Mini diesel engine.

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GreenTwin

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I burn diesel in my foundry furnace, and it burns cleanly (cleanly being a relative term), with no smoke at all.
I had some concerns about fumes from burning diesel, but it is not like I stand around and inhale the exhaust or anything.

But everyone should remember that if drive your car down the expressway in the US (or perhaps anywhere), you are breathing in tons of exhaust from the diesel engines that are in the trucks all around you.
Nobody seems to be concerned about that.

I did notice that the indoor air quality at the 2019 NAMES show was very bad.
They would announce over the loudspeaker every 30 minutes or so for everyone to turn off their engines so the smoke could clear, and they would partially raise an overhead door for a few minutes.
The combination of all the exotic fuels and fuel/oil blends being burned in all of the internal combustion engines affected my lungs and breathing for days after the show.
There is no place at NAMES to get away from the fumes. The whole building is a "heavy smoking" section.
I am not complaining, it was a great show, but that was a toxic mix of partially burned fuel coming out of all those high-revving IC engines.
They need to keep a roll-up door open at all times at NAMES.

All that being said, I think the exhaust from a single scale model engine is negligible compared to any fumes you will breathe by just driving down the expressway.
So while I fully believe in using great caution with material data sheets for every foundry product I use, and I adhere to every safety warning about foundry products, I think with a single small scale engine, we need to realize that only a tiny amount of fumes are produced.

You can easily die from drinking too much water, but nobody is sounding the alarm about water and how toxic it can be.

Common sense must dictate safety.
I think if you did an analysis on a hamburger, or a grilled steak, or any fried food, you would be shocked at the number of potential carcenogenic things are in those (I don't often grille out for that reason, and I don't eat fried food often either, because I don't want to look like the Goodyear blimp).

We should all be safe in this hobby, but in a reasonable and logical way, with an appropriate amount of caution to match a corresponding danger.

Edit:
The trend these days is to go overboard about safety.
One guy from Australia told a story on a casting forum a few years ago about how his local council decided that all foundry sand was a deadly toxin that destroyed the lungs. They were planning on banning all foundries and all foundry sand.
The guy went to the next council meeting, and spoke at the podium, and said "You are going to have a very hard time banning sand because our city is on the coast, and 100 yards from here are miles and miles of beaches with the very same sand as you are trying to ban".

There is too much fear-mongering these days about seemingly everything.
Awareness is one thing; obsessing about the toxicity of every substance on the earth is not necessarily reality.

.
 

Nerd1000

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Indeed, for perspective: we can safely assume our models, with no emissions control, make 10- 100x as much nasty fumes as an equivalent engine with emissions control systems.

But who here has made a model engine bigger than 50cc? Even assuming 100 fold more pollution per cc, a 50cc model is not going to be much worse than a car with a 5L V8, and there are not shortage of people running those daily, vs our engines which maybe get run once a month on average. Application of common sense is all that is required.
 
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Thanks Nerd, I agree with you about perspective. But maybe you are forgetting that since the mid-1970s, car manufacturers have been adding precious metal catalysts in car exhaust systems, and doing a lot of clever re-design inside the engines - and with fuelling and ignition strategies - so the CO NOW is around 1/1000th of the CO from just pre-emissions laws...
The emissions laws have also doubled the efficiency of the engine, so modern cars use less than half the fuel of "pre-emissions laws" engines.
Mostly, Modellers do not model such high tech modern beasts, but usually the "older" engine designs, and because of a "scale" (linear to surface area to volume) factor, these can be much dirtier than the full sized versions. But like smoking cigarettes, 1 won't kill you, but 60 years at 20 per day (400,000 fags) probably will affect your health... = Perspective.
I run steam engines, using LPG fired boilers. If the burner is "wrong" (too rich), I hear the CO alarm in the garage, and turn off the gas and ventilate the garage. But if I start my Moto-Guzzi V50 (1979 version) in the garage, the CO alarm sounds almost instantly. Even a cloud of exhaust from outside the garage blowing into the garage will set it off! So many modern safety levels (scientifically developed for the legislators!) are much tighter than we appreciated when we grew up... I remember in bad weather, how, walking to school, we would sometimes cough because of the accumulated coal-fire smoke in certain streets... and when I cycled to work in the mid-1980s, passing a steel mill, I nearly collapsed one day from breathing fumes coming out of the open door to the mill! (I just managed to free-wheel into fresh air!) - I guess from a bubble of oxygen-free air? That was how life used to be. We don't NEED to replicate that with our modelling. The local model steam locomotives now have to run on "Smokeless" fuel... and smoking cigarettes and pipes is banned on the footplate of heritage railways with steam locos that now must use "smokeless" coal...! The engine-drivers and firemen must also wear anti-COVID masks! - You have to laugh!
Probably the worst thing that can happen is someone with an engine making a lot of CO (No smell!) runs it in an enclosed space... and falls asleep with intoxication. But if the smoke is sooty and smelly, one is quickly prompted to open a window or door to ventilate the space!
K2
 

