The Bucket Foundry

[diesel62]

Can I ask what the thermal lining. Thanks

Sent from my SM-G900F using Tapatalk

[husaberg]

Just make it out to Christian Adult Society Helpers. Yes that is a long name, just the initials will do.
(Credit to the New Statesman)

Now if I could just find my cheque book. Think I left it in the previous century.

I was thinking about that one but wasn't it the christian appraoch to society handbooks
9 min

https://youtu.be/oU1ys-D_CD0?t=9m5s

[Lightbulb]

Husa, is that 3d printed or is it from a flexible core molds?
Neil

[F5 Dave]

Probably was but I think he used that joke a few times on constituents

[WilDun]

I am very interested in that printing technique for sand casting patterns (and I guess I could eventually get used to the lines) but would be much more interested in the printed metal powder (non pattern) products ready to be sintered into a finished metal product afterwards. - Guess it's already in production for some stuff, I dunno.

[ken seeber]

Careful Willy, this just might mean another thread (eg Additive Manufacturing) that we have to follow.:facepalm:

[WilDun]

Careful Willy, this just might mean another thread (eg Additive Manufacturing) that we have to follow.:facepalm:

Yes Ken,
That's the trouble I already had a rap on the knuckles - Not sure, I think it may have been addressed to me, (amongst others) suggesting that certain people were not welcome if they were not actually involved with bucket racing, but then he refused to discuss it further!

So therefore if it was left up to me I guess I would be all on for another thread on that! (ie if it did somehow relate to bikes) and it probably would, but it is also closely related to foundry work of course so it'll still fit here!

[husaberg]

Probably was but I think he used that joke a few times on constituents

this whole LUCF/ryger thing reminds me of

https://www.youtube.com/watch?v=1TsdXa_7kzs

mixed in with Bellbooths Maxicrop.
https://en.wikipedia.org/wiki/Maxicrop
https://teara.govt.nz/mi/video/15856/maxicrop-case

[husaberg]

Husa, is that 3d printed or is it from a flexible core molds?
Neil

You lost me neil?
If you mean the cylinder of mine that Flettner showed it was constructed in the traditional manner but italian artisans with multiple hot/cold and co2 set parts glues together.

[Flettner]

Bugger, it all just got too hard around the cylinder attachment, back to the manual pattern making bench.
I've moved the center line of the cases so the two middle cylinder 6mm capscrews don't go through the part line.

[Frits Overmars]

I've moved the center line of the cases so the two middle cylinder 6mm capscrews don't go through the part line.Does that mean that you're only going to use cylinders with lateral exhaust ports from now on? :p
331908 331907

What made you decide to switch from horizontally to vertically split cases Neil? The epicyclic ring weel?

[ken seeber]

Fletto,
Could you just index the cylinder round by 30 degrees and not have to worry about the screws on the split line?

[Lightbulb]

Looks like Neil is getting the most made with the least amount of casting while at the same time optimising his NC capabilities and getting the most done at a time. That is my take on it anyway. I like what he is doing.
Ken, It may not be quite that simple to change the lugs on the already cast units he may already have, is my guess.
Neil
PS well done Mr Hintz, and thanks for sharing the fruits of your labour's and some of your special techniques.

[Flettner]

Does that mean that you're only going to use cylinders with lateral exhaust ports from now on? :p
331908 331907

What made you decide to switch from horizontally to vertically split cases Neil? The epicyclic ring weel?

No, I have several cylinders with exhaust straight out the back, rear lug just doesn't get a bolt in it. Four side lugs might go to 8mm. I intend to use different screw in fillers inside the crank case (in the pattern) for different cylinder requirements.

This set of reed cases is all well and good but I made a bad choice in using a YZ gearbox. Just too hard to find spare units. The one spare gearbox I do have is in the sleeve engine and I'm not ready to pull that engine apart just yet.

Yes the reed cases were never very well designed to accept the epicylic crank. Plus putting the epicylic aside I just like to have a nice set of RV cases for a small engine that will fit in my YZ 250F frame.

I'm using initially two types of cylinder on these RV case. One an FOS like Ken's the second a more normal cylinder but also sliding. I want to totally throttle the engine by the cylinder height.

[Pursang]

No, I have several cylinders with exhaust straight out the back, rear lug just doesn't get a bolt in it. Four side lugs might go to 8mm. I intend to use different screw in fillers inside the crank case (in the pattern) for different cylinder requirements.

This set of reed cases is all well and good but I made a bad choice in using a YZ gearbox. Just too hard to find spare units. The one spare gearbox I do have is in the sleeve engine and I'm not ready to pull that engine apart just yet.

Yes the reed cases were never very well designed to accept the epicylic crank. Plus putting the epicylic aside I just like to have a nice set of RV cases for a small engine that will fit in my YZ 250F frame.

I'm using initially two types of cylinder on these RV case. One an FOS like Ken's the second a more normal cylinder but also sliding. I want to totally throttle the engine by the cylinder height.

https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/strong.jpg

What would be a Good choice for a generic Gearbox?
Perhaps KTM would sell complete, new assemblies, wholesale?

Cheers, Daryl.

[Grumph]

What would be a Good choice for a generic Gearbox?
Perhaps KTM would sell complete, new assemblies, wholesale?

Cheers, Daryl.

Depends on the end use. Flettner's main focus has been dirt usage so a medium to wide ratio box is preferred. The trouble with that in NZ is that we're a pretty limited market and not many of any given model come in. Hence the problem finding the Ymaha boxes..Offhand other than the XR/XL Honda 250's i can't think of a dirt bike that will be available in numbers at the wreckers.
Road use is a bit easier as there are quite a lot of suitable close/semi close boxes available.

If you want new, a guy I know here formed a connection with the kawasaki factory in the Phillipines and bought 10 400 4T twin engines complete with carbs and ignition. He wanted to start a small car class. Quite cheap - and they were easy to deal with apparently.
I remember unpacking a new Suzuki GSX1100 gearbox for John Britten. Ordered through the local agents, it was boxes and bags of separate parts. About an hour of checking it was complete...

[Flettner]

Mmm, yummy piston and it fits in this barrel :msn-wink:
And three 360 cylinders back from heat threatment. Couriers lost one for a day, got my blood pressure up!

[husaberg]

Depends on the end use. Flettner's main focus has been dirt usage so a medium to wide ratio box is preferred. The trouble with that in NZ is that we're a pretty limited market and not many of any given model come in. Hence the problem finding the Ymaha boxes..Offhand other than the XR/XL Honda 250's i can't think of a dirt bike that will be available in numbers at the wreckers.
Road use is a bit easier as there are quite a lot of suitable close/semi close boxes available.

If you want new, a guy I know here formed a connection with the kawasaki factory in the Phillipines and bought 10 400 4T twin engines complete with carbs and ignition. He wanted to start a small car class. Quite cheap - and they were easy to deal with apparently.
I remember unpacking a new Suzuki GSX1100 gearbox for John Britten. Ordered through the local agents, it was boxes and bags of separate parts. About an hour of checking it was complete...

I was thinking the xr series as well, they were pretty much unchanged for a big number of years, by if 5 speed is his thing a CRF450 might be a little more current they are based n the CR250/500 gearbox.
if he was using the horozontal split i would go for a VT250 gearbox beefy gears and also used on MVX and CBR250's obnly thing is they have a planetry sector mechanism
i can't imagine any of these motors would wear out a gearbox before totally killing an engine

[Ocean1]

Offhand other than the XR/XL Honda 250's i can't think of a dirt bike that will be available in numbers at the wreckers.

I managed to kill third, (iirc) gear on two XL350s. Not sure if they improved them with the K2 but I didn't hear of too many issues other than mine.

Neither of them were exactly a 350s though.

[Grumph]

I managed to kill third, (iirc) gear on two XL350s. Not sure if they improved them with the K2 but I didn't hear of too many issues other than mine.

Neither of them were exactly a 350s though.

From the intro of the XL350, the 250 and 350 boxes were the same. The original 250 Motosport is actually closer ratios.
I've got a 250 motorsport roadrace project I may actually finish one day and it took a half day searching at the Timaru wreckers to assemble an early box...

[F5 Dave]

I was told the diff between the 250 and 500 was they spent money on better hardening for the 500 and welched on the 250. Part number search would find out if my source was FOS, as he occasionally was.

[Ocean1]

From the intro of the XL350, the 250 and 350 boxes were the same. The original 250 Motosport is actually closer ratios.
I've got a 250 motorsport roadrace project I may actually finish one day and it took a half day searching at the Timaru wreckers to assemble an early box...

I'd have been quite happy with 4 gears. They were bloody near square standard, and mine were stroked, torque at 4k was almost the same as 8k.


I was told the diff between the 250 and 500 was they spent money on better hardening for the 500 and welched on the 250. Part number search would find out if my source was FOS, as he occasionally was.

The first time I had trouble there was some wear involved, but teeth were also broken. The second I actually split in half. Like I said, I suspect the second at least was an aberation.

By the time the 500 came along they'd made quite a few changes. A mate had a 350K2 and while "nimble" wasn't a word that'd spring naturally to mind wrt mine, his required a lot more warning of impending corners. I only ever rode one 500, and I liked that better.

[guyhockley]

Depends on the end use. Flettner's main focus has been dirt usage so a medium to wide ratio box is preferred. The trouble with that in NZ is that we're a pretty limited market and not many of any given model come in. Hence the problem finding the Ymaha boxes..Offhand other than the XR/XL Honda 250's i can't think of a dirt bike that will be available in numbers at the wreckers.
Road use is a bit easier as there are quite a lot of suitable close/semi close boxes available.

If you want new, a guy I know here formed a connection with the kawasaki factory in the Phillipines and bought 10 400 4T twin engines complete with carbs and ignition. He wanted to start a small car class. Quite cheap - and they were easy to deal with apparently.
I remember unpacking a new Suzuki GSX1100 gearbox for John Britten. Ordered through the local agents, it was boxes and bags of separate parts. About an hour of checking it was complete...No idea about the relevance to "down under" markets, but I believe there's a lot of commonality in Rotax gearboxes and there used to be/are lots of different ratios available for the 125s and 250s including the karting clones, maybe?I
If they're not too wide, what about Yam twins - Banshee for off-road, couple of different road sets and TZ/Nova for the high end?
Grumph, did Britten use standard ratios? Think I remember you talked him out of the GSXR750 6 speed?
I thought it was slightly odd that the Tularis, Melly Blue Rage and Ian Cramp's Lionheart all used Duc boxes when the Ducati works riders were complaining about having no alternative ratios.

[Grumph]

No idea about the relevance to "down under" markets, but I believe there's a lot of commonality in Rotax gearboxes and there used to be/are lots of different ratios available for the 125s and 250s including the karting clones, maybe?I
If they're not too wide, what about Yam twins - Banshee for off-road, couple of different road sets and TZ/Nova for the high end?
Grumph, did Britten use standard ratios? Think I remember you talked him out of the GSXR750 6 speed?
I thought it was slightly odd that the Tularis, Melly Blue Rage and Ian Cramp's Lionheart all used Duc boxes when the Ducati works riders were complaining about having no alternative ratios.

I suspect that anywhere in the world, you use what you can get...Yes, there are a lot of Yam twins here, gearbox karts, probably a lot of Rotax max - but they don't seem to get written off. JB's first iteration was the Denco built, Colin Lyster designed speedway engine which used an XS650 Yam box - again, just what Bob Densem could find at the local wreckers...Later versions used initially the GSX1100 box then I'm pretty sure all the "production" bikes went to the GSXR1100 box - bought new - and probably at full price too.
Homebuilt stuff in my experience anyway generally has no thought given to alternative gearbox ratios - you're too keen to see it run.....

[Flettner]

At the end of the day I could just make the buggers but where do you draw the line? I can get a pull broach from out of India (for making splines real quick) at $800 NZD . Not a bad price I thought considering, but I would need a gear shaper as my hobb won't do teeth up to an edge. The Indian company I deal with has made all my gear hobb cutters and they are nice, concentric and hard wearing. For one off why bother, I can use Precision Gears in Rotorua to do my one off oddball stuff, they are not too bad price wise.

