Scaled-Up Engine Design

[BronxFigs]

I just joined this forum, and I would like to know from the more experienced engine builders if the following idea is even possible, and more to the point, will it yield a viable, model, engine that might/will actually operate?  Or, am I a lunatic?

I would like to scratch-build a larger air-cooled, single cylinder, 2-stroke engine, with a bore of about 1.500"  Similar to an old Maytag, or, marine engine.  I have some old vintage airplane engine plans that I purchased from Roger Schroeder.  The plans show the dimensions and timing events for some small, piston-ported airplane engines.  If I scale up the plans, can I use a dial caliper and measure all the important relationships, and build a working engine from the new, larger dimensions?  Resulting engine will just be used for display purposes.

Now, I know you just can't scale up plans because...you just can't.  Weight of materials, volume displacements, air-flow rates, etc, etc.  don't scale up.  My question is really, can a scaled-up version of an engine be used as a prototype, and then, make the necessary adjustments that are needed to get the engine to run?

I know just enough about engines, to know, that I know nothing about engines.

Should I forget the whole idea?  Should I seek professional help?


Frank

[gbritnell]

Hi Frank,
You are correct in stating things like weight, strengths, etc. There are also things to consider like fastener size although it's not a big issue. The biggest problem is that increasing sizes of all the parts doesn't take into account volumes. Here you're taking about squares of numbers. (pi x r sq. x stroke) This would affect compression ratios. It's not that by increasing the size it wouldn't work, it's just that after all the work of building it, it might not work as well as you would have hoped for.
gbritnell

[b.lindsey]

Frank, when I began the 1/2 scale Briggs & Stratton engine project, I had many of the same questions with the exception that I was scaling down rather than up. A lot of the same issues come into play however...namely...will it work at some size other than it was originally designed.  I was lucky I guess in the end but I was also 2+ years into the project before that answer became clear.  The only advice I would offer is to see if something has been done in the size you wish to build...in your case a 2 stroke of 1.5" cylinder diameter. If it has then that should give you some confidence that the core criteria can be done successfully...even if the overall appearance of your scaled up design may differ from other successful designs.  In my case the 1/2 scale resulted in a 1" bore and 1" stroke...both fairly common in the modeling world. No that didn't answer all the questions, but at least gave me a confidence boost at the outset.

Bill

[Ramon Wilson]

Hi Frank - Whilst I agree with everything that George has just said regarding the problems of weight/bulk and certainly heat that needs to be considered when scaling this is not something that should put you off at this stage. Reading your post gives me the idea that you are after something similar to what I have been doing for a while which is taking a commercial model aircraft engine design and scaling it up.
In this case the finished size chosen has been 5cc so quite a bit smaller than something with a 1.5" bore but so far the original engine parts have been carefully measured and drawings prepared to give the relevant capacity by multiplying them by a scale factor concluded by trial and error from the original bore/stroke dimensions.

All the engines made to this method have so far proved to be a very enjoyable machining exercise rewarded with some good running characteristics. You may be interested to read this post on HMEM for the Super Tigre 1cc diesel scaled to 5cc
http://www.homemodelenginemachinist.com/f31/super-tigre-g32-1cc-diesel-5cc-version-17674/
and this one, a 2.5 cc scaled to 5cc currently running on here
http://www.modelenginemaker.com/index.php/topic,1334.0.html

Should you need anything enlightening from the above you only have to ask

Hope that helps - particularly if it encourages you to have a go - do you have any specific engine types or subject in mind - diesel, spark or glow?

Regards - Ramon

[BronxFigs]

gbritnell,

Thank-you for the quick reply.  I surmised that a scaled up version of a proven design would need some major tweaking to get it to run.  I have no clue as to how to go about doing this.

*****************************************************************************************************************

Let me ask you and the forum members this:

Question:  Are there programs, or web-sites, or some general formulas that can help a novice like me get some dimensions/relationships for a working, 2 stroke engine?  In other words, plug in some values e.g. bore and stroke, and then get computer generated timing events, port sizes, and distances, con-rod lengths etc. figured out for you.  Does something like this exist?

