Eatherbreather

Oh! I was going direct drive - any suggestions what size might be ok? The prospect of carving my own horrifies me, I need something "off the shelf". Doesn't have to be awesome, just safe and permit the engine to run.

G'day all! Thanks for the info! Yes mine has cast iron cylinders (with steel liners?) and a Tillotson carby. Some time back I kitted the carby with genuine parts still being made (in Ireland now). It also had the disgusting (useless) Victa twin ignition that I have removed including the fin-less Victa flywheel. Previous attempts to get this engine running have failed to produce more than a few consecutive coughs - the compression felt pretty low as I recall. When the weather improves I hope to re-visit it to get it running. I have got new head gaskets to fit (Victa 160cc same bolt spacing) and need to make and fit some lower cylinder gaskets and fix the pull start that died. Also need to replace at least one of the reed sets as some bored f*#kwit thought it would be good to make origami out of one of it when I had them out of the engine to try to find replacements - I am reliably informed that new reeds work much better than old ones even if they aren't damaged in any way. I don't like my chances but I will try to get it going anyway. If none of this sees it running I may get it off to someone more knowledgeable it may need a bore/pistons/rings rebuild? It is such a simple engine there really so little in it to prevent it from running otherwise. The notion of fitting a "Scout" propeller to it and having it work is encouraging though as that is the propeller I have been using and the only "loose" propeller I have! The Jimbo.

There is a guy in Northam that can teach - I can get his number to you if you want or there's good old (sorry Jim!) Jim Cuthill in Victoria (Falconhawk flying school). I had excellent results with Jim. He's a great guy and I would have qualified if it not for a minor mishap that put his Thruster out of action for a bit : ( I haven't tried the Wagin guy yet. Wagin being so much closer to home obviously appeals to me.

Ah yeah there not many of these types around unfortunately. Instructors are very few and far between too

Thanks matey! Thruster T300

Excellent! Fingers crossed they can teach three axis

Hey all, Any word on the Wagin flying school? Will they be teaching three axis or trikes? My machine as pictured is ex Bindoon. Some of you may recognise it James.

Woohoo! Look at them trophies! I have here his pulse jet starter and some engine mounts that appear to be for a "Dynajet" pulse jet. It is my understanding that he used to do night flying demos of pulse jet control line at the Perth Royal show. He certainly seem to have been a very keen and capable guy. A wee update for the Skylark twin - I fully re-kitted the carby a couple of days ago when the parts arrived from Tillotson - in Ireland! They moved their operations there some years ago. They had no record of my particular model of carby but true to their word the kit they sent fitted perfectly. I have removed and re-examined the reeds. They appear to be completely fine just as I recalled but I will replace them anyway. Once I have these sorted and I have repaired the pull start cord I will have another go at blowing the fence over (hopefully) Coming up after the break a look back at the stories still to come....

I see! If we're talking the same "Len" (and I suspect we are) then I have couple of things here that he used to own. I never had the pleasure of meeting him myself unfortunately. One of the items is a letter opener made from an old bit of streamline section flying wire? It has some numbers stamped around the threaded end (metric M5) but I have no idea what they mean or what aircraft this came off. I made a brass handle for it and use it every day I can fire off some pics to you of what I have if you like. Is there some way of sending private messages om here or do I need an email address?

Are you related to Len per chance?

Woohoo! Shelley beach! Just up the road from me! - Just checked out your hang gliding pics : )

It ran ok - I wouldn't say great but as you probably know Cox problems are often solved with more nitromethane in the fuel. I should re-visit it sometime and give it a damn good thrashing with some different fuels and maybe try different glow heads. It seemed to favour one cylinder more than the other as I recall (the one that's offset slightly to the rear closer to the intake?). I think this condition may also be because the rotating innards of the engine tends to pump the incoming fuel air mix towards one cylinder more than the other. It's because of this I am considering retaining the carbies mounted on the cylinders for my "flat twin whipper snipper parts engine" project. Two carbies will be harder to tune doubtlessly and make for a heavier and bulkier engine. My thinking being that if one cylinder is a bit weak I can hopefully correct (optimize) the fuel air mix for that side of the engine - this hopefully being possible by the piston ported carby enabling the incoming fuel/air mix being placed more or less directly under the piston and filling the transfer ports of that cylinder rather than having the fuel air/mix pass through the bottom end of the engine so much. If this doesn't work I can blank off the intake ports and mount a single carby on the crankcase (offset if need be to position the carby nearer whichever cylinder is weaker) with reeds. If this doesn't work I will have a beaut paper weight.

