are by default) then stoichiometric(lambda=1) is 14.7. Even though diesel is 14.5:1 you still want to see 14.7:1 on the gauge if it’s set for gasoline. So you may be just slightly richer than you thought.

[@DavidMcLuckie]

Excellent point. One day I want to revisit with a better exhaust setup.

[@mattlyster8508]

FYI with diesel engines, more fuel doesn't cool the engine/prevent knock etc. It will increase cylinder temperatures

[@timk404]

Hey my friend, you are correct up until you reach stoichiometric. Adding more fuel after that increases the mass of the charge but does not increase the energy released there for the combustion temps are decreased.

[@HavingWandered]

This is great info. I got the dial controller to save myself from going down rabbit holes ;-)

[@NoahTheFacts]

Diesel combustion my have a stoichiometric equivalence ratio of 14.4:1, but you’ll find most diesel engines are designed to run very lean. At peak torque, it’s not unusual to run 25:1 to avoid excessive smoke. Admittedly, I don’t know enough to apply this compression-ignition to the thermal ignition of a burner. I would imagine that a stoichiometric burn would be the most powerful, but not necessarily the cleanest. In the 80’s lean-burn gas engines frequently ran at 18:1 and were efficient (for the time) in terms of fuel/horsepower, if not displacement/horsepower. The reality might be, like engines, that efficiency, power and emissions can all be optimized for, but only one at a time.

[@ianaristotlethompson4186]

Not that scientific but I measured the flame chamber temp, runs between 155c and 165c on base settings no smoke no noise. Great video by the way. If you want hotter or cleaner burn maybe add a little petrol to the diesel.

[@nv400adventurer13]

Please do the smaller unit. As a fellow Scotsman I'd love to have mine set up so I'm not listening to it and wondering if I'm wasting money. 🤣

[@andrewbartleman9169]

You can buy a cheap gas analyzer for around 25$ Canadian. So "cheap as chips" . And do your own heater. We have had people test their heater and tune them clean as they possibly can. And some others will come and use those settings and have their heater soot up in hours. Not all heaters are the same... even from the same supplier we found. And they definitely don't ship with good tunes either. Now there is some makes that spend the time tuning their heaters. And they also use the kyocera glow plugs and sensors with all good quality parts for quite cheap. Their name is Tian river. Or you can add me on Facebook I can send you the link

[@andrewbartleman9169]

There heaters are running great from the factory.

Stoichiometric AFR on diesel means it just start to produce soot this is why diesel engines are usually run lean. Diesel tuners like Banks say no less than 17:1 AFR adds the best performance IMO the CO meter aided fine tune is more accurate

[@tyroncalta]

You had me at "Focus you fack!" Great content!!!

[@TOMAS-lh4er]

YOU ALLWAYS crack me up !! thanks !!

[@martprice7726]

Yes please do more we love experiments👏👍😷

[@sebxj25vm]

There do seem to be differences in build quality of these heaters. I have a 5KW heater I bought circa September 2020, and the fan runs really smooth at 1500 RPM. Also, another way to achieve an approximate good fuel mix seems to be to set your fan speed to the target you want (in my case 1500, for less noise) - and then, after the heater warms up, to adjust the pulse rate until you achieve one single red bar - which in my case is somewhere at 1.7 - 1.8Hz for 1500 RPM. That seems to be a nice even point - hot enough to burn diesel properly, but not too rich. Then again, this setting might need adjusting again as the outside temperature changes. This might not be as precise as measuring the exhaust gasses though. Also, I wonder if there are several different firmware versions in the controllers for these heaters. I have an identical looking controller as the one in this video, but I can adjust the target pulse rate on the fly while it is burning, without going into the advanced settings menu. I do have to go in the advanced settings to adjust minimum and maximum pulse rate though.

[@oojimmyflip]

same here for my 2kw heater heating my living room and mounted on the outside wall in a box, only I am heating internal air. the code for the extra functions on my 2 blue controllers is also 9009 Not 1688. the heater ecu's are the old type blue boards with the silver strip running across the board and a coil of copper wire in the top right hand corner with a carbon rod in the centre of the coil one of which I bought from flea-bay with a blue lcd screen and lcd remote and replaced the limited function black controller and ecu I got with the 5kw heater, these older boardss are apparently compatable with all Lcd screens that have the triangle shaped wiring connectors and the Austrailian made advanced controller.