I ask because in order to get a two-stroke engine to work, certain things must happen at a specified time.  Ports must open and close, gas/air vapor gets sucked in, compressed, ignited, exhausted, etc.    A small, vintage, airplane engine has transfer ports, exhaust ports and and intake ports all working in relationship to crankshaft rotation and where the piston is inside the cylinder.  An engine that's 5 times larger than the original size still will need to have the same events, and  the same features, but just where ports are drilled and located on the cylinder, and port sizes/areas will change when scaled up, as will fuel supply.

So, e.g. I want to design an engine that has a 1.500" bore and stroke.  How do I figure out the porting, port sizes, distances etc. to get a working engine.  There has to be parameters, rules-of-thumb, programs,  that one can use to get critical values as guidelines.

Just curious.   

Frank

[ScroungerLee]

I would think that a moped or scooter engine would be roughly that size if you can find one to inspect.  A small motorcycle engine might have something near that bore, but is probably overly complex to copy.

I am probably wrong, but I don't see why the port timing, i.e. the positions in the cylinder would be different.  They just need to be in the same relationship to the position of the crank.

Lee

[tangler]

Frank,

Probably not terribly helpful but Edgar Westbury's (ETW)2-stroke Bee range of engines were about the size you describe.  The plans for the Busy Bee are available from Myhobbystore.

Rod

[BronxFigs]

Thank-you all for the comments and opinions.  At this point I am inclined to think that I am entering into virgin territory, and that nothing can be gained from not trying.

As a point of departure, I will use a photo-copy machine enlargement of one of the vintage airplane engines.  All of the porting will be above the crankcase, and easily visible...no inside passages for fuel transfer.  Simple carb. hanging off the back of the engine, cooling fins, exhaust pipe, etc.  Very vintage looking engines like the Original Ohlsson, or, Jr. Brown are what I have in mind, but only much larger in scale.

Taking dimensions off a scaled up photo is easy.  But the port areas may have to be changed to get the correct fuel mixture and exhaust speeds in line with the original designs.  A two-stroke is nothing more than a pump with a spark-plug, but getting fuel and exhaust in and out is key to a successful design.  I may just have to use a "sacrificial" cylinder drilled with with scaled, hole  locations, try the design, plug holes and re-drill  porting the holes in different locations, until a viable design is found.

Thanks for the encouragement to go forward.  You can be sure that I will let you know about all the failures, and IF I ever work out a successful design.

Frank

[b.lindsey]

Go for it Frank...full steam ahead as they say!!!  Once you get your arms around the overall design, i am sure some of the many experts here can help out as the rest of us sit in the cheering section watching and adding encouragement.

Bill

[Jasonb]

I'd suggest basing it on a largish engine and then your less likely to run into problems than if scaling a smaller engine several times.

Soemthing like this maybe, and all you need to do is multiply by 1.5 and make small adjustments so shafts etc fit stock sizes

http://modelenginenews.org/tinysuper/index.html

You also need to remember these will still be quite high reving engines, I think you said elsewhere that you wanted a slower running 2 stroke.

J

[Ramon Wilson]

Playing around with a few figures here Frank and taking an average 60 cu in (10cc) engine as you suggest I would think, depending on the prototype you will need to enlarge it somewhere around 1.5, 1.6 to get the roughly 43cc (1.5 x 1.5 bore and stroke) you first suggest. If however you want the original parameters of the timing to work the same as in the original design you will need to keep the bore and stoke in the same relationship. Scaling up will increase the area of the porting by a factor of four - if you feel that is too large then as long as you keep the top position of the transfer and exhaust openings relative to the shaft centre line changing the area will only alter the flow characteristics and not the timing (of the original design).

Some time back over on another forum (control line model aircraft) I was wondering just how big a 'diesel' (model aircraft type that is) could be made. I was directed to a site which had a 22cc diesel scaled from the 2.5cc Taifan Orkan engine, which according to the builder exhibited the same characteristics as the original. I'll have a look for this for you later

An enlarged photocopy will give you the outline - I'd strongly advise making a set of drawings in the scale you want first though.

