The Bucket Foundry [Archive] - Page 15

Flettner

27th December 2017, 20:59

i love waht neal dose and the motovation , enery to do all this stuff ..but would like him to go 1 step more and make these engine's for a race class and do well ! with them ! rather than just a running engine (-; come on neal , challange time

I guess so. I have raced the F9 for many years in various classes (with its heavily modified fuel injected engine). Wayne Blackwood and I have raced the YZ TPI for many years in the Acerbis four hour, an enduro race class and as to TPI sucess I think KTM are taking care of that.My 700 twin was not ever designed for any race class but never the less is powering my Autogyro at the moment (what it was designed for) a success in my book.
Most of my developments are just too far out there to be completed , fetteled and built to any race class (on my budget or time) e.g. HCCI engine, linier crank engines, sleeve valve engine etc.
The 360 is most definitely aimed at racing, I'm just not sure what class yet, probably just next year's Acerbis four hour or possibly get a young hot shot to MX it. Can be made back to a 250 easily for the class.
These small RV cases I'm casting up now are also aimed at a race class, probably enduro again as that's about all I'm good for now, this engine is destined for the mark two TPI.
I know what you are saying, you are talking bucket class I guess. This set of cases would probably make a great bucket engine but I don't have the resorses to make a complete bucket (I just concentrate on engines)
I post here half hoping someone will take up casting their own project, I don't mind helping, I do what I do and enjoy it, I've learnt some valuable lessons just having a hack at it, lessons you will not ever read about as there just is no information available (no ones actually done it to see what happens), success? Depends on how you look at it. I would certainly like to win some class but I might have left that a bit late now.:second:

Flettner

27th December 2017, 21:27

This case half has a tricky part line. I had to make this special base with inserts. I'll post pictures of packing the mold so you can see how they work. Also has the pattern insert installed so it might run the epicycloid crank. I'll be casting more normal cases, this one with the insert is just a one off.

WilDun

28th December 2017, 14:16

I guess so.........
............My 700 twin was not ever designed for any race class but never the less is powering my Autogyro at the moment (what it was designed for) a success in my book.

The fact that you have a complete self designed engine built and running is a huge achievement in itself!

The 360 is most definitely aimed at racing,
I know what you are saying, you are talking bucket class I guess. ....................... (I just concentrate on engines)
Probably some cooperation amongst those interested, rather than sitting waiting for one to appear might go a long way to acheiving that!

I can only speak for myself here of course not all the other guys (I only know a couple of them personally) but I would suggest that many of us are watching your developments in awe and are afraid to put forward any useful (or otherwise) theories we might have on this subject! - I'm sure many of our ideas (or parts of them at least) are relavent and may actually be useful, but we do need some input from others as well - look at the ideas on ESE - naked and unashamed questions and comments made by all!

I post here half hoping someone will take up casting their own project, I don't mind helping, I do what I do and enjoy it,
I've learnt some valuable lessons just having a hack at it, lessons you will not ever read about as there just is no information available (no ones actually done it to see what happens), success? Depends on how you look at it. I would certainly like to win some class but I might have left that a bit late now.:second:

If I could gather all my ideas, thoughts and aspirations from way back ( I have done that to some degree) and have the confidence to give it a go, I would do that.
However there is a time when it would reach a stage where my expertise in the design and fine tuning (both in engines and foundry work) would probably run out!
I might need some help to achieve my goal, which would not include Bucket Racing of course, (way past that) just to design, cast and build a very mediocre engine (not intended for anything in particular) - don't hold your breath!

To be honest, I am a very late starter, working (read fumbling) in cramped conditions, and do not have the single mindedness or the energy that you seem to have, but I would be pleased to take some direction from you!
I did have an offer of some help by another member but didn't take it up, (sorry about that) - At that time I really just wanted to ease myself in slowly, feel my way around and see where I stood in the scheme of things!

Neil, as I see it, you are more or less explaining to us, that we should just give it a go anyway without worrying about failure (failure is just part of learning)!
I did find that out when building my furnace, burner and various associated tools, I designed it as I went along with minimal input from anyone and it all worked fine - very simple really.
But patternmaking and moulding? well, a lot of lessons to be learnt there!

Frits Overmars

28th December 2017, 21:50

there is a time when it would reach a stage where my expertise in the design and fine tuning... would probably run out!That goes for all of us Will; we all reach our limits when trying to be creative.

Flettner

29th December 2017, 14:33

Oops, went back to the 'drawing' and realised I'd forgotten a drain bung boss. Attached now.
Rubbing the plumbago in is also useful to detect lumps and irregular surfaces by feel, surprising how well this works, dirty old job though.

Flettner

29th December 2017, 16:55

The underside of the mold plate, then mold plate removed leaving cavities for the top sand mold to fill and follow the part line. Wire rods are to leave escaping gas vent holes. Also help with the CO2 gassing.

Flettner

29th December 2017, 17:14

I'm doing the CC601 melt first as I'm copy casting some core mold parts for one of my cylinders. CO2 sand is just too weak and to fiddly to pack the core box. Copied into metal allows me to use Shell core Sand, much stronger and easy core box fill.
Next week LM13 and some cylinders that should have been done a year ago, better late than never I guess.

ken seeber

29th December 2017, 21:03

Well, not a patch on Fletto's progress, but have been dabbling at brief intervals with the fish mould. So, mounted the 3D printed half on a basic pattern plate. This had 2 off 5 mm holes printed in on the back face on the centreline, these were tapped out to M6. Then on the pattern plate, 2 holes were put in for these screws and another 2 for the 2 exposed 6 mm dowels. This will mean that 2 mould halves will be made and then located together with dowels so that the 2 fish cavities will perfectly align (I bloody well hope so :sweatdrop), due to the symmetry of the simple shape.

Then it was waxed, not that it might have needed it, to help in the release, this being assisted by the 4 off M6 screws that are shown flush with the pattern plate. I reckon if I used plumbago it'd be everywhere but in the right place.

Then it was filled with a 50:50 mix of foundry sand and plaster of Paris. Used this cos it'll give a good finish and I don't have any sodium silicate to go the CO2 route.

With two halves being made, then it's a matter of cutting in an ingate and some small vent grooves and then filling with lead, with the secret feature being cast in during the process.

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WilDun

30th December 2017, 08:44

Then it was filled with a 50:50 mix of foundry sand and plaster of Paris. Used this cos it'll give a good finish and I don't have any sodium silicate to go the CO2 route.

I'm a fan of the plaster/sand mix, - reckon it is a good, cheap and simple way to go - It could also actually be taken to red heat to melt out a sacrifical printed plastic pattern - saving a lot of time ( an alternative to doing it in the traditional good and well proven manner!)

WilDun

30th December 2017, 08:55

............. I'm copy casting some core mold parts for one of my cylinders. CO2 sand is just too weak and to fiddly to pack the core box. Copied into metal allows me to use Shell core Sand, much stronger and easy core box fill.

How do you intend to put the coresand into the hot metal mould? (sorry, using the good old Pommie/Kiwi spelling here - all very confusing these days!).

Flettner

30th December 2017, 14:14

See what I have to work with, bugger, this is a two piece pattern. Forgot about the second piece when packing the first mold but I'm not giving up, I'll make a special side insert that will glue on and keep the molten metal from escaping.

Flettner

30th December 2017, 14:19

How do you intend to put the coresand into the hot metal mould? (sorry, using the good old Pommie/Kiwi spelling here - all very confusing these days!).

Here is the process, this is the water core sand box I want to copy, I've already molded up one half.

Flettner

30th December 2017, 14:32

The sides of the pattern are tapered but I don't want to taper the ends so I've made straight to taper end pieces. Makes the mold more complicated with more parts but will allow for none tapered pattern.
Pack the mid section, set then one end, set, then the other end. Bottom done.

Flettner

30th December 2017, 14:41

Top half pack and set. Disassemble, remove pattern, reassemble and stick together with some Core Fix foundry glue. Runner and riser, ready to pour hot metal in.
This will make two replicas of my core mold but in metal so I can use the hot Shell sand mold system.

Flettner

30th December 2017, 14:50

Sorry Will, to answer your question, I don't have a Shell molding machine so for this one off / low run stuff I pour the fine shell sand into a cold metal mold, place in the oven at 180/200 for a time, about half an hour, then with gloves on undo the capscrews holding it together, remove sand core.
Then wait for the core box to cool off, repeat.
Sloooow but makes real nice cores.

Flettner

30th December 2017, 18:32

The patch up.

ken seeber

30th December 2017, 19:30

Did a another of the plaster/sand moulds. Came out pretty well, "smooth as a baby's bum" as they say. Dowels fit too. Still quite damp, so as it was 35 deg today, I reckon a couple of days outside will do it. I think I'll preheat them to around 100 deg prior to pouring though. Design weight is around 1.9 kg.

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Flettner

30th December 2017, 20:07

Grumph

30th December 2017, 20:50

Would that mixture be suitable for an aluminium pour?

I'd doubt it - in a previous career I used plaster of paris for moulding some electrical components. It's damm near impossible to get the water content down far enough to withstand thermal shock. The sand mixture may give it better qualities but it's quite a temperature stretch from lead to aluminium.
I had several moulds crack from thermal shock - even preheated.

ken seeber

30th December 2017, 21:31

I sort of think Greg is right, in that some time ago we did a "lost PLA" printed casting and after a lot of heating to burn the PLA out using lots of heat with an LPG burner(and it was really smelly), the plaster did crack. But I reckon going to a 150 deg or so in a slow fashion it should be right.
In terms of gas generation I think the plaster in itself should be ok as my memory of hot plaster is that it doesn't smell, whereas shell core sand etc does smell, probably due to the binder going of, creating gases. Irrespective, being essentially non pervious, any gas that is generated must be able to escape via venting, no worse that a regular permanent mould situation.
I'll do a couple of extra moulds and when back, we have to do another piston batch pretty much straight away, as well as another lead batch, so I'll do them then.

Here’s an excerp from Wikipedia:

"Details[edit]
The plaster is not pure plaster of Paris, but rather has additives to improve green strength, dry strength, permeability, and castability. For instance, talc or magnesium oxide are added to prevent cracking and reduce setting time; lime and cement limit expansion during baking; glass fibers increase strength; sand can be used as a filler.[1] The ratio of ingredients is 70–80% gypsum and 20–30% additives.[2]
The pattern is usually made from metal, however rubber molds may be used for complex geometry; these molds are called Rubber plaster molds. For example, if the casting includes reentrant angles or complex angular surfaces then the rubber is flexible enough to be removed, unlike metal.[1] These molds are also inexpensive, reusable, more accurate than steel molds, fast to produce, and easy to change.[citation needed]
Typical tolerances are 0.1 mm (0.0039 in) for the first 50 mm (2.0 in) and 0.02 mm per additional centimeter (0.002 in per additional inch). A draft of 0.5 to 1 degree is required. Standard surface finishes that are attainable are 1.3 to 4 micrometers (50–125 μin).[1]
Process[edit]
First, the plaster is mixed and the pattern is sprayed with a thin film of parting compound to prevent the plaster from sticking to the pattern. The plaster is then poured over the pattern and the unit shaken so that the plaster fills any small features. The plaster sets, usually in about 15 minutes, and the pattern is removed. The mold is then baked, between 120 °C (248 °F) and 260 °C (500 °F), to remove any excess water. The dried mold is then assembled, preheated, and the metal poured. Finally, after the metal has solidified, the plaster is broken from the cast part. The used plaster cannot be reused.[1][2]
Advantages and disadvantages[edit]
Plaster mold casting is used when an excellent surface finish and good dimensional accuracy is required. Because the plaster has a low thermal conductivity and heat capacity, the metal cools more slowly than in a sand mold, which allows the metal to fill thin cross-sections; the minimum possible cross-section is 0.6 mm (0.024 in). This results in a near net shape casting, which can be a cost advantage on complex parts.[1] It also produces minimal scrap material.[3]
The major disadvantage of the process is that it can only be used with lower melting temperature non-ferrous materials, such as aluminium, copper, magnesium, and zinc. The most commonly used materials are aluminium and copper. The maximum working temperature of plaster is 1,200 °C (2,200 °F), so higher melting temperature materials would melt the plaster mold. Also, the sulfur in the gypsum reacts with iron, making it unsuitable for casting ferrous materials.[1][2]"

WilDun

30th December 2017, 22:54

I would have thought that if the plaster section is kept to a minimum and the pour is done straight after a damn good heating in the furnace (or whatever), wouldn't that solve any cracking problems? - then again I could very well be wrong!

Flettner

31st December 2017, 16:30

Some success and some failure.
The casting I actually wanted came up short
The surface area verses in gate size was not matched well with the fill happening too slow with too much cooling on all the thin sections. Solidified before filling the mold. Both molds, same fault.
The rest turned out ok.

guyhockley

1st January 2018, 01:29

Saw an american website where he was investment casting with "dry-wall mud", whatever that is.

Michael Moore

1st January 2018, 04:59

Rubbing the plumbago in is also useful to detect lumps and irregular surfaces by feel, surprising how well this works, dirty old job though.

Good head porting people often seem to spend more time feeling/rubbing fingers in the ports than they do looking in them. A bare hand run over a body panel can find the parts that aren't smooth, just make sure you did a good job of deburring edges first.

jasonu

1st January 2018, 05:44

Saw an american website where he was investment casting with "dry-wall mud", whatever that is.

AKA gib sheet plaster.
Dunno what you Poms call it.

guyhockley

1st January 2018, 08:17

AKA gib sheet plaster.
Dunno what you Poms call it.

I meant more in terms of ingredients, there are various different plasters available in the UK.

husaberg

1st January 2018, 13:12

I meant more in terms of ingredients, there are various different plasters available in the UK.

Alpha Gypsums calcined under pressure are called gypsum cements - These Alpha Gypsum casts are harder and stronger with limited absorptive power. They require 22 to 45 lbs of water per 100 lbs of gypsum cement (this is called the Use Consistency Ratio). They are used primarily when greater strength is required. Because of their extreme hardness some Alpha gypsums can not be carved or scraped after hardening. Alpha Hemihydrate is produced in many different formulations. You can mix an alpha gypsum with a beta gypsum such as moulding plaster to increase the plaster's strength or hardness. I use 3 scoops of plaster to one scoop of HYDRO-STONE in my sculpted model work. To help you choose the ones that best suits your needs, check out the list below.

Beta Hemihydrates are known as industrial plasters, plaster of paris, kettle plaster and kettle stucco. Beta Gypsums are made by calcining in a kettle at atmospheric pressure. They require more water to make a workable slurry because of their irregular crystalline structure. They require 65 to 160 lbs. of water per 100 lbs of plaster ( consistency ratio). Beta Gypsums are not as hard as the alpha gypsums. That's why they are easier to carve and scrape. Because of their high water absorptive power, they make excellent pottery molds. There are many beta Gypsums from which to choose. Use the list below to help you in making your decision

google.............

guyhockley

1st January 2018, 18:25

google.............