[@twocvbloke]

Seeing the frustration of using that controller makes me think how nice it is to be able to tweak settings with a screwdriver, cos computers slow such things down a lot... :S

[@SirJJames]

That sound at 15 mins sounded like a pulse jet engine. Could it be caused by the long tube between the heater and the silencer?

[@888johnmac]

tuning a diesel is easy .. no smoke = no poke .. oh hang on a min, but in all seriousness this is really interesting, thanks David

[@TheCraftyTech]

1.5 hz / 1450rpm. high is 5.0 hz / 4500 rpm, this is a ssetting i found that works for me,

[@KonKrom]

The moment he start to swear i clicked like button.

[@oojimmyflip]

our 5kw in a case arrived with Low 1.2 Hz fan speed 1680 and High 5.5 Hz fan speed 4500. it seems to run ok like this without any strange exhaust noises, however our 2kw makes that noise when you drop the low setting to 0.9 Hz from the standard 1.2 Hz with the fan speed at 1400 the lowest it will go. at this setting it blows dense black smoke.

[@YankeeCherokee]

All for the ratio for the smaller one! It's the more popular and would be curious to see if it behaves like the bigger one.

[@andrewbartleman9169]

The 2kw(d2) does not behave like the bigger (d4) its tuning is not as forgiving. It's a fine line and they like to soot up. They give us the most issues over on the forums.

[@randydicotti3975]

For those of you tuning 2kw heaters, there are a number of pumps (volume wise) used on them. I've seen anywhere from 16mL to 18.5mL and even 22mL Oddly, the 18.5mL pump seems to be the perfect compromise, yet is nearly impossible to find.

[@dansmith6990]

what makes the 18.5 better than the 16 or 22?

[@tonystacey3347]

Do the controllers like the one in the vid come with same settings on the 2kw. I knacked one on my van and swapped it out with one from a redundant 5kw all in one and it’s smoked/clogged up fairly quickly . Any ideas anyone?

[@SamWolfandCo.fossickandfind]

Hi Again David , well after watching the adjustments you made I had a go at seeing how my heater would go which it did for about 4.30 minutes then it totally sooted up and white smoke then black after I tried to restart it so some minutes later I turned the heater off before I smoked out the neighbours. I figured that these diesel heaters don't do very well running at a low Hz setting which I previous discovered when I first used my heater at low speed settings , they just aren't meant to run on lower settings for the now obvious and somehow annoying chore ahead of cleaning out the expansion and combustion chambers as well as the exhaust pipe. Those numbers gave you previously must have been pretty near close to the best heat to rpms/power ratio. I've tweaked the high end Hz to 5.9Hz. I was wondering about trying to run my heater on Kerosene as one UK KZbinR runs his on kerosene and he doesn't seem to have any problems, but I'm always open to solutions for fuel economy = less $'s and less consumption so if you can let me know what difference there is apart from fuel cost because kerosene here is around $98-$99AUD for 20 litres while diesel is almost half. If you can give me some advice I would be ever so happy. Cheers Mate👍👍👍😎💨🏴‍☠☕☕🔧💡

[@DavidMcLuckie]

Kerosene runs absolutely fine. The rumors about it harming the pump are unfounded as well. I'd have a look at the newer videos using a CO gauge to tune the heaters are that is a much more accurate and reliable way of setting the heaters up.

[@Bennytet]

Thank you for posting. On my 5kw heater the high setting is at 5000rpm and 7Hz The low setting is 1500rpm and 1.0Hz. I would love to know how efficiently the low setting is because this is where the heater mostly runs. Thank you

[@DavidMcLuckie]

That's when you need to CO meter to see how well your heater setup is working.

[@SamWolfandCo.fossickandfind]

My brain is hurting, make it stop Please !! I have a 5Kwatsit my settings were trial and swear a bit then try it again ,Hang about I'll double check, Yep 2500 and 5000rpm/2.5Hz low and 3.8Hz high and I have 32degrees no black smoke on start up and I have run at those settings for almost 18hours non-stop and about 7-8litres of fuel/ diesel which is from a dodgy servo that sells crap tastic discount fuel. I'll give you more info when I get worried. I have the 8Kw version on the way so that can of worms will be my next trauma by trial and swearer. Appreciate the time and effort you put into this Mate Cheers👍👍👍😎💨🏴‍☠☕☕☕☕🔧💡

[@craftbrewer5401]

I have the 22 ml pump. Fan rpm 1600 - 5000. Pump 1.6 -8.0. I am at 16 m above sea level. No black smoke.