[F5 Dave]

So you have an eBay search setup?

http://m.ebay.com/itm/YAMAHA-YZF250-GEARBOX-BREAKING-COMPLETE-BIKE-2004-/262963360195?hash=item3d39d671c3%3Ag%3AYjcAAOSw0fh XkM3o&_trkparms=pageci%253Af5668e04-7331-11e7-b1b0-74dbd180ff79%257Cparentrq%253A86c1610215d0a8670d68 5269ffffd4c8%257Ciid%253A6

Surely there are junkyards in the states littered with blown mx bikes that could post you 5 at a time. Get Husa on the search.

[husaberg]

So you have an eBay search setup?


Surely there are junkyards in the states littered with blown mx bikes that could post you 5 at a time. Get Husa on the search.
I offered ages ago, but he doesn't appear like Americans.

[Grumph]

At the end of the day I could just make the buggers but where do you draw the line? I can get a pull broach from out of India (for making splines real quick) at $800 NZD . Not a bad price I thought considering, but I would need a gear shaper as my hobb won't do teeth up to an edge. The Indian company I deal with has made all my gear hobb cutters and they are nice, concentric and hard wearing. For one off why bother, I can use Precision Gears in Rotorua to do my one off oddball stuff, they are not too bad price wise.

Guy down here specialises in vintage AJS stuff. Got a broach made in India for a spline which is used on them for pedals, brake lever arms, gearbox and engine components. Told me it cost him about $300NZ 6 years back. He's been selling new components ever since. Good business.

[Michael Moore]

There's a lot of Ducati gearboxes and other engine parts on eBay here in the USA and the prices look quite reasonable. Since they are off of big twins they are sized for a 400-500cc 4T single torque spike.

[WilDun]

Sorry, but Just butting in to change the subject for a minute!

Someone a few pages back mentioned a plastic material ("Blue Stuff) which can be softened in boiling water and "puttied" into or around an original pattern then used to make a rigid corebox (such as Flettner was doing way back, with Vinamold) - eg transfers etc. so I ordered some just for interest sake.

It has arrived and it seems about the same consistency as a soft school eraser when cool and firmer than your average silicon from a gun - so it's quite firm and appears to retain it's shape well after extraction.
It looks to me that it might work as well as "Vinamold" - probably cheaper too! but whether or not it can be heated to a pourable state without destroying it I'll have to find out - this in many cases, might not really be necessary anyway!

Fortunately I have found somewhere about three quarters of an hour away where I can carry out my foundry work (as opposed to just talking about it :rolleyes:) I will also have some help available and will not have to worry about neighbours. My neighbours here are all fine of course and I want to keep it that way! - starting up a foundry in cramped quarters like mine is not really the done thing! :no:

BTW Neil I would like to see you doing a pour sometime as well, might help me resolve a few questions in my mind on how to go about it! - ie if I can ever manage to divorce myself from family duties!

[ken seeber]

Got the slider engine running on the dyno again. Only problem was that it put out so much power that the quality $16 fishing scale/accurate load cell failed, the needle breaking off.

332004

Nah, to tell the truth, at around 10k, the needle went into a frazzle and, like a pommy Smiths speedo, the needle gave up and found happiness lying horizontally at the bottom of the dial.

Irrespective though, the dyno water circuit is still not right, offering either no load or running into a brick wall.

[WilDun]

Got the slider engine running on the dyno again. Only problem was that it put out so much power that the quality $16 fishing scale/accurate load cell failed, the needle breaking off.

Nah, to tell the truth, at around 10k, the needle went into a frazzle and, like a pommy Smiths speedo, the needle gave up and found happiness lying horizontally at the bottom of the dial.

Reminds me of when I was over there in Aus.- I saw a clock on the wall of a café with all the numbers lying in a heap at the bottom and the words "No Worries" printed on the dial. - thought that was a good one! :clap:

[breezy]

Got the slider engine running on the dyno again. Only problem was that it put out so much power that the quality $16 fishing scale/accurate load cell failed, the needle breaking off.

332004

Nah, to tell the truth, at around 10k, the needle went into a frazzle and, like a pommy Smiths speedo, the needle gave up and found happiness lying horizontally at the bottom of the dial.

Irrespective though, the dyno water circuit is still not right, offering either no load or running into a brick wall.

er..." pommey smiths speedo" thats not very pc! do you live anywhere near frankston... get my dad to come round and sort you out:laugh::laugh::laugh ( talk you to death:bleh::bleh::bleh:)

[Frits Overmars]

Got the slider engine running on the dyno again. Only problem was that it put out so much power that the quality $16 fishing scale/accurate load cell failed, the needle breaking off.
To tell the truth, at around 10k, the needle went into a frazzle and, like a pommy Smiths speedo, the needle gave up and found happiness lying horizontally at the bottom of the dial.That brings back another memory from my old Heenan & Fraud Froude water brake. Despite being of Pommy origin, its needle did not break off, but it became a blurr. Replacing its solid pull rod with a piece of rubber strip cured that.

[Vannik]

Irrespective though, the dyno water circuit is still not right, offering either no load or running into a brick wall.

My experience with an engine water dyno is that the dyno load curve had a lower slope than the engine torque curve leading to exactly this type of instability - it either runs away or stalls.

[Frits Overmars]

My experience with an engine water dyno is that the dyno load curve had a lower slope than the engine torque curve leading to exactly this type of instability - it either runs away or stalls.Same here Neels: https://www.kiwibiker.co.nz/forums/showthread.php/162399-The-Bucket-Foundry?p=1130883533#post1130883533

[Flettner]

https://s3.amazonaws.com/WEBPOSTS/KIWI+ESE/strong.jpg





Cheers, Daryl.

Typical 125 carb, 38?
Amount needed to adjust cylinder from closed to full open 13mm , approx three to one advantage
I am ultimately going to get the ECU to do the job via a small servo or a ballscrew.
No combustion pressure is exerted on the servo/ballscrew apart from ring/piston friction and that seems to be in the downward direction.
But yes it may not be as easy as I think

[Frits Overmars]

No combustion pressure is exerted on the servo/ballscrew apart from ring/piston friction and that seems to be in the downward direction.It is, so you won't even need a 'throttle-closing' spring. But an ignition cut-out provision would be nice, just in case....
If you use one of those Honda 'pull open/pull shut' throttles, you could use the shut-cable for this cut-out, so you would not need to take your hand off the bar
(always awkward when a throttle sticks WOT).

I once used one of those pull-pull throttles to operate a valve lifter on an ice speedway bike. These have no brakes at all, but when lifting the exhaust valve 1 mm,
this bike would really throw an anchor, compared to the competition. It would have given the rider a big advantage, but he deemed it too dangerous, with all those
other guys with huge spikes and no brakes right behind him. Oh well, it probably would have been forbidden anyway...
332056

[husaberg]

It is, so you won't even need a 'throttle-closing' spring. But an ignition cut-out provision would be nice, just in case....
If you use one of those Honda 'pull open/pull shut' throttles, you could use the shut-cable for this cut-out, so you would not need to take your hand off the bar
(always awkward when a throttle sticks WOT).

I once used one of those pull-pull throttles to operate a valve lifter on an ice speedway bike. These have no brakes at all, but when lifting the exhaust valve 1 mm,
this bike would really throw an anchor, compared to the competition. It would have given the rider a big advantage, but he deemed it too dangerous, with all those
other guys with huge spikes and no brakes right behind him. Oh well, it probably would have been forbidden anyway...
332056

Decomp valves were comonly used in US flat track and trails bikes in the 60's.
The push pull throttle is a very intersting twist on it though.
It would be nice though if that bleed of energy could be used effectively.

[Frits Overmars]

Decomp valves were comonly used in US flat track and trails bikes in the 60's.Are they still being used? And if not, why not?

[Pursang]

Are they still being used? And if not, why not?

Here is AMA Pro Flat Track racer Joe Kopp, winning the Bultaco Astro Cup in 2015, a "Point of View" indication of the value of the decompressor, at least in that style of racing.


https://www.youtube.com/watch?v=8KnTk4SGDDI

Joe Kopp was AMA Grand Champion in 2000. In the Final he passes and beats 7x Grand National Champion Chris Carr.

Wonderful that such top level riders enjoy racing Old 2T Astros.

Cheers, Daryl.

[Pursang]

Are they still being used? And if not, why not?

In the early 70's a very influential guide for dirt racers was Gary Bailey's "How to Win Motocross".

A whole section, derided the decompressor, because motocross requires maximum Acceleration or maximum Braking & nothing in between.

Flat track, on the other hand, requires maintaining maximum Speed, throughout the corner, without loosing rear wheel traction by excessive acceleration or braking.

As my Old Mate would say...You don't need brakes...they just slow you down.

Cheers, Daryl.

[Michael Moore]

I had a compression release on my 1971 TS185 Suzuki. It made a wonderful flatulence sound, but the brakes did a better job of slowing it down.

[Grumph]

Are they still being used? And if not, why not?

They were used in the era when real brakes were banned. The game changed when brakes were allowed - from memory, at the same time as the 750 OHV engines came in.
I have sympathy for your ice racing fellow, I've seen an attempt to run true speedway bikes - brakeless - with flattrack bikes which are braked.
The red flag went out after one lap as it was immediately apparent it was far too dangerous.

[F5 Dave]

I had a compression release on my 1971 TS185 Suzuki. It made a wonderful flatulence sound, but the brakes did a better job of slowing it down.
. . . barely:msn-wink:

[Ocean1]

I use the decomp on my 525 EXC all the time, it's good at controlling the back end going into corners on loose stuff, where the back brake is more or less useless.

Also on extreme descents, helps manage speed and helps keep the back from getting too far out of line.

[F5 Dave]

I'd like a robust thumb brake for when legs are flailing (part of my dirt riding style) and as a poor man's traction control in the mud.

[peewee]

I was thinking the xr series as well, they were pretty much unchanged for a big number of years, by if 5 speed is his thing a CRF450 might be a little more current they are based n the CR250/500 gearbox.
if he was using the horozontal split i would go for a VT250 gearbox beefy gears and also used on MVX and CBR250's obnly thing is they have a planetry sector mechanism
i can't imagine any of these motors would wear out a gearbox before totally killing an engine

the cr500 had probly the finest gearbox of any dirt bike imo. it shifted very well and near perfect spaced gaps in the late 80's-early 90's. after that they increased the 4th-5th gaps which i didn't really like but mechanically it still functioned well. the problem is, that bike hasn't been made for 15yrs and the spare parts have started to dry up. if you could make one gearbox last a lifetime then you would be fine but if something needed replaced you might be in trouble. if you could find a used 6spd gear box from the newer ktm dirtbike it might be worth a shot. atleast youll have extra parts for a good long time

[Flettner]

the cr500 had probly the finest gearbox of any dirt bike imo. it shifted very well and near perfect spaced gaps in the late 80's-early 90's. after that they increased the 4th-5th gaps which i didn't really like but mechanically it still functioned well. the problem is, that bike hasn't been made for 15yrs and the spare parts have started to dry up. if you could make one gearbox last a lifetime then you would be fine but if something needed replaced you might be in trouble. if you could find a used 6spd gear box from the newer ktm dirtbike it might be worth a shot. atleast youll have extra parts for a good long time

I guess having to make the odd gear from time to time as a spare part is not the end of the world.
The YZ 250 twostroke gearbox is an excellent gearbox, also good in that you can buy new YZ X gear clusters, wide ratio.
But YZ twostroke gearboxes are hard to find. YZF gearboxes are different, I've already cast a few sets of cases to suit this 250 twostroke gearbox and I'm not about to bin them because of this. I have investigated gearboxes out of USA but by the time you add freight they cost almost a new one from Blackwood Yamaha.
No problem I'll just keep an eye open for another gearbox, I've found one at the Chatham Islands of all places just have to get it sent out in a box with some crayfish.
The new 125 RV cases have a common Kawasaki trail bike gearbox, robust enough with a nice wide ratio just what I want with this engines power spread.
I couldn't use a KTM gearbox if you paid me.