ajoeiam

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Thanks Nerd, I agree with you about perspective. But maybe you are forgetting that since the mid-1970s, car manufacturers have been adding precious metal catalysts in car exhaust systems, and doing a lot of clever re-design inside the engines - and with fuelling and ignition strategies - so the CO NOW is around 1/1000th of the CO from just pre-emissions laws...
The emissions laws have also doubled the efficiency of the engine, so modern cars use less than half the fuel of "pre-emissions laws" engines.
Mostly, Modellers do not model such high tech modern beasts, but usually the "older" engine designs, and because of a "scale" (linear to surface area to volume) factor, these can be much dirtier than the full sized versions. But like smoking cigarettes, 1 won't kill you, but 60 years at 20 per day (400,000 fags) probably will affect your health... = Perspective.
snip

Your comment is quite interesting.
I bought a VW diesel Rabbit (Golf in most of the rest of the world even at that time) in 1980 and averaged over 75 mpg (us) over the life of the vehicle.
Drove other previously very abused gas pots in the 90s - - - with most I got a touch over 45 mpg.
Drove a late 60's Mercedes 220D and in longer distance urban traffic was able to get into the same 45 mpg country and that was an over 3 ton vehicle.

Today I drive a Chev Aveo - - - - I don't get into 40 mpg country.
Every newer vehicle I look at - - - dunno if there are any that get into even 40 mpg country.
Most are bragging about economy and they're in the mid 30s.

Please - - - I need a list of these oh so wonderfully fuel efficient vehicles - - - I haven't been able to find them.
What are the brands model and the years?
 

Badhippie

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Just to be clear my comments had nothing to die with the toxic by- products of diesel exhaust. It was all about the harm the by-products of diesel exhaust cause to the internals of the engine. I am pretty sure that was clear when I was talking about seeing rod caps being corroded in half and rod bolts and other internals. It was about maintenance of a Diesel engine. See I don’t have a PHD in anything but what I have is about 40 years of experience working with Diesel engines. It comes from a professional level. Not under a shade tree in the back yard.
 

Vietti

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I agree with Green Twin, the air at the 2019 NAMES show was really poor. I asked the organizers more than once to open the roll up doors but they refused, something about security. I suggested getting someone to stand by the door to provide security. At previous shows the doors were at least partially open and the air was OK.

That being said, I was probably part of the problem by blowing smoke rings. I really hope they will put on the show next year, it was great!!
 
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A Joe I am. I am an odd ball. I worked with Emissions testing (as well as loads of other different jobs) on new models for around 15 years.... So did not drive around comparing cars. But on pretty accurate and repeatable test, had to report the results of testing production cars, for both emissions and fuel economy. So we measured the total fuel consumed during the legislation test. Quoted in gms per 100km. I saw fuel consumption of cars go from 185gms/100km to 100gms/100km. in that relatively short period. But I didn't drive your cars.... Maybe my scientific approach isn't suitable to relate to your world.
Obviously (to me), a car using 100gm of fuel instead of 185 gms of fuel, and meeting emissions regs that are exceedingly difficult to achieve, tightening every 5 or 10 years, will produce lower tailpipe emissions than the older models.
I understand the US of A follows a similar strategy for cars?
I was probably being too general in my statements, for which I apologgise.
Enjoy your motoring!
K2
 

GreenTwin

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Just to be clear my comments had nothing to die with the toxic by- products of diesel exhaust. It was all about the harm the by-products of diesel exhaust cause to the internals of the engine. I am pretty sure that was clear when I was talking about seeing rod caps being corroded in half and rod bolts and other internals. It was about maintenance of a Diesel engine. See I don’t have a PHD in anything but what I have is about 40 years of experience working with Diesel engines. It comes from a professional level. Not under a shade tree in the back yard.
I misinterpreted your post.
Sorry about that.
.
 

minh-thanh

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I have a question :
Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
My answer is : NO , What about your answer ???
So, the whole argument...bla,bla ...for what?
to prove what ?
Remember: this is a homemade engine forum
Reminders such as : Beware of high pressure oil in contact , run with all internal combustion engines in a well ventilated area .... simple , short . perhaps 1000 times more valuable than what is being discussed here.
 