[@HostileHST]

Yesterday, 10-14-2021, was my first time to have an overheating issue, sooooooo, found some info, and simply increased the lower limit of the fan speed to max and has "seemed" to cure the issue as well as it now is starting up on first try, BUT, MAJOR DISCLAIMER, I've only had one day to know the full outcome.....crossing fingers....oh crap, also change the sn-1 to sn-2 which has solved some issues with people having start up problems including flame out. Will do my best to come back with any new info/changes as I continue to use the heater....sn-1 and sn-2 means one or two magnets, but where those magnets are, have not figured it out, but supposedly will affect fan speed which also affects how much are the intake, "air ratio" works. Sorry to make you have to read all of this, but...the overheating was on Pulse, aka, Hz of 3.0hz, not when higher. Also note, more vent tubing ultimately can affect what fan settins you can use to prevent overheating, more vent length, higher fan speed to keep it from overheating....EDITED, just seen the pinned post, ALL true, my elivation is 430 feet for what it's worth.

[@HostileHST]

Very next day after my post, heater refused to fire up. After a major cleaning of the main burner, it's running again! Thank you David for all the great video's, it made the tear down and reassembly quiet easy!

[@v8snail]

Furnaces are usually set up with an excess of air in the flue gas. 15% excess air for a diesel furnace is a good ballpark point so based on that you should be looking for around 16.7 to 1 on your AFR gauge. I'd be interested to see if the pump Hz end up closer to expected if set to that. There is nothing wrong with using an AFR gauge for this purpose as long as you work out how to interpret the numbers. It is more accurate than using a CO meter on its own.

[@DavidMcLuckie]

I'm curious now to see the relationship between the AFR and CO output on these heaters.

[@timk404]

You dont want to tune diesel in this or really any application to actual stoichiometric values. Simple fuels like methane, natural gas, propane and even more complex fuels like gasoline can be tuned to a lambda value of 1 in a combustion chamber like this but not diesel. If you were to preheat the fuel and combustion air, fuel atomization is absolutely perfect, combustion chamber temps are high enough, turbulence is aggressive and dwell time in the chamber is long enough, you can get close to stoich but that is not the case with one of these diesel heaters. Common rail diesel is injected at somewhere around 30000 psi and even the old diesels see several thousand psi at the injectors. That little pump isnt going to generate anywhere near enough pressure to actually atomize diesel enough to run near stoich. Your test is pretty much all that can be expected. Cool test though, Nice work! If your aim is to burn all the diesel with a minimum of excess air you will need a smoke opacity meter. It looks at the exhaust as it is traveling past the meter and measures how "cloudy" it is. You can then reduce excess air until the meter starts seeing particles in the exhaust and you add a little more air and call it good. Thanks for the videos!

[@DavidMcLuckie]

Oooh a smoke opacity meter. Like they use for MOTs? Interesting.

[@timk404]

@@DavidMcLuckie I had to google MOT ( Im in Canada) but yes, it looks like that would be the same type of test. I forgot to ask if you had re-calibrated the wide band for the correct AF ratio. Most meters come calibrated with Lambda 1 being equal to 14.7:1 for gasoline. If you didnt reprogram for lambda 1 to read as 14.5:1 then aiming for 14.5:1 is already rich and would be at least part of the reason you were seeing smoke. You dont have to recalibrate, you just have to aim for 14.7:1 as lambda 1 regardless of fuel type. Again, I love the test!

[@DavidMcLuckie]

I was just aiming for 14.5 in my head. But yeah, the hot surface atomisation isn't really getting it fully atomised. As you say, it was interesting if nothing else. I've looked for an opacity meter but they are way too expensive for me just to tune diesel heaters with. :)

[@martinpanks992]

My Vevor 8kw (probably 5kw) heater responds to changes without having to shut the machine down, I'm sure yours will do the same as they are pretty much all from the same place.