Interesting stuff and I have similar information in a suppliers catalogue but doesn't tell cheapskates like me if eg. UK finishing plaster is the same as the US sheetrock. I'm away from home and wi-fi too so using the internet burns through my phone credit...
Never the less, I have found the site I was on about as googling "aluminum casting submarine" was a pretty sure bet!
www.submarineboat.com/casting_aluminum.htm

WilDun

4th January 2018, 16:19

...........I have found the site I was on about as googling "aluminum casting submarine" ........

Thanks Guy,
Some very good information for the up and coming foundryman! (like me! :laugh:).

Flettner

7th January 2018, 19:36

Got it, in the pile with the rest, off to heat treatment this week.

Flettner

13th January 2018, 10:13

Wooden core box copied into metal so as to make Shell Sand cores, much stronger and easier to manufacture, I just use capscrews to hold the die together. Spend a little time with bearing blue and my small die grinder to get a nice fit.
This water core is to suit this cylinder.

WilDun

13th January 2018, 11:19

Guess shellsand is the best way to go, but I do hope your "cooker" isn't too near the house!

Will you still be using graphite for a release agent?

Have you considered making the external moulds with shellsand?
I remember seeing brass bathroom fittings and various bronze valves being produced from shellsand moulds (with shellsand cores) - and saw some very good castings appear at the end.

Arifidyan

14th January 2018, 04:34

Got it, in the pile with the rest, off to heat treatment this week.

Super cool Flettner!! please show step by step how to heat treatment this part. :niceone::headbang:

Arifidyan

14th January 2018, 04:39

Flettner

14th January 2018, 08:54

Super cool Flettner!! please show step by step how to heat treatment this part. :niceone::headbang:

I send these castings away, its a an exact process and I'm not willing to risk wreaking them.
With my business I get a lot of CC601 cast and heat treated, I just tack these home cast units on to a treatment run.
Out of interest the treatment involves heating the casting to almost melting for something like 16 hours then when time is up, they get quickly quenched in 80 degree C water.

Flettner

14th January 2018, 09:07

Baked sand cores? no need sodium silicate? :niceone::niceone:

The Shell Sand process uses sand that has been pre treated with a heat activated bonding adgent.
The sand is designed to be blasted into a metal die, a very quick and accurite process. Experimenting like I do I just pour the sand into the die (It flows like water) then place it in the oven for a while. Slow but makes for a strong sand core. Useful with thin, intricate water cores.

WilDun

14th January 2018, 15:00

Baked sand cores? no need sodium silicate? :niceone::niceone:

He has just changed from using sodium silicate, - it seems this resin sand will give better results (using heated metal dies) for core production .

Michael Moore

15th January 2018, 06:33

please show step by step how to heat treatment this part.

This will give you a good idea of the process:

http://www.eurospares.com/graphics/metalwork/MIL-H-6088G.pdf

I've done a few pieces at home and it is a long, all-day process. Unfortunately it doesn't seem to be an exact science, because the times/temps listed by various references can have a fair bit of variation. The time given as needed for soaking once solution temperature is reached may easily vary several hours depending which reference you look at. My friend Jeff's cylinders were soaked for just under 7 hours at 1000F, quenched in 208F water (the temp of the quench is important too) and then aged for 7 hours at 310F once the oven temp had dropped (which took about an hour). Jeff said they were very nice to machine.

cheers,
Michael

Flettner

18th January 2018, 12:02

Here we go, first shot, 1 x Shell Sand core.

ken seeber

19th January 2018, 16:45

Seeing Fletto is charging ahead with the shell cores, I thought I’d just show a little core I also made using shell. Essentially it’s a little core strip that supports a link and Ø5 cross pin. The pin will be cast in into the final product with the link being free to move about after the core is removed. Note the shell cylinder core in the pic, this is over 20 years old and still as good as new.

So, a simple block was made up, plus a bottom to stop the dry sand escaping when filled from above, when cold. A paper clip was used to hold the link central and vertical when filling.

Then it was a simple matter to stick it onto a small gas burner til the sand went a golden drown and wait for it to cool. First couple didn’t release successfully, so I wacked a series of M6 screws into the back to use for ejection.

Not perfect, but good enough for the prototype nature of the job.

Note the clean fingernails.

Now here’s a thought. CO2 sand is convenient, but not nearly as strong as shell sand. Shell cores are good, but require metal coreboxes to take the heat required, say around 200 C. Wot if one both mixed the sand with the sodium silicate plus the resin for the shell core? Set off the and with CO2 in plastic/timber boxes. Remove, then bake to achieve the shell qualities. Could be total crap with mixing of different chemicals, but it’d be nice if it worked.

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WilDun

19th January 2018, 22:19

Now here’s a thought. CO2 sand is convenient, but not nearly as strong as shell sand. Shell cores are good, but require metal coreboxes to take the heat required, say around 200 C. Wot if one both mixed the sand with the sodium silicate plus the resin for the shell core? Set off the and with CO2 in plastic/timber boxes. Remove, then bake to achieve the shell qualities. Could be total crap with mixing of different chemicals, but it’d be nice if it worked.

Well, I believe the place I was talking about did just that, I remember a guy in the foundry telling me that they did use sodium silicate in the sand and that they cured it by heating it - I thought that they might be using shellsand (judging by colour) and possibly he didn't really know ..... now, I think that they could have been using that very combination!
Think the metal dies might really be the best way to go (except for a one-off!).

Good to see you back Ken.

Frits Overmars

19th January 2018, 23:41

Note the clean fingernails.
334835I did. I also noticed that your forefinger is longer than your ring finger, which normally is only found in the female species of the human race.
Good to have you back so I can pull your leg again Ken :msn-wink:.

WilDun

20th January 2018, 08:45

ken seeber

20th January 2018, 13:42

I did. I also noticed that your forefinger is longer than your ring finger, which normally is only found in the female species of the human race.
Good to have you back so I can pull your leg again Ken :msn-wink:.

Frits & Willy, jeez you’ve even got me questioning my sexuality: am I straight or am I a closet LGBTI? Scary really. Probably the best advice I can give is for all is to stand well clear of me…:confused:

So, whilst I’ve got your attention Frits, I have a question related to squish % area. In a homogeneous charge engine, what would be the downside of having a squish area of 60 – 70%, this being in a low BMEP application, say 100 cc, 3kW output @ 5000 rpm. Detonation? Poor HC emissions due to a quenching effect? Obviously set with a min’m squish clearance. I know it's an ESE question really, but with today's confused world....

Frits Overmars

20th January 2018, 23:17

Frits & Willy, jeez you’ve even got me questioning my sexuality: am I straight or am I a closet LGBTI? Scary really. Probably the best advice I can give is for all is to stand well clear of me…:confused:
So, whilst I’ve got your attention Frits, I have a question related to squish % area. In a homogeneous charge engine, what would be the downside of having a squish area of 60 – 70%, this being in a low BMEP application, say 100 cc, 3kW output @ 5000 rpm. Detonation? Poor HC emissions due to a quenching effect? Obviously set with a min’m squish clearance. I know it's an ESE question really, but with today's confused world....ESE questions are not necessarily easy to answer, but let's have a go.
Persuading a 100 cc 3 kW rpm engine to detonate requires some serious labour. You could try 50° ignition advance, a heat range 5 spark plug, blocked cooling
and 50/50 petrol/diesel fuel :devil2:.
If you minimize the squish clearance to its minimum, quenching would be limited. Scavenging the combustion chamber might suffer because the wide squish band counter-acts decent loop scavenging, but with the power you quote, that won't matter much either. I can't really think of one clear disadvantage, so just try it and let us know.

Michael Moore

21st January 2018, 15:07

I thought that a long finger like that was a sign of lycanthropy.

In olden days cores were made with things like molasses as a binder and were baked afterwards to harden them and that may be getting revisited in modern times:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.888.5492&rep=rep1&type=pdf

cheers,
Michael

Frits Overmars

21st January 2018, 23:38

I thought that a long finger like that was a sign of lycanthropy.I had to look it up: https://en.wikipedia.org/wiki/Werewolf
If what you suggest is true, we can come to the conclusion that wolf-man Ken was civilized enough to shave the back of his hand before taking that picture :p.

WilDun

22nd January 2018, 18:13

I had to look it up: https://en.wikipedia.org/wiki/Werewolf
If what you suggest is true, we can come to the conclusion that wolf-man Ken was civilized enough to shave the back of his hand before taking that picture :p.

Closely parallels the hatred of the innocent two stroke engine, by lies being spread about by the dumb polititians whose minds have been poisoned by the great devil H**da (and others)! ....... can we save the two stroke? We must be in there quickly, before we forget what happened in the middle ages .... I mean, there is hardly a Witch or a Werewolf in sight these days and let's face it, the two stroke could also be relegated to folklore!
And to think, all this furore caused by poor old Ken showing his hand! :facepalm:

Getting back in the groove again,
https://www.youtube.com/watch?v=UPiFRPxlscY&list=PLzYor9155-1F6xpZ5Pt35WxljKs4OCmdH&index=29
I like this guy's style in the videos and much of the stuff he talks about is (to me) correct, but he can get it into words much better than I can!

The application for which a two stroke engine is being used is a very important factor though - in the case of light aircraft the modern two stroke is a winner, requiring more or less constant speed (RPM), a high power to weight ratio (very important in aircraft), but still requiring a relatively mild state of tune and of course simplicity in the maintenance department. Fuel consumption and pollution can probably be improved too with EFI.)
I think that these are the main things Neil is trying to achieve, but maybe I should leave that for him to discuss!

PS. - I decided to move over to the Oddball Engines and Prototypes thread because it was maybe getting a little off topic here :rolleyes:

ken seeber

27th January 2018, 22:18

Well, had a lead casting experience this morning. Not even successful. The 50:50 sand/plaster mould had been indoors for the last few weeks and felt dry (my subjective perception anyway). Irrespective, I heated it to 100 C for about an hour prior to pouring.

Started off ok, but virtually immediately it started spitting back. With stupidity at hand, I just kept pouring hoping it’d stop. It didn’t, so the bulk of the metal in the small crucible ended up outside the mould. Opening it up revealed that it had sort of completely filled, but the casting surface was very heavily pitted and the once “smooth as a baby’s bum” plaster mould was quite eroded in spots.

Conclusions:
1. Bit of a pisser :crybaby:
2. I’ll give it a retry, I have another set of moulds (100% plaster, as it happens), but on the basis that the issues were a result of residue moisture within the plaster, heat it up to 250 or so for at least a couple of hours.

Anyone had experiences with plaster?

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WilDun

28th January 2018, 08:12

Flettner

30th January 2018, 18:06

I see you.
I'm over Ignitec, familiar outcome. This Ignition has cost me a fortune in time and pistons. One channel can not be controlled (or trusted) and I don't know why but I'm not going back for another holed piston! I'm fitting my old home made CDI, it doesn't give a fuck about input interference (it is the maker of interference) gets a trigger and goes off, simple (like me).
Ill leave the Ignitec to do the servo power valve duties only, at least I can see if its fucking that up.

Flettner

30th January 2018, 18:09

:angry:
At least with an autogyro you just go into auto land mode. :facepalm:
Wasn't a good look at the national Autogyro Association meeting.

F5 Dave

30th January 2018, 19:45

Do you have a Knock gauge?

WilDun

31st January 2018, 17:00

Thats bad luck! I hope that there's a way out with some other proprietry ignition - otherwise it'll make life more difficult by having to build your own ignition as well!

Flettner

31st January 2018, 18:56

O the sadness, I can build all this stuff but can't afford decent test equipment. I guess I'll just have to save up.

Will, no such thing as bad luck, it was a problem just waiting to happen as I didn't test it fully before departing for Dannevirke. Got what I deserved.

Though it wont happen again at least not with this Ignitec. Already got the home made CDI trigger installed on the rear of the engine running off the balance shaft gear bolted to the crankshaft, two steel pins, one trigger, dual 12V CDI funneled into a single, dual lead, coil (RD350LC), wasted spark. No fancy electronics to bugger up the input signal. This CDI would light up tar as a fuel.
I'm sure the Ignitec can be sorted eventually, I've just run out of patience (and pistons)

speedpro

31st January 2018, 21:18

After much testing and tinkering with all the gear supplied by the large aviation company I used to work for, my homemade CDI would fire a 10mm gap with a fat blue spark at some huge rate. The charge pulses looked like a picket fence on the oscilloscope. IIRC it pulled about 10A @ 12V. No more fouled plugs.
I'm surprised you have so many problems with the Ignitech. I sort of suspect a possible shielding problem though I expect you have looked at that

Flettner

1st February 2018, 06:30

I too expect the problem is input signal interference but I'm just over playing games with it. Like your CDI mine will do the job nicely and I know it will work. I just want to go flying and get some time on this engine.
Next engine I'll be running a Link ECU with the mark two TPI so won't need the ignitec.

Frits Overmars

1st February 2018, 07:06

I too expect the problem is input signal interference but I'm just over playing games with it.I can understand that Neil. Just one final question if I may: did you use resistor plugs, resistor plug caps or both with the Ignitech?

Flettner

1st February 2018, 07:42

plug caps are not but plugs are.
One channel is crystal clear, timing light on the timing mark. Other timing mark (other cylinder) is always goasted. This is clearly the cylinder that gave the trouble.
Piston one is in top condition, with no sign of over heating, under side of the piston is nice.

speedpro

1st February 2018, 12:30

The Link ECU could trigger the Ignitech CDI. I was quite impressed with the Ignitach CDI output when I was using it though only with one channel. Having a dumb CDI and having the Link do all the smarts is probably going to work best though.

Flettner

1st February 2018, 20:21

New balance shaft drive cover. Inset piece can be rotated to get the trigger in the right time, Oring seals inside. Housing gets a bearing pushed in for balance shaft support, hollow dowel location on the housing.

WilDun

3rd February 2018, 18:25

I'm assuming that the large shiny disc is the "inset piece" and is being held in position by the capscrews and washers?

Flettner

3rd February 2018, 20:19

I'm assuming that the large shiny disc is the "inset piece" and is being held in position by the capscrews and washers?

You got it Will. Pulled the engine apart today to clean the debris out of the crankcase and reeds etc. Reassembled with new pistons, already to run up tomorrow with the my CDI fitted. Just spent some time securing the capacitors to the CDI board so vibration doesn't cause problems. Can't wait to hear the difference. Probably need to line the inside of the box it lives in with lead sheet;) so all the radios at Matamata airfield don't stop working when my engine is running.