I haven't looked at the reeds recently but when I did previously they looked ok - no cracks, stting flat. Having said this I had chats with a mate of mine and he told me of a 125 moto-x/trailbike he had years ago. He said that when it came time for a rebore he did this and it of course ran great afterwards, much better than before as expected. When asked if he had replaced the reeds too he said "no, they looked fine". They were fine in that they worked but that is all they did. At someone's insistence he replaced the apparently "ok" reeds and the bike was again massively improved. Makes sense to me now that I know this. I guess reeds by their very nature and the job they do in their working enviroment are going to fatigue and change with age/use. This is what I like about projects like this, especially this Skylark twin that I'm messing about with. I have been wrong about several aspects of it already and have learned a great deal about engines from it. It's probably better that this engine continues to throw challenges at me. If it had worked and run properly from the outset I would have learned little or nothing. Now to source new reeds. If I can't find any I can make them.

G'day riverduk! Thanks for the info lead, I may very well contact them soon. An update: Got the beast mounted, costing more time and money than it did to get the engine complete and of course, it doesn't run. I am now gonna try kitting the carby but I suspect the problem is in the piston/bore fit. I took the cylinders and heads off to see if the rings were free and they are but the compression still feels soft. Doesn't appear to have any cylinder base or head gaskets but it's not leaking either. I will make and fit some anyway just to be sure. No obvious bore wear or damage however. It may just be that the tolerances were bad to start with? The pull start worked very well! As suspected the inertia of the prop carried the engine past compression - albeit not great compression. The cord has since broken though. It was a bit shabby to begin with. The engine would run for a second or two if I dried the plugs. Fuel is getting into the cylinders (and dribbling out the exhausts) but not wanting to fire. The spark is good. A spot of crankcase porosity was found and subsequently sealed. Doing so has made no difference. Pics shown use of whipper snipper fuel tank and throttle and model plane tacho and battery voltage meter. Throttle assembly was useful for having a fail "safe-ish" spring loaded throttle lever. That is when released it goes to idle and not flat out as a simple friction system might. Also the stop switch is used. The "run" and "stop" positions are in fact reversed as the switch is used to close and complete the circuit to run instead of closing only to short out what would have been magneto ignition. Another feature I hoped would be useful is the throttle lock that hold the throttle at about 1/4 throttle for starting. All these things have been quite useless so far, time will tell though. If it doesn't run after carby kitting and gaskets a rebore/piston/rings may be needed. Not sure I want to spend that kinda money and the cylinder walls look pretty thin to me already.

Great minds! The twin ignition I'm now using on the "Skylark" (Skylaugh?) engine was to be used on a homemade twin using whipper snipper pistons, cylinders etc. If the twin carbs didn't solve the problem I was going to maybe make an intake manifold to both ports with a single carby or just blank off the intake ports and put a single carby on the crankcase. I expect that twin carbys might at best just be swapping one problem for another i.e. may or may not help with fuel/air distribution but at the expense of syncro hassles. My understanding of the poor mix distribution in flat twin two strokes is caused by the rotating engine innards favouring one cylinder over another by sort of pumping the mix in the direction of rotation? Or in the case of rear induction as with my glow twin the cylinder nearest where the mix enters the crankcase is "favoured".