[@dietmarw]

I'd be very interested in a similar test for the 2kW air heater for obvious reasons. Would be happy to help with the purchase of the new controller ;-)

[@timdeans6403]

agree

[@RGD-Audio-Repairs]

So higher numbers on AFR gauge.. means Leaner?!?! Lower numbers means Richer?!?!

[@fisherkieds6282]

I had an issue with my cheap 2kw diesel heater,I put into high altitude mode that slowed the fuel pump and now it works like a champ....I'm at sea level

[@Nerd3927]

My biggest concern is soot at low settings. I just disassembled my clogged up heater. I will try a higher minimum rpm next time.

[@englishrupe01]

The reason that it's not easy to calculate those Hz numbers from 1 or 2 readings is, i think, that it is on a logarithmic scale and NOT a linear scale.....so very difficult to calculate/extrapolate. Excellent video, though, thanks.....very funny whilst being extremely informative.

[@cdaxfiles6435]

Lmao. Sounds like it was about to launch. Might make a good Pulsejet LOL :) Good interesting video.

[@GatorOverland]

@David McLuckie & @Andrew Bartleman thanks for the great video and valuable information. After reading through all the comments i see many folks referencing to test the CO for proper tuning, but don't say any values that would be ideal. Could either of you shed some light on good CO values to test by? keep up the good work David!

[@jezwinters1574]

@Gator_Overland Hi - I've been researching this too and tuning a 5kw diesel heater using a CO meter. I always run it at 2.1hz and never change that setting, it chugs away c. 5-10hrs a day all winter. It was measuring c. 60ppm with the stock settings (been running for 3yrs on these settings). I experimented with the fan speed and found it was optimised @ 1700rpm, with CO values dropping to c. 20ppm, so low that it doesn't even set my CO meter alarm off. When I changed fan speeds I left heater running for 15mins before taking another CO reading. CO meter was placed in the exhaust airflow c. 5 inches away from the exhaust. So I've set my heater low values at 2.1hz / 1700rpm. Very happy with the results and still seems to be generating a decent amount of heat...will monitor regularly to make sure my results are consistent, have checked the past few days and getting consistent readings. Great video David cheers 👍

[@GatorOverland]

@@jezwinters1574 thanks for the incredible insight… Just curious what meter you’re using and what your geographic elevation is? I will be using mine to heat my rooftop tent, which is a very small space relative to the output of the heater so I would have a preference of being low ppm at the low setting, but Max efficiency at that setting 😂😂

[@jezwinters1574]

@@GatorOverland I'm at 85m elevation and used a cheap yellow CO meter off Amazon which seems to work well. You could apply the same approach but tune/test on a lower hz pulse than I did... gonna try the same on my van, just fitted another heater in there and it's very hot at 1.6hz. Sorry if you got 2 replies, I typed last one out and it disappeared after I pressed send... so I've had another (shortened) attempt!

[@DavidMcLuckie]

Ideally you want little to zero CO. This means that you are burning all the fuel available and not turning it into soot. Be mindful of going too low on your tune. This can be seen by the CO reading going up and down like a yoyo as the flame lights and extinguishes over and over until it finally goes out. I'm going to make a new video on tuning once my combustion analyser arrives.

[@GatorOverland]

@@DavidMcLuckie awesome! Thanks so much for chiming in! As a fellow KZbinr, I appreciate the time you, info, and humor you out into your videos. A big Texas thanks 🤝

[@davidj9729]

(i do this for a living) o2 at 7.2 is a little high you should shoot for 6.5 as it produces fewer harmful emissions and tends to lend itself better to stability on most burners. some burners like weishaupt or riello can run as low as 3% without making bad gasses

[@TheOriginalAndysGarage]

After seeing this I'm not messing with my pump, LOL I don't want to end up with a farting heater

[@DavidMcLuckie]

As long as you take note of the settings before you start messing around you'd be fine.

[@campervancreations7656]

Excellent video, have a 5kw on order for my camper build, just waiting on Delivery. I work on diesel/Kerosene heaters as part of day job, very hard to hear the noise on low Hz and pump speed but is it a high speed pulsed combustion, if so, your making a fuel/air bomb motor.ie. scram jet. Possibly getting pulsed fuel detonation rather than a clean burn. It's probably going to take a while as air/fuel sweetspot will lead to many new swear words being invented and some you though you'd forgotten.