Grumph

3rd February 2018, 20:31

I was CoC at a Ruapuna meeting back in the 90's when a guy turned up with a homemade CDI ignition....we lost all the radio links when he fired it up.
If it hadn't failed in short order, I suspect we'd have heard from Civil Aviation as the approach path to Harewood that day was right over the top of us....

TZ350

3rd February 2018, 20:57

Probably need to line the inside of the box it lives in with lead sheet;) so all the radios at Matamata airfield don't stop working when my engine is running.

Inside or outside will be just as good a Faraday cage. Maybe easier to wrap the box.

WilDun

3rd February 2018, 22:39

Can't wait to hear the difference.

Are you flying the gyro now?

I was CoC at a Ruapuna meeting back in the 90's when a guy turned up with a homemade CDI ignition....we lost all the radio links when he fired it up.
If it hadn't failed in short order, I suspect we'd have heard from Civil Aviation as the approach path to Harewood that day was right over the top of us....

Grumph, you forgot to tell us who the guy with the rouge CDI was - but I guess we'll never know! :msn-wink:

speedpro

4th February 2018, 08:06

You got it Will. Pulled the engine apart today to clean the debris out of the crankcase and reeds etc. Reassembled with new pistons, already to run up tomorrow with the my CDI fitted. Just spent some time securing the capacitors to the CDI board so vibration doesn't cause problems. Can't wait to hear the difference. Probably need to line the inside of the box it lives in with lead sheet;) so all the radios at Matamata airfield don't stop working when my engine is running.

Early on running my bucket at Whenuapai with the CDI I had "enquiries" from the control tower. The usual suppression stuff sorted it. I think it was the super quick rise time of the ignition which resulted in a lot of RFI over a broad spectrum

Grumph

4th February 2018, 08:14

Grumph, you forgot to tell us who the guy with the rouge CDI was - but I guess we'll never know! :msn-wink:

No idea who it was - faces came and went. Memory says it might have been a Ducati - so the failure we welcomed might not have been the ignition....

It was an early CAMS day I think - but they've always welcomed everything else to their meetings as it's more $$ to offset costs.
In the past I've run meetings for CAMS and Canterbury before they became MCI.

Flettner

4th February 2018, 15:21

Un bloody believable, two lots of similar wires emmiting from my CDI, hooked the wrong set to the 12V supply, now the trigger circuit dosent work! How hard can it be to just make a twostroke twin ignition work?
Clearly out of my ability. Time for professional help I think.
That HCCI engine is looking better all the time.

WilDun

5th February 2018, 09:25

That HCCI engine is looking better all the time.

Yeah, then all you'll need is an old B&S ignition or similar, just to get it all going and then forget ignition! but maybe that's over simplifying it?.
Problem then will be the necessity for variable compression (to keep timing right)? also an electronically operated system for that (another even bigger hurdle!) :facepalm: - no free lunch! ...... never ending!

Flettner

5th February 2018, 14:24

no, my HCCI has no spark plug or electric ignition system at all, not even for start.
just a timed compression rise, perhaps a little pre heat.

WilDun

5th February 2018, 16:14

So in HCCI, how can you get it to ignite at the optimum time (ie not too early or too late, isn't that controlled by compression? or is it controlled by direct injection timing? (as in diesels) - will this completely rule out carburettors then?
Not trying to be a smartass you understand, .... but what is a timed compression rise? - I haven't been following it closely so not quite up with understanding it all, I'm genuinely interested though! :yes:

Flettner

5th February 2018, 20:33

https://youtu.be/TOHKls3Cxjs

See this Will, small piston is at twice engine speed and timed. Rapid compression rise just as the big piston rocks over tdc.

speedpro

5th February 2018, 21:38

WilDun

5th February 2018, 22:45

A HCCI engine doesn't need a spark prior to TDC to allow for turbulence to propogate the flame front burning all the fuel and raising pressure at the more or less appropriate time, or some small period.
With HCCI there is no flame front, no progression. The lot catches fire at the same time, give of take.

I think.

Yes I just came in to shut down my computer and found these replies and haven't yet read all Neil's stuff.

SPEEDPRO (forgot your name)
I already understood the instantaneous combustion part but I hadn't (haven't) yet got the part where it decides to combust or what makes it combust - I mean it can't just be allowed to do that at any old time it decides is suitable! like the little model aircraft diesels, eg maybe long before TDC. (that would make it very inefficient and destructive!) and I'm sure that something has to change to suit each different condition it encounters - that's what I'm trying to find out.
NEIL,
No doubt when I've read and absorbed your post I'll be a little bit wiser! - I need to think about the double speed of the little O/H piston - I don't think it would last too long at "Ryger" main crank speeds (30,000 X 2)! - but you've got an experimental one working at least, so I can't argue with that!- it's still just an embryo with me and I really hope it doesn't remain just that! :rolleyes:

Frits Overmars

5th February 2018, 23:18

Problem then will be the necessity for variable compression (to keep timing right)? also an electronically operated system for that (another even bigger hurdle!) :facepalm: - no free lunch! ...... never ending!Will, you don't need a variable compression ratio to control the onset of HCCI combustion. Varying the amount of residual exhaust gases in the cylinder is another possibility that the auto factories are experimenting with. They call it Intelligent Exhaust Gas Recycling, although for a two-stroke I'd rather call it Exhaust Gas Retention (intelligent goes without saying for a two-stroke) :msn-wink:.

So in HCCI, how can you get it to ignite at the optimum time (ie not too early or too late, isn't that controlled by compression? or is it controlled by direct injection timing? (as in diesels)The fundamental difference between HCCI and diesels is the Homogeneous Charge Compression Ignition. Diesels have everything except the homogeneous charge.
The optimum timing is controlled by pressure x temperature.

I need to think about the double speed of the little O/H piston - I don't think it would last too long at "Ryger" main crank speeds (30,000 X 2)!Don't think revs - think piston speed. With the short stroke of Flettos agitator piston the revs need not be a problem. Come to think of it: don't think Ryger either :facepalm:.

A HCCI engine doesn't need a spark prior to TDC to allow for turbulence to propogate the flame front burning all the fuel and raising pressure at the more or less appropriate time, or some small period. With HCCI there is no flame front, no progression. The lot catches fire at the same time, give of take.
I think.You think right. But a little turbulence can't hurt; not for the purpose of flame spreading but to improve the homogenity (does that word exist?) of the charge.

Niels Abildgaard

6th February 2018, 00:00

Will, you don't need a variable compression ratio to control the onset of HCCI combustion. Varying the amount of residual exhaust gases in the cylinder is another possibility that the auto factories are experimenting with. They call it Intelligent Exhaust Gas Recycling, although for a two-stroke I'd rather call it Exhaust Gas Retention (intelligent goes without saying for a two-stroke) :msn-wink:.

The fundamental difference between HCCI and diesels is the Homogeneous Charge Compression Ignition. Diesels have everything except the homogeneous charge.
The optimum timing is controlled by pressure x temperature.

Don't think revs - think piston speed. With the short stroke of Flettos agitator piston the revs need not be a problem. Come to think of it: don't think Ryger either :facepalm:.

You think right. But a little turbulence can't hurt; not for the purpose of flame spreading but to improve the homogenity (does that word exist?) of the charge.
Turbulence gives higher heat tranfer to and from engine and this is unwanted.

Frits Overmars

6th February 2018, 00:20

Turbulence gives higher heat tranfer to and from engine and this is unwanted.That's right Niels. Turbulence prevents areas in the combustion chamber from remaining so rich that they won't encounter sufficient oxygen in time (lean areas are no problem for HCCI). We do want to burn every molecule of fuel, but as you point out, we do not want to loose that combustion energy to the surrounding metal.
It would be good if we could stirr up the mixture before it enters the cylinder. A crankshaft in a two-stroke crankcase does a wonderful job at it. But then we'll have oil in the mixture. No free lunch...

speedpro

6th February 2018, 09:24

A turbocharger would do it.

WilDun

6th February 2018, 10:28

.......It would be good if we could stirr up the mixture before it enters the cylinder.......

Must say I am learning fast! - taking in information like a grounded boat takes in water - can't stop it!

So where the hell do I start ?

Frits - what you said in that line has got me delving through my (documented) thoughts again! - I came up with an idea on that, possibly way out, but I believe in it. I think that I may have briefly mentioned it to you in an earlier post somewher.
It's all done in my usual haphazard, non scientific way and is really an ongoing thing - definitely unfinished.........

I had hoped to try it out but as only Neil knows I am severely cramped at home, I'm running out of time, not all that fit anymore and being gently coerced into geting rid of my workshop to become a normal person living inside the square! :violin:
So just in case that terrible day might come sooner than expected, I decided to gather up and document some of my thoughts, based on my limited knowledge of this HCCI engine stuff, (more hunches really) - some sensible, some downright cuckoo, but all done to the best of my knowledge and ability, hoping like hell that someone else could be interested enough to make use of it by actually trying it, or who might at least be able glean some inspiration from it.

I didn't really have the courage to talk anyone about it. - I didn't want it to become a non event nor did I want to be exposed to ridicule (all a bit sad, but this has happened to some previously successful people recently, when they appear to have got things wrong!) - but I don't know all the details of why that happened or what has been going on behind the scenes there of course.

Don't really know what to do - need to think about it . :scratch:

Frits Overmars

6th February 2018, 10:58

I didn't really have the courage to talk anyone about it. - I didn't want it to become a non event nor did I want to be exposed to ridicule...If you can't do everything yourself and you don't talk about, you can be sure it will become a non-event. If you do talk about it, you risk being ridiculed. So what?
Take your pick:
335063 335061 335059 335062 335060

WilDun

6th February 2018, 16:15

If you can't do everything yourself and you don't talk about, you can be sure it will become a non-event. If you do talk about it, you risk being ridiculed. So what?
Take your pick:

Ha,Ha! - Very good Frits!

Earlier on somewhere (in the "oddball" thread ?) I did after all support that guy on you tube talking about bike engines and not giving a stuff what people thought of his comments!

Slept in this morning and was obviously in a melancholy mood!- no, not a hangover (you don't get hangovers if you barely drink).
While the gist of the rant was true & correct, as the day wore on my perspective of the situation changed! so I decided to battle on a while longer - can't just throw in the towel and miss out on all the foundry work and never get to see my major breakthrough in action! :laugh:! - still probably got time to have a shot at it!

BTW, What will be the benefit to the fresh charge if it is intermingled with residual exhaust charge? - extra heat? still burning charge? I see the point in Neil's timing piston giving a precise time to the start of combustion (control of which seems to me to be important!) and this could be controlled, but I fail to see how the residual exhaust gas can be used to control timing of the combustion! - maybe I'm blind.
I think I did make a slight mistake when I asked earlier if the timing would be controlled by fuel injection, as in a diesel (on HCCI? :doh:).

As for a hyper rotational speed crankshaft driving a reciprocating piston?..... I do have my doubts!
But, as always, I could be wrong!

NEIL, I did see that video before and was quite impressed seeing it actually work.

Flettner

6th February 2018, 17:50

small piston was like 5mm stroke or somthing I think in that engine. New engine has 16mm stroke, still not much.

Grumph

6th February 2018, 18:57

BTW, What will be the benefit to the fresh charge if it is intermingled with residual exhaust charge? - extra heat? still burning charge? I see the point in Neil's timing piston giving a precise time to the start of combustion (control of which seems to me to be important!) and this could be controlled, but I fail to see how the residual exhaust gas can be used to control timing of the combustion! - maybe I'm blind.

Surprise - Bradshaw was playing around with bleeding exhaust into adjacent cylinders in the mid/late 50's. He had a 4 cylinder Ford Consul going as well on the road as a family member's Zephyr 6 - Yes Will, you and I remember them, lol. Ford were interested enough to cast up a block for him with provision for the needed ports. Benefits were economy and better acceleration. Harry Ferguson was interested amongst others. Bradshaw took out patents.
I've loaned my copy of the Bradshaw book, when I get it back, I'll post what's there.

WilDun

6th February 2018, 21:47

Surprise - Bradshaw was playing around with bleeding exhaust into adjacent cylinders in the mid/late 50's. He had a 4 cylinder Ford Consul going as well on the road as a family member's Zephyr 6 - Yes Will, you and I remember them, lol. Ford were interested enough to cast up a block for him with provision for the needed ports. Benefits were economy and better acceleration. Harry Ferguson was interested amongst others. Bradshaw took out patents.
I've loaned my copy of the Bradshaw book, when I get it back, I'll post what's there.

Yes Grumph, I remember the Ford Consul well! - steering shimmy was the order of the day and if I rightly remember those bloody unbelieveably stupid vacuum wipers!
Bradshaw a clever engineer (till he actually made one or two great cockups) and Harry Ferguson's extremely successful Ferguson tractor, produced by taking advantage of Edsel Ford's big cockup of using Ferguson's hydraulic system on the Ford (2N ?) tractor, thereby ending up by having to hand over the complete package to Ferguson who eventually fitted it with the then new (and eventually very successful) Standard Vanguard engine and I think a David Brown gearbox and the rest is history! - now what were we talking about?? - ah yes, HCCI!

Neil, I musn't have been paying much attention at the time you were playing with your OHP? engine and I had no idea that it had such a short stroke. I do hope that it works out well with the new one! - does this suggest that the charge needs a swift "kick in the guts" to set it in motion? - How about a half speed 180 deg twin up top to make me feel more at ease? :msn-wink:

I must be thick, because I still can't see how residual exhaust gas in the cylinder can make the HCCI thing happen at a precise time if the exhaust gas is coming back from the pipe - to me it all seems a little vague (despite Frits's simple formula to explain what makes it happen).
There must surely be a right time for this to happen and this timing surely must vary according to what is required of the engine at various times?? - just as in common or garden spark initiated combustion.
I feel that some form of reasonably precise timing is required in all engines, from extremes like small model aircraft "diesels" which just rely on compression (but still need to be set by a manual screw adjusted static contra piston) to modern automotive diesels using high pressure common rail fed injectors, probably using computer controlled timing (I don't know).
By the same token, doesn't this issue also need to be addressed in the case of HCCI.