I reckon 30 deg would be too advanced too. I will reset mine to 26 deg and start from there. I had quite forgotten about the prospect of using DA or 3W ignition and hadn't thought of doubling up the systems - are much better arrangement I'm sure. The spark plugs. Yes that's exactly what I was going to do - I don't imagine this engine will be run very often and the heat range of the plugs I have is pretty well in the middle so I can't see any horrors like holed pistons happening. I will keep an eye on it though. The sensor holder - with age comes some brains apparently. I thought ahead a bit and deliberately machined a "tail" on it to accomodate a zip tie to prevent the sensor wire being strained at the sensor. Also (not shown) I drilled and tapped a 3mm hole right through the magnet disc under the 4mm diameter magnet before fitting the magnet. This way if I need to I can remove the magnet by screwing a 3mm bolt into the disc under the magnet and effectively press it out. The reeds looked ok no cracks that I could see. I don't think this engine has done a lot of work. I haven't kitted the carby. I am going to "suck it and see" on that one but I fully expect it will need kitting. I have had it apart and thoroughly cleaned it all. The various rubber bits and diaphragms that typically dry out looked ok - I have seen worse but running it will be the only way to really know if they're any good or not. I contacted Tillotson some time back and as I recall they said this carby was REALLY old - made well before 1980. They didn't have a kit specifically for it any more but had a "generic" kit that would probably do. "Eatherbreather". Yes I am mad for a bit of model diesel engine action! They smell bad (read "awesome"), are harder to start and run, are messy, noisy and are often odd looking things. What's not to love! My user name was meant to be "Etherbreather" but I accidentally typo'd it when I was setting up my Youtube account? For whatever reason I couldn't change it and the typo stuck and now I use it everywhere. Well spotted

Yes this engine has reed valves. I figured it may be hard to get to get an even amount of fuel/air to each cylinder. There's not much I can do for that except to run it and see what happens. The flat twin glow engine I built has this same problem. I wonder if the problem might be resolved by the use of twin carbys on a piston ported twin cylinder engine?

Thanks for your continued interest guys! I have gone the Rxcel ignition route. I worked out that "Victa" timing (for their 160cc single mower) is 23 deg btdc so I have set mine there. Downunder do you suppose this is correct or should I opt for the 30 deg that everyone seems to use when converting model glow engines to petrol? The machining involved was pretty straight forward, the result being what I liken to being a "record player" arrangement - that is the magnet is mounted in the face of a rotating disc passing under a fixed Hall sensor pickup that is itself mounted at 90 deg to the shaft. Timing is adjusted by loosening the starter cup and the two grub screws that secure the magnet housing disc to the shaft then rotating the disc to the desired position. The fitting of the ignition gear after the machining is a breeze. So simple, neat and tidy. I reckon it has a far more sophisticated, RELIABLE, lightweight and better shielded ignition now than it ever did. I have no plans to fly this engine in anything but if I was to do so I'd take this new Chinese ignition over the old stuff any day, even though the manufacturer specifically said not to. I expect this admonition is more for their benefit than mine Any thoughts on the correct spark plug to use? I've put a couple of plugs in it (NGK BP6ES) that were working perfectly when removed from my Mini Moke whilst chasing an ignition problem there. These plugs have exactly the correct length of thread on them but as for the correct heat range for this engine I have no idea. Attached are some pics for your amusement that show the new ignition being fitted. I apologise for all the cr*p in and around the engine. Only now have I noticed how cluttered it makes the pics. Made the tool with dial gauge to establish T.D.C. and 3mm B.T.D.C. as per "Victa" mower timing. The portion of the tool threaded into the head is made from the bottom of an old dead "Victa" decompressor! I kept that part for years. I knew it would be useful one day! The other bits of metal picked up at the tip shop. I only had to add my dial gauge, two grub screws and some time on my lathe. Other pics show flywheel and other now obsolete parts removed including a small wooden wedge, very possibly fashioned from a clothes peg, that was used to jam the coil in place on it's "E" core (this engine came from a plane that crashed apparently remember). "Here's one I prepared earlier" - a small glow flat twin that I made some years ago, total capacity of 0.65cc. Also visible is an empty brown bottle that until recently contained an apple based "thinking juice". I'm not sure it works very well, but I'm going to keep trying it until it does