Good luck with it, what ever you choose.

regards - Ramon

[BronxFigs]

Jasonb, and Ramon....now were talking! 

The engine that Jasonb suggests is already very close to the size that I had in mind.  At least doing it 50% larger would be easier for me to conceptualize than doing a big version of a tiny engine, and making it look like it was on steroids.  The "look" of the engine can be what I want it to be...it ain't critical.  It's the timing events and port sizes that had me over a barrel.  But Ramon mentioned some things that made me stop in my tracks when I read it  His whole first paragraph almost told me what I must think about when up-scaling any design.  If the ports are in the same positions the timing doesn't change...just the area of the ports change. Ummmm....a clue!  Keep the bore to stroke ratio the same, etc, etc.

A while back the now defunct, "Strictly IC" did a series on constructing a "Double-Dyno".  The "DYNO" is a vintage, diesel, airplane engine.  The revamped plans called for doubling most of the original dimensions, and the finished engine looked the same, but just twice the size.  Nice, but still too small for my blood.

Gas Engine Magazine also showed drawings for a two-stoke, 1/2 HP, Crown Motor Works engine.  However, the original drawings are not complete, and some critical dimensions are missing.  Not being very clever, I cannot reverse engineer the engine, and deduce the missing port locations.

So...I'm going to do as suggested.  Either look for plans for engines that are about the size that I want, or, take dimensions from a scaled up copy of a proven engine design and Finagle-Factor the port areas until the contraption works.

I love a challenge.  I am psyched at this point, and have already bought steel tubing for the cylinders.  The con-rod will come from scrap plate.  I have some odd size cut offs of bronze oil-lite bushings for the con rod ends and crank shaft.  See, the engine is already half built!  Just some minor details to work out.

I'll be back.  Thanks, one, and all, for not telling me to forget trying to build this pipe-dream.

Frank

[Jasonb]

Be careful machining teh oilite, it needs a very sharp HSS tool. Carbide will close the pores as will trying to ream it.

Also what plate will the con-rod be, it usual to use a higher spec alloy such as HE15 (2014), probaly OK for lightly stressed engines but if it should fail it could undo a lot of hard work.

J

[Ramon Wilson]

Yep definitely need higher strength ali for the con-rods and the use of oilite bearings in the con rods is a no no really as it will soon compress under the stresses involved and quickly give a worn big, and in all probability, little ends. Either use a roller bearing - which you will probably be able to on this size of engine or a hard drawn phosphor bronze bush for the big end and nothing on the little end.

I'm not sure what you mean when you say 'doubling'. Be careful about making it twice 'physical' size that will be a big increase all round. Doubling the capacity on the otherhand is toatlly different and that's where I'm referring to about using the original bore and stroke ratio to obtain your scale factor.

Eg Original (arbritary figures) bore 20mm stroke 24mm = 7.54cc

Scaled version - say 1.8 = 20 x 1.8 / 24 x 1.8 = 43 .97cc

if you now scale all your dimensions of the original engine by 1.8 you have your working dimensions

Back later if need be - I'm off to watch the box 

Regards - Ramon

[gbritnell]

Hi Frank,
To answer a couple of your questions from earlier on.
1. 2 cycle engines are totally different from 4 cycle engine. I don't mean that in a condescending way but they are.
2. There are a couple of different types of 2 cycle engines in regard to intake charging. One is called a piston port and the other is a rotary valve.
3. The size and locations of the ports, intake, exhaust and transfer, can be varied quite a bit depending on the operating rpm of the engine.
4. 2 strokes have another feature in the combustion chamber called a squish band. This aids in the burning of the fuel on the combustion cycle.
5. 2 strokes are much more sensitive to exhaust design. A process called scavenging comes into affect.
I haven't elaborated on any of the 5 issues listed as it would take way too long to explain them. The best thing to do is just Google 2 stroke engines and study the material.
I grew up with 2 cycle engines on dirt bikes and as with everything I get involved in I buy books, or go to the library, to study the theory and operation.
I wouldn't say that you couldn't just 'dive in' but a little background on the theory would certainly clear up a lot of questions that you might have.
gbritnell

[BronxFigs]

Holy crap!  I know even less than I thought. 

