Laser Engines development.

[Nick Somerville]

13 hours ago, Ron Gray said:

For anyone who is interested, I will be documenting fitting the 160 in line twin into an ESM P51 (brand new, old stock!) including chopping the front off the fuse to set the bulkhead back to take the longer engine. Hoping to get started on the build in a couple of week’s time.

Looking forward to to following this.

[Jon H]

46 minutes ago, Nigel R said:

I bet it did! Don't suppose you got any video of it running?

 

Sorry for minor derail.

 

Just for you guys 

 

 

[Graham Davies 3]

That Jon, is borderline filth! 

 

The throttle response is, er, crisp to say the least. 

 

I'd be tempted to fit it to me pushbike...

[Jon H]

40 minutes ago, Graham Davies 3 said:

That Jon, is borderline filth! 

 

The throttle response is, er, crisp to say the least. 

 

I'd be tempted to fit it to me pushbike...

 

Believe it or not, Its hampered by timing errors due to a mix of available parts that were kicking around and the design issue i mentioned earlier. Timing on the front cylinders is hopeless, especially right front exhaust. If i am able to make another one it should be much better. This conversation prompted me to get my cad drawing out and give it another once over ? 

[Martin Harris - Moderator]

2 hours ago, Jon - Laser Engines said:

 

I designed an x4 and x8 some time ago. The x8 has perfect even spacing of the firing pulses and would be quite a monster. The 4 cylinder would have uneven fire and, i suspect, would sound rather good as a result. 

 

The V4 has uneven fire as well and it did sound nice

I’ve just been playing with a recently acquired (wash my mouth out) Saito 182 twin which has a shared crank pin (does this count as a 2 cylinder radial?) and this gives it a very distinctive - and rather attractive - sound with 180 degree intervals between power strokes. 
 

Unfortunately the plain pipes allow too much of a good thing so my next project will be to fabricate a silencing system for it. 

[Jon H]

I am surprised its that loud Martin. I fly my OS FF240 on straight pipes and its not that loud. My club mates keep asking me to make it louder!

 

 

[Nick Cripps]

A Laser flat-twin would be nice...

[Jon H]

3 hours ago, Nick Cripps said:

A Laser flat-twin would be nice...

 

Yep. Flat twin would be fun but only if we can do it with a single throw crank. Twin throw cranks with split big end rods are a pain and it would make a flat twin much more costly than a V. As a v will fit where a flat will there isnt much point. 

 

That said, i would like to try a single throw flat to see how the balance is. if the balance is ok then fair enough, if not then i dont think a double throw crank is very likely. 

[Martin Harris - Moderator]

11 hours ago, Jon - Laser Engines said:

I am surprised its that loud Martin. I fly my OS FF240 on straight pipes and its not that loud. My club mates keep asking me to make it louder!

 

 

Approximate measurement of 90dB on a 16 x 8 APC lookalike  and 88dB rather over propped on an 18 x 10 G-Sonic which has done limit compliant service on an ASP 180FS. Work is in hand on a silencing solution…

[Jon H]

4 minutes ago, Martin Harris - Moderator said:

Approximate measurement of 90dB on a 16 x 8 APC lookalike  and 88dB rather over propped on an 18 x 10 G-Sonic which has done limit compliant service on an ASP 180FS. Work is in hand on a silencing solution…

 

good lord. My OS is nowhere near that loud i am sure of it. Admittedly i have never tested it, but even my more noise sensitive flying club have said its not worth testing. I run a 19x8 menz @ around 7000rpm. I wonder if the saito valve timing and compression ratio are to blame as i have a saito 45 in my Nieuport and it is quiet as a whisper. However, i also have a saito 45 special (high comp ratio and different timing) and it is really loud on an open exhaust. 

 

Is it all exhaust noise? I would prop it with an 18x8 menz or APC wide blade and see how it works out. Then borrow some mufflers off saito 82-100 (i think they are all the same) and see how it behaves. 

 

I would also check the noise meter is set up correctly. I just cant see how its possible for it to be that loud. 

[Martin Harris - Moderator]

I found the same with a Saito 40 special which I had to silence to get anywhere near the noise test - where a friend’s 45 whispered along on an open pipe. Saito claim the 182 is a high power model…

 

My immediate plan is to try two spare FS 120 silencers via flexy pipe adapters - with the option of adding baffles a la JE quiet versions. Hopefully this will retain the character of the distinctive firing order but knock off enough exhaust noise. 
 

I’ve often suspected that cam profiles have a lot to do with noise… Lasers have an odd (to me) combination of what appears to be a lower lift and duration inlet cam and what you’d assume was a more aggressive cam on the exhaust - maybe a lot to do with their smoothness and easy handling?

 

P.S. I’ve literally just had a brainwave while typing this - if it works out I’ll update you!

[Jon H]

with the exception of the 70 inlet, all of our engines use identical cams and apart from the 180 glow, all use the same timing as well. The profile and timing are, as it happens, very similar to Enya 4 strokes which, again, have a similar design layout. 

 

In all cases except the 180 our inlet cam is running slightly ahead of the exhaust so that at tdc on the non compression stroke the inlet valve is open a tiny bit more than the exhaust. They do work with symmetrical timing, but this small lead on the inlet was deemed to be better. I wish i could comment as to exactly how this was all worked out, but i wasnt even born at the time! 

[Martin Harris - Moderator]

I was going by an early 62 which I renovated a few years back - is the 70 still based on the older designs?

[Nick Cripps]

16 hours ago, Jon - Laser Engines said:

That said, i would like to try a single throw flat to see how the balance is.