G'day all! Bit of an update for you here. Minor disassembly of the engine to get a look at the ignition has revealed the coil to be a Victa twin coil and the other part is a Victa module. I swapped the module with another Victa module of unknown heritage and still had no spark. I tried another type of module called "Nova" (which is presumable similar to the "Atom" but of much more recent manufacture) also of unknown heritage and still no spark. I had the coil tested at a mower shop and they said they had trouble fitting it to their machine but should have gotten something out of it - but again no spark with them either. I reckon my coil is dead. It certainly seems to confirm what I was told almost 20 years ago and have read again recently on the net about the Victa twin mower - these coils are very probably the worst coil (or part outright?) that Victa ever made. It was largely the reason for the demise of the Twin mower, along with high production costs no doubt. The rear cylinder would quickly end up with a weak spark and soon after, no spark. Victa even fitted a a domed higher compression piston to the rear cylinder to try to help (not sure how it would). Hardly aviation material! Eventually a "revised" coil was produced apparently but I've seen and heard nothing of these. Anyhoo, it looks like I'm going to be fitting my Rxcel ignition after all. I need to know the ignition timing for this engine. If I get stuck I'll go with the Victa 160cc timing which is given as 3mm before TDC (easily converted into degrees). The Skylark engine has exactly the same bore and stroke as the Victa 160cc. It wouldn't surprise me if it uses the same pistons too. It does however have a significantly higher compression ratio I think. I think this affects combustion rates and in all probability therefore the ignition timing too. Any ideas anyone? I have found "28" stamped into each crankcase half if this helps anyone. http://pickersyard.weebly.com/ I found some "Atom" modules at this site. Mine are on their way. I was gonna upload some more pics but the server says no for some reason : (

You sir are a champ! One pic really says a thousand words -and most of them say something like "OMG I thought the pull start was some homemade cobbled together junk, I can't believe it left the factory like this"! Apart from the angled carby mount shown in your brochure pic my engine is identical! Actually my cylinder heads appear to be very slightly different too - mine having an extra cooling fin on each side. Also viewers should note that the red paint on my engine was added by the previous owner many years ago when he was a teen because " he thought Holden red would look good". I am reluctant to disagree with him! Many thanks for your input.

I still need to have a closer look - at a glance it's actually not as I remembered - it's more like a rectangular module thingo about the size of matchbox split vertically along it's length. It may very well do the same job as the "Atom" module you've mentioned which is great because it may mean my engine is more complete than first imagined - it may even be entirely complete : ) Thankyou for your input.

G'day there! Yes I have considered the use of an Rcxel ignition system - I actually have one here for another engine project. I may go this way if I need to but at this stage I'd prefer to have the engine make it's own spark by finding and fitting the bits it was meant to have - this has got to be part of the fun! : ) Presently the engine has a two lead coil, the two spark leads, the Victa flywheel and some sort of electronic looking module thingo - maybe a condenser? - It's about the size of a postage stamp. I haven't pulled anything apart yet but as far as I can tell it doesn't have any points although I imagine it should have/did originally. Thank you for your interest.

It could be the 170cc twin motor that Victa imported from Canada around 1975? G'day there! I measured the capacity of this engine some time back and if my memory is correct it is 330cc total? I thought it might be a Victa twin too but it isn't I'm sure. The pull start on it and probably the flywheel are modifications made to either make the engine go in lieu of missing original ignition parts or perhaps to "convenience" the operator. I know trying to pull start a Victa mower with no decompressor will just about pull your arm off when it fires and is very hard on the pull start cord - it will break in a very short time. I can't imagine the pull start fitted to this engine would have been any good either at twice the cc's of a mower and still no decompressor, it can't have been "convenient" at all. Also my specimen appears to have had it's engine mounts altered or replaced entirely to acomodate the installed Victa parts. A suspicion I held before I saw and supported by what I can see of the engine shown in the link. I don't think this is a "Victa", it's just got some Victa parts fitted to it. I am prepared to be corrected however. Thankyou for your interest.

G'day all! I have what I think is an Aussie made "Skylark" ultralight aircraft engine. It's taken me a full 12 months just to get a name for this otherwise unmarked engine. I'd like to run it for a bit of fun but I'm not sure mine is complete in the ignition department. It also appears to have been subject to some modifications - i.e. the addition of a pull start that is almost certainly a "Victa" part, the flywheel is most certainly marked "Victa"! The only info I have been able to find is the tiny bit of info at this site where I think what is the same type of engine is pictured; http://victoriancollections.net.au/items/51085d662162ef0e30b5463f Has anyone got any info, parts or manuals that I may buy, borrow or copy? Amusing anecdotes or other info for this type also welcome. Any and all help is greatly appreciated. Jimbo ~ eatherbreather.