[@phuquetwo]

So I just got my 8kw version with the blue lcd and red remote. It goes factory from 1.4 to 5.4 hertz. I've noticed a couple of wierd things though that I haven't seen mentioned in any of these videos. Maybe it's a new function? Anyways my heater will start out on high no matter what I do. Set to 1.4 when I turn on, but takes 5 min and runs on hi as it goes until all bars are reached and then it will slowly go down to where you set it. Another weird thing is I can smell the diesel coming out of the main blower while it's just starting to warm up. I thought these were totally separate chambers? It goes away after it warms up or at least I can't smell it anymore. The last thing is I notice when it's on the highest setting, the pump is usually fast. But then it will instantly "no slow down" jump to half speed pumping with the fan going the same speed.? After a min or so it will instantly go back to fast pump. It will continue this cycle every min or so. Is this normal? Like it thinks it's getting too hot and lowers the fuel amount without adjusting the fan speed.

[@DavidMcLuckie]

Other than the smell of diesel that's all normal. They start high to get the burn chamber up to temperature. At full power the unit throttles the pump to control temperature, if it can't throttle back enough it decides it's overheating and shuts down. I'd take the lid off your heater and make sure the rubber cover on top of the glow plug is fully in, that might be the source of the smell on startup.

[@mouses911]

What size is your pump? I have a 5kw version and was curious.

[@andreasarncken8309]

Hello David, thanks for the video, explains a lot. Just bought a 5KW unit to heat a (living -) container, had it on a test-run and it sooted up in about 6-8hrs of mixed operations. Problem is that I am located at 2.850 mts above sea level (9.350ft) and the factory settings are obviously not adequate, although the display surprisingly shows the altitude. I thought that it was maybe self compensating for high altitude... Problem is that the display provided is of a different type (only 3 buttons on the bottom), so I´ll have to figure how to do the adjustments....Would you happen to have any suggestions on which parameters to start with, running on Diesel???

[@DavidMcLuckie]

As you're higher up with less air to burn, you'll want to dial back the fuel injected into the heater. May I also recommend a cheap CO test meter.

[@MittyNuke1]

I was told by someone very familiar with these heaters, that the altitude reading seems to have no impact on the control of the fuel pump, which I agree is strange since they obviously went through the trouble of reading the sensor value. Maybe some day in the future? But yeah you want to dial the fuel back for higher altitude operation.

[@viscous3936]

Can you please explain the PF (pump frequency) setting along with the magnet 51 or 52 settings? Im very confused on how this part works and my heater wont run high rpm.

[@garyreed354]

The noise is only when it starts up when there's too much fuel and it goes away and probably will run fine once it warms up it only happens sometimes not broken

[@ContentCentral1]

Any chance of you testing a little forced induction with a small 12v fan and that bigger 65ml pump?

[@wilvandendoel6782]

Hi David, nice video, but tuning it to 14,5 is giving you max power, not max efficiency in my opinion. Diesel engines are tuned between 18 and 24. Wouldn,t that be the correct setting for the heater to?

[@DavidMcLuckie]

If it was an engine yes. But we want true stochiometric ratio so all the fuel burns in all the air giving maximum heat output. Running leaner would simply be less heat, great for an engine, not so great in a heater. :)

[@wilvandendoel6782]

Thanks for your answer, I am using a dieselburner for 20 years now on my barge, When I put in a new nozzle I always richen it up untill I see smoke, then lean it up a bit, put a sheet of toiletpaper in front of the exhaust, and if I see some black deposit, lean it up a bit more. Always been perfect this way, never used a lambda. Would be interresting to see what the lambda value of my setting is. This method is not possible with this chinese burners because you have to shut down before adjusting, have one in my van now. So your video on using the lambda is a good tip. I will trie it some day.

[@GaryMcKinnonUFO]

Very cool indeed.

[@kevinmcdermott3668]

Hello there , I wonder if you have came across fault E07 Disconnection fault, I have just installed a new 5kw diesel heater & this fault has came up on the control panel & I am finding it very hard to get rid of it , My manual I got with the heater tells me it's the communication line or plug between the switch and the controller is open or falsely connected . I have undone all plugs & sprayed some WD40 & made sure they click back together but I am still getting the same fault .