If I'm wrong then would someone who has a handle on it, please explain it to me in simple terms (and perhaps talk more slowly) and maybe I'll finally get it and accept it! :rolleyes:

husaberg

6th February 2018, 22:55

Awesome channel. A true blue retired Aussie foundryman

https://www.youtube.com/channel/UC90RoN_IjSRF18jAG0HIA6g

WilDun

6th February 2018, 23:15

Awesome channel. A true blue retired Aussie foundryman

https://www.youtube.com/channel/UC90RoN_IjSRF18jAG0HIA6g

Yes ok Husa, got the message :facepalm:

husaberg

6th February 2018, 23:50

Yes ok Husa, got the message :facepalm:
The only message was it was a great channel:lol:

Frits Overmars

7th February 2018, 00:23

What will be the benefit to the fresh charge if it is intermingled with residual exhaust charge? - extra heat? still burning charge? I see the point in Neil's timing piston giving a precise time to the start of combustion (control of which seems to me to be important!) and this could be controlled, but I fail to see how the residual exhaust gas can be used to control timing of the combustion! As I wrote yesterday, the optimum timing for the onset of HCCI combustion is controlled by pressure x temperature. Fletto does it via the pressure, with his small double-revving overhead piston (I never dreamt that I would write 'overhead piston') that gives a sharp pressure-rise right before TDC.

The alternative is raising the mixture's temperature to a fraction below self-ignition by adding a controlled amount of still-hot spent gases and let the normal pressure rise near TDC do the rest.That is what the car manufacturers are investigating. Hence their claims that HCCI needs exhaust gas recycling and can therefore only be done at part-throttle. Neil has already proved them wrong.

WilDun

7th February 2018, 06:25

Thanks Frits, I'm now getting up to speed on the subject - yes Neil is certainly doing a lot of research not only for himself, but also for the manufacturers research teams who (unfortunately) will no doubt be taking note of his failures/successes!
You just answered an earlier question, ie when I asked if it was heat in the charge, or actual "still burning" mixture which was required - I feel that it would be a little hard to control that combined with fixed pipe characteristics, but now I remember Honda were experimenting with modified power valves a while back, I didn't pay much attention at the time though - of course we really need to remember that not every two stroke will be used for competition, most won't in fact! - maybe an inappropriate statement in a bucket Racing thread!

Neil, why do you need to use double speed (OHP)?

Husa, thought you were suggesting that I was getting off topic and you wanted to get back to foundry !!

Flettner

7th February 2018, 11:42

Will, using exhaust gas to set off HCCI is in fact quite difficult. Needs to be controlled very well so as to not destroy your engine. I guess that's why there hasn't been any commercial HCCI car engines until now, electronic control has grown up and as I understand it, its a cruse only operation, full throttle is as normal with spark plug. Don't know about the Mazda one yet.
My little rig was just a 'lets see what we can achieve' project even I was a little stunned it worked first off. This has lead to a much better version (with actual control) but still just shade tree tinkering really. It's nothing without real test equipment.
Little piston needs two to one to get the rapid compression rise at the right time. A cam would possibly be better but I'm buggered if I'm going to be responsible for an over head cam twostroke:rolleyes:
Note, first version was going to be three to one.

Will I've got too many things on my plate, this jolly old gyro engine was supposed to be nail up and flying by now but it just won't go away. Spent yesterday quietly going over the ignitech setup and found a few things, First, the cheap arse coils I was provided with the unit I can't trust. One having a semi failure, sometimes will conduct, sometimes won't (depends on how you hit it with the hammer :lol:) it's vibration dependent. Second, (Frits) you must use resistor plugs and caps! Now my timing light will work:rolleyes: Third, it's important to have the correct trigger to flywheel gap. Fourth, I still struggle with the this base timing thing, sorted now, possible had a little much advance before ( I know I did.)
Also now the ghosting on channel two is gone, that's the one that had the doggy coil.

It can be frustrating fighting against your own stupidity (and possible some pigheadedness), instructions, what do they know!

So there you go faith restored:rolleyes:

Grumph

7th February 2018, 13:10

Instructions are only the manufacturers opinion as to how their product should work...

When the Boyer-Bransden ignitions were new to the market, no less a person than Paul Dunstall managed to blow a unit while installing it.
He found a path to earth that B-B hadn't forseen - himself...Came as a bit of a shock apparently, to B-B and Paul...

They changed the installation instructions forthwith.

ken seeber

7th February 2018, 13:58

Just wondering if, at the part load HCCI operating regime, that if one could simply turn on the "glow plug(s)" to provide some additional extra localised heat to initiate combustion. No idea if it would have enough thermal capacity though. Alternatively a retractable "hot spot" shaft(?), utilising the heat from the previous cycle (whether it was HCCI or not).

Cleaned up the shitty lead casting and with a bit of spot putty and primer, looks half way reasonable, good enough for an initial assessment.

335083

WilDun

7th February 2018, 18:44

If you can't do everything yourself and you don't talk about, you can be sure it will become a non-event. If you do talk about it, you risk being ridiculed. So what?
Take your pick:

Frits, but when I start to talk, the governor jams and as a result I have to go back over everything and repair the damage!
In that last picture and quote by Einstein, he looks like he is wringing his hands in despair!
Thanks for the kind words though!

Ken I reckon that isn't a fishing lure at all, I think that its a new Burt Munro style streamliner shell for that three wheel wonder wagon of yours!

Flettner reckon you should concentrate on the gyro engine, after all it's just about there!
Thanks for the info - whether or not I can use it I dunno, but it's bloody interesting!

husaberg

7th February 2018, 19:18

The alternative is raising the mixture's temperature to a fraction below self-ignition by adding a controlled amount of still-hot spent gases and let the normal pressure rise near TDC do the rest.That is what the car manufacturers are investigating. Hence their claims that HCCI needs exhaust gas recycling and can therefore only be done at part-throttle. Neil has already proved them wrong.Wasn't Honda acheiving that 30 years ago with the traping valve on the EXP2. (The EX gas recirculation)

Grumph

7th February 2018, 19:36

Just wondering if, at the part load HCCI operating regime, that if one could simply turn on the "glow plug(s)" to provide some additional extra localised heat to initiate combustion. No idea if it would have enough thermal capacity though. Alternatively a retractable "hot spot" shaft(?), utilising the heat from the previous cycle (whether it was HCCI or not).]

I may well be wrong but Neil's HCCI is the only one I've seen with no "conventional" ignition running in parallel with the HCCI events.
If the car engines are getting HCCI at part throttle, surely the rest of the time they're relying on the spark ignition ?

Anyone know better ?

Frits Overmars

8th February 2018, 01:03

Spent yesterday quietly going over the ignitech setup and found a few things, First, the cheap arse coils I was provided with the unit I can't trust.Their pickups used to be (and maybe still are) rather dodgy as well. We used Honda pickups instead.

When the Boyer-Bransden ignitions were new to the market, no less a person than Paul Dunstall managed to blow a unit while installing it.
He found a path to earth that B-B hadn't forseen - himself...Came as a bit of a shock apparently... They changed the installation instructions forthwith.335091

Just wondering if, at the part load HCCI operating regime, that if one could simply turn on the "glow plug(s)" to provide some additional extra localised heat to initiate combustion. No idea if it would have enough thermal capacity though. Alternatively a retractable "hot spot" shaft(?), utilising the heat from the previous cycle (whether it was HCCI or not).Glow plugs can provide plenty localized heat but I know the buggers from model engines, and they are a real pain: they advance the ignition as the cylinder filling improves, exactly the opposite of what you need. That can easily lead to deto, which will destroy the plug filament in milliseconds.
Apart from this, glow plugs would be far too slow in varying their temperature for decent ignition timing control, which might also be true for 'hot spots'.

But the key word here is localized. Spark plugs, glow plugs and hot spots all initiate combustion locally. And then it's not HCCI anymore.
Locally igniting a mixture that is already on the brink of self-ignition is asking for deto.

Flettner reckon you should concentrate on the gyro engine, after all it's just about there!From a commercial point of view you are probably right Will. Me personally, I'd love to witness all his other projects reach maturity.

Wasn't Honda acheiving that 30 years ago with the traping valve on the EXP2. (The EX gas recirculation)Yep. It's a bloody shame the Honda politicians blew the whistle on the Honda engineers.

I may well be wrong but Neil's HCCI is the only one I've seen with no "conventional" ignition running in parallel with the HCCI events.
If the car engines are getting HCCI at part throttle, surely the rest of the time they're relying on the spark ignition ?
Anyone know better ?I think you're right.

Flettner

8th February 2018, 07:41

Spoils of the home foundry, all heat treated and nice to machine.
Just got to make this epicylic crank fit this case. Then for the special top end.:msn-wink:

WilDun

8th February 2018, 08:36

Wasn't Honda acheiving that 30 years ago with the traping valve on the EXP2. (The EX gas recirculation)
Yes, I think that is the one I was thinking of and which I mentioned of a couple of posts back.

Spoils of the home foundry, all heat treated and nice to machine.
Just got to make this epicylic crank fit this case. Then for the special top end.:msn-wink:
Guess we'll all have to wait and see which one it'll be! :scratch:

How about flats on the big end eye running against bearing pads (crosshead style) to stabilise it? too much drag perhaps?

Everything is already a completely new concept top to bottom - let's have a go anyway! :2thumbsup

If the car engines are getting HCCI at part throttle, surely the rest of the time they're relying on the spark ignition ?
We'll have to wait and see what Mazda have come up with as well! but, if it's anything like their great "engine stopping/starting gimmick at standstill" (trying to emulate Prius) then I wouldn't be holding my breath!

Frits Overmars

8th February 2018, 08:58

We'll have to wait and see what Mazda have come up with as well! but, if it's anything like their great "engine stopping/starting gimmick at standstill" (trying to emulate Prius) then I wouldn't be holding my breath!I think Mazda have something pretty good this time (although not very KISSable). But they're still using a spark plug.

WilDun

8th February 2018, 10:06

I think Mazda have something pretty good this time (although not very KISSable). But they're still using a spark plug.

KISS is really a concept which is dying out these days.
Retaining a spark plug (just in case) reminds me of the cars of the fifties where they always had a crank handle (just in case).

Kickstarts seem to have disappeared from motorcycles too but that took a lot longer! (probably over about 50 years) - I think the electric start came out on the old Honda 50cc way back in the early nineteen sixties?

Flettner

11th February 2018, 13:16

WilDun

11th February 2018, 15:08

beautiful to machine and not a void to be found.
Don't overheat the metal, use virgin bullet alloy and make sure you feed it well into the heavier parts of the casting. Use magnesium powder on the risers.

Looks good, - what sort of gauge do you use to measure the temperature of the melt so you know exactly when it's ready to pour? (or can you tell by just looking?)

I take it that you use huge risers to make sure it goes in properly? (got pics of those? to get an idea of proportion) Guess you get magnesium powder from the foundry materials supplier?

Are you now using Shellsand exclusively? - big improvement?

Michael Moore

11th February 2018, 15:21

A "K" thermocouple and cheap digital display works fine for aluminum, and you can source that at such a reasonable price these days that it really doesn't make sense to try and guess at the melt's temperature.

You don't want to use "huge" risers because then you end up with a lot of excess metal that gets cut off the part and which may not be quite as close to the original spec when remelted for another use. The feed/gating system volumes/areas can be calculated to keep the metal's progress in a range of speed that isn't too slow so that it freezes too soon but isn't so fast that you cause problems from turbulence entraining oxides or eroding sand from the mold and taking it into the part. Campbell's "Complete Casting Handbook" goes into a lot of detail on that (and many many many other things).

cheers,
Michael

F5 Dave

11th February 2018, 17:01

We don't get so much cast anymore these days but if they did as good as that I would be more than happy.

How would you go with an order for a few hundred that sort of size?

Where you say? Ohh that might sting.

WilDun

11th February 2018, 18:31

A "K" thermocouple and cheap digital display works fine for aluminum, and you can source that at such a reasonable price these days that it really doesn't make sense to try and guess at the melt's temperature.
Thanks Michael, I did actually buy a thermocouple a while ago but it was so ridiculously cheap that I didn't trust it! - maybe I should at least try it, but I'll probably need to make some sort of sheath to protect it and once I know where the proper temperature is on the readout, then I guess I'll know "when" and just disregard the actual figures it shows! (just used as a comparator I guess!).

You don't want to use "huge" risers because then you end up with a lot of excess metal that gets cut off the part and which may not be quite as close to the original spec when remelted for another use. Campbell's "Complete Casting Handbook" goes into a lot of detail on that (and many many many other things).
cheers,
Michael
Yes, and to be honest, as I don't know what sort of scrap I have, (all castings though) I think I'll just practice with that and purchase some "reliable" ingots to do the real thing.
Will check out that book, although I do have a Foseco book somewhere.

Michael Moore

11th February 2018, 19:09

You can get a graphite rod and drill down the center almost to the other end and use that as a protective sheath for the thermocouple. The thermocouple readers are readily available from eBay and similar sources, I think this is the same thing I bought:

https://www.amazon.com/Dodolight-Digital-Channel-Thermometer-Thermocouple/dp/B0084JQL1Q

Here's the Foseco book

http://www.eurospares.com/graphics/metalwork/Foseco-Non-Ferrous-Foundry-Man.pdf

Campbell was the originator of the Cosworth casting process and co-inventor of several other casting processes. His book is expensive, but at 1100 pages it sure has a lot of information in it.

cheers,
Michael

Flettner

11th February 2018, 19:46

all the parts fit, a bonus.

ken seeber

11th February 2018, 21:16

You can get a graphite rod and drill down the center almost to the other end and use that as a protective sheath for the thermocouple. The thermocouple readers are readily available from eBay and similar sources, I think this is the same thing I bought:

Here's the Foseco book

cheers,
Michael

Michael, you're right as to how cheap T/C controllers are and how good they are. We were fortunate in getting a couple of blind ceramic sleeves about 18 dia * 10 dia around 500 long. This allows us to leave the T/C in the melt for the duration (it controls the furnace burner), which is quite a few hours as we ladle directly from the furnace. Stainless steel, or even mild steel will disappear fairly quickly into the melt, destroying the quality of the melt at the same time. We also have a couple of others in the (permanent mould) dies so we can also control the temps of these.

Thnx also for the Foseco book, the one I have is much, much older, the new one has some good pics.

Mechanism looks good Fletto....another productive Sunday..

Flettner

11th February 2018, 21:27

yes went out to the shed to do a completely different job but bugger it I felt like machining something, it was raining, no better time to work on these sorts of things than a rainy Sunday afternoon.

WilDun

13th February 2018, 16:02

Neil, what is the significance of the small "tit" at the bottom of the big end ring?

Grumph

13th February 2018, 18:16

Neil, what is the significance of the small "tit" at the bottom of the big end ring?

Guide peg keeping the bearing aligned ? Effectively, it's an overhung crank isn't it ?

WilDun

13th February 2018, 19:54

Guide peg keeping the bearing aligned ? Effectively, it's an overhung crank isn't it ?