It is a great thing for you guys to step in and make comments about my rather naive intentions to build a larger, two stroke by scaling up plans.  The more questions that I ask, the more complicated it gets.  But I'm glad that you guys are setting me straight and correcting many of my misconceptions.

Jasonb:   re: Oil-lite bushings....  Thanks, now I won't use them, and I have been warned about their machining difficulties, and deformation under stress.  You have no idea how you saved my blood pressure.  I'm glad you let me know that there are better choices for bearings, and con-rod material.

I will need to do a lot of research before I make some chips.  I will let you know what I plan to do, and how I will do the machining of the parts. I hope you guys jump in and give me suggestions about materials, etc.  That's how I will learn.  I'm looking at some piston ported, vintage 2-strokes.  When I chose a design I will post the engine specs. for consideration.  Also, I will post the scaled-up specs. and critical distances for the ports, etc.  I don't think I could just post drawings because the original plans may be under copyright.

If this project ever gets built, it should be interesting, to say the least.  It will either be a triumph, or, an abject failure.  Either way, I will be learning something.

Thanks for all the great input.

Frank

[Bogstandard]

Maybe to help anyone interested in the engine 'Tiny Super' that Jason gave a link to.

The pages were all muxed ip, so I have put them all into correct order and turned it into a simple PDF for download.


John

[BronxFigs]

UPDATE......

Pulled out some old magazines from my dusty closet, and found some drawings for some larger two-stroke, "working engines", vintage designs,  from the early 1900s.  One drawing shows a 1/2 horse, two stroke, and most, but not all, critical dimensions.  Actually, the engine looks like an old-fashioned, single cylinder air compressor.  I wonder if I can use an old compressor and rework it to become a two-stroke?

Anyway, I now have some working dimensions for a few engines.  When I get started on this "reinvention-of-the-wheel" I will keep you posted.  This whole idea just morphed from scaling-up old, vintage engine plans, to just duplicating an existing design...but giving it a new exterior look.  The "fun factor" is starting to fade....

Frank

[BronxFigs]

So, I read, and then read again, all the comments, suggestions, caveats, provisos, etc.  I'm still hooked on the idea of scaling-up the dimensions of some vintage airplane engines.  Why?  Can't answer that. 

Downloaded plans for a vintage diesel engine called "NOVA-1".  It's a slower RPM-er, long-stroke, engine, piston-ported...with all porting holes drilled externally on the cylinder in the proper locations.  So basically, I need a crankcase, cylinder, piston/con-rod/crankshaft, carb, cooling fins.  I will only use the timing events, and scaled-up port locations.  The external appearance of the engine is of no importance, and I will not be reproducing this engine.  I chose this engine because of the external porting locations, ease of construction, and because I don't have to deal with ignition timers, plugs, etc.

Now a question:  Let's, for the sake of argument, say that I manage to build this engine-on-steroids.  I need to also worry about crankcase volume in respect to fuel/air.  I would guess that the internal volume of the crankcase should be kept to a minimum so that the fuel/air mix can be sucked into the cylinder at the correct rate when the piston opens the lower transfer port, at BDC. I need help here.  The side-views of many of these model engines show very small crankcases with just enough room to enclose the crank-disc, and lower con-rod.  This must be by design, and critical for air/fuel mix to flow efficiently, and, at the right speeds.

I can make the con-rod, piston, cylinder, crankcase, crank, cooling fins, contra-piston.  Can't figure port areas, and crankcase volume.  I could start by drilling smaller holes in the cylinder for the porting and open the holes gradually until the engine runs, but the crankcase volume will be difficult to change...