[@philwalton1009]

Had to strip my new 5kw just after 5 days as it was absolutely caked up inside. Just on factory settings. If its sooting up that quick what recommendations does anyone have for me to reduce this in the advanced settings, is it sooting up quick because its overfueling.

[@johncampbell4498]

with diesel combustion you are better always to have a comfortably lean mixture meaning Lambda>1.5, that is +50% compared with the ideal, in terms of AFR that would be 14.7 x 1.5= 22:1. That is actually the smoke limit(most rich setting) of the majority of diesel engines, which are Always operating with excess air, it is the fact that a diesel engine runs without an air throttle. If you calibrate your AFRs lower than 22 i think despite the appearance of smoke free, you will be running the combustor at a too rich condition which will create excessive soot inside over the course of time, you will not notice this unless you perform a long endurance test. What would be useful is if you repeat your AFR measurements on an out of the box high cost Webasto or Eberspaecher diesel heater to see how is their factory setting AFR on peak heating, and you should also benefit by logging the gas temperature by adding a gas thermocouple in your exhaust path near to that Lambda(AFR) sensor. Q. Can you get a 0-5v signal from that AEM? this you could send to an Arduino and log that value against time, which will become more meaningful if you also logged the gas temperature at same time.

[@ZerHour]

Update : re my previous post about humming noise , found the problem air intake pipe was insufficient either deformed or to much restriction ,replaced with new pipe now no humming at all ,pretty amazing how slight restriction /bends in the pipe can effect it

[@DavidMcLuckie]

Well done. Same goes for exhaust. That's why one persons settings might not work for someone else. Every bend is a restriction and alters how the heater runs.

[@ZerHour]

@@DavidMcLuckieGreat stuff David , one thing I have noticed is listening to the pump ,set on full the HZ (ticking rate )seems to vary on the HZ the tick tick goes faster for a few seconds then slower for 5 secs then faster is this normal ? There's a fair bit of difference in HZ I thought the pumps stayed at a certain HZ dependant on the control setting

[@andrewbartleman9169]

Yay some good content for us. Glad to see you looking at tuning. We are pretty good at this stuff over in the Facebook groups. We use carbon monoxide analyzer or combustion analyzers for boilers and furnaces. 7hz!?? You are nuts my friend.

[@DavidMcLuckie]

That's a good way to do it as well, those boiler gas analyzers are expensive too. The AFR gauge will end up in one of the Subarus. :)

[@andrewbartleman9169]

@@DavidMcLuckie yeah the people in the groups will buy one of the cheap Amazon gas analyzer and that measure carbon dioxide and monoxide. They work great. Your setting of 7hz is unheard of in the community so I'm interested in seeing what your co ppm is. And that low resonance hum you have is when your mixture is off. Either by a sooted heater that is not atomizing the fuel properly. But I think its because the top of your fuel map is way up at 7hz. People that try to start them at 8hz cant even get them to light. Also you can adjust while it's running by the way :). I posted you video on our groups page.

[@DavidMcLuckie]

Have you got a link to one of the analysers you use, I think an AFR to CO comparison would be interesting.

[@jamesknowlson9278]

Hi david great videos and very informative. Ive a query are the fuEl pumps supposed to speed up and down every 30 seconds or is there something wrong with my new unit. Thanks James.

[@DavidMcLuckie]

At fuel power and if you use the heater on Hz mode instead of temperature I can hear the pump speed up and slow down to stay under the overheat temperature.

[@jamesknowlson9278]

@@DavidMcLuckie ah OK, can hear it when 5.5hz as well. Will try in temp settings. Thanks for reply

[@ZerHour]

Hi David , I get that humming noise but mine is the controller that you can not adjust settings , any idea what causes the humming ,new burner fitted all cleaned out but still hums especially when warming up , is it to much fuel or to little that makes the hum ?

[@hunter00047]

Can tell you watch Ave, same camera problems!

[@curtism7203]

Focus you F#$%!