[husaberg]

the cr500 had probly the finest gearbox of any dirt bike imo. it shifted very well and near perfect spaced gaps in the late 80's-early 90's. after that they increased the 4th-5th gaps which i didn't really like but mechanically it still functioned well. the problem is, that bike hasn't been made for 15yrs and the spare parts have started to dry up. if you could make one gearbox last a lifetime then you would be fine but if something needed replaced you might be in trouble. if you could find a used 6spd gear box from the newer ktm dirtbike it might be worth a shot. atleast youll have extra parts for a good long time

The CR box is hamstrung with its 5 speeds, ESP in the tight going, if it is geared for first to be useful in tight woods sections it loses too much top speed on the open. (I hate getting blown away by smaller four strokes with 6 speeds)
6 speed imo is far more verstile
PS i have a Cr500 and a HRC supplied wide ratio transmision (Honda of Holland came up with it i think, for the ISDE) i have never bothered to fit it, as it is escentually the same as the later model gearbox. (Which i have anyway)
The fax from HRC that came with it, is rather cool though.


Here is AMA Pro Flat Track racer Joe Kopp, winning the Bultaco Astro Cup in 2015, a "Point of View" indication of the value of the decompressor, at least in that style of racing.

Joe Kopp was AMA Grand Champion in 2000. In the Final he passes and beats 7x Grand National Champion Chris Carr.

Wonderful that such top level riders enjoy racing Old 2T Astros.

Cheers, Daryl.

My Husaberg has a manual decomp on the left ktm and husky used the same lever control, I must say i have never used it.........
Either this a thumb throttle off an atv mounted upside down on the left side would be a neater install than the pro/am AMA set up.


Are they still being used? And if not, why not?

I know not.
To tell you the truth I am not even sure if they still use the 2 strokes for the Juniors/Am's
They were used back in the Bultacco/OSSA/Montessa days
pretty sure Bultacco did a production flat track racer that was the model to have. (Looks like pursang has posted it above) Astros
Plenty of old villiers trials bikes had the decompression valve fitted for downhill sections.

[F5 Dave]

So aren't there wreckers in the US that can sell you several at a Time? Forget eBay.

Then YouShop them back. Its all easy.

[husaberg]

Google says
\The span adjuster is from a VFR400 carb
332066

[F5 Dave]

I do have a spare master cylinder. Not sure I have the bar space. Means losing the foot brake.

[husaberg]

I do have a spare master cylinder. Not sure I have the bar space. Means losing the foot brake.

I posted one in the chassis thread ages that worked off both plus one that used a push bike like lever that pulled on a remote mater cylinder with a cable much like a car set up only cable rather than rod.

okay it didn't
332096
but no reason you couldn't feed pressure from on to the other

if you are worried about the pull MC
https://www.aliexpress.com/item/MAYITR-New-Motorcycle-Aluminum-Pull-Hydraulic-Clutch-Master-Cylinder-Brake-Pump-Rod-System-Performance-Efficient-Transfer/32814874813.html?spm=2114.search0302.4.22.yua5SF
332097
or pull slaves
https://www.aliexpress.com/item/Free-Shipping-motorcycle-Pull-brake-rear-master-cylinder-rear-brake-pump-modified-motorcycle-refitted-for-scooter/32226554233.html?spm=2114.search0302.4.2.xS0pB2

[guyhockley]

Could you have a master cylinder inside the handlebar, maybe? Not sure what size masters that thumb brakes use.

[TZ350]

So aren't there wreckers in the US that can sell you several at a Time?

I once brought six Suzuki T500 engines and six spare sets of barrels from these guys plus other bits, half a tones worth. Great service. http://www.ricepaddy.com/contactus.html

Here is a list of North American bike wreckers. http://bikelinks.com/directory/Parts/Salvage_Yards/Salvage_Yards_North_America/

[Flettner]

Could you have a master cylinder inside the handlebar, maybe? Not sure what size masters that thumb brakes use.

How did we get on to this?
I run a rear brake on the left handle bar, no clutch leave at all. Auto rekluce clutch, great system. It's like riding a mountain bike with 50 HP.

[F5 Dave]

Sorry my fault.
Though I'm addicted to the clutch lever, too many years racing 50s.

[Frits Overmars]

I run a rear brake on the left handle bar, no clutch leave at all. Auto rekluce clutch, great system. It's like riding a mountain bike with 50 HP.:niceone: https://rekluse.com/products/dirt-bike-products/

[husaberg]

Sorry my fault.
Though I'm addicted to the clutch lever, too many years racing 50s.



:niceone: https://rekluse.com/products/dirt-bike-products/

As i think Frits is suggesting You can get a rekluse that still has a clutch lever override, the best of both worlds

https://rekluse.com/product/core-exp-3-0-clutch/

https://www.youtube.com/watch?v=bE-PBo0M2S4

[Flettner]

But I don't want a clutch leaver. It was more about fitting the rear brake to the handle bar when my hip was rooted and I had a lot of trouble operating the foot brake pedal.
At first I tried both clutch and brake leavers on the left bar but enevitably I'd grab the wrong one so I made a peg that holds the small clutch leaver down in the case as if the cable was there. So now its auto like a PW 50. I love it, bikes should be sold off the showroom floor set up like mine.

[WilDun]

I hope this thread doesn't end up being the Bucket "Floundry" instead of the Bucket "Foundry"!!

I had thought that there would have been more people interested in foundry work, especially those experimenting with engines ...... guess it's an entirely "stand alone" and different hobby really.



:laugh:

[guyhockley]

OK, Wil, in an effort to keep things going...
I saw somewhere that some people use a mixture of cement and motor oil for casting. Sounds like it could be a bit smokey/smelly!

[Frits Overmars]

I saw somewhere that some people use a mixture of cement and motor oil for casting. Sounds like it could be a bit smokey/smelly!They use that mixture for speedway tracks. If you are going to use it for casting moulds, please let me know, so I can make sure I'm not in the same time zone.
I've seen the effect of a little moisture left in moulds and with the temperatures at hand I suppose oil won't behave much differently.

[ken seeber]

They use that mixture for speedway tracks. If you are going to use it for casting moulds, please let me know, so I can make sure I'm not in the same time zone.
I've seen the effect of a little moisture left in moulds and with the temperatures at hand I suppose oil won't behave much differently.

Jeez Frits, you're a bit of a scaredy cat, nothing wrong with a bit of hot metal flying thru the atmosphere. :laugh:

I always thought that they used a small % of linseed oil in green sand moulds, so had a look. https://me-mechanicalengineering.com/molding-sand/

Clearly there is a big range of ingredients. As Frits was suggesting, I think moderation is the go when it comes to liquids into the melt though. My personal experience is to never, never, never put anything (eg a freshly sprayed ladle) into the melt unless it has been heat soaked at well over 100 deg C. Having said that, I did hear of some (obviously from "back horme" Guy...:yes:) who used to plunge part- cut potatoes into the melt to degas aluminium.

[WilDun]

They use that mixture for speedway tracks. If you are going to use it for casting moulds, please let me know, so I can make sure I'm not in the same time zone.
I've seen the effect of a little moisture left in moulds and with the temperatures at hand I suppose oil won't behave much differently.

Oilsand is actually still used - probably it's a little better than engine oil and cement of course! and sometimes builder's lime is used in the making of furnaces amongst other stuff like fireclay, refractory cement and sand.(and yes, ordinary Portland cement is known to have been used as well!).

I think that a lot of different mixtures could be used (especially in the making of cores) from molasses, to flour, to cow dung! Then some moulds are made with plaster of paris and silica sand. Greensand for moulds is made with a little bit of fireclay and water. (yes water Frits).
Flettner makes his moulds from sand mixed with silica gel and hardened by passing Co2 through it, making it a very good mould which stays together when moved around - he gets some great results.
Ken is also into casting pistons amongst other things.

However, it's not a very precise process really, a bit like being a baker with all the ingredients in your head and the ability to know how much of what to use without a book! - In fact, desigining a burner is a bit like building and tuning a Bucket engine, except that you can't take it for a test ride!

[husaberg]

They use that mixture for speedway tracks. If you are going to use it for casting moulds, please let me know, so I can make sure I'm not in the same time zone.
I've seen the effect of a little moisture left in moulds and with the temperatures at hand I suppose oil won't behave much differently.

petrobond is very commonly used in the industry. that mix mentioned above with cement, just replaces the sand with finer cement it doesn't actually set like concrete.
Also they should still use synthetic two stroke instead of motor oil.
here is a simple reciepe
http://www.foundry.ray-vin.com/k-bond/k-bond.htm
Greensand is I note also dampening with water to make it bond.
Using concrete is another mater. any moisture traped within the concrete can cause an explosive release of superheated steam.

[WilDun]

A very interesting subject, this foundry business and although I haven't progressed very far as yet, I have learnt a lot here and I hope that this summer will bring more results.
It's good to be able to experiment with the different mixes, techniques etc. and also be able to make things you couldn't possibly buy off the shelf or afford to have done by a commercial foundry.
It's really a seperate hobby, but it does tie in well with experimental bikes!

[Flettner]

The spoils of home foundry, just back from Ashburton, nikasil plated.

[Grumph]

The spoils of home foundry, just back from Ashburton, nikasil plated.

And the little pots of castor base assembly lube too...

[Flettner]

And the little pots of castor base assembly lube too...

Don't forget the smarties

[Grumph]

Don't forget the smarties

Damm - they're still sitting on the bench in the workshop, tomorrow.

[F5 Dave]

They look every bit as good as my CPI cylinders. Unbelievable what you produce.

[WilDun]

The spoils of home foundry, just back from Ashburton, nikasil plated.

Are those castings in LM13? easily plated?
Think I'll have to ask you to explain those slots around the exhausts to me again, I haven't quite got it yet! musn't have been paying attention! :facepalm:

[Flettner]

They look every bit as good as my CPI cylinders. .

Yes they come back from NZ cylinders looking nice, they do good job.
Yes they are LM13 and nikasil will stick to this material well.
Slot is for the power valve blade.

[Flettner]

Bottom end is back together, new cylinders installed, will have to organise some power valve blades and an actuating system.
Valve blades will have a gear rack cut into them. There will be a small gear that will engage with this rack.

[WilDun]

Bottom end is back together, new cylinders installed, will have to organise some power valve blades and an actuating system.
Valve blades will have a gear rack cut into them. There will be a small gear that will engage with this rack.

I guess the power valve blades are made of steel? - Will you need a damper (seeing it's rack and pinion)?

Those photos make it quite clear that the injectors will be facing into the stream!

[Flettner]

I guess the power valve blades are made of steel? - Will you need a damper (seeing it's rack and pinion)?

Those photos make it quite clear that the injectors will be facing into the stream!

No injectors on this engine but lugs are for the future. This is the same cylinder I'm using on the 360 reverse cylinder YZ engine.
PV blades will be anodized aluminium.

[TZ350]

332381

A and B port injectors, I wanted to take Flettners advice and do that too but on my NSR cylinder the power valve pulley gets in the way of the front right "A" injector.

332382

[F5 Dave]

Surely if it can't be rotated around and still have the travel, it could be moved outbound enough?

[Grumph]

Surely if it can't be rotated around and still have the travel, it could be moved outbound enough?

If you've got room in the frame I'd have thought it could be moved outboard.

[Flettner]

Breezy you asked about the pull start?
Seen here, screws into the left hand thread used to screw the flywheel puller into. The rest of the mechanism is from Robin.

[breezy]

Breezy you asked about the pull start?
Seen here, screws into the left hand thread used to screw the flywheel puller into. The rest of the mechanism is from Robin.

thanks, now i can see how you’ve managed to attach this:2thumbsup

[Flettner]

The gyro engine ready to run with new power valve cylinders, R6 servo to operate these blade valves. Ignitech runs the R6 servo, same as the one under the Kawasaki seat that runs the variable rotary valve via push pull cables.

[F5 Dave]

That so needs to go into an RG50 frame.

[Flettner]

A step closer

[WilDun]

Who is going be the test pilot? - you?

[Flettner]

Well Yes, this time. I've been building gyros for years and never flown them on my own. But I've been taking lessons recently. I'm ready to go, so will the gyro be ready by next weekend. Probably the guy training me will fly it first but then my turn. It will be just up and down the strip stuff for a start, too bad if the engine stops, pretty sure I can land it, probably do some more engine out training on the two seater first.
This gyro has flown before but with an earlier version of this engine.

[Niels Abildgaard]

What is state of art today for prop diameter,RPM and horsepower?
And what RPM ,cyl volume and mass for engine?