I think it possibly will be a two sided crank, but I don't have many clues as to what the "tit" is for, except that it might be just temporary to hold in the chuck for machining the rod( on the lathe)! :scratch:
No doubt we'll find out .....

Flettner

13th February 2018, 20:03

husaberg

13th February 2018, 20:05

O, the tity, it's just a place to put the center when I was grinding the hard chrome shaft. Thought it best not to cut it off just in case I need it again.
Grumph, it not an over hung crank I just haven't shown the other half yet (cause it's not made yet), no, unlike other epicylic systems this has a fully supported crank.

I was wondering how you were hiding the overhung crank with those shorts Neil.
Have you seen the facing sand how to on the old foundaryman site?

https://www.youtube.com/watch?v=L9qP39y3E4k

WilDun

14th February 2018, 09:25

husaberg

14th February 2018, 19:29

Well that's all "fine" of course (:rolleyes:), but I don't think that guy was wearing any sort of mask at all - in my book that's a no-no in conditions like that and to tell the truth I reckon there could be better ways of spending a weekend!
On the upside or positive side he was ending up with a plentiful supply of good quality facing sand - enough to see him out really! (sorry, slipped into negative mode again) :facepalm:
I note he is using a natural sand that has a element of clay already in it.
You could of course just mechaically sieve sand using a vibrating set of sieves.
it will take more material but its a bit easier and less messy then add some ground bentonite.
You will remember someone ages ago linked a cement and oil mixture, Cement is very very fine plus easy to obtain rather cheaply.
From what i can undestand the oil doesnt actually cause the hydration process to start.ie what makes concrete set, so its not going to explode in a steaming mess. With these mixes you use oil so it makes sense to use a two stroke oil, for less smoke as in petrobond which tublicain uses in his videos.

Yes Will you are right regarding the grinding of sand as most NZ sands are silca based and it it is a real silicosis risk. Which for those who are unfamilar with it, is a rather nasty way to slowly die.

I came across the olfoundryman due to him advising some one about there feeders being uninsulated and thus cooling too fast and not feeding the mold correctly. like Fletner recomends he also uses the Mg powder in bigger pours.
the guy he advised ended up using thick plaster of paris feeders and risers with great success.

Flettner

15th February 2018, 13:45

https://youtu.be/cuSnfRgyEZk

backup linear crank assembly

Flettner

15th February 2018, 13:48

the insides of the HCCI head, I guess what you would expect to see. 16mm stroke

WilDun

15th February 2018, 14:58

the insides of the HCCI head, I guess what you would expect to see. 16mm stroke

At the risk of appearing incredibly stupid (or at least a little slow), I still haven't got my head around the "double speed OHP" concept!
Why double speed? and is there some benefit of having a blast (of whatever - spent charge?) coming from the OHP as the main piston arrives at BDC - or is it timed to be out of phase? :scratch:

Flettner

15th February 2018, 16:17

WilDun

15th February 2018, 18:30

Flettner

15th February 2018, 21:37

Will, that information is restricted
The idea is the small piston helps with expansion, a little bit, but the big deal in my opinion is because the little piston is at it's BDC when the main piston is half way up (when the exhaust pulse is doing it's 'supercharging' there is more room to shove fuel air back in. But the small piston is not involved with the cc rating of the engine as it's at it's BDC when the main piston is at it's BDC and it's TDC.

WilDun

15th February 2018, 23:09

Ok, thanks, that's all good :niceone:

Frits Overmars

16th February 2018, 00:42

yes I guess the small piston is a little out of phase. 2 to 1 so there is some urgency in the compression rise. Small piston is rapidly heading for it's TDC as the big piston loiters around it's TDC. Comes a point where pressure / temperature is just too much and ignition occurs.

The idea is the small piston helps with expansion, a little bit, but the big deal in my opinion is because the little piston is at it's BDC when the main piston is half way up (when the exhaust pulse is doing it's 'supercharging' there is more room to shove fuel air back in. But the small piston is not involved with the cc rating of the engine as it's at it's BDC when the main piston is at it's BDC and it's TDC.
Ok, thanks, that's all good :niceone:I'm timing the arrival of WilDun's next question:
"How can the small piston be at BDC when the main piston is at BDC, if the small piston is a little out of phase at TDC and it is geared 2:1 ?" :devil2:

Flettner

16th February 2018, 06:21

tops and bottoms, opps, when the small piston is at it's TDC, it's so confusing late at night.

WilDun

16th February 2018, 08:15

I'm timing the arrival of WilDun's next question:
"How can the small piston be at BDC when the main piston is at BDC, if the small piston is a little out of phase at TDC and it is geared 2:1 ?" :devil2:

Ha Ha well, at least then you could say that I'm predictable, more predictable than a lot of two stroke powered machinery ( perhaps a little slower!).
I do need a night's sleep for my brain to sift through and take in what's been said! - this morning? I dunno - think I may have accidentally shut down my brain instead of my computer last night! :msn-wink:

( I also understand of course that the message wasn't actually intended for me!)

Frits Overmars

17th February 2018, 06:03

tops and bottoms, opps, when the small piston is at it's TDC, it's so confusing late at night.Let me put you out of your misery Neil :msn-wink:.

Will, here is some basic explanation, leaving the phase difference between the main crank at TDC and the small crank at TDC aside for now.

When the main piston is at its BDC, the small piston is at its TDC.

When the main crank turns 90°, the main piston is about half-way up, about to close the exhaust, and the small crank has turned 180°, so the small piston is at BDC.

Another 90°-turn for the main crank and another 180°-turn for the small crank, and the main piston is at its TDC, and the small piston is also at its TDC.

Below is a little program you can play with, provided you use Win98 (on some computers it will also run under Win XP) or a Win98-emulator.

335269

WilDun

17th February 2018, 10:42

Frits,
I haven't got WIN 98 computer running at the moment, but last night I had drawn a few basic sketches (which I should have done in the first place!) and so had it already 99% sussed.

Neil,
Sorry to put you through having to answer all those basic crappy questions - it's pretty easy demonstrating things to people when they are present but on a forum and when you're about to shut down...... maybe not so easy!

I still expect you guys to make some allowances for me though! - At least I'm interested! :laugh:

Flettner

24th February 2018, 20:33

clutch cover, fitted.

Flettner

25th February 2018, 20:21

oiler attached, water pump is on the opposite end of the oiler drive shaft.

WilDun

28th February 2018, 19:02

oiler attached, water pump is on the opposite end of the oiler drive shaft.

I haven't been here much lately - how is the progress with the experimental engine project? I am assuming that this one is straight line piston assembly, FOS? or HCCI (with the little piston that I couldn't get my head around?) or just conventional up top? my guess it's completely new from the bottom of the crankcase up!
Have you got the Gyro engine sussed out and flying?

Flettner

28th February 2018, 19:44

Will, this is a relatively standard engine, I just want something to ride other than the F9.
this is a rotary valve engine, with the sliding throttle Gibs.
also using the mark two TPI, all technology with no risk. All ready run these systems, but separately.
360cc, I just want lots of power with a wide usable torque curve and burn fuck all fuel, simple really.

Flettner

28th February 2018, 19:47

a double sided tooth belt (5mm pitch) and 10 tooth pulleys, throttle linkage, one shaft has to turn backwards.
gyro is sorted, it needs a new Ignitech.

WilDun

28th February 2018, 21:38

a double sided tooth belt (5mm pitch) and 10 tooth pulleys, throttle linkage, one shaft has to turn backwards.
gyro is sorted, it needs a new Ignitech.

If this 360 works well with all the new gear, is there the possibility that it could eventually become a single cylinder test bed for a revised (Mk 2) gyro engine? - sounds to me that it might be a good candidate for that role - especially if it has a good torque spread and fuel economy - enjoyable way of testing too! ..........(bigger and more efficient prop maybe ?).

Flettner

3rd March 2018, 13:39

yes, same cylinder.

WilDun

4th March 2018, 12:37

yes, same cylinder.

Looking forward to watching it evolve! :niceone:

Flettner

4th March 2018, 21:02

another step, rear pipe fitted, end will be plugged with exhaust gas being drawn off the center section. I have run the swing arm, with wheel, full travel to be sure nothing collides.

WilDun

5th March 2018, 10:12

another step, rear pipe fitted,
.......... I have run the swing arm, with wheel, full travel to be sure nothing collides.

Looks like you have found a satisfactory way of routing the rear exhaust considering that it will be longer than say a road racing machine!
( my life's ambition is to save the two stroke by getting rid of the bulky chambers and smokey exhaust - is that possible?):laugh:

.........end will be plugged with exhaust gas being drawn off the center section

As usual, I haven't really got what you mean about the end being plugged with exhaust gas etc! :rolleyes: but.... having looked in ESE, could it be this new fangled and mysterious W.T.F. "I.P." thing they are discussing?? ..... Injection Pulse ?? or could "IP" stand for inverted pipe/stinger as proposed by Gordon Jennings, who wrote the famous two stroke tuning book? (it'll come to me ..... eventually!)

Guess you used the flat surface of that "hefty" nameplate and the bearing boss (same level?) as a hold down surface/datum on the mill table?

husaberg

5th March 2018, 20:08

another step, rear pipe fitted, end will be plugged with exhaust gas being drawn off the center section. I have run the swing arm, with wheel, full travel to be sure nothing collides.

As usual, I haven't really got what you mean about the end being plugged with exhaust gas etc! :rolleyes: but.... having looked in ESE, could it be this new fangled and mysterious W.T.F. "I.P." thing they are discussing?? ..... Injection Pulse ?? or could "IP" stand for inverted pipe/stinger as proposed by Gordon Jennings, who wrote the famous two stroke tuning book? (it'll come to me ..... eventually!)

Hes putting the stinger outlet in the pipe mid section. rather than the end of the baffle cone.
https://www.treatland.tv/v/vspfiles/photos/MLM-HOBBIT-pipe-310-2.jpg (https://www.google.co.nz/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwiq8eSc4NTZAhVCVbwKHU0gCMUQjRx6BAgAEAY&url=https%3A%2F%2Fwww.treatland.tv%2Fmoped-exhaust-pipes-s%2F23.htm%3Fsearching%3DY%26sort%3D5%26cat%3D23%2 6f-motion%2520left%3D165%26show%3D200&psig=AOvVaw0He47ZettqTm5eoV31dSxV&ust=1520324472756705)
He needs to do something like ths as he has a lowish reving two stroke with a reverse cylinder so hes runing out of room.
Remember where and how a normal front exhaust MX bike curls arround Will.
335574

You should call it the V1 Neil.
https://upload.wikimedia.org/wikipedia/commons/thumb/2/2b/Peenem_Museum_V1_Modell.jpg/266px-Peenem_Museum_V1_Modell.jpg (https://www.google.co.nz/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwj-uOfp4NTZAhWLu7wKHb4gDU4QjRx6BAgAEAY&url=https%3A%2F%2Fwikivisually.com%2Flang-nl%2Fwiki%2FV1_(wapen)&psig=AOvVaw06CSdO7EjpoM_BZ8-wCISU&ust=1520324643947988)

WilDun

6th March 2018, 08:20

Hes putting the stinger outlet in the pipe mid section. rather than the end of the baffle cone.

AHA! - this brain fade thing does have it's advantages too you know, life becomes more exciting all the time - I get to learn new concepts every day!!..... (sort of W.T.F. is this? what have they done with megaphones anyway?). :rolleyes:

Seriously however, I haven't heard of this before, (may have seen pictures which I didn't really check out) - I guess it does a lot towards shortening the system at least. - still bulky compared to say, a straight pipe, but a step in the right direction!
Husa thanks for the clarification!

........ end will be plugged with exhaust gas being drawn off the center section.......

BTW, After checking, I found why I didn't understand what you meant - I misinterperated that statement as "the end will be plugged with exhaust gas" instead of "the end will be plugged....with exhaust gas being drawn..... etc " :scratch:

Another question, - does that stinger coming out of the mid section extend into the tail section? or does it come directly from the mid section?

WilDun

6th March 2018, 08:33

........ end will be plugged with exhaust gas being drawn off the center section.......

After checking, I found why I didn't understand what you meant - I misinterperated that statement as "the end being plugged with exhaust gas" instead of "the end being plugged, with exhaust gas being drawn..... etc " :scratch:

Flettner

6th March 2018, 12:22

directly off the mid section. very important to flare the outlet pipe (bell mouth) from the main pipe into the tail pipe. In a normal system this is done by the taper cone leading into the tail pipe.
This is important because there is a restriction (in my system, swapable) in the outlet pipe and you don't want a restriction further up the pipe doing the job instead. You will see.

Frits Overmars

6th March 2018, 14:21

AHA! - this brain fade thing does have it's advantages too you know, life becomes more exciting all the time
Ah yes, the three advantages of Alzheimer: you meet new people every day, you can hide your own easter eggs, and you meet new people every day :rolleyes:.

WilDun

6th March 2018, 19:51

Ah yes, the three advantages of Alzheimer: you meet new people every day, you can hide your own easter eggs, and you meet new people every day :rolleyes:.

Frits that's right, I'd forgotten what else there was ......... :msn-wink:

Neil, has anyone else tried this layout in Motocross etc. or is it all brand new?

ken seeber

7th March 2018, 16:28

Frits that's right, I'd forgotten what else there was ......... :msn-wink:

Neil, has anyone else tried this layout in Motocross etc. or is it all brand new?

Will,

The following is an extract from the Two Stroke Tuners Handbook by the late Gordon Jennings:

"These several difficulties should convince anyone that a different approach to the problem of effectively silencing the expansion chamber is required. Lacking a more effective solution to the problem, we may eventually be forced to revert to a straightforward muffler in place of the expansion chamber and live with the loss of power and performance that entails. I do not believe that will be necessary, as I stumbled upon a phenomenon a few years ago that meant very little at the time but now assumes major importance: The then-existing general racing regulations required that a motorcycle's exhaust system terminate at some point forward of the rearmost edge of the back tire, and I was planning to race a bike with its cylinders reversed to provide rear-facing exhaust ports (for reasons that were important, but not pertinent here). The only major flaw in this scheme was that even with the motorcycle built on a longish wheelbase and with its engine located well forward, there was not quite enough room for the exhaust pipes within the length allowed by the rules. The expansion chambers themselves would fit, but there was some 12-inches of outlet pipe left hanging back behind the rear tire, and not enough room to curl these outlet pipes back within the limit. While groping for a solution, I hit upon the idea of simply sliding them forward, inside the baffle cones. There, they would still function as pressure-bleed resisters, and further contemplation led me to the conclusion that the expansion chambers might even work better with their outlet pipes positioned inside. With the forward end of the outlet pipe located at the chamber's maximum diameter, ahead of the baffle-cone, there should be a somewhat stronger reflection from the baffle, and that might very well give the engine a somewhat better boost. Or so I thought.