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I have a question :
Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
My answer is : NO , What about your answer ???
So, the whole argument...bla,bla ...for what?
to prove what ?
Remember: this is a homemade engine forum
Reminders such as : Beware of high pressure oil in contact , run with all internal combustion engines in a well ventilated area .... simple , short . perhaps 1000 times more valuable than what is being discussed here.
i think these members just need some friends , instead get on a forum & gasbag about their (apparent) huge knowledge of everthing except model engines , gets way off topic real quick , solves nothing from the original poster , end up with pages of totally irrelevent crap , see it here a lot , in fact , most post get polluted (pardon the pun) just like this diesel post
 

Mechanicboy

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I have a question :
Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
My answer is : NO , What about your answer ???

This also applies to the model engine, .. if you see a lot of smoke or a lot of oil spewing out of the exhaust, then it is an indication that there is something wrong with the model engine. Model engine with little or almost no smoke and good combustion = good economy on consumption and less pollution.
 

minh-thanh

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If you read and understand my post #338 then it's really simple to solve the smoke problem
Just increasing the force of the needle spring almost solves the problem
With my engine , 19 mm diameter and 38 mm stroke and I said it has 10 cc , I don't care much about the 1,2,3 cc difference and who on the forums cares about that , who cares ?
who cares how much fuel a 10 cc or 20 cc engine uses in an hour of running ? who cares ?
who would care about comparing fuel consumption between 10 cc and 20 cc engines, who cares?
Or simply: if a well-aligned engine consumes 20 ml of fuel for 10 minutes running, and with a similar engine that is not well-aligned it consumes 30 or 40 ml of fuel for 10 minutes, with that 10 or 20 ml difference, who cares ???
I see no problem with my engine , the problem is you .
You know what is most important with homemade engines??
Most of the members of this forum or elsewhere, the most important : when building and make engine run , and perhaps no one cares how much fuel it will take in 30 minutes or an hour run (I say " most of members " because I don't know about you)
Pollution problem again , Yes, my engine is very polluted 😁😁😁😁😁
Again, This is a homemade engine forum , Please !!!
 

GreenTwin

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I tend to get off-topic at times, and that happens on forums.
I try to not deliberately hijack threads, and split off a new topic if that seems appropriate.

The reason I post here is that I have learned a lot from all the talented folks on this forum, and I hope I have shared some useful information to others.
Its all about communicating ideas with others, and sharing information and ideas.

Discussion of a variety of aspects of model building is part and parcel to the hobby.
I would suggest that if you find someone's posts irrrelevant, just ignore them and move on with what it is you want to discuss/highlight/showcase.
Everyone has different motivations for what we do, and our interests are as varying as our personalities.

In my opinion, its all good, I enjoy it all; the builds, the discussions, the side talk; it is fun interaction with great hobby folks.
Live and let live as they say.
.
 

minh-thanh

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Hi GreenTwin !

Like I said , some side posts it doesn't matter to me , sometimes I learn something , and I thank you for your post !
The problem is that some people here are trying to prove something and I really don't understand for what !?
They go too far
If you've looked at this thread, you'll find almost 80% of the debate are fruitless,
As you have seen, with a lot of experimentation and time translating into English, just to share some information just hope it helps someone (or not) and the result is dozens of toxic information. harmful effects of smoke, pollution...
 

GreenTwin

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You have a choice.
You can focus on the comments that don't necessarily have much to do with this thread, or you can focus on what you are doing, and share your work with others.
Sometimes I put on virtual "blinders", such as the ones they put on horses, so that the horse is not distracted, and can get its job done.
I enjoy your work, and your videos. Great stuff for sure; you have talent.

Keep doing what you are doing.
Life can be a 3-ring circus; my advice is to focus on what you want to achieve, and keep moving towards those goals.
Stay focused; don't let the side shows distract you.

This is pretty much my motto for living my life too.

.
 