Hi Jon,

If you ever get the chance to build one (or a batch), please put my name on the list for development testing.

[Engine Doctor]

John . Just out of interest How on earth could you make a single throw flat twin  without  a heavy cumbersome  balance shaft ?

Surely a single throw flat twin is a non starter .

Edited August 14, 2021 by Engine Doctor

[Dirk Witvrouwen 1]

17 hours ago, Jon - Laser Engines said:

 

Yep. Flat twin would be fun but only if we can do it with a single throw crank. Twin throw cranks with split big end rods are a pain and it would make a flat twin much more costly than a V. As a v will fit where a flat will there isnt much point. 

 

That said, i would like to try a single throw flat to see how the balance is. if the balance is ok then fair enough, if not then i dont think a double throw crank is very likely. 

Someone made one in the past using Laser components.  It's detailed in one of the Strictly IC magazines.

[Dirk Witvrouwen 1]

Just now, Dirk Witvrouwen 1 said:

Someone made one in the past using Laser components.  It's detailed in one of the Strictly IC magazines.

... might not be single throw, don't remember.

[Jon H]

8 minutes ago, Engine Doctor said:

John . Just out of interest How on earth could you make a single throw flat twin  without an a heavy balance shaft ?

Surely a single throw flat twin is a non starter .

 

The saito 180 flat was a single throw i think. And basically all i would do is build one and see if it vibrated like mad. If not, winner, if so its a non starter. Assuming it didnt vibrate like crazy development time would be somewhere in the region of 2-3 minutes as all the components would be standard and a known quantity. 

 

As crazy as it sounds, i could have the thing ready for commercial sale in a day if i had the parts and it wasnt a vibrating mess...oh and assuming any form of support from the company. 

[Tim Flyer]

Obviously a flat twin would be lovely in a Cub but it would also be very nice in Extras or any of the very popular aerobatic designs. 

[Martin Harris - Moderator]

No terrible vibrations from the Saito182.  I haven't looked inside but from the parts diagram it appears to use a normal looking counterweight but of course eliminates any rocking couple by use of a master con rod like a traditional radial.

Some earlier Saito twins had an air pump built in to the rear of the crankcase driven off the crankshaft.  Its function was to pump air/oil through the engine to lubricate the cam and front bearing area as the common crankpin layout eliminated the change in volume that normally performs this function on a single or double throw twin. They no longer have this so I'm a little intrigued whether there's some other arrangement or if it wasn't actually necessary.

[Lima Hotel Foxtrot]

I'm pretty certain this thread violates the forum terms and conditions for advertising a business one is involved with. 

[Ron Gray]

Absolute rubbish. We are grateful that a manufacturer actually helps out on all aspects of flying, including help about his own engines!

[Frank Skilbeck]

58 minutes ago, Lima Hotel Foxtrot said:

I'm pretty certain this thread violates the forum terms and conditions for advertising a business one is involved with. 

Where else do you get a manufacturer sharing technical advice, new product development and asking for users feedback. As regards advertising a lot of Jons posts are "apologises" for shortage of supply, hardly advertising.

[Lima Hotel Foxtrot]

On 06/07/2020 at 14:17, Jon - Laser Engines said:

I was going to revive the old thread we had on this topic but it was suggested by the mods i start another..so here we are.

Firstly, i want to know how many people would be interested in a reduction drive for our engines. The idea would be to drop propeller RPM to a much lower level to reduce noise. Props make a great deal of noise and a larger prop at lower RPM is much quieter and more efficient. If these were available would you want to retrofit one? What sort of price would be reasonable?

As a guide, the smallest engine i would attempt to convert would be a laser 100. Using this as a base line, you would exchange (in theory, i gotta test it!) 15x8 @ 8000rpm for a 20x14 @ 4500rpm. Fitted in a scale model this would also look great, and perhaps allow the use of 3 blade props in a warbird. These could be made available for a whole bunch of engines and would be well suited to our twins. If you would actually buy one, please post your comments below.

Part 2, Many of you will know there are a number of things i am working on in the background and i am making some headway. Our new fuel is being tested by a number of guys with positive results and there is also a move to get 180 petrol development back on track as well as the potential for some new glow engine designs.

What this means is i am going to need people to give me a hand testing new engines.

The exact format is yet to be worked out but we are going to have to have some sort of system in place to prevent the same problem i had the last time i sent engines out for testing where only 3 of 10 people actually used their engines. Its a real shame, but the whole thing is pointless if i get no feedback.

In essence, when the time comes the engines need to be fitted and in the air immediately. No asking for one for a project that is a year away and no wanting one just to be the first to get one and stick it on the mantle piece as its likely there will be only a few of each available. I need them fitted and flown within a week and the engine may become available at very short notice. If that is not for you please dont ask for one.

Also note that these will all be prototypes and not production spec. The engines may be a bit rough and ready and while i will do my own testing ahead of time they might need parts changed or updated as we work through the testing. They might have to come back to the factory if things to wrong and the model might be grounded as a result. There is also a chance the engine might stop so i wouldnt recommend fitting them to a model you spent a decade building. If you are not prepared to accept potential inconvenience of this nature, please dont ask for an engine.

So with all that in mind i need a show of hands for those willing to test one or more of the following:

Petrol 30cc
Glow Multi cylinder 25-30cc
Glow Multi Cylinder 50-60cc

Take your pick and let me know.

 

 

If the above quote isn't a puff piece advertising a business, I'd like to know what is! ?‍♂️

[Eric Robson]

I would call it market research.