Anyway, I gave the scheme a try, and while certain other modifications prevented drawing any absolute conclusions from the experiment, the bike did prove to be very fast, and it seemed certain that while my inside stingers might not offer any real power advantage, they probably were at least as effective as those attached in the more conventional manner. But that is not to say that I did not notice a difference - and the difference was in sound. With those inside outlet pipes, the typical expansion chamber crackle was very noticeably subdued. That made sense, as the chambers' outlet to atmosphere was taken from a point where the pulse was at its lowest amplitude - rather than from the high-pressure area at the tip of the baffle-cone.

More recently, I have been able to perform a series of tests using a dynamometer, to see if my inside-stinger idea (which, I had learned, was an idea also advanced by an obscure German researcher some several years earlier) had any real merit. An expansion chamber was constructed with its baffle-cone terminating in a clamp, to allow rapid changes in outlet pipes. and we tried pipes of different diameters and lengths, and moved them back and forth in the clamp to find the change in output as the outlet's forward end was advanced up the baffle-cone. The results were most interesting: There was absolutely no difference in power output with the outlet pipe in full-forward and full-back positions, but we did find a quite noticeable drop in power with the pipe's forward end pushed up to the approximately-halfway point in the baffle-cone. We also found that the same outlet pipe diameter produced optimum results no matter what the location, but that the system was rather less sensitive to outlet pipe length when the pipe's forward end was located an inch or so ahead of the baffle-cone's forward end. Finally, we found that the noise output with the forward-located outlet pipe was very much reduced: to about the same level as a conventional expansion chamber fitted with a bolt-on, fiberglass-packed muffler. I was, of course, a bit disappointed that my inside-stinger pipe did not show a big advantage in power over the conventional variety (there may be a slight broadening of the power curve, but the differences observed were too small to offer conclusive proof). Still, by that time, the sound-damping properties of the inside-stinger arrangement had become extremely important, as they could be used in conjunction with a low-resistance muffler, located farther downstream, to meet the AMA's new noise-limit rule without any loss of performance. For that reason, this idea - the creature, indirectly, of the AMA competition rules book - did prove to be a success, even if not in precisely the form I had anticipated."

Whilst Neil's tailpipe starts at the surface of the mid-section chamber, G Jennings had the tailpipe cantilevered or (sort of) freely suspended within the volume of the chamber.

What a great book it is.

husaberg

7th March 2018, 19:05

Will,

What a great book it is.
http://www.amrca.com/tech/tuners.pdf

speedpro

7th March 2018, 21:31

WilDun

7th March 2018, 22:08

Will,

The following is an extract from the Two Stroke Tuners Handbook by the late Gordon Jennings:
........What a great book it is.

Yes Ken, I remember reading that a long time ago - If that guy had lived in Britain instead of America, he would have been Sir Gordon Jennings! - I think he had a great way of getting the message across to the average two stroke tuner - without all the computer development coming from a department at Queens University run by Dr. Gordon Blair. Then there was the work of Walter Kaaden at MZ. who inadvertantly launched the Japanese into Orbit! when (apparently) his work was stolen by Ernst Degner and sold to Suzuki when he defected. - Not forgetting "our" Jan Thiel of course!

In buckets there has been a few bikes with the exhaust exiting the side of the pipe midsection. Neil is friends with one builder who did it. I've also built at least one pipe with the stinger supported in the centre of the exhaust cone and extended to where it meets the mid-section. As stated above, no obvious performance change but the noise was gone. In my case I was looking to make it more crash proof by getting the exhaust fully tucked under the bike and not extending around the swingarm to a muffler.

How the hell did I miss all this stuff? but then I completely lost all my enthusiasm and almost forgot about bikes for about 25 years or so after health problems and I'm glad to see something like this come up! :niceone:

WilDun

7th March 2018, 22:18

In buckets there has been a few bikes with the exhaust exiting the side of the pipe midsection. Neil is friends with one builder who did it. I've also built at least one pipe with the stinger supported in the centre of the exhaust cone and extended to where it meets the mid-section. As stated above, no obvious performance change but the noise was gone. In my case I was looking to make it more crash proof by getting the exhaust fully tucked under the bike and not extending around the swingarm to a muffler.

How the hell did I miss all this stuff? but then I completely lost all my enthusiasm and almost forgot about bikes for about 25 years or so after health problems and I'm glad to see something like this come up! :niceone:

husaberg

7th March 2018, 22:52

I have often wondered if the noise effect was real (as in measurable DB) or just a result of a different less objectionable frequency.
Or if it’s really a measurable and is actually the result of attenuation much like white noise is?
I always thought Roe and co were on to something with their original annular discharge silencers.
It’s a real shame there isn't a Dutch physicist with an interest in two strokes lurking about.
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husaberg

7th March 2018, 22:56

I have often wondered if the noise effect was real (as in measurable DB) or just a result of a different less objectionable frequency.
Or if it’s really a measurable and is actually the result of attenuation much like white noise is?
I always thought Roe and co were on to something with their original annular discharge silencers.
http://yorkshireferret.blogspot.co.nz/2016/02/geoffrey-roe-annular-discharge-silencer.html
It’s a real shame there isn't a Dutch physicist with an interest in two strokes lurking about.

ken seeber

7th March 2018, 23:05

It’s a real shame there isn't a Dutch physicist with an interest in two strokes lurking about.

Yeah Hooser, I am pretty sure you are referring to someone in particular. And fair enough, it's 1.00 pm in the land of tulips, wind turbines, bikes and dykes so surely he is awake by now...:yes:

husaberg

7th March 2018, 23:16

Yeah Hooser, I am pretty sure you are referring to someone in particular. And fair enough, it's 1.00 pm in the land of tulips, wind turbines, bikes and dykes so surely he is awake by now...:yes:
https://www.dutch-biketours.com/phpThumb/phpThumb.php?src=%2Fupload%2Ffile%2Fwidgets%2F442% 2F8%2F1476954500_7-00.jpg&w=2000&h=650&zc=1&hash=2904d371001baa18dc229f99dc84c310 (https://www.google.co.nz/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwiqy6vYitrZAhWImZQKHacrDroQjRx6BAgAEAU&url=https%3A%2F%2Fwww.dutch-biketours.com%2Fbike-tour-lake-ijssel-and-the-north-sea-7-days&psig=AOvVaw06ZKtTYhyav1vyW5Rv2V4O&ust=1520507504113300)
I know right, Gosh it was hard to find a pic with all four. Five if those two are more than just friends:whistle:

Frits Overmars

7th March 2018, 23:58

I always thought Roe and co were on to something with their original annular discharge silencers.
http://yorkshireferret.blogspot.co.nz/2016/02/geoffrey-roe-annular-discharge-silencer.html
It’s a real shame there isn't a Dutch physicist with an interest in two strokes lurking about.

Yeah Hooser, I am pretty sure you are referring to someone in particular. And fair enough, it's 1.00 pm in the land of tulips, wind turbines, bikes and dykes so surely he is awake by now...:yes:On the presumptuous presumption that you're talking about me, no worries: I usually hit the sack after midnight: too much interesting things to read on internet forums, but I'm done sleeping at 6. In fact, the older I get, the less sleep I seem to need.
And on the subject of silencers: I did try some Roe annular discharge silencers but I wasn't impressed with the results.
I also tried Flettner's plan of an exit at the pipe belly (which I used to call a stoma when there was no-one around).
Back then I rode a Kawa H2 (for you youngsters: a 750 cc two-stroke triple) with a couple of mods, like three 38 mm Mikunis and a homebrewn exhaust system, consisting of three conventional expansion chambers, but without the tailpipes. Instead they had exits at their bellies that came together in a big empty pot,
120 mm Ø x 350 mm length, under the engine, in front of the rear tire.
My mates still made me ride at the rear of the group on our sunday tours, but its tin-can sound was a little quieter than three stingers with absorbtion dampers.

husaberg

8th March 2018, 00:03

On the presumptuous presumption that you're talking about me, no worries: I hit the sack far after midnight.
And on the subject of silencers: I did try the Roe annular discharge silencer but I was not entirely satisfied with the results.
I also tried Flettner's plan of an exit at the pipe belly (which I used to call a stoma when there was no-one around).
Back then I drove a Kawa H2 (for you youngsters: a 750 cc two-stroke triple) with a couple of mods, like 3 38 mm Mikunis and a homebrewn exhaust system, consisting of three conventional expansion chambers, but without the tailpipes. Instead they had exits at their bellies that came together in a big pot 120 mm Ø x 300 mm length under the engine, in front of the rear tire. They still made me ride at the rear of the group when we went on our sunday tours, but it was a little quieter than three stingers with absorbtion dampers.
I was more hoping for the why explanation to the buried stinger or the mid exit being quieter.

ps I heard Heisenberg went for a drive in Munich and got stopped by a traffic cop. The cop asked, "Do you know how fast you were going?" Heisenberg replied, "No, but I know where I am."

Frits Overmars

8th March 2018, 00:14

I was more hoping for the why explanation to the buried stinger or the mid exit being quieter.As Gordon Jennings wrote:
the chambers' outlet to atmosphere was taken from a point where the pulse was at its lowest amplitude - rather than from the high-pressure area at the tip of the baffle-cone.
I heard Heisenberg went for a drive in Munich and got stopped by a traffic cop.
The cop asked, "Do you know how fast you were going?" Heisenberg replied, "No, but I know where I am."Do you happen to know if Heisenberg was driving his new car?
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Grumph

8th March 2018, 07:10

I too played around with annular discharge silencers in the late 80's. I'd got tired of losing packing material...

My empirical conclusions were that they were fine for 4T's but 2T's not so much.
I'd assumed that the 4T's lower frequency pulses suited this system better.
It may however have simply been a too large annular gap. Can't be bothered retrying now.

husaberg

8th March 2018, 17:09

As Gordon Jennings wrote
:Do you happen to know if Heisenberg was driving his new car?

Chairs for the explanation re jennings
I heard Heisenberg actually got off the ticket as he said to the policeman he was in a rush taking Schrodinger’s cat to the vet, it turned out the cat was so sick the vet couldn't work out if it was dead or not.

Husaaaa!! ......... didn't you know? - Tulips just won't grow behind dykes, that'll be why!
I heard that was why van Gough cut of his ear...

Frits Overmars

9th March 2018, 00:56

I heard that was why van Gough cut of his ear...Don't let the facts spoil a good story...
Van Gogh didn't cut off his ear, he 'merely' cut off one ear lobe. Not because of tulips or dykes, but because he had mental problems all his life.
I somehow get the impression we're a bit off-topic...

WilDun

11th March 2018, 07:59

Yes let's keep international relations on an even keel (within reason) - I am guilty of getting really off course (of course)! :laugh:
So to that end, I have decided to delete a couple of my even more pathetic contributions! :rolleyes:

Getting back to the exhaust with the closed end and side discharge stinger - why did this not become generally accepted practice earlier?
As for those people who did find that it worked ok, including Speedpro, with his similar adjustable internal stinger - what made you guys revert to the conventional layout again?

Frits Overmars

11th March 2018, 11:33

Getting back to the exhaust with the closed end and side discharge stinger - - - what made you guys revert to the conventional layout again?Simplicity. If you don't work on slow-revving engines, you won't have to accommodate long pipes and then the silencer behind the end cone is the simplest solution.

WilDun

15th March 2018, 18:19

Simplicity. If you don't work on slow-revving engines, you won't have to accommodate long pipes and then the silencer behind the end cone is the simplest solution.

Does there come a point where there might be the possibility in the world of everyday two stroke workhorses (probably none left on the roads anymore) of having a relatively "tame" engine with a wide torque spread with good fuel consumption figures - would it then become feasable to have a parallel pipe (or something close)?
Probably I'm wrong of course, but all this harmonic stuff seems to add a lot of (unseen) complication and if it works really well, it only works well in one area of the rev band, not particularly good on the streets or highway in the hands of a lunatic who is fond of wheelies!
Of course, in competition it is necessary if a tenth of a horsepower increase means a lot to you! (see ESE). ;)

Flettner

15th March 2018, 18:59

trouble is a twostroke without a chamber is a lawnmower.
The chamber makes sooòoo much difference.

Frits Overmars

15th March 2018, 23:45

Does there come a point where there might be the possibility in the world of everyday two stroke workhorses of having a relatively "tame" engine with a wide torque spread with good fuel consumption figures - would it then become feasable to have a parallel pipe (or something close)? .. All this harmonic stuff seems to add a lot of (unseen) complication and if it works really well, it only works well in one area of the rev band, not particularly good on the streetsWe passed that point a long time ago Will: the two-stroke workhorses of the 1960s with four speeds, enclosed chains that had eternal life compared to what we have to put up with now, and silencers that didn't yet double as resonant chambers. But as Flettner says: "The chamber makes sooòoo much difference".
On the Aprilia racers the pipes tripled the power. If you want to get rid of that pipe, you'd have to triple the cylinder capacity. Worth a thought...

You're right about "this harmonic stuff" only working well in one area of the rev band. Six-speed street bikes can be fun for a while, but I can assure you that twelve speeds are no fun at all. For everyday use I prefer a bike that doesn't need a downshift each time I want to overtake someone. I'd rather have a CVT, or an E-bike, once we get batteries with half the weight and five times the capacity. I can do without the noise, although I think the absence of noise will eventually kill the public interest in motor sports.

Michael Moore

16th March 2018, 05:16

WilDun

16th March 2018, 17:30

Well, I guess that in Neil's Gyro, a chamber is an asset because of it's engine revs staying inside the powerband most of the time, same for fixed wing aircraft
.
Trouble is, that whatever we say to the contrary, tuned pipes more or less equate to a turbo! (did I really dare say that?).
A turbo (or supercharger) in everyday street use is acceptable, however our thinking unfortunately seems to be always driven by racing rules and this is actually taking the two stroke off our roads.

If I possibly have broached this somewhere before - forgive me, but if some built in (integral) mild forced charging could be introduced and combined with milder exhaust porting without being affected by the need for the (finicky) resonance thing, to address the charging problems and help keep the fresh charge completely out of the exhaust system.

If we wanted to keep the "sound" going, we could use the two stroke (suitably tuned) driving a generator in a Hybrid! - maybe that would be a bit of a travesty, ie losing all those beautiful (and costly) gearboxes! :msn-wink:

And yes Michael. I had meant to say, take a look at trials bikes!

Vannik

16th March 2018, 18:45

I've long thought that a 650-700cc 2T twin with tuning and flywheel mass like my 325cc Bultaco Sherpa T would make a pleasant street engine. The exhaust system on the Bultaco is straight pipe and mufflers. I suppose the closest thing to that would be the Silk version of the Scott.