Bentwings

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i think these members just need some friends , instead get on a forum & gasbag about their (apparent) huge knowledge of everthing except model engines , gets way off topic real quick , solves nothing from the original poster , end up with pages of totally irrelevent crap , see it here a lot , in fact , most post get polluted (pardon the pun) just like this diesel post
what kind of diesel are you planning 2 stroke 4 stroke. ?
Davis company had model diesels many years ago. They use his special diesel fuel 2 strokes had a screw in the head so compression ratio could be changed on the fly. I never had one so don’t know the exact construction . I YHINK the screw moved a tight filling piston to achieve variable compression ratio. The fuel was reported as having ether in it . It was supposed to be tightly capped at all times . They has a Venturi intake similar o glow fuel model engines ofvthe era. The small engines could swing a pretty big prop for the size compared to glow fuel engine of same displacement . That’s about all I know of them . There were few at model flying fields . I was into screaming rpm glow engines and twin engine lanes at the time.
 

Richard Hed

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I have a question :
Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
My answer is : NO , What about your answer ???
So, the whole argument...bla,bla ...for what?
to prove what ?
Remember: this is a homemade engine forum
Reminders such as : Beware of high pressure oil in contact , run with all internal combustion engines in a well ventilated area .... simple , short . perhaps 1000 times more valuable than what is being discussed here.
Personally, I like the discussion. I doubt that the last bit of discussion helps build anything but it might help psrevent getting poisoned in you garage. Maybe you are just having a bad day. I know I have had a bad 3 days in a row from traveling and the airlines screw ups.
 

minh-thanh

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GreenTwin !

You have a choice.
You can focus on the comments that don't necessarily have much to do with this thread, or you can focus on what you are doing, and share your work with others.
Sometimes I put on virtual "blinders", such as the ones they put on horses, so that the horse is not distracted, and can get its job done.

Thanks for your opinion !
That's a good idea, maybe I'll give it a try
Or simply start a new thread
Another opinion: " Silence is golden "

I'm a person who doesn't like to argue, this topic I argue 10 times more than I've argued in 2 years in real life, it's too bad with me.
Sorry that my arguments have bothered everyone. I'm Sorry !
This is the last post in this thread .
 

Bentwings

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GreenTwin !



Thanks for your opinion !
That's a good idea, maybe I'll give it a try
Or simply start a new thread
Another opinion: " Silence is golden "

I'm a person who doesn't like to argue, this topic I argue 10 times more than I've argued in 2 years in real life, it's too bad with me.
Sorry that my arguments have bothered everyone. I'm Sorry !
This is the last post in this thread .
I just Hightower another tidbi. The Detroit big diesels had th gmc positive displacement blowers often fed by a turbo. These were 2 stroke enginges very messy by today standards. Various attempts at making miniature replicas of these blowers have not been very good. One that has made them work is Conley engines. H gets positive boost but not much . I’ve followed various turbo charger constructions on the internet but these have not been very good. It’s hard to keep them together at very high revs and they simply do not flow much air. One attempt at a screw bore with 3D printed parts while cute could not inflat a plastic garbage bag. I’d guess even compounding them would not be very successful. Some impeller more or less fake turbo or centrifugal blowers work only to stir up the incoming air fuel
Mix so ok for that purpose . The design of these is pretty complex and the air itsel does not scale well . I have two model turbines and can spin them pretty fast but output air is minimal at best. So if you go after this aspect I’m just saying others have tried it and not succeeded but made some nicely machined parts.

At on pint OS glow engines had a functioning positive displacement supercharge. It apparently worked as it was very competitive with other engines of the era. It was very sensitive o dirt or dust as I recall du to tight tolerances. As I noted it was easy to just add more nitro to make a lot of power. I blew up a bunch of model engine hotrodding them like this but I did have fun.

Byron
 

GreenTwin

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Open forums are a mixed blessing.
I have had people say "I want to post things without my thread being filled up with a lot of side-chatter".
There are forums where you can do that.

Then I have had people post to a forum where there is no side-chatter, and then they say "I am going to another forum, there is no activity here".

There is no free lunch, it can't be both ways.
You can post and get a lot of comments if you thread is interesting, or you can post somewhere with no comments for a clean thread, but then get no feedback.

For me, the feedback is the only way to learn new things.
To each their own.
I like this thread, or I would not be commenting on it, so there is that.

.
 

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