I remain undaunted.  All the construction problems can be worked out.  The 'Finagle-Factor' will be employed.  With your help, someday we can watch the engine blow up on You-Tube!  : ))))))))))))))))

Frank....Non compos mentis

[Jasonb]

What size are you thinking of increasing the design to? There is likely to be a limit to how far these compression ignition engines can be scaled up. You also need to make sure you can source the fuel or ingrediants to mix your own, its getting a bit difficult here in the UK unless you move in the RC aircraft circles.

Ramon should know whats a safe factor to increse these designs by plus I think he has built a Nova-1

[BronxFigs]

Jasonb:

The original, 1943 plans call for:
bore: 16 mm
stroke:22 mm
4.5 cubic cm.

I want to try to double the scale.  You-Tube shows this strangely proportioned, tall-looking engine.  I will NOT reproduce the "look" of the engine.  I just need, and will use, the critical relationships, timing events, port locations, etc.  I'll make the rest to my own whim.

You-Tube shows a 12 cc "monster" diesel engine from WWll vintage, and it's a nice size.  I also wondered if there was a limit to how big this style of diesel engine could be built.  Ramon refers to a large diesel in an earlier post on this thread, so it might be able to be done without too many problems.

Thanks for the speculations.  I haven't thought about fuel issues at all.  Maybe Ramon will chime in with some hints.

Frank

[Jasonb]

When you say double the scale do you mean 32mm bore x 44mm stroke giving 36cc capacity or double the capacity to 9cc?

The Nova is a tall engine due to its longish stroke.

[steamer]

Yes as Jason asks...doubling the scale or the volume?....multiply all the linear dimensions by 2 and you get 8 times the displacement  (  about 36 cc)

If you want double the displacement, multilply all the linear dimensions by cube root of 2 or 1.259  ( about 8.6 cc)

Dave

[BronxFigs]

Oh boy!  I meant doubling the dimensions to 32mm X 44mm.  Sorry, but now I realize that I know so little that I was inadvertently unclear about stating my intended goal.

I just wanted to make a bigger engine.   The final displacement is not a concern.  It will only be used for showing.  A novelty.

Thanks for catching my mistake in not specifying my goals and intended use for this experimental engine.

Frank

[steamer]

Hey Frank

No worries mate....normal line of questions is all...Cheers!
 
Dave

[Ramon Wilson]

Frank, As your intent is to scale up a vintage type - long stroke, side port engine I would not recommend the Nova to begin with.

My reason for that is that though full of character it's actually rather ungainly even in it's correct size. The cylinder barrel is quite a lump of steel doubling it up just in capacity alone will mean a fairly large lump to machine - take it further and it's going to be quite considerable.

I have a suggestion to make - you say you are not too interested in the original design but in it's details of design such that you want to build an engine of your own external profile but using those original parameters. As already explained the timing will not change but the porting areas may have to. Keeping the crankcase volume to a minimum makes for better transfer but how far up in volume one could go doing what you intend I'm not sure.

My suggestion is that you take something more aesthetic - still vintage and a side port and preferably diesel and scale the capacity up as referred to in a previous post. A Mills 1.3 or the Gotham Deezil, or even that Dyno would be ideal subjects for which drawings are readily available in the original scale. Take it up to something reasonable to begin with - say 5-6cc and learn about the methods of machining to achieve a good running engine - then once successful do it again say to 10- 12 cc. Starting out too big in the first instance you are going to be tackling a lot of material on basically an unknown quantity.

So far most of the scaled up 5ccs built have been from 2.5cc originals as described before. The Super Tigres on the other hand were scaled from 1cc to 5cc a considerable enlargement in percentage terms. One of the things most noticeable is the bulk of material in the finished engine compared to the others.

The large engine I referred to in a previous post is herehttp://www.ronald-valentine-engines.com/75_Orkan_28.html Fuel is definitely something to consider here if making a diesel  of this scale
This engine BTW was to be my next 2.5 to 5cc project after the Tigres but the Eta's got in the way  - it was Taifan's answer to the Eta 15d anyway

Regards - Ramon

[Maryak]

Frank and Ramon,

I was wondering, rather than a side port what about an Oliver port engine. IMHO they are easier in as much as your not playing around trying to fix the side port to the cylinder. Then again I don't know if such would qualify as a vintage engine.