[@hunter00047]

@@curtism7203 precisely

[@VANFLIPPINGTASTIC]

my controler starts with the message p12v and i cant get rid .. any ideas. and when i turn up or down the temp it come up with h-1 to h-6.. h-6 been the hotest and fastest

[@zygielful]

Hi David, would 6.8ml flow rate super silent Autoterm Planar pump work with 5kw chinese heater? I have just ordered one and I hope I would find the way to adjust the settings accordingly. Any advice please? Great channel 👏👍👌

[@DavidMcLuckie]

It will work in the sense that it will connect and pump fuel. But you will need to adjust the fuel settings to match the pump. I'm not sure what their 'flow rate' is measured as.

[@STRUTZKOFF]

To add this is actually a lambda sensor. And it’s display is dumbed down a clean burn would be lambda of 1 and this display should show 14.7

[@STRUTZKOFF]

To add. I noticed this when using the sensor on flex fuel or going to ethanol methanol . Methanol is afr of 7-1 and ethanol 9-1 . This sensor will indicate 14.7 when at stoic of methanol and ethanol. Of this make what insaid clearer . So the sensor should really read I’m lambda 0.5 -1.5 to make things little more intuitive. Luckily diesel and petrol the stoic afr is very close so your tests did make sense

[@dannywilliams6643]

I'm new to these. I have one of the all in one variants. I'm 735 obove sea level. Do i need to tune mine? Ive only hear of people doing this that are above 1000?

[@andrewradford6267]

Are lambda's aimed at explosive combustion configuration vs almost low pressure jet turbines continuous burn? My settings are 1hz 1450 and 5hz 4500.

[@DavidMcLuckie]

These / This sensor is for downstream in the exhaust. Somewhere between the manifold and the first catalytic converter in an exhaust. In turbo cars you have them ideally 12 - 18 inches after the turbo but as far from the exit of exhaust so they don't get any fresh air to skew the reading. All they want is a flow of gas over them. This sensor will end up in one of the Subarus.

[@andrewradford6267]

@@DavidMcLuckieWhere did you get this from? Handy thing to have! Very neat welding fyi.

[@s2oooo]

@@DavidMcLuckie I have one in my Honda S2000 running 22psi on a gen2 gtx3582r 👍👍

[@dougferguson5581]

Hi is it best to start my Planar 8DM on high. For a few minutes then turn it down to burn off the build up inside ? And how do I check the hertz from my pump? It burps and facts a bit some nights. Wondering if that's the diesel air ratio .

[@moonhead911]

Hi mate great vedio. Question I have. Do those pink fuel pump dampeners sound deadening things make a difference to the ticking noise many thanks

[@DavidMcLuckie]

Not really no.

[@harryharry8384]

love the video, you re a tryer lol. or you could use a meat thermometer measuring heat output starting by setting low on 0.9 and fan at original 1450. take the temperature and adjust only the fan up in increments of 100 checking the temp until you find the point it drops then go back 50 or 100 and that's it for low setting and then you can find you re own way on high setting. By the way I set my heater while its running so I assume you can and it s that clever it speeds up the fan while you set the fuel then settles back down etc... suggest you treat yourself to building a lithium battery and demonstrate how they can supply an indicated 12.8v constant voltage for one of the heaters and you open up a whole new avenue of youtube videos for you to advocate them for motorhomes and boats !

[@MittyNuke1]

I wonder if the afterburner controller could use the AFR gauge as an analog input to automatically adjust the hz once the heater is up to temp 🤔

[@randydicotti3975]

Your results make me wonder if a slightly higher pump volume might help with your particular heater? 28mL ??

[@plllot9713]

no point in trying and hitting the stochiometric AFR in these in my opinion. yes, you will get potentially better burn and higher combustion temperature hence more heat output BUT diesel can run lean. the leaner it gets the MORE CO (this is why I'm not a fan of tuning these based on CO readings) but the less carbon deposits and this is our main concern I think. you might set it up perfectly but then it gets a bit sooted over time, the air flow becomes lower, the mix gets richer, soots up even more and more and more and you go downhill from there. best to set it leaner, get as little carbon deposits as possible and run it trouble free for longer. I set up mine years ago just based on my gut feeling, it was 0.8 - 4.5Hz 1950 - 4500 RPM and over years of occasional use it barely sooted inside. I traveled Alps number of times and stayed 2000m asl for days and never had any troubles. it ran lean enough at sea level so that it didn't even need tuning while going high up.