[Flettner]

Don't know about 'state of play' but this engine is 80 /90 HP , weighs 42KG, reduction ??? cant remember, approx 2.6 to one, 66" prop (limited by mast height, rotor clearance). electric start, balance shaft equipped (doubles as a pre rotator drive) and is pre equipped for TPI injection. Gear reduction is internal not a bolt on extra.

[Niels Abildgaard]

Don't know about 'state of play' but this engine is 80 /90 HP , weighs 40KG, reduction ??? cant remember, approx 2.6 to one, 66" prop (limited by mast height, rotor clearance). electric start, balance shaft equipped (doubles as a pre rotator drive) and is pre equipped for TPI injection. Gear reduction is internal not a bolt on extra.

Thank You and good luck
Small aircraft engines is the best bet for two stroke survival.
What cylinder dimenson and how many revs max?

[Flettner]

70 x 80 bore, approx 7000 / 7500 rpm, depending on prop pitch.

[WilDun]

Do carburetted two strokes deal well with the atmospheric pressure changes (at different altitudes) without problems?

Do they need to be jetted to run rich on the ground?

[Flettner]

Ha ha, I won't be off the ground far enough for that to be a problem. The slide carbs seem very tolerant to air pressure changes.

[Frits Overmars]

Do carburetted two strokes deal well with the atmospheric pressure changes (at different altitudes) without problems? Do they need to be jetted to run rich on the ground?What made you say that, WilDun? Rich on the ground will only mean even richer at altitude, where the air is thinner and the atmospheric pressure is lower.
Rich on the ground was used in piston-engined fighter planes that used lots of blower boost for take-off and needed to cool the engine internals with fuel in order to keep them alive.

[guyhockley]

What made you say that, WilDun? Rich on the ground will only mean even richer at altitude, where the air is thinner and the atmospheric pressure is lower.
Rich on the ground was used in piston-engined fighter planes that used lots of blower boost for take-off and needed to cool the engine internals with fuel in order to keep them alive.

We went to Granada in Spain, last year. Lovely city but there was a constant smell of petrol, especially when half a dozen scooters left a traffic light. I said to my wife that it was like every bloody scooter in town was running rich, then I realised we were about 750m/2500' ASL...

[Flettner]

Time for TPI on those scooters.

[WilDun]

What made you say that, WilDun? Rich on the ground will only mean even richer at altitude, where the air is thinner and the atmospheric pressure is lower.
What made me say that? ...... Ignorance! - that's why I came to this esteemed forum in the first place (ie to be rid of my ignorance) :laugh:
Maybe I should explain - where I come from, we had a nasty habit of asking a question in the form of a statement (not in this case though), which we understood of course, but this could be misinterpreted by people from other countries (eg like England, New Zealand etc).... so do please make allowances for me :rolleyes:


Rich on the ground was used in piston-engined fighter planes that used lots of blower boost for take-off and needed to cool the engine internals with fuel in order to keep them alive.

Well we learn something new every day but I suspect I had heard all that in my youth (when I was so fond of the WW2 aircraft) and that was what was driving my question!

However, I had also heard recently that two strokes in light aircraft if not properly managed have some problems (especially in descent) - but of course those problems could be lube related.

[Flettner]

Only Rotax have problems, cast iron push in sleeves, not even cast in, have trouble dissipating heat. Long decent, cold engine, sudden full power (assuming some sort of cock up in landing) then seizure as the piston suddenly expands and the sleeve don't. Next minute you landing whether you want to or not!

Machining a gear rack into the power valve blade. Just need to cut the pinion that will mesh with it. There are back up rollers on the other side of the blade to take any side load.

[WilDun]

Only Rotax have problems, cast iron push in sleeves, not even cast in, have trouble dissipating heat. Long decent, cold engine, sudden full power (assuming some sort of cock up in landing) then seizure as the piston suddenly expands and the sleeve don't. Next minute you landing whether you want to or not!

Machining a gear rack into the power valve blade. Just need to cut the pinion that will mesh with it. There are back up rollers on the other side of the blade to take any side load.

Surprised at Rotax not addressing that problem!

I like it so far, - has that actuation method been used before, sorry, I'm pretty unfamiliar with modern stuff! are the rollers held in bearings? - (guess they wouldn't be running free) :no: - how many rollers?

[Ocean1]

Only Rotax have problems, cast iron push in sleeves, not even cast in, have trouble dissipating heat. Long decent, cold engine, sudden full power (assuming some sort of cock up in landing) then seizure as the piston suddenly expands and the sleeve don't. Next minute you landing whether you want to or not!

Machining a gear rack into the power valve blade. Just need to cut the pinion that will mesh with it. There are back up rollers on the other side of the blade to take any side load.

Shit, that takes me back, haven't used a hob like that for years and years....

Nice work too mate, good to see.

[Flettner]

Surprised at Rotax not addressing that problem!

I like it so far, - has that actuation method been used before, sorry, I'm pretty unfamiliar with modern stuff! are the rollers held in bearings? - (guess they wouldn't be running free) :no: - how many rollers?

That's Rotax, an engine designed in the 70's, no competition so they just keep making the same thing. 300 / 400 hours life and the home built aviation engine buyers consider this the industry standard. Will pay $14,000 NZD and walk away with a smile on their face. I started off thinking I'll just make new cylinders for them so they don't seize, then got to thinking, their crankshafts also have trouble with 70's designed big end bearings so will fail in short order. Rubbish engine really.
Hence the push to build my 700 (2x my 350 cylinder) engine with inbuilt gearbox and integrated pre rotator, nikasil cylinders, case reed, balance shaft, power valve. Trouble is I can never productionise this engine but I can and will build a few more test units. At the end of the day who cares, I'll have my own 'state of the art' autogyro engine, everyone else can stick to their shit Rotax (and expensive) engines.

Two needle rollers on the opposite side to the gear rack. Pinion gear will also have rollers with the dia at gear root size so will pinch the power valve blade between them.

Screw Photo Bucket, I see they have blocked all my pictures on this thread. bastards, I guess they just want me to pay them. That's not going to happen any time soon, I've invited a few people to this site to to get a handle on pattern making / casting stuff and now the pictures are blocked, if anyone wants to see something in particular just say so as I can bypass Photobucket.

[Niels Abildgaard]

ROTAX their crankshafts also have trouble with 70's designed big end bearings so will fail in short order. Rubbish engine really.




How have You improved on these?Bigger or better or both?

[Flettner]

Modern bigend cadge, modern rod design and power taken off from the center of the crankshafts, not the end of both.

[WilDun]

That's Rotax, an engine designed in the 70's, no competition so they just keep making the same thing. ........ At the end of the day who cares, I'll have my own 'state of the art' autogyro engine, everyone else can stick to their shit Rotax (and expensive) engines.

Screw Photo Bucket, I see they have blocked all my pictures on this thread. bastards, I guess they just want me to pay them........... That's not going to happen any time soon, if anyone wants to see something in particular just say so as I can bypass Photobucket.

Good thinking on all counts and having held one of the cylinders I bet that the engine is about half as heavy as the Rotax! I hope it is a success. Still hopeful to see it all one day, but my life has been in a bit of a turmoil recently so there is always something preventing me, but I'll get there!

Bet Husa has most of your photos tucked away somewhere! -I have kept a lot of the more recent ones on my computer as well.

My foundry stuff is in Raglan ( my son relented and let me store it at his bach) but says I mustn't try any casting on my own! - I don't get to visit it often anyway, However I have been invited to do that sort of stuff near Pukekohe and I might soon take up that offer! - only little more than half an hour away.

[Flettner]

I think I might have a sheep here in my paddock that may have a drinking problem. Twice now I've found my furnace fuel drum knocked over with the push on pipe removed and all the fuel gone. Just thought it was those clumsy sheep, or the wind but yesterday I see the fuel drum being shunted around the yard by an angry looking sheep, for all the world looked like it might have a hangover, it was certainly looking for more. This morning it come barging into my shed clearly looking for something. I hate to think what the 15% petrol and the castor oil are doing to it's insides. Best it doesn't go near any naked flames:eek:
Where did I put that lighter?

[F5 Dave]

Sprinkle some Oregano cumin and chilli and some spuds before sparking it up and before you can say spca you'll have dinner sorted.

[Grumph]

I think I might have a sheep here in my paddock that may have a drinking problem. Twice now I've found my furnace fuel drum knocked over with the push on pipe removed and all the fuel gone. Just thought it was those clumsy sheep, or the wind but yesterday I see the fuel drum being shunted around the yard by an angry looking sheep, for all the world looked like it might have a hangover, it was certainly looking for more. This morning it come barging into my shed clearly looking for something. I hate to think what the 15% petrol and the castor oil are doing to it's insides. Best it doesn't go near any naked flames:eek:
Where did I put that lighter?

What a marinade...That one definitely shouldn't go on a barbeque, very slow cooked is the way to go.
If you believe in reincarnation, I can suggest several names to try on it....

[husaberg]

I think I might have a sheep here in my paddock that may have a drinking problem. Twice now I've found my furnace fuel drum knocked over with the push on pipe removed and all the fuel gone. Just thought it was those clumsy sheep, or the wind but yesterday I see the fuel drum being shunted around the yard by an angry looking sheep, for all the world looked like it might have a hangover, it was certainly looking for more. This morning it come barging into my shed clearly looking for something. I hate to think what the 15% petrol and the castor oil are doing to it's insides. Best it doesn't go near any naked flames:eek:
Where did I put that lighter?

Seems you have got into a pickle.............

[WilDun]

......... I hate to think what the 15% petrol and the castor oil are doing to it's insides. Best it doesn't go near any naked flames:eek:
Where did I put that lighter?

More likely - what is it doing to it's brain? - then I guess it wouldn't change things much, they were never that well known for brain power! ....... Bird brains are way ahead ....... bucket brains even !! :laugh:

[ken seeber]

I can confirm that over here, petrol or aviation fuel, even just some basic sniffing, doesn't appear to be any good for the human brain at least. Fletto, just monitor that sheep, it may produce some exotic wool fibre that's stronger than carbon fibre, otherwise to the edge of the cliff.

Well, dunno if you remember me, but I used to post some enchanting dribble on here for a bit. :yes:

After some total distractions, be it work, keeping the good wife happy, karting and karting politics, I got some time to re-plumb the dyno. A friend in South Oz has a STUSKA water brake dyno which is very similar to the TRIK unit I am playing with and, best of all, he had a manual which had some useful info re the circuitry.

Just gave it a whiz and it sort of worked, but clearly needs a much finer adjusting inlet feed valve rather than the gate valve I had fitted. Think I stopped the load needle quivering off by adding a heavy mass to the body of the scale. I do recognise the scale is just junk, but I just needed some indication of load to even see if the dyno could be controlled. If it does go ok, then I’ll just put on a load cell and display, for <$100 via good old Alibaba. The 3 exhausts still make a shitload of noise too.

So, the plan Sam is to to fix the valve then take it home and set it up and annoy the neighbours. It has to go cos we do have some big bulky work coming thru pretty soon.

332596

[Flettner]

Will, don't underestermate sheep, they are cunning bastards, I notice it always checks the gate after I've been through it. And if by chance it does get out into the garden it conveniently forgets how to get back into it's paddock, unless food is involved. Bastard sheep.

[WilDun]

Will, don't underestermate sheep, they are cunning bastards, I notice it always checks the gate after I've been through it. And if by chance it does get out into the garden it conveniently forgets how to get back into it's paddock, unless food is involved. Bastard sheep.

Well, maybe you are right, we used to have a couple of renegade sheep who could always find a way out of the paddock, I often chased them on my old Model G Royal Enfield - it eventually got to the stage that all I had to do was start it up in the yard and they immediately disappeared back into the paddock at high speed!


KEN who?
Where the hell have you been, we've been worried sick about you! :msn-wink:

[Flettner]

Rack and pinion. With back rollers and support bearings.

[Flettner]

Just need to make a housing to house it all.

[Flettner]

Housing made. All works nice.

[F5 Dave]

That's pretty cool, certainly easier than the TSS CPI conversion, although maybe you made those too?

[ken seeber]

Slider update, NO downdate.