I designed and built one some 5 years ago and it's a runner, mind you it's 10cc with a 16" prop and something of a beast.

http://www.modelenginemaker.com/index.php/topic,499.msg3917.html#msg3917

Best Regards
Bob

[BronxFigs]

Thank you so much for all the helpful comments, suggestions, warnings. I know you would like me to succeed with this engine build, and I needed some direction from the experienced builders on the forum.  I have taken all your comments very seriously.   I planned on attempting a project like this only because I have unlimited access to tons of Aluminum, steel, brass, large capacity machinery, lathes, milling machines, surface grinders, welding equipment, and a friend that has the ability to use all this. 

However, as many suggested, I should start with doubling the capacity, and not the physical size of the original engine.  Points, well taken.

I am not aware of many, many, things in the model engine world, and I had no idea that getting the correct fuel to run a large diesel engine might be a problem.  This never entered my mind.  Is there a problem getting the correct fuel/ingredients in The States too?  Why?

The cylinder for my pipe-dream engine, was going to be made from a piece of steel, tubing with a wall thickness of approx. .250".  I have tubing with various bore diameters, finished, honed, and ready to be cut to whatever length I need for many different engines.  The cooling fin assembly will be separately machined from large diameter aluminum rod stock, or, very thick walled tubing, and then pressed onto the top end of the cylinder.  The head will be bolted to the cooling fins.  The gas tank/carb, exhaust, and transfer porting will also be bolted, or silver soldered to the cylinder. 

If I had the knowledge to post some sketches of my version of a vintage diesel, I would.  I'm not very good with computers.  The crankcase will be made from a short piece of either thick-wall Aluminum, or steel tube.  The front, bearing housing, and back cover will be separately machined and fastened  to the main crank-case with standard hardware.


Anyway, that was my plan.  Maybe it is laughable, maybe not.  I will search out the plans for the "Double-Dyno", and try to build a working engine from a proven design.  Truly appreciate your interest, honesty, and very helpful suggestions.  If successful, I will let the forum members know.  Also, if it fails.

Frank

[steamer]

Hey Frank

If your going that way....1.25 is probably close enough...though I would defer to any advise from Ramon.

Dave

[BronxFigs]

Yes sir....

Consensus seems to go with starting with a proven design for a larger engine, and then, work my way up.  I guess the "Double-Dyno" is a good place to start. 



Frank

[Ramon Wilson]

Frank and Ramon,

I was wondering, rather than a side port what about an Oliver port engine. IMHO they are easier in as much as your not playing around trying to fix the side port to the cylinder. Then again I don't know if such would qualify as a vintage engine.

I designed and built one some 5 years ago and it's a runner, mind you it's 10cc with a 16" prop and something of a beast.

http://www.modelenginemaker.com/index.php/topic,499.msg3917.html#msg3917

Best Regards
Bob

Bob,  that looks like a real finger biter - do you start it by hand? I've never been keen on electric starters always prefering a good flick - you can 'feel' the engine so much better but I think I might be a bit wary of that one  last year when I ran some of the engines at a local event I got a couple of real good whacks which drew a knowing and appreciative gasp from those nearby 

Yes, agreed,  a radially ported cylinder is relatively easy to make - these are the two from the 5cc Racers - one is high tensile steel the other cast.  The ports were easily cut with a home made cutter.


I wouldn't say 'we aeromodellers' over here would consider the ED Racer a 'vintage' motor but the Mk1 dates back to the fifties. I have a full set of drawings for this if you want Frank.


Frank - forgive me if I'm misjudging you but you perhaps are not aware that 'diesel' fuel for these small engines consists of four parts,
Ether, usualy around 30%, Oil, preferably castor, around 25% and Paraffin (kerosene to you I think). An igition improver of around 2-3% though not absolutely neccesary makes for much smoother running.