I've got something like that with my 670 Honda 4T parallel twin which makes a massive 45 or so hp. I like the DCT transmission too, not shifting/clutching is fine with me, but I can always punch a button to change a gear if I feel a need for that.

cheers,
Michael

Then you should use a tripple with a log manifold, it stays mostly in tune through the rev range if the blowdown pulse for one cylinder is used as the plugging pulse for the previous cylinder. This only works for 3 cylinder engines and is why outboards prefer I3 or V6 layouts.

WilDun

16th March 2018, 22:18

Have often heard that - good suggestion of course ..... but does it keep the fresh charge out of the exhaust? - still a resonance problem??
Mixing of the fresh charge with the exhaust gases is the main problem and I feel it has all but killed the two stroke! If this didn't happen surely the oil would be burnt completely and there would be no smoke but when a two stroke starts up from cold, there is always oil in the exhaust which almost disappears when everything heats up, and of course there is the unburnt raw petrol as well! - second only to the Wankel!! - Sorry Frits. :facepalm:

EssexNick

16th March 2018, 22:18

Would there be any difference in stinger nozzle size, between a straight pipe and one that exits mid chamber?

Frits Overmars

17th March 2018, 04:30

If we wanted to keep the "sound" going, we could use the two stroke (suitably tuned) driving a generator in a Hybrid!I have actually been thinking about that. It's not new of course; diesel-electric locomotives have been around for decades, but I wanted both a continuously variable transmission and kinetic energy recovery, which led me to the combustion engine - generator - supercapacitor - E-motor setup.
A small two-stroke engine with such a setup, running at maximum power 100% of the time, would be unbeatable.

But forget about keeping the 'sound' going. It would be horrible. In fact it was horrible. Williams tried it in a Formula 1 Car and test driver David Coulthard reported more power and a much stabler car. But the FIA vetoed it even before the first race of the season.
It would have chased the spectators away: instead of the thrilling F1-noises they were expecting, it sounded like a horn going round the track: just one constant pitch.
http://www.youtube.com/watch?v=x3UpBKXMRto&feature=related

Then you should use a tripple with a log manifold, it stays mostly in tune through the rev range if the blowdown pulse for one cylinder is used as the plugging pulse for the previous cylinder. This only works for 3 cylinder engines and is why outboards prefer I3 or V6 layouts.How about a 180°-twin Neels? It would require an exhaust timing of perhaps 220° but think of the stuffing pressure: a multiple of the pressure that an expansion chamber could manage.
I imagine a very short, small-volume manifold directly from one exhaust port to the other, and a rotating drum underneath, that opens the manifold to the atmosphere once the cylinder that had to be stuffed, has closed it exhaust. And maybe the drum could double as a balance shaft.
Wishful thinking, I know. But Flettner has some nice 180°-twins...

Vannik

17th March 2018, 05:08

How about a 180°-twin Neels? It would require an exhaust timing of perhaps 220° but think of the charging pressure: a multiple of the return pressure that an expansion chamber could manage.
I imagine a very short, small-volume manifold directly from one exhaust port to the other and a rotating drum underneath that opens the manifold to the atmosphere once the cylinder that had to be charged, has closed it exhaust. And maybe the drum could double as a balance shaft.
Wishful thinking, I know. But Flettner has some nice 180°-twins...

Frits, I have been looking at it but it also has a further issue if the practicalities of connected exhausts are considered and that is that it is more rpm dependent. I think once Flettner looks into 3 cyl engines he might start making triples.... :laugh:

Frits Overmars

17th March 2018, 05:22

Frits, I have been looking at it but it also has a further issue if the practicalities of connected exhausts are considered and that is that it is more rpm dependent. I think once Flettner looks into 3 cyl engines he might start making triples.... :laugh:Surprise: a Fletto-triple :D.
335747

WilDun

17th March 2018, 11:22

Surprise: a Fletto-triple :D.

Yes I was going to mention that! ....... not much he hasn't tried! - while most of us talk (and talk) he just does it!
:niceone:

Cvt is pretty good I reckon (I had it in my 2010 Nissan Qashkai) and I thought it was fantastic - we changed the car to a little Mazda because my wife thought the Nissan was too big. It had some unusual noises which you got used to, no jerks and when you put your foot down it went to a certain rev level, stayed there and the car just kept accelerating, loved it
So when it was banned in racing they changed to seamless gearboxes? - why weren't they banned too?

BTW has "Fletto" become the official name now? - It's that Aussie influence creeping in (courtesy of Keen Seeber), - haven't seen him for a while!

Frits Overmars

17th March 2018, 13:30

[/QUOTE]
Cvt is pretty good I reckon... So when it was banned in racing they changed to seamless gearboxes? - why weren't they banned too?
BTW has "Fletto" become the official name now? - It's that Aussie influence creeping in (courtesy of Keen Seeber)CVT was banned from Formula 1 in 1993, in the 3,5 liter V10-era. I don't know exactly when seamless shift was introduced, but I expect it was a bit later.
The reason for banning CVT was not valid for seamless boxes because with seamless you'll still hear the revs go up and down; the sound won't differ very much from old-fashioned shifting.

I wrote Fletto instead of Flettner just because 'Fletto-triple' gave a nice t-alliteration.
Now that you mention it, 'Fletto' may have been introduced by Ken Seeber. I didn't recognize the Aussie influence...
BTW, was your 'Keen' instead of Ken a typo or a deliberate spelling? Ken won't object, I suppose.

WilDun

17th March 2018, 15:45

CVT was banned from Formula 1 in 1993, in the 3,5 liter V10-era. I don't know exactly when seamless shift was introduced, but I expect it was a bit later.
I wrote Fletto instead of Flettner just because 'Fletto-triple' gave a nice t-alliteration.
Now that you mention it, 'Fletto' may have been introduced by Ken Seeber. I didn't recognize the Aussie influence...
BTW, was your 'Keen' instead of Ken a typo or a deliberate spelling? Ken won't object, I suppose.

The spelling of Ken was a definite typo - sorry.
The Aussies often shorten a word or name and add an 'o' at the end, - I reckon that's good in this case! - dunno what "Fletto" thinks but I'm sure he has other more important stuff to think about.

BTW what they could do is put mufflers on the engines and have a V8 style noise introduced using speakers then everyone will be happy!....... 0h and they could drip feed Castrol R into the exhaust manifolds as well! :msn-wink:

ken seeber

17th March 2018, 23:50

The spelling of Ken was a definite typo - sorry.
The Aussies often shorten a word or name and add an 'o' at the end, - I reckon that's good in this case! - dunno what "Fletto" thinks but I'm sure he has other more important stuff to think about.

That’s ok Willy (or could/should it be Willo?), I’m still Keen. :killingme

Jeez, you guys have been busy, both here and on Oddball. Lot’s of things going on here (in Oz), but distractive.

Frits bought up a couple of points that I have always thought of for ages. For instance, if say one was making a small crank scavenged (even if it was air only) 2 stroke engine with an integrated generator (ie the rotor & its magnets part of one or both crank webs), then there is the decision to be made about the relative sizing of the engine.

Do we want to have a smaller engine at high BMEP “revving it’s tits off” with a relatively large expansion chamber OR a much larger engine at much lower BMEP, a small can style exhaust and, as Frits pointed out, “that had eternal life”? In the latter case I am thinking of some sort of passive and low emission fuelling system like the Husqvarna X Torq or some other “DI less” alternative.

Bit of a mental ramble I know.

Now, how’s your memories? Have been doing a bit on the slider, main thing was chasing up an M6 stud of the correct length as part of the sliding cylinder height control. In the end it was a matter of threading one end of a long screw.

Cylinder is tight to move, but as observed during the previous running, it has a natural tendency to lower itself, logical when you consider the piston ring friction, albeit a very slow or creeping action. The plan it to replace the previously troublesome actuating lever and just use a simple series of quicly replaceable stacked spacers that will allow me to set the height of the cylinder in small incremental steps. And using a simple& proven inertia dyno.

Otherwise, nothing broke in it, except for the 3D printed ABS coolant flow guide that surrounded the head insert. Will do another, but perhaps with a 3 layer thickness and strengthened by giving it an acetal brush coating.

335762335763335764335765335766335767

WilDun

18th March 2018, 13:32

That’s ok Willy (or could/should it be Willo?), I’m still Keen. :killingme

Ken (Keen?) (Keen Ken?) - You can call me what you like (within reason) but just read my rants and dumb questions and criticize them if necessary (but in a constructive, as opposed to a cynical manner) and if you disagree, then let me know why you disagree (make it stick) then I may concede that I might even be wrong.
That's how guys like us learn you see, as opposed to doing everything to the letter from the instruction manual!

Frits bought up a couple of points that I have always thought of for ages. For instance, if say one was making a small crank scavenged (even if it was air only) 2 stroke engine with an integrated generator (ie the rotor & its magnets part of one or both crank webs), then there is the decision to be made about the relative sizing of the engine.
Do we want to have a smaller engine at high BMEP “revving it’s tits off” with a relatively large expansion chamber OR a much larger engine at much lower BMEP, a small can style exhaust and, as Frits pointed out, “that had eternal life”? In the latter case I am thinking of some sort of passive and low emission fuelling system like the Husqvarna X Torq or some other “DI less” alternative.

Think that the straight line piston rod being used as a generator (spinoff from the free piston idea) is good and if "Fletto" and his idea comes to fruition then who knows!
Anything could happen in the future, but If the two stroke is to survive, it will surely survive in a very different form!

Now, how’s your memories? Have been doing a bit on the slider, ...........nothing broke in it, except for the 3D printed ABS coolant flow guide that surrounded the head insert. .......

Keep plugging away with that one Ken, glad to see you still in the land of the living and up and running (don't run too fast!):niceone:

Flettner

21st March 2018, 10:48

two sliding GIBs machined, one advancing and one trailing, just need to cut them out and machine to thickness (6mm) then get them hard anodized. slots are for the small activating cranks to engage into them (not made yet).

Flettner

21st March 2018, 12:06

ok, there they are.

Flettner

21st March 2018, 14:28

actuator cranks made, now see why the double sided belt.

F5 Dave

21st March 2018, 16:52

That' smoking cool, but I can' work out how you'll have enough space near the whirley around bits.

Flettner

21st March 2018, 17:52

That' smoking cool, but I can' work out how you'll have enough space near the whirley around bits.

I'll assemble it up with pictures when the GIBs come back from Anodising. Had to put the heat on and get them finished today to go away with some real work that needs to be hard anodized as well. You know, minimum charge and all that, probably still way under the minimum weight.

WilDun

22nd March 2018, 19:48

actuator cranks made, now see why the double sided belt.

Just shows how wrong you can be, I thought that you were going to be using pinion gears on those spindles with a rack (as it were) on the inside of the curve. (I haven't been paying attention I guess!).

ken seeber

22nd March 2018, 22:58

ok, there they are.

Neil alias Fletto alias creator of lots of swarf, excellent work. Still a legend. :niceone:
Question. The cover to go over all this, will this have bores to accept the two actuator shaft bearing pillars? If this is the case, will the belts will be "dry"?

Frits Overmars

22nd March 2018, 23:15

Neil alias Fletto alias creator of lots of swarf, excellent work. Still a legend. :niceone:Still a legend? Becoming more and more of a legend, I'd say. And you could add Uniflow to the Neil-Flettner-Fletto list, Keen Ken :msn-wink:.

Flettner

23rd March 2018, 06:31

[QUOTE
Question. The cover to go over all this, will this have bores to accept the two actuator shaft bearing pillars? If this is the case, will the belts will be "dry"?[/QUOTE]

yes, same as my F9, only that runs push pull cables, dry.

WilDun

23rd March 2018, 09:15

Question. will the belts will be "dry"?

Talking of dry or wet belts, I know of one case where the belt actually runs in the oil spray with apparently no problems - that is the cam belt on the little four stroke Honda weedeater engine!

diesel62

23rd March 2018, 09:21

husaberg

23rd March 2018, 10:35

Talking of dry or wet belts, I know of one case where the belt actually runs in the oil spray with apparently no problems - that is the cam belt on the little four stroke Honda weedeater engine!
Some of belts are designed for running in oil.
The ones Tony Hayward uses for his primary conversions certainly are.
https://www.contitech.de/en-GL/Solutions/Power-Transmission/Mechanical-engineering/Drive-Belts/Timing-belts/Products/Product-range/CONTI-SYNCHROFLEX

https://www.mitsuboshi.co.jp/english/prime-stars/timing.html

Flettner

23rd March 2018, 11:03

In my little tooth belt drive set up is a TPS and I don't think they like to be in oil. Ironically the belt I'm using will work in oil, I think but it won't need to.

WilDun

23rd March 2018, 13:07

Regardless of whether they work in oil or not, its nice to see some innovative thinking!.

Have you got a built in fail safe? ie will the throttle close fully if something happens (to prevent something worse happening - like reaching Ryger RPM or higher - unlimited revs!). :eek5:
....... not thinking that you would forget that of course!

ken seeber

23rd March 2018, 20:23

S’pose not casting directly, but it shows the use of simple patternmaking and machining to make the Jamathi motor, way back in the 50 cc days. No CNCs and big billet stuff way back then.

https://www.youtube.com/watch?v=ITwBgeKHGZw&feature=share

Was looking out for a young, fresh-faced Frits in the background (or even foreground), but must have missed him. ;)

There is a second vid with more of the same plus some track action.

https://www.youtube.com/watch?v=y_e_HNEy4mo

Frits Overmars

23rd March 2018, 20:24

Have you got a built in fail safe? ie will the throttle close fully if something happens... Until recently, cutting the ignition would have done the job. But I remember Flettners video of a runaway engine that didn't even have a spark plug.
Cutting the EFI would be the next option. But I remember a video of this same engine running away on the oil puddle in the crankcase.
Maybe we should think about hammering a wooden stake in the inlet opening, Dracula-style...

Flettner

23rd March 2018, 21:12

ha ha, yes, like the Detroit diesel with a flap spring loaded over the supercharger. If you can't cut the ignition or fuel, air is the last resort. I suppose you could always shove a fire extinguisher up it.
At 360cc I'm sure it will 'draw blood' at some stage.

Frits Overmars

23rd March 2018, 21:24

If you can't cut the ignition or fuel, air is the last resort. I suppose you could always shove a fire extinguisher up it.That fire extinguisher gave me a fresh idea: choke the engine with a CO2 overdose. One small cartridge should do.