Well, after further dyno plumbing enhancements, we gave it another run. Then it happened. For some reason under some load when trying to slowly increase the revs, the thing suddenly unloaded, revs went to just under 30k, an exhaust spring broke, an exhaust fell off and the sliding cylinder M6 actuation (push/pull) rod snapped. Bit of a pisser really. :(

This is the second time the rod has broken, in this case a plain shank, no thread stress raiser (as in the previous failure). See pic.

332700

I think the actuating lever effectively floating and restrained in the fore/aft direction only by the rod is just imposing some severe cyclic fatigue loadings on the rod, snapping it. The good news is that the piston etc looks ok and the things turns over ok.

So, for the moment, I’ll remove the lever assy and replace the rod with a longer one and just use a series of light spacers to provide the cylinder height variation, in some incremental fashion. Gotta partially strip it to do this. And also further educate myself on the control of a water brake.

In the meantime, Fletto will have a built a half dozen new engines and/or flown around the world in his autogyro. :niceone:

[F5 Dave]

Pity the dyno couldn't grab the reading, it was bound to have just broached 70.

[WilDun]

Slider update, NO downdate.

Well, after further dyno plumbing enhancements, we gave it another run. Then it happened. For some reason under some load when trying to slowly increase the revs, the thing suddenly unloaded, revs went to just under 30k, an exhaust spring broke, an exhaust fell off and the sliding cylinder M6 actuation (push/pull) rod snapped. Bit of a pisser really. .............So, for the moment, I’ll remove the lever assy and replace the rod with a longer one and just use a series of light spacers to provide the cylinder height variation, in some incremental fashion.
Ken,
Does it mean that there is a definite case for the introduction the "straight line" piston rod movement instead of the normal conrod in order to reduce piston/cylinder friction? - the frictional forces at work here I feel will be much more of a problem than was first thought!
I am a quite an open proponent of the MCE5 idea of a straight line piston/rod movement which probably could be used to produce an effect similar to a sliding cylinder ...... or if still using a sliding cylinder then the (rod snapping) effect of friction on the cylinder wall will be much reduced - ( I do realize that I only have ideas which never progress into anything thing tangible and I could be misreading the whole bloody concept anyway :rolleyes:) - so I'll understand if you don't listen!
Keep up the effort
:niceone:

[Grumph]

Slider update, NO downdate.

I think the actuating lever effectively floating and restrained in the fore/aft direction only by the rod is just imposing some severe cyclic fatigue loadings on the rod, snapping it. The good news is that the piston etc looks ok and the things turns over ok.


Reminds me a lot of a bike here that had a history of breaking the rear shock shaft - usually while warming it up with no rider.
After they took my suggestion of never firing it without leaving someone in the seat, things got better.
What about a nylon/teflon guide bearing to damp out the rod's vibration ?

[Frits Overmars]

I'm on the road, between country D and country I, wifi is not too good (so don't worry if you don't hear from me over the next few days) but I love it! Carry on.

[guyhockley]

http://www.hotrod.com/articles/made-mast-motorsports-cylinder-head-casting-process/

[Frits Overmars]

I think the actuating lever effectively floating and restrained in the fore/aft direction only by the rod is just imposing some severe cyclic fatigue loadings on the rod, snapping it.I think so too. The lever is hovering over an engine that is violently shaking fore-aft. The rod takes the whole beating. Maybe you can build some guidance for the head and nut of the bolt that holds the rod.
By the way, revving to just under 30k is not bad at all. The port layout in this cylinder doesn't suffer from lack of time-area :2thumbsup.

EDIT: a balance shaft might solve the problem. Maybe you should switch to one of Flettners new cases, Ken.

[WilDun]

http://www.hotrod.com/articles/made-mast-motorsports-cylinder-head-casting-process/

Some interesting stuff there, basic foundry techniques haven't really changed a lot over the years, but the modern resin sand technology etc these days seems to be evolving to a stage where it has superceded die casting - not the rough old sand castings we used to see!

[Flettner]

Power valve all set up.

[Frits Overmars]

Power valve all set up.Now all it needs is two wheels Neil ;).
BTW: you might want to pull a rubber hose over that coupling, or cover it with some silicon gasket compound in order to dampen vibrations there.
Yes, I know there's a balance shaft, which is great. Still...

[WilDun]

Power valve all set up.

All looking good! :niceone:
Three feet ( or is it one metre?) off the ground, for a while?

[Flettner]

Will do Will;)

[ken seeber]

SLIDER (& MORE) REPORTING.


Just thought I’d check in and let you know that I’m still alive & well and still in country (A). After a series of distractions (wedding anniversaries and birthdays, both significant it seems), karting, karting politics and work focus, getting back into it. However, this could all be bullshit 'cos a friend says, “if you’ve got more than one excuse, then you've got no excuse at all”. One job at work has been casting lead into the pockets of these counterweight wheels. They weigh 70 kg empty and 125 kg when filled. We had to do another 24. Bit of a task for different reasons, but got there.

332830

For some reason they are called, possibly affectionately, “exciter wheels”, which are mounted on a gearbox with two contra rotating shafts. Not too sure, but believe these are for vibratory screening machines for use in the mining industry of which is quite extensive in Western Oz..

332831

OK, the slider. Couldn’t be stuffed fixing the actuating rod, so just removed the entire arm mechanism. Did this on the basis that the sliding cylinder, from previous observations always has a tendency to work its way downwards, ie into a low port height position. This is sort of logical in that the nett piston ring friction will be higher on the power/downstroke, so it will naturally want to lower the cylinder, all other things being equal.

332832

So, after reviewing the water connections, we gave it another brief run this arvo, and it did seem slightly better in terms of holding a speed, but when it comes onto the pipe, it just runs away. Too much power? Full credit to that Fletto for designing such an efficient scavenging & gas flowing cylinder design. :yes: Anyways, will give it another bash tomorrow morning(Saturday), when those winging industrial neighbours won’t be around. If I can’t get any sense, then I dunno what to do. Try an inertia dyno, do some form of disc brake load mechanism, chuck it on a go kart (might be interesting with the exhausts) or , or, or, or ??

[Frits Overmars]

... we gave it another brief run this arvo, and it did seem slightly better in terms of holding a speed, but when it comes onto the pipe, it just runs away. Too much power?That water brake is doing what it can be expected to do Ken: https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130937167#post1130937167

[WilDun]

That water brake is doing what it can be expected to do Ken: https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130937167#post1130937167

I realize that this has possibly been discussed somewhere here before, but how effective are the eddy current retarder units for trucks when used as the basis of a homebuilt dynamometer? - expensive or cheap way to go? (assuming the use of secondhand parts of course).

Maybe even a disc brake on it's own?

[diesel62]

I realize that this has possibly been discussed somewhere here before, but how effective are the eddy current retarder units for trucks when used as the basis of a homebuilt dynamometer? - expensive or cheap way to go? (assuming the use of secondhand parts of course).

Maybe even a disc brake on it's own?I'm using eddy current retarders with aftermarket controls on 4x4 chassis dyno. Working well can also just use it as an inertia dyno.

Sent from my SM-G900F using Tapatalk

[Frits Overmars]

how effective are the eddy current retarder units for trucks when used as the basis of a homebuilt dynamometer? - expensive or cheap way to go? (assuming the use of secondhand parts of course). Maybe even a disc brake on it's own?I wouldn't name an eddy current retarder as the basis for a homebuilt dyno; that would be a flywheel. But the retarder would be a fine extension, and not expensive at all in secondhand form.
One thing you need to know: its braking torque is not linear with exciter input and it will also vary when the retarder's temperature climbs during a brake session.

A disc brake is fine for slowing a flywheel down after a dyno run, but I would not recommend it as a measurement instrument. It can be done, with a torque arm, but the generated heat will play havoc with the desired constant temperature in a dyno room. And in case you fancy outdoor dynoing, you should know that braking sessions will be severy limited by disc cooling down periods.
In the early 1970's we experimented with a brake disc running in a water bath. I can now say 'don't go there' :shifty:.

[WilDun]

I wouldn't name an eddy current retarder as the basis for a homebuilt dyno; that would be a flywheel. But the retarder would be a fine extension, and not expensive at all in secondhand form.
.............A disc brake is fine for slowing a flywheel down after a dyno run, ............ And in case you fancy outdoor dynoing, you should know that braking sessions will be severy limited by disc cooling down periods.
In the early 1970's we experimented with a brake disc running in a water bath. I can now say 'don't go there' :shifty:.

I guess the easiest answer for the garden shed experimenter would be the one Alex made with the big electric motor!
At least he did it, so we now know it can be done, but was he being very brave in trying it? -
Probably all depends on who built the motor and how strong it is to begin with, but I'm sure it wasn't built for such high revs!

Then we do take our lives in our own hands racing bikes - except in my case, I now specialize in falling off excercycles,
mobility scooters and the odd ladder etc.:facepalm: - but that's just life!
Racing bikes is all just trial and error anyway, so really, what's difference between that and trying a (potentially unsafe) dyno? :rolleyes:

[Ocean1]

Racing bikes is all just trial and error anyway, so really, what's difference between that and trying a (potentially unsafe) dyno? :rolleyes:

Well, in my experience the shrapnel usually comes from the engine...

[diesel62]

Have a look at dtec.net.au should give you a good idea of what you want

Sent from my SM-G900F using Tapatalk

[WilDun]

Have a look at dtec.net.au should give you a good idea of what you want

Thanks there is a lot of good stuff there!.
Quite honestly I don't think I'll ever experience shrapnel from any bike engine of mine - haven't got one likely to run!

[ken seeber]

AMBIENT TEMPERATURE CASTING MOULD.

Well, not really foundry, but it is casting. We had to do a quick prototype mould for encapsulating a circuit board in a 20 mm dia section using pourable resin. Rather than making it in metal, which would have cost lots, both in time and $s, so sparking up the 3D printer was the logical choice. Not completely ideal in that one has to contend with contour line that are evident on angled faces. Our printer was set at 0.3 Z increments. Could go a lot finer (eg down to 0.05), but is a compromise between a practical build time (around 4+ hours) and waiting much,much longer, with the not unusual disappointment when something goes wrong when close to finishing. So, after a dose of spot putty, primer surfacer and sanding, we (they actually) have something to work with.

332979332980332981

We have also done small coreboxes using this technique, obviously limited to C02 or Fenotec type room temp processes.

[F5 Dave]

So I'm guessing it's SLA. FDM is going to be well bumpy without heaps of work. Pissing around too much with our Polyjet at work of late. Great for prototypes but a drag for production. Good finish though.

[ken seeber]

So I'm guessing it's SLA. FDM is going to be well bumpy without heaps of work. Pissing around too much with our Polyjet at work of late. Great for prototypes but a drag for production. Good finish though.

Well bumpy it was. Hence the spot putty and primer surfacer. It's a Leapfrog Creatr with twin head, one of the early ones.

Now Dave, you've now got yourself into a bit of a pickle. With an SLA machine at your disposal, we at Foundry are now looking forward (no, expecting) to see some moulds, lost SLA printed castings etc etc. :clap: Even if it's 50 cc we don't mind.

[F5 Dave]

Polyjet is slightly different to SLA. Well quite different. It lays down layers on a tray with a mat of support material like an inkjet printer and UV cures that layer at a time. Don't think for a minute that I actually know what I'm talking about.

[husaberg]

Polyjet is slightly different to SLA. Well quite different. It lays down layers on a tray with a mat of support material like an inkjet printer and UV cures that layer at a time. Don't think for a minute that I actually know what I'm talking about.
For some reason i thought you worked at a musical instrument factory.
But seeing your work sig the other day it was more like you arrange the orchestra for the 1812 overture.

[WilDun]

Don't think for a minute that I actually know what I'm talking about.

Same here Dave, but if you aren't afraid of being wrong now and again, just make a statement (somewhere in the ball park of course) and by the end of the day you will know - someone will quickly clarify things!

[husaberg]

not foundry
Hydroforming with grease

https://www.youtube.com/watch?v=A66iw8P5NQ4
with rubber and a jack

https://www.youtube.com/watch?v=xw5yEMsDxR8
hands and water

https://www.youtube.com/watch?v=P6LrTAQyvb0

[Frits Overmars]

Don't think for a minute that I actually know what I'm talking about.
Same here Dave, but if you aren't afraid of being wrong now and again, just make a statement (somewhere in the ball park of course) and by the end of the day you will know - someone will quickly clarify things!Very philosophical Will, and quite correct.
We all start our knowledge by not knowing anything, so our first statements won't even be in the ball park. But we will either be put straight by someone with a bit more knowledge or experience, or we will repeat our mistakes so often that we will start noticing them ourselves. And suspecting that we may be wrong is the first step to wisdom.
I was lucky enough to work and live with the Master of two-strokes, Jan Thiel, and three things come to mind: his elephant-like memory, his unequalled experience
and his eternal doubt about everything (and his handwriting; it was nearly identical to mine and sometimes, looking over old notes, we were not sure who wrote what).