Most model engine fuel readily available tends to be for the glow ignition motors so tracking diesel down can be a task at times. Here in the UK there are only two main suppliers and one of these only supplies via model shows. Two of the ingredients are easy enough to obtain but the ether and ignition improver can be difficult.

I don't know if 'Dieselpilot' is a member on here but he is on HMEM - he may be able to help you source some fuel over there.

Regards - Ramon

[Maryak]

Bob,  that looks like a real finger biter - do you start it by hand?

Regards - Ramon

No  way friction start with a rubber bucket in the electric drill

Best Regards
Bob

[Ramon Wilson]

Aw really Bob, I know I said I'd be wary but I'd just have to try  .

Seriously though these engines can give you some nasty cuts despite their size. I've had quite a few 'nips' over the years but my first is clearly etched into the memory bank.
I had just turned fourteen year old when a little 1cc AM 10 diesel turning a Frog 7x4 nylon prop decided to run backwards. I reached round to stop it with my left hand with a finger over the intake and the prop cut itself into the side of my index finger for near it's full length. The scar can just be seen on a cold day after all these years. My mother who for some reason was mortified by the sight of blood was really impressed 

Happy days 

Ramon

[steamer]

Aw really Bob, I know I said I'd be wary but I'd just have to try  .

Seriously though these engines can give you some nasty cuts despite their size. I've had quite a few 'nips' over the years but my first is clearly etched into the memory bank.
I had just turned fourteen year old when a little 1cc AM 10 diesel turning a Frog 7x4 nylon prop decided to run backwards. I reached round to stop it with my left hand with a finger over the intake and the prop cut itself into the side of my index finger for near it's full length. The scar can just be seen on a cold day after all these years. My mother who for some reason was mortified by the sight of blood was really impressed 

Happy days 

Ramon

Don't tease him too bad Ramon...I saw the video of that thing running!...It was strapped down to a bench...on the other end was a bench grinder...and while running the grinder was dancing all over the place! ....I wouldn't put my fingers in it either!

[BronxFigs]

Ramon, and everyone else...honestly, I'm flattered that you stuck with this subject and actually have given me lots of confidence to go ahead and try to build a larger engine. 

Nothing is ever simple, if it's worth building.  The old-style vintage, European piston-ported, diesels, always appealed to me.  I thought.... bigger is usually better, so, why not make a giant diesel engine?  Now, you guys taught me that just sticking plans in a photocopier and hitting the enlarge button will not give me what I expected.  I hate complications.  You all looked into the future, and smelled "failure", then steered me in the right direction.  I'll try a "Double-Dyno" first.

Thank you for putting up with my rather silly questions, for your extraordinary patience, for your thoughtful and diplomatic answers, and for not telling me to buzz off and join another forum.

I will report my triumphs and failures.

Frank

[Maryak]

Frank,

We were all where you are now at one time or another. Don't sweat it. Your turn will come to help others. Speaking for myself you can teach an old dog new tricks and many who are new to this hobby have brought with them a wealth of skill and understanding from which I for one have learned a lot.

And now it's time Gerry and the Hat Tricks was in bed, (with a good book).

Best Regards
Bob

[Admiral_dk]

Ether is considered a dangerous substance in today's society, since it can be used to "extract" the "useful" stuff when making many different drugs and like wise for some explosives. So for that reason it's become an illegal substance in it self  Partly understandable, but also a drag.

Most, if not all the ignition improvers where also known as "poppers" and can be considered a heart medicine / booster and are all fatal if taken (or inhaled) in to big quantities - so they are all banned substances too nowadays.

Most consider a beginners diesel to be about 2-2.5 ccm. => not to fiddly in size and not too expensive to scrap the first many flawed parts (we all do them - especially in the beginning). That's not to say that we can't or shouldn't build them bigger, but since bigger than 5ccm. is considered a potential digit remover by most experts - one should perhaps not do them bigger until a certain expertise in running them is acquired