[@jarlare2826]

It would be interesting to see if vegetable oil would burn if you change the air/fuel ratio. The stoichiometric ratio for veg oil is 13:1, so even lower than diesel. Additionally that would mean less air that the glow plug would need to heat up, so it should get warmer. Is it possible to run the glow plug longer? Keep up the good work!

[@DavidMcLuckie]

The problem with veg oil isn't AFR or energy density. It's viscosity. Veg oil will burn, but you need to pre heat before it enters the burn chamber. On these heaters the glow plug isn't heating air. It's heating the fuel to the point it vaporizes and ignites.

[@irishrover63]

Hi David, I have a 2kw heater and my lowest pulse setting is 1Hz and highest 3Hz. I don't understand why I don't get a full display on heat up. Only getting 2 green, 2 yellow and 1 red segment. Only had the heater installed a few days ago. Any ideas?

[@DavidMcLuckie]

3hz is a bit low. Great for CO emissions but not for producing heat.

[@oojimmyflip]

​ my 2kw is producing a steady 20 degrees C in my house with one red bar at 2.0 Hz turning it up to 3 Hz at start up easily lights up both red bars. my lowest setting is 0.9 Hz at 1400 rpm and the higest is 3.1 Hz at 4500 rpm. are you heating internal air or outside air? ouiside air in winter may be making it struggle a little. at startup it does take around 15 to 20 mins to reach full temperature. 2 red bars. I tend to set the temperature to 2.5 Hz for startup it will throttle to max 3.1 Hz starting up reach two red bars and throttle back to 2.5 Hz I usually wait for the ambient temp to reach 20 degrees C and drop the setting to 2.0 hz after about ten minutes at 2.5 Hz. then it seems to maintain 20 degrees C at one red bar nicely. sometimes I do think there isnt quite enough heat being produced but witrh my adventures in changing the settings being such a failure and raising carbon monoxide levels, I am a little fearful of trying again. David when you tested your Planar 2kw heater you told us the max settings were 3.1 Hz factoy settings are you thinking of a 5kw unit in your answer to the O/P? 3.0 Hz would be low in a 5kw heater but not in a 2kw heater which seems to flood at settings higer than 3.1 Hz or mine does anyway maybe thats Abbey-Normal. This is exactly why I wqould like to see more from you on 2kw heaters please?

[@daan3298]

Yes 2KW version please!

[@philliplopez8745]

A lean mixture burns at a higher temperature . I run my heater at 1.5 Hz and 2550 rpm at idle and 3.5 Hz and 5000 rpm at heating for best economy at 5500 ft altitude . No soot build up experienced.

[@BensWorkshop]

I would have thought that you would want a mixture that leans towards lean to prevent carbon build up.

[@garyclough7115]

Hi David. Could you advise what the best settings are for a 5kw. ie min and max hz for fuel and min and max for rpm. Thanks

[@xxbambamxx7261]

I have 1.7hrz 1450rpm on the low, 6.5hrz and 4500rpm on the high side.. There are no soot and no smoke coming out of the heater.. But this makes the heater hit the max the temp protect before it turns itself down for a few seconds to reach 245°C and stabilize again, so maybe I need to adjust the high fan speed a little more..

[@peterlambert9123]

Not sure if it's been said Air fuel ratio for Diesel is in the range 18:1 to 22:1 that.s why the Hz to fan speed was so far off and it black smoked. Obviously on a Diesel engine you don't restrict the air so there is no fuel ratio to speak of. the ratio above is the minim air for complete combustion, you can't have a weak mix, although in a boiler you can have too much air it takes the heat away but then that's a draft ish...

[@AlinCarpOnTargeT]

Hi what are the consumption differences between 5kv and 8kv (diesel fuel and electricity) thnx

[@SpoonerTuner]

"5Kv" = 5000 Volts. And 5Kw = 5000 Watts. The heaters are rated in watts which is a measurement of energy (in this case heat) being produced at any given moment in time. Heat energy and electrical energy can both be measured in watts.

[@scattkiwiman]

didn't know you could tune these things. good idea to use and AFR gauge. But I guess these are calibrated for 14.7 petrol engines, but sure it will give a good indication. But I wonder what would be economic?. Trying to run as lean as possible without the flame extincting (and loosing less heat through the exhaust ?)