I used to make a living as technical editor, and searching for the most lucid way of explaining something often enhanced my own insight as well.
It's what I still do: writing in forums and creating the impression that I know what I'm talking about. Hell, sometimes I even believe it myself :msn-wink:.

[lohring]

I used to make a living as technical editor, and searching for the most lucid way of explaining something often enhanced my own insight as well.
It's what I still do: writing in forums and creating the impression that I know what I'm talking about. Hell, sometimes I even believe it myself :msn-wink:.

I knew we had something in common. In the distant past I was a technical writer for General Dynamics Electric Boat Division. I didn't know anything about submarines, but was surrounded by ex navy chief petty officers that did. I did know how to edit their knowledge into "proper" (American) English. The experience was very educational. I still write articles on model boating and engines as a hobby.

Lohring Miller

[WilDun]

Good to hear all that stuff, sort of gives you the feeling of knowing the people you are talking to!
I think I would have enjoyed doing the type of work you guys did.

Unfortunately I never progressed in the field of engines and motors (which was what I really wanted to do), I was a farmer's son and was expected to be only interested in farming, so went to work on my father's farm where I was a bit of a misfit, I spent my days watching various types of military aircraft constantly flying around us, mostly unnoticed by the majority of people living in the area - didn't excite them at all!
Later on, motorcycles, often with me on board were also flying around the area, that did arouse interest (mostly negative).

My interest in metal casting came from going into the local foundry on the way home from school and spending the odd half hour just observing what went on, I also visited the local scrapyard every day for a while to admire two Bristol sleeve valve radials recovered from a Wellington bomber which had crashed locally, but they eventually disappeared (no doubt to the furnace!).

Then, after moving to NZ I managed to dabble in all the stuff which interested me, but was really too busy trying to make a living to get deeply involved ...... unfortunately,
:rolleyes:
Must say though that I have acquired a lot of info on metal casting right here on this forum.

[lohring]

Will, you are becoming one of my internet "friends". I think I majored in shop in high school. I started out in manufacturing with an eye toward becoming an engineer. I worked in the engineering departments of companies that made everything from atomic submarines to zippers, but never as an engineer. All of these companies are gone but two; Lyman Gunsight and Electric Boat. These days I'm a dentist and engineering model engines is my hobby. I have a 1960s machine shop with a vertical mill and a Monarch lathe. I'm thinking of moving into the 21st century with a 3D printer, but I need to master 3D model design first. We'll see if a really old guy can learn Fusion 360.

Lohring Miller

[WilDun]

Will, you are becoming one of my internet "friends". I think I majored in shop in high school. I started out in manufacturing with an eye toward becoming an engineer. I worked in the engineering departments of companies that made everything from atomic submarines to zippers, but never as an engineer. All of these companies are gone but two; Lyman Gunsight and Electric Boat. These days I'm a dentist and engineering model engines is my hobby. I have a 1960s machine shop with a vertical mill and a Monarch lathe. I'm thinking of moving into the 21st century with a 3D printer, but I need to master 3D model design first. We'll see if a really old guy can learn Fusion 360.
Lohring Miller

Flettner (Neil) has proven to us all just what can be done using pencil and paper, old style foundry technology, modern two stroke design and will power to actually produce his home designed two stroke aircraft and motorcycle engines, all built from scratch using his own innovations as well as modern day proven ideas.
Not so sure that a lot of people actually appreciate just how unique he is in this field.

I would have loved to have been able to do all this stuff too, but now I don't think I have the drive (probably never had), nor the time left to do all that and so my thoughts will probably remain as thoughts in my head.
However I think that 3d printers are very interesting and perhaps better and safer for this old guy to be playing with, than a messy home machine shop/foundry which isn't very conducive to keeping friendly with the family or neighbours!

My son seems to think that 3D printing would be a great hobby for me, (probably thinks that it could get me out of my unsafe workshop!) but I see it as just an aid for patternmaking to be used in conjunction with my crude foundry and not as a hobby in itself.

Most people don't quite understand this! - the first thing they think of is making a gun or some miraculous machine to put on the shelf for people to admire.
I probably couldn't justify spending money on one of these - a worthwhile one (as opposed to the many gimmicky ones on the market) could be quite expensive for me and yes, of course there's the software to buy and then learning it is something else - etc. etc.

3D printers I find fascinating, but only as an addition to a budget home foundry, and expensive, .....well .... maybe better not! - I think that doing patterns the old woodworking way is probably best for someone in my position to do - traditional patternmaking can also be a great hobby in itself of course!

[Flettner]

Lohring, Ha ha, your screwed, if you are like me I start to learn Geomagic (? , I think that's what its called) and end up cornered somewhere in the program. Usually just turn the computer off and go out to the shed and just make the part I was trying to draw. it's jolly frustrating. Personaly I need to sit down with someone that knows the program and every time I'm stumped just ask. I find Help file would be better named Helpless! Just need to keep at it I guess.
From what I see in your back ground I think you will be way more patient and master your program quickly, I'd say good luck but if you are relying on luck you are never going to get there:laugh:

[Flettner]

Will, I'm going to do a cast up before Christmas, some cylinders and crank cases. You are welcome to attend if you like.
That goes for others on this thread too if they want to.

[WilDun]

Will, I'm going to do a cast up before Christmas, some cylinders and crank cases. You are welcome to attend if you like.
That goes for others on this thread too if they want to.

Yes, thanks count me in, I'll do my best to actually be there this time!
Just let me know in advance when it's on (weather permitting of course).
Hope some of the others do manage to go as well.

[Ocean1]

I have a 1960s machine shop with a vertical mill and a Monarch lathe.

Anything like this one?

[ken seeber]

As an alternative to green sand, which is water based, there are oil based alternatives, which give a better finish. Reading the blurbs, it appears that because the steam generated by the water based green sand is a lot more voluminous than the vapours of the oil based sands, much finer sands can be used, hence the better finish. One type being Petrobond.

http://smelko.com/?page_id=322
http://fennetic.net/gingery_machines/petrobond.html
http://castinghobbyfaq.bareboogerhost.com/moldingsand.shtml

Of interest is KBond, some thing which one can make oneself (= good). Appropriately, it calls up for 2 stroke oil, which makes perfect sense, given the reason we are all here for. Aren’t we ?

http://castinghobbyfaq.bareboogerhost.com/kbond.shtml

Anyone had any experience with either ?

As a total aside from hot metal splashing, how was the MGP (& also M2 & M3 which we normally never get to see, certainly on free-to-air) racing yesterday. Absolutely brilliant. Who’d ever, ever watch F1 after that ?

[Frits Overmars]

Flettner (Neil) has proven to us all just what can be done using pencil and paper, old style foundry technology, modern two stroke design and will power to actually produce his home designed two stroke aircraft and motorcycle engines, all built from scratch using his own innovations as well as modern day proven ideas.
Not so sure that a lot of people actually appreciate just how unique he is in this field.I daresay you simply can't, not until you have tried something of the sort yourself.


how was the MGP (& also M2 & M3 which we normally never get to see, certainly on free-to-air) racing yesterday. Absolutely brilliant.For those who missed it:
http://www.multiup.eu/fr/mirror/94d3b6a45478bcd2fa7270d52bca1ae5/MotoGP_2017_GP16_Phillip_Island_Australie_22-10-2017__Fr__Xor.mp4 (French-spoken, but all pictures are in English :msn-wink:)
You can either watch it online or download it.

Downloading took me > 3 hours but it was worth every minute of it. It wasn't 'just' wheel-to-wheel, it was wheel-to-opponent, regularly!
333043 333044

[lohring]

Anything like this one?
No, this one.
333045

I've learned more than I ever wanted to know about electrical systems trying to keep the Ward Leonard drive running. It's a great example of an era where manpower was cheap and technology was expensive.

I have lots of problems with todays digital thinking. I still find it easier to sketch out things with an ancient K&E drafting machine than to draw it on a computer. Most of the time I just play around in the shop and destroy a lot of metal with mistakes until I get it right.

Lohring Miller

[Ocean1]

No, this one.
333045

I've learned more than I ever wanted to know about electrical systems trying to keep the Ward Leonard drive running. It's a great example of an era where manpower was cheap and technology was expensive.

I have lots of problems with todays digital thinking. I still find it easier to sketch out things with an ancient K&E drafting machine than to draw it on a computer. Most of the time I just play around in the shop and destroy a lot of metal with mistakes until I get it right.

Lohring Miller

:laugh: You're a braver man than me.

As a general purpose lathe the only real disadvantage is the size of the headstock bore, maybe a few more revs when using carbides. In most regards they're at least as good as any modern machine, mine was a superior device to the Colchester in the background and A South Bend I had.

Yes, I use Rhino3D, often initially just for the ability to present screen shots or renderings as proposals but once you've done that to any reasonable level it's no work at all to produced workshop drawings. Occasionally it also reveals potential issues with a design that may not have been apparent on paper, components attempting to occupying the same space not visible in traditional views, etc. Having said that there's absolutely nothing wrong with the concept of "mulitple, incrementally refined prototypes". :laugh:

[WilDun]

I daresay you simply can't, not until you have tried something of the sort yourself.

I would have been in that group too until I gave it a go, my efforts are pathetic by comparison but it gave me an insight into how much dedication and hard work is required! I had to push myself to do it, but glad I did and I need to keep on pushing myself.
I'll keep going till I can't anymore and with a bit of luck I'll inspire someone much younger to help me out and carry it on! Maybe I'm getting a bit ahead of myself here, I've only fired it up 4 times!:rolleyes:


As an alternative to green sand, which is water based, there are oil based alternatives, which give a better finish. One type being Petrobond.
Good simple and easy to digest article on Pertobond style sand - Got to at least try it anyway!


Of interest is KBond, ............ (= good). Appropriately, it calls up for 2 stroke oil, which makes perfect sense, given the reason we are all here for. Aren’t we ?
I think from memory that Shell produce a good detergent oil for compressors (called "Rotella") which might be suitable.


.......... how was the MGP (& also M2 & M3) racing yesterday. Absolutely brilliant. Who’d ever, ever watch F1 after that ?

Very good racing, you see them pass and repass with their elbows and knees on the deck, very exciting!
In F1, a pass is a major event!, you never even get to see any action from the driver cocconed in his "safety cave" nor do you see them on the podium smiling and discussing an exciting race - only smiling for the cameras. - Moto GP and Superbikes win hands down (or should it be knees and elbows down)! :laugh:

BTW I have finally forgiven Marquez for his behaviour towards Rossi a year or so back - he is obviously a fantastic rider and loves every moment of racing. Dovisioso (unfortunately) didn't shine this time!

[Flettner]

Long time project, the 360 mark 2 TPI engine is back together with a wide ratio YZ X gearbox, all sealed up. Time to build a clutch cover pattern. This is not the cylinder I'll be using.

[ken seeber]

. This is not the cylinder I'll be using.

Looks like the injector entry points are near horizontal on this pic. Nevertheless, KTM might try to patent it anyway..:(

[Flettner]

The beginnings of another clutch cover, 360 TPI

[Ocean1]

The beginnings of another clutch cover, 360 TPI

What are you using for glue Neil?

[Flettner]

There we go, 4.5mm wall thickness. Paint and sand a few times.
Glue, just five minute epoxy, I don't have the patience for anything longer.

[WilDun]

There we go, 4.5mm wall thickness. Paint and sand a few times.
Glue, just five minute epoxy, I don't have the patience for anything longer.

Will be watching all this with interest!

[Flettner]

Progress I guess.

[Frits Overmars]

Progress I guess.That will provide a spacious accommodation for your Rekluse clutch, Neil.
But why put the inlet disc at the clutch side? Just because it was that way in the original Bighorn, or are there other reasons?