Flettner

24th March 2018, 06:44

Frits do remember this 360 is not running HCCI but there is another on the bench that does, it has no rotary valve, no reed valve, and no crankcase as normal. It's throttled but with fuel (and a small amount of air) , a function of all I've learnt so far. this is the one that I'd like to run a small % of hydrogen with ethanol as the main fuel.
this 360 will have the throttle Gibs operated direct via cable ( then to tooth belt) with return spring for initial running, the real worry is later when the two throttle Gibs are operated separately via their own servo drives, ( fly by wire) when the ECU can't make it's mind up, that's when we will have issues. What did Frits once say, crash by wire.

Flettner

24th March 2018, 10:16

after a long consultation with Blackwood Yamaha, the 360 is going to be electric start. Always said I would never do this but he has convinced me on how small and light the systems are now. It was going to be pull start, a bit optimistic perhaps, although I have big arms.

WilDun

24th March 2018, 15:05

.........the 360 is going to be electric start. ........ It was going to be pull start, a bit optimistic perhaps, although I have big arms.

Good idea! :niceone: - big arms (or legs) are a complete waste of time if you don't have big shoulder and big hip joints to go with them!
I may know sweet FA about bikes really, but I do know about that .... first hand!

Flettner

27th March 2018, 19:02

I guess that has to be the best start ever at the Acerbis four hour, in gear (second), auto clutch, push button electric start, with the guaranteed fire on the first compression TPI will deliver.
Acerbis starts are dead engine,

Flettner

28th March 2018, 18:02

Mmmm, hard anodized parts.

Grumph

28th March 2018, 19:09

husaberg

28th March 2018, 20:08

Not foundry
I knew most Honda gears were made like this but i didn't know how much stuff is now done this way.
First video is short
second shows the whole process and how it works etc.

https://www.youtube.com/watch?v=Vb9iqhPP9I0

https://www.youtube.com/watch?v=O7U4HWjYcqo

WilDun

29th March 2018, 07:20

Not foundry
I knew most Honda gears were made like this but i didn't know how much stuff is now done this way.

Good find Husa - very interesting!
It's really just a good example of how foundry is morphing and (to me) this is most suitable for high volume production.
The first time I really took notice was when caride tips for machine tools started to become popular in the late sixties but it's certainly progressed since then.
However the first time I actually came into contact with the process was in an Ariel Arrow gearbox where they tried to be cheapskates by making one of the bearings in the gearbox out of sintered iron! - that wasn't a howling success I might add.
The idea was that the loose bond would made it porous, therefore keep it permanently lubricated with oil, however, normal bronze was (often) used as a replacement when the iron failed!

Flettner

29th March 2018, 07:23

Saw you were hard anodising those gibs - or as I prefer to call them ASS - Aeroflight sliding segments...

Don't fully understand the rationale there. I know the Bighorn has lasted well past any life expectancy Kawasaki may have had but I wouldn't have thought you'd see a lot of wear on those bits for it's replacement.

the hard Anodising is not for the rotary valves benefit so much as its because these GIBs slide in an aluminium housing so will wear quickly. Hard against soft, you know
it.

Grumph

29th March 2018, 08:45

the hard Anodising is not for the rotary valves benefit so much as its because these GIBs slide in an aluminium housing so will wear quickly. Hard against soft, you know
it.

Yeah, but I'm a cheap bastard, probably would have used brass.

Hard against soft, I think I can remember back that far...

Sintering - while I can't see what Husa has posted, it's definitely the way of the future for a lot of components. GM I believe were using it to make conrods a while back. Pretty well all valve guides in modern 4T's are now sintered. Every modern bike gearbox I've pulled down seems to use sintered shift forks now. Except for the Classic replica stuff which as they're small batch production are using investment castings.

Flettner

30th March 2018, 11:09

GIBs installed
throttle belt lay out, bottom pully will be on an eccentric bearing housing for system tension, top pully will have the TPS and cable drive quadrant (throttle cable). left hand pully is 10T , right hand pully is 12T, I want one to open a little more than the other.

F5 Dave

30th March 2018, 13:50

That is cool. I still dont fully understand it, but its still cool.

husaberg

30th March 2018, 15:43

Thank god I don't either.
This I different from the original one Neil?

TZ350

30th March 2018, 15:56

GIBs installed, throttle belt lay out, bottom pulley will be on an eccentric bearing housing for system tension, top pulley will have the TPS and cable drive quadrant (throttle cable). left hand pulley is 10T , right hand pulley is 12T, I want one to open a little more than the other.

Very Clever.

You need to go to the original post to see the pictures but this is a very interesting project. Throttling the inlet and changing the inlet timing by opening/closing the aperture on the rotary valve cover.

F5 Dave

30th March 2018, 18:47

Yeah that bit is obvious but I'd kinda need to see it working to fully click what operates what. . . when.

Flettner

1st April 2018, 13:39

Manufacturing the water pump/autolube plastic drive gear.

Grumph

1st April 2018, 14:10

Manufacturing the water pump/autolube plastic drive gear.

That's machining quite well - what's the material ?

Flettner

1st April 2018, 14:23

acetal, should work well.

breezy

5th April 2018, 06:32

Fletto.... what kind of range will you be able to acquire with the inlet timing?

Flettner

5th April 2018, 14:43

I guess I should measure it?
bit loose with my designing sometimes.
The idea is to set the Gibs full open and cut the valve to the maximums I want, then just live with the timings I get as the Gibs shut. My Kawasaki has a useful range with the GIB only covering half the valve hole at low speed on the shut side.

guyhockley

7th April 2018, 05:54

http://forum.woodenboat.com/showthread.php?221277-Herreshoff-Steam-Engine-Fabrication-MIT?r=wbstnews.wed.03.28.18
Clue's in the link, although, to me, fabrication is often the alternative to casting...

WilDun

7th April 2018, 16:28

........ Clue's in the link, although, to me, fabrication is often the alternative to casting...

GUY, Haven't looked closely yet at your link, but ..... clue to what? It all looks very interesting and foundry orientated though - even if it is for steam engines!

Neil, the exhaust pic you posted in ESE does look a bit agressive (scrutineers would probably react!) but I reckon that "stinger" is a bit 'tongue in cheek'!
Regarding the opposed piston four cylinder engine you designed and tried in the boat, did you learn any valuable lessons using that layout? - it did seem to run very smoothly, even at idle I noticed! Did you use a conventional bore/stroke ratio for each piston/crankshaft or was it a comparatively short stroke? - is there a future for that setup for HCCI (eg like Achetes are attempting)?

Flettner

7th April 2018, 17:27

WilDun

7th April 2018, 19:52

you know it Will. Yes always learn stuff
Many ideas swirling around in my head, some even printable, easy way to stop hydrocarbons heading out the exhaust, using carburetors even.
this engine did quite a lot of work on the end, reliable and fun testing in the boat.

Yes, I have been thinking for a long time that cylinder and piston distortion (uneven heating/cooling) in a conventional two stroke must play havoc with clearances - as I see it, this layout must allow tighter piston clearances etc. Guess the two cranks and extra cost does neuteralize things somewhat!

Flettner

10th April 2018, 20:12

WilDun

11th April 2018, 10:54

Flew the 700 twin (single seat gyro) Saturday, pilot in command this time. Have to say it felt good to finally get the bugger flying, with me in the seat not having to watch from the ground. It's thirsty though, 20 L per hour.
Experimental engine with an experimental pilot, what could possibly go wrong?:facepalm:

Good to hear that, did you fly it for long?
It must feel really light and agile when compared to how it would fly with the usual 'normal' powerplants! - fuel injection and throttled rotary valves next?

husaberg

11th April 2018, 11:57

Hello Flettner i found these.
14 and 19 amp 12v or 24v
Tiny and well made to boot.
plenty of people have adapted these to Bikes and old planes.
$109 for aftermarket or 140 US for oem kobota.
336100336101336098336097

Grumph

11th April 2018, 13:05

Pegasus Engineering local to me were using those on their short lived half a VW aero engine.

I went in there for some reason and once they realised what I did, there was a half hour grilling on small bike alternators.
I couldn't help them much.

Flettner

11th April 2018, 14:46

I've got an aulternater, shelf full of them. Cheap as chips and is the flywheel as well. Scooter flywheel / alternator I think.
Besides when I go injection I will need more than 19 amps with twin pumps and twin ignition plus other avionics lights etc.

speedpro

11th April 2018, 18:00

Hijack - I'm looking for a small alternator, output only needs to be about 60-80W, bit more OK. Ideally rotor able to be mounted direct to crank boss and I'll make bracket for body/stator. Needs to be short, 20-30mm and about 80mm OD tops. Motor will hopefully rev close to 20K so good chance a reduction drive needed. PM me with ideas. Thanks

WilDun

14th April 2018, 11:24

Neil,
I just saw your more comprehensive collection of pics on facebook, and saw (for the first time), pics of your three cylinder project - is that one still in progress or is it having a holiday?

I saw that amongst all the other projects including the FOS, the straight line geared crank,the (Honda type) straight line crank, the Subaru flat 4 gyro engine, the tandem twin gyro engine, the parallel twin gyro engine, the reciprocating sleeve engine (Crecy), the everlasting Bighorn, the 360 project, etc etc etc - didn't see the HCCI experiment though!

Never ends!!

Think I'm winding down (have been for a couple of years really), already too cramped for me here and we may be downsizing yet again, health isn't fantastic - think I got into this sort of stuff too late, it does piss me off somewhat as I would like to have kept going on with the foundry etc. (most of which is at a mates place at Pukekohe at the moment) - many outlandish plans but not enough time (or space) to see them work.
Good to watch your efforts, all interesting to me and I will continue to watch them as they are posted and also will no doubt continue to pester you with dumb questions!

:niceone:

Flettner

14th April 2018, 15:57

time and money Will, the three cylinder is taking a break.
Ironicly when I cast the original cases I cast two sets of three cylinder cases but because of financial constraints I decided a two cylinder was more practical so cut a crankcase off one of the case sets I'd made, instantly making it into a two cylinder project.
The three cylinder will cost a pretty penny so will have to wait. Besides the twin has plenty of power for a single seat gyrocopter, will fly on just 4000 revs.
All other projects are 'concurrent' as in I throw myself into each of them as the interest is there, then onto another while I have a think about the next step of the previous one, I guess what it would be like to be a Mormon.
Unfortunately I found a photo of my old supercharged Honda 100, straight out to the shed two nights ago, spread all the parts out on the bench that I've been squirreling away for the ultimate 4stroke 100 supercharged, crank being roughed out now from a piece of 4140 bar. 360 degree twin cylinder, half an FZR Yamaha head, miniature lobe supercharger, MX 250 clutch and gearbox, methanol, nitro and 1 atmosphere pressure.
28mm stroke, 18 / 20000 RPM. Bugger the rules, when I built my first one the rules were 100cc fourstroke 'open'.
So long as you are asking questions Will, the brain is still working.

Grumph

14th April 2018, 16:59

360 degree crank ? You've let yourself in for the job of making cams too then ?

Got enough rods etc ?

Flettner

14th April 2018, 18:00

sidecar bob

14th April 2018, 19:00

yes, cams, no problem as I want special cams anyway.
One will drive the fuel pump off it's end and the other some ignition triggers ( off the exhaust cam, closest to the crank drive pully via the belt).
Hmm, rods, they look a little spindly, might make some from 4340 perhaps.
360 crank is for even induction sequences, as you know.
Balance shaft should take care of vibration, or at least help reduce it.
Fuel, I'll just put it in a can marked PETROL in big letters

I remember that supercharged Honda at baypark in the '80's. I seem to remember a very long intake tube with a drain plug at the lowest point, so it could be drained when the intake flooded.
Is that the same bike?

Flettner

14th April 2018, 19:55

Grumph

14th April 2018, 20:00

Nothing wrong with the stock cam profiles for a blown motor. Easy enough to rephase the cams to suit what you want in overlap.
I've done a blown 180 crank parallel twin. Very satisfactory with a plenum chamber three times engine volume. In your case that's still a very small plenum, LOL. Do you know the swept volume of the blower ? The one I used had been developed specifically for high rpm with anti turbulence bars on entry and exit ports. Builder had tested it to 10,000 rpm and it had a flat delivery curve. We ran it to 12000 - 15lb boost just off idle and right to redline.
Belt driving cams ? In oil or sealing the belt off ?

Flettner

14th April 2018, 20:07

for simplicity, one belt to rule them all.
easy enough to seal the cams off and also drain the valve cavities too.
The supercharger I'm using is quite large ( for a 100cc) so I'll have to under drive it somewhat. If I can't get the efficient I want I'll Teflon TIP seal the rotors. Also the fuel will be introduced into the induction side of supercharger, there will be a potion of Castor oil added to the Fuel, this will help with efficiency and the alcohol with intercooling.

Grumph

14th April 2018, 20:14

for simplicity a single belt to rule them all.
easy enough to seal the cams off and also drain the valve cavities too.

Okay...but in my experience you want some give in the blower drive, Your cams will have to be a toothed belt.

In my experience with mid size blowers, the problem is load reversals when you back off. Unless your toothed belt is pretty wide, you're going to lose teeth.
The ideal IMO is what i think you used on the Honda - a polyvee belt. They will slip on the overrun.
I went through several drive setups on a speedway TQ before realising what the problem was. When i did the blown F3 bike I didn't even consider anything else - and it was one of the few things on the bike that never gave trouble.

sidecar bob

14th April 2018, 20:15

side car Bob, yes that was the one and same. Do you have photo's of it, I never had time to be bothered with pictures.
Do you remember the noise it made? That was the first time We fired it up, there was a guy on the back of my Thames Trader finishing it off on the way over to bay park.
The Thames broke a piston on the way home ( Zepher six engine became a Zepher five but still got us home) the super charger drive belts spat off in the end. Home made pullys didn't fit as well as they should have? all in all an entertaining day.

No pics unfortunately. I didn't own a camera until nearly a decade later.
I do remember it being a bitch to start & lent a hand at some point, that's when I remember you pulling a bolt out & letting the spare fuel run out on the ground.
I was probably riding a red CB125 I called the menstrual cycle.
Do you think the blower was a wee bit big now with the benefit of a few decades?

Flettner

14th April 2018, 20:20

yes-------

Grumph

14th April 2018, 20:25

No such thing as a too big blower - only the wrong drive ratio, LOL.

Flettner

14th April 2018, 20:33

sidecar bob

14th April 2018, 20:39

I guess that's what I ment, home built vain type supercharger but I fucked up the calculation for volume (I was an apprentice and you know what they are like) so the pumped volume was about double what I thought, I know now.

I seem to recall that it was bigger than the barrel & head combined, I had no idea what it pumped like, it was just huge.
If you were only ever there once with it then you certainly got my attention.
Anyway, sorry about the thread hijack. Back to the interesting stuff?

husaberg

14th April 2018, 21:10