[Flettner]

There are reasons, just give me time to think of some.

[Flettner]

I guess one would be.I need a reasonable charging system
Flywheel on the left side of the engine, also it might have my new favorite, a pull start. Plus no carb or throttle body says there will plenty of room for the intake and still air box. And I just like my 350s layout. There you have it no reason really.

[Frits Overmars]

There are reasons, just give me time to think of some.Sounds like a set of reasonable reasons to me :niceone:

[Flettner]

One of the down sides of not doing complete drawings (or any drawings) is when it comes time to actually fitting stuff in can be a challenge. The throttle Gibbs were always one of those 'I'll work it out when I get there' , well I'm there now and the mind's eye is still blank.
What usually happens now is just start and make something, then the right idea will introduce itself.:sweatdrop

[WilDun]

One of the down sides of not doing complete drawings (or any drawings) is when it comes time to actually fitting stuff in can be a challenge. The throttle Gibbs were always one of those 'I'll work it out when I get there' , well I'm there now and the mind's eye is still blank.
What usually happens now is just start and make something, then the right idea will introduce itself.:sweatdrop

The upside (for you) is that you have all the gear required to be able to do it the trial and error way!

I have been told that there is much more trial and error used (even by the high tech big boys!) than we are led to believe and I think that a lot of guys here would be able to testify to that! - meaning that designiing it properly on paper really just gives you a good idea on how to get going!

Well, that's my take on it anyway! :rolleyes:

[ken seeber]

Question: Is there a phone app (Android) that one can stick on a phone in one’s pocket and do a (straight line hopefully) acceleration run and this is recorded. Essentially the output will be velocity vs time or preferably, acceleration rate vs speed. Don’t care whether it is just GPS based or utilizes the phone’s accelerometer.

Why? I have been working on the sliding cylinder engine https://www.youtube.com/channel/UCg24eWF2LE0nEmf8YrX0RYQ and have tried to run it against a water brake dyno. So far, I just can’t make it work, seemingly the engine power curve exceeds the absorption curve at some point and the engine just revs up to infinity (well, just over 70,000 rpm). Figuring I don’t want to be developing a dyno, I reckon that for cheap thrills I am just going to wack it onto a kart and drive up some bitumen road or track.

Given this, if I could record the accel (at varying cylinder height steps), it’d be extremely useful. I can back calc the engine rpm from the kart speed.
The few apps I have looked at seem to have things like 0 to 60 mph, 1/8 mile, ¼ mile test ranges, but I just want to be able to press start, do a run and then press stop and have an accel run log.

Any ideas?

[Frits Overmars]

Is there a phone app (Android) that one can stick on a phone in one’s pocket and do an acceleration run... Figuring I don’t want to be developing a dyno...
https://play.google.com/store/apps/details?id=ch.perfectpower.PerfectPower&hl=en
Quote from the above website: "It will also allow you to perform motor development with efficiency thanks to its perfect regularity"I don't doubt the perfect regularity of the app, but what about the regularity of track conditions, wind, tires? Building an inertia dyno can be quite simple, there will be hardly any need to develop it as the necessary software and electronics can be found all over the internet, and it will be a much better tool for engine development.

A couple of examples of simplicity:
333253333252

[Grumph]

Interesting visit yesterday. Had to go to see Wallace (marsheng) and was in time to see and assist at the first run of the rebuilt 350 Koenig engine.
He may well post up a vid of it running and I didn't have a camera with me anyway.
Turned into quite a social affair - the owner, Wallace, myself, Russell Bleach arrived with a load of 250 Suzuki parts - and Glenn Hayward (of the Flying Kiwi sidecar record crew) turned up to collect a couple of bikes.

Good to hear the crackle and scream of the unsilenced Koenig echoing across the neighbour's paddocks.

[ken seeber]

Just saw the latest (in Oz anyway) homologation docco update for the Rotax Max kart engine cylinders.

333279

Pity they didn't actually show the actual ports (a typical failed homologation procedure of not showing the specific & important details) so we could see the finish. I can guess the process is similar (same) as this one:

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

Would think the finish and resolution would be mainly dependent on the sand grain size used.

Fletto, you need one of these. Not exactly a low cost consumer item as yet. :cry:

[Frits Overmars]

Good to hear the crackle and scream of the unsilenced KoenigKönig engines deserve to be unsilenced, as does the Honda 250-6. There should be a law against silencing such jewels.
https://www.youtube.com/watch?v=A0BwMeRTQ0E (concert starts at 1:39)
http://www.youtube.com/watch?v=eaRop_ZMwo0

[Frits Overmars]

Just saw the latest (in Oz anyway) homologation docco update for the Rotax Max kart engine cylinders.... Would think the finish and resolution would be mainly dependent on the sand grain size used.
"Rotax have developed a new manufacturing technology where the sandcore is a single piece that is printed with a digital printer, creating less variation of the casting geometry".Good on Rotax for developing a new technology that was used for the Aprilia racing cylinders ten years ago.
333285

Frankly the casting quality of the previous Rotax cylinders wasn't all that bad, with the exception of the coolant passages alongside the exhaust duct,
that were often partially or even completely blocked by casting skin.

333287 333288

[ken seeber]

Frankly the casting quality of the previous Rotax cylinders wasn't all that bad,

With karting and the classic karting rules that you can't touch anything, put them under pressure to be consistent in this area. As always though, there were rumoured to be good and bad cylinders, whether real or not.

Yeah Frits, I remember looking at those core pics ages ago and figured something smart was going on. No flash lines, the interlocking coolant and transfer passages and the coarse finish. Good on them. Do you have any memories or pics of the actual cast surfaces? Looks like it might be coarse, but then again they could have coated the cores in some form of wash that might have smoothed things a bit, or a lot.

Have also seen some Max cylinders that have those passages almost blocked off with flash. These are cast by Gilardoni.

[Niels Abildgaard]

Question: Is there a phone app (Android) that one can stick on a phone in one’s pocket and do a (straight line hopefully) acceleration run and this is recorded. Essentially the output will be velocity vs time or preferably, acceleration rate vs speed. Don’t care whether it is just GPS based or utilizes the phone’s accelerometer.

Why? I have been working on the sliding cylinder engine https://www.youtube.com/channel/UCg24eWF2LE0nEmf8YrX0RYQ and have tried to run it against a water brake dyno. So far, I just can’t make it work, seemingly the engine power curve exceeds the absorption curve at some point and the engine just revs up to infinity (well, just over 70,000 rpm). Figuring I don’t want to be developing a dyno, I reckon that for cheap thrills I am just going to wack it onto a kart and drive up some bitumen road or track.

Given this, if I could record the accel (at varying cylinder height steps), it’d be extremely useful. I can back calc the engine rpm from the kart speed.
The few apps I have looked at seem to have things like 0 to 60 mph, 1/8 mile, ¼ mile test ranges, but I just want to be able to press start, do a run and then press stop and have an accel run log.

Any ideas?

My son and I wanted to know how many kW our Fiat Punto used at different speeds.We had a very straigth and level road close by with very clear marks per 200 meter at the sides.Illegal speed(more than 80 km/h) neutral gear and take times for 200 m marks.
Excell can then easily make a fourth order polynomium giving distance run as function of time.Differentiate once and You have speed and once more and You have acceleration.method will also function In Your case going faster and faster.

https://imgur.com/kAifQZ6

Today I think I would try and make a side looking mobile phone video of passage of at least 5 coloured premeasured roadside buckets and then analyse.
The internal clock in phone is more accurate than a stopwatch,

[Flettner]

Jolly old gyro engine, will not run smooth down low, acts like one cylinder is not firing right and won't pull above 6000 revs. The whole engine vibrates, everywhere not smooth like it used to be???
So today I stripped the bugger again looking for perhaps an air leak. Ha Ha, on inspection I found it! Cranks are twisted out of phase, perhaps one of the press fits was not as good as it should have been? Best to press it apart and measure I guess, bugger, and I was all ready to fly it like that. Build your own aviation engine from scratch, how hard can it be I said to myself, seems harder than I anticipated.
Running the drive off the center shaft I thought might lessen the twisting seen from the cranks but there is still a lot of force with load reversals, with one cylinder being pushed up to TDC while the other is being forced violently toward BDC rotationaly apposing each other continuously.

[Niels Abildgaard]

Jolly old gyro engine, will not run smooth down low, acts like one cylinder is not firing right and won't pull above 6000 revs. The whole engine vibrates, everywhere not smooth like it used to be???
So today I stripped the bugger again looking for perhaps an air leak. Ha Ha, on inspection I found it! Cranks are twisted out of phase, perhaps one of the press fits was not as good as it should have been? Best to press it apart and measure I guess, bugger, and I was all ready to fly it like that. Build your own aviation engine from scratch, how hard can it be I said to myself, seems harder than I anticipated.
Running the drive off the center shaft I thought might lessen the twisting seen from the cranks but there is still a lot of force with load reversals, with one cylinder being pushed up to TDC while the other is being forced violently toward BDC rotationaly apposing each other continuously.

If You have any drawing of cylinders and crankshaft as is ,let me scheme a 90 degree V2 .This can be lower mass and much smoother powerflow.
Mr Overmars has shown torque variations for different cranks somewhere called Fallacy of Big Bang or something like it.

[WilDun]

Got to be just the press fit surely, ie if everything was smooth previously,nothing really different is there? - It's still good to know what the problem is and that it's not going to happen again, ie before you go flying!

[Grumph]

Jolly old gyro engine, will not run smooth down low, acts like one cylinder is not firing right and won't pull above 6000 revs. The whole engine vibrates, everywhere not smooth like it used to be???
So today I stripped the bugger again looking for perhaps an air leak. Ha Ha, on inspection I found it! Cranks are twisted out of phase, perhaps one of the press fits was not as good as it should have been? Best to press it apart and measure I guess, bugger, and I was all ready to fly it like that. Build your own aviation engine from scratch, how hard can it be I said to myself, seems harder than I anticipated.
Running the drive off the center shaft I thought might lessen the twisting seen from the cranks but there is still a lot of force with load reversals, with one cylinder being pushed up to TDC while the other is being forced violently toward BDC rotationaly apposing each other continuously.

Weld the critical bits. You know I do a lot of post classic stuff - some with pressed up 4 cyl cranks. Running a bead round the visible ends of press fits is often the only way to keep a crank in phase at power levels around twice what they were designed for.

[Flettner]

All back together and back in the gyro frame. Yes I did tig weld assist the press fit, both ends just to be safe, spent today running it up again. Doesn't shake like it did and seems it will rev out more now but still under 4000 rpm it runs like a bag full of arseholes, rough as guts.
I guess a process of elimination, back to the original cylinders, just need to re nikasil one of them. I've pissed around with the jetting, timing and power valve settings, seems to make no difference?

[WilDun]

........ Yes I did tig weld assist the press fit, both ends just to be safe, Doesn't shake like it did and seems it will rev out more now but still under 4000 rpm it runs like a bag full of arseholes.........
......... I've pissed around with the jetting, timing and power valve settings, seems to make no difference?

I know I shouldn't, (for my own credibility) but .... I will anyway - the balance shaft timing?

[Flettner]

You might not believe it but I put timing marks on the balance shaft drive gears and a key for each bob weight. Because I did assemble the assembly wrong one night, and did it shake. Hence I stupid proofed it:eek:
No, I'm sure it's an ignition problem probably haven't stupid proofed that yet. Twisted crank is a consequence not a cause I think.
But yes the press fit was a bit light also.

Ok, more searching, seems the problem is self inflicted, one of the push fit plugs from one of the ignition triggers was only just (or not, depending on how the engine moved) in. Now it's fixed the engine runs much better, still rattles around a bit but not harsh. I need to stupid proof all the electrical plugs. Yay.

[Flettner]

Fly you bastard! And it did.
https://youtu.be/xAAqQukouLk

[Ocean1]

Fly you bastard! And it did.
https://youtu.be/xAAqQukouLk

Was there ever any doubt? :laugh:

Nice work mate, good to see.

[WilDun]

Fly you bastard! And it did.

Great stuff! - all sounding very crisp - ground speed (when airborne) is quite frightening!
Hope everything is good in the engine now and maybe we'll see some more.
I see you took my advice and had it just clipping the grass! :laugh:

[Flettner]

I'd love to say it was me flying it but no, my test pilot.
He won't let me fly it yet, airspeed indicator is not working so a new one is on order. Old one was a freebie from a crashed gyro. Thursday might be the day!

[WilDun]

Did he say if the power to weight ratio was a big improvement?

[Flettner]

He loved the power!

[chrisc]

Congrats! :clap:

[Frits Overmars]

Fly you bastard! And it did.
https://youtu.be/xAAqQukouLk
333585

:niceone:

[WilDun]

:niceone:

Thats why he wouldn't let Neil fly it any more!:laugh:

[Flettner]

333585

:niceone:

Ha Ha, small steps.

[ken seeber]

And the lawn looks to be nicely mowed as well.
Good work Fletto..

[Grumph]

Neil, what shrinkage factor do you work to for your general LM25 equivalent patterns ?

I'd better make up patterns for the Lyster calipers while I have some here...

[Flettner]

About 1% / 1.5%
My old alloy shrinkage ruler was about 4mm in 300.
I must say it was a dangerous ruler to have just lying around the workshop.

[Flettner]

Rotary Valve/ clutch cover pattern reaching further across the engine. Lump out the back of the clutch is the oil pump/water pump drive, one either side of the plastic drive gear.

[Flettner]

This is quite a tricky case to make, including the inner spacer/Rotary valve cover And variable Gibbs.

[Frits Overmars]

This is quite a tricky case to make, including the inner spacer/Rotary valve cover And variable Gibbs.I like your Gibbs description Neil. Where does that word come from? Has it any meaning in English or is it just a word that aptly describes the part?

[Michael Moore]

I thought he was referring to a gib, but I don't see any:

gib noun
1. a wood or metal bolt, wedge, or pin for holding part of a machine or structure in place, usually adjusted by a screw or key. "gib screws"

[Grumph]

A crane Jib - raises and lowers. Or possibly the triangular Jib sail ?

[Flettner]

I like your Gibbs description Neil. Where does that word come from? Has it any meaning in English or is it just a word that aptly describes the part?

Frits, I wasn't sure what to call the sliding throttle/timing parts. To me 'sliding gibb' seemed the right term or just gibb, a bit like a lathe sideways gibb only curved, so there you go, and no the actual gibbs are not made yet this is just the housing they will work in. You can see the two machined cavity's that small cranks fit into to move the gibbs. Same system as in my Kawasaki only two of them, open and close valve adjustment.

I'm planing on a big cast up before Christmas, including this clutch case and a number of different cylinders. A melt of CC601 and also a pot of LM13.

[Flettner]

The sliding Gibb housing, two parts to allow for assembly.

[husaberg]

I thought he was referring to a gib, but I don't see any:

gib noun
1. a wood or metal bolt, wedge, or pin for holding part of a machine or structure in place, usually adjusted by a screw or key. "gib screws"


A crane Jib - raises and lowers. Or possibly the triangular Jib sail ?


Gibb, A set of brothers with high voices and short lifespans and a strong sense of irony?

https://www.youtube.com/watch?v=XfwQ_7xqO7Y

[Flettner]

Sounds about right,

[Grumph]

Sounds about right,

You need a snappy acronym - come up with one before someone copies it.

[husaberg]

You need a snappy acronym - come up with one before someone copies it.
Flettners Air Restriction Technology, Has a ring to it..................

[Frits Overmars]

You need a snappy acronym - come up with one before someone copies it.
Flettners Air Restriction Technology, Has a ring to it..................:killingme
Please excuse my childish sense of humour.
But I agree with Grumph: a good name will be advantageous. When I realized that, I came up with '24/7' for my open-all-hours inlet system.
I think the idea would not have spread like it has, if I had used a longer, less-catching description.
Now if some company would use it on their production bikes, people would probably holler: "Hey, look, KTM is going 24/7!" :msn-wink:

[WilDun]

"NSRT" - (Neil's Selective Restriction Technology), - "NSTT" (Neil's Selective Timing Technology). or NSIT (Neil Smart Inlet Timing).

Hang on, I know! - "ET" (Eureka Timing).
(For those who don't know, Neil lives at a place called "Eureka").
Sorry Neil, maybe I'm being a bit of a Dickhead here! :facepalm: :o

[Grumph]

Gotta get the trade name in somewhere too...What about AVIT

Autoflight Variable Inlet Timing

The "must 'av" addition to your inlet tract....

[Flettner]

Throttle Inclusive, Timing System. TITS

What a fun game.

[WilDun]

Gotta get the trade name in somewhere too...What about AVIT

Autoflight Variable Inlet Timing

The "must 'av" addition to your inlet tract....

That sounds good to me - a "Eureka"" moment for you! - but Neil obviously thinks TITS would be hard to beat! (whats the betting HUSA thinks that
too?).

[husaberg]

I'd call it the Weasel
As its that clever and cunning. You could pin a tail on it and call it one.
https://i.giphy.com/media/D4TA4imVkbMwU/giphy.gif

[TZ350]

Throttle Inclusive, Timing System. TITS.

TITS ..... :laugh: ... I shouldn't laugh, not PC but it is funny.

[ken seeber]

Well, you kiwis have 5 hours of thinking time ahead of us across the ditch, so here’s my acronym submission:

“DATT” meaning Double Action Timing Throttle.

Now DATT sounds good to me....:niceone:

[WilDun]

Phuctifino ! :scratch:
(Latin for I dunno).

[Frits Overmars]

Throttle Inclusive, Timing System. TITS. What a fun game.Isn't it?
Me, I prefer TITS over FART (sorry Husa). But I bet you didn't bother to consult the girls in your family, Neil.

[Grumph]

Well, seeing as it has degenerated into the usual KB style, I'll back into the argument...

ASS

Autoflight's Sliding Segments

[WilDun]

Throttle Inclusive, Timing System. TITS

What a fun game.

Well, it is coming up to Christmas - we need to take our minds off the stress about to hit us! (not the casting session).

AVIA (Autoflight Variable Inlet Aperture)?

[Flettner]

Isn't it?
Me, I prefer TITS over FART (sorry Husa). But I bet you didn't bother to consult the girls in your family, Neil.

Ha ha, no. Thankfully they don't read this Webb site.
Thanks guys, I've truly had an LOL, resulting in nearly LBL, funny stuff.

[Grumph]

At least now, when you describe an engine you're building, you can simply say "I'm throwing the usual T & A at it - and may toss in a FART as well...."

[WilDun]

ha ha, no. Thankfully they don't read this webb site.
Thanks guys, i i've truly had an lol, resulting in nearly lbl, funny stuff.

lbl?....lbl?.......wtf?

[Grumph]

lbl?....lbl?.......wtf?

I deduce from the time posted that it's "Lost breakfast laughing..."

[Flettner]

I deduce from the time posted that it's "Lost breakfast laughing..."

Close enough:lol:

[husaberg]

lbl?....lbl?.......wtf?

It means he almost wee'd himself
ie light bladder leakage:whistle:

[WilDun]

I means he almost wee'd himself
ie light bladder leakage:whistle:

Lets hope the cat in your picture doesn't become a victim of LBL!

Neil is the "Big Pour" still on before Christmas? or will you postpone it, till the new year?

[Flettner]

Not sure, I've ordered a stack of CC601 but haven't seen it yet. The cast might end up a Christmas day treat for the family.
Some how I don't think the good wife will think that is appropriate:rolleyes:
I would imagine between Christmas and New year then?
Keep in touch.
Clutch cover pattern is moving along.

[WilDun]

Not sure, I've ordered a stack of CC601 but haven't seen it yet. The cast might end up a Christmas day treat for the family.
Some how I don't think the good wife will think that is appropriate:rolleyes:
I would imagine between Christmas and New year then?
Keep in touch.
Clutch cover pattern is moving along.

Ok, look forward to that (whenever it takes place) - I know from experience, it will be less stressful than the actual Christmas thing!

[Flettner]

And I'd like to cast a few of these as well.

[WilDun]

And I'd like to cast a few of these as well.

A few? Not 100% sure which one I'm looking at here!- FOS? - straight line geared crank? - Ryger like creation?....nah maybe not!- :no:?

All of the above? ....... ok, definitely off to bed now! :laugh:

[Grumph]

And I'd like to cast a few of these as well.

What's the pump in the background ?

[Flettner]

What else but Kawasaki, KE 175
This unit is driven straight off the end of 175s crankshaft. So it's the smallest autolube pump I've ever seen, and priority one, it's free.

[WilDun]

What else but Kawasaki, KE 175

Should have recognised it! - getting it confused with the experimental common bottom end/gearbox model (models) you were trying.
Maybe up a bit too late last night!

[Flettner]

A few? Not 100% sure which one I'm looking at here!- FOS? - straight line geared crank? - Ryger like creation?....nah maybe not!- :no:?

All of the above? ....... ok, definitely off to bed now! :laugh:
Yes this crank case is useful for the FOS, slider and epicylic crank. So I'll need a few to play with
Also I'll be running one of these cases with the TPI mark two. Many uses.

[Flettner]

Just organised (paid for) 180Kg of aluminium, so got some serious casing to do, LM13@60kg and CC601@120kg.
Nearly a ton of sand and a bucket of sodium silicate, so it begins.

[WilDun]

Just organised (paid for) 180Kg of aluminium, so got some serious casing to do, LM13@60kg and CC601@120kg.
Nearly a ton of sand and a bucket of sodium silicate, so it begins.

Never seen these things in the flesh but will understand once I've had a look. Looks like a good scheme for experimentation using the "one case fits all"method!

Things are looking imminent now for the casting process - hopefully I'll be able to break away from the Christmas and family stuff for a day!
I'm sure I will, but they (my "kids") have arrived back with their families this year from overseas for the occasion!

[ken seeber]

Still here fellas, just been a bit distracted with lots of things of late.

So, for something that is foundry, but not bike related, I am doing a little project in conjunction with a buddy in Tassie. It is a thing called a “downriggger bomb”. Traditionally these are just lead balls that are dragged along behind a boat at some controlled depth. From these a lure is attached for the fish to bite. Rather than a plain ball, this is a more hydrodynamic shape which will help to reduce the tension on the drag line. These are also available, but of course, one has to think of a “better mouse trap”, which I think we are working on. Gotta say at this point that I know absolutely nothing about fishing, other than that sharks over here like to bite people in half.

Anyways, as part of the new design, we printed one half up to create a pattern. This will be mounted on a mould board and two moulds made, probably in a 50:50 sand & plaster of paris mix. This is possible as both halves will be symmetrical. It will be cast in lead.

Must say that smoothing the 3D print with the spot putty and sanding it smooth is almost theraputic (not that I need therapy, or do I ??:rolleyes:). Can see now why Neil makes lots of patterns.

Will be working on the slidingcylinder engine this week, with the goal to get it on an inertia dyno.

Have a good xmas & new year etc.

334145334146

[WilDun]

Happy Christmas everybody, - :niceone:
Too hot for foundry stuff! ( its all too much Ken it's around 26deg. here!) happy fishing!

[Flettner]

An almost not suitable mold box, its used for another job but a small modification means I don't have to build a new one. Black stuff is plumbago, carbon powder, rub it into the pattern surface to make it real slippery.
An old Kawasaki exhaust is used to hold my spring balance from the roof (what else)
Sodium Silicate tipped in to the sand ready to mix.

[Flettner]

The mixing process. The bits of metal in the sand mixing drum help by making sure nothing sticks to the drum as it turns. Picture shows the drum turning fast, its only doing about 30/40 RPM ish.
Starting to pack the mold.

[Flettner]

Using welding wire to poke gassing holes.
Gassing with CO2.

[Flettner]

The finished mold. A spare because I know the machinist and he is likely to bugger one up.

[Frits Overmars]

The finished mold. A spare because I know the machinist and he is likely to bugger one up.You'd better do it yourself then. Or....? :devil2:

[Flettner]

Next patterns to mold. Six bolt cylinder attachment to suit slider cylinder and some other cylinder configurations
Inserts will be placed in the crankcase to suit the different cylinder requirements.

[Flettner]

Some of the cylinders that will be tested.

[Flettner]

These depressions are carved in by hand as locators for the top half of the sand mold. Opposite lumps will be generated as the top mold is packed and set so two halves will go back together in the same orientation. Handy little tricks.