Laser 180 Petrol

[Martin Whybrow]

See you there Jon; I'll be on Tx control, as usual!

[Jon H]

Sounds good. If anyone wants to find me, either to ask a question or hurl abuse then I will be quite conspicuous in a blue Laser shirt. Unless its cold, then I will probably look like an eskimo

[Jon H]

I am not sure how many people were able to watch the 180 fly about at old warden on Saturday but all in all it was a very good day.

I discovered something new about the engine and was able to replicate a fault that caused deadsticks on 3 or 4 occasions. This was really helpful as I know what the problem was (bubbles in the carb due to my clunk not being floppy enough) and can make a recommendation to prevent bubbles getting in there in the first place and am well aware of the symptoms which is good info for customers.

Fuel consumption was astonishing with an exuberant 17 minute flight using less than half of my 14oz fuel tank when turning the menz 18x8 prop.

I still have a little work to do in perfecting the last parts of the carburettor for maximum throttle response but overall I was happy with the performance of the engine.

I also hope everyone enjoyed my La7 displays, I certainly did!

Edited By Jon Harper on 18/05/2015 08:54:38

[Artto Ilmanen]

Hi Jon

Thanks for the update. Are there any videos or pictures on the event and th 180 petrol prototype available?

Artto

[Jon H]

Hi Artto

No idea about video, I was too busy flying! I did see some people with camera's though so I am sure something has been recorded. I will try and find it.

As for selling the engines we are a little way off but not far. I plan to get my pre production batch underway soon so final testing can be completed. Then its onwards and upwards

[Tomtom39]

Sorry Jon , just spotted this post!

[Martin Whybrow]

Good to see you on Saturday Jon, the 180 petrol is a lovely engine, runs beautifully (like all Lasers). The LA-7 was fantastic, really enjoyed watching (and listening) to it, the engine has a fantastic over-run crackle! Am I right in thinking it's a 310 you have fitted?

Good to see Neil getting so much fling in this weekend, espceially when we had 5 Laser powered models up at once.

I don't know about video, although I think I did see Colin Hutchinson clutching a camcorder at some point as well as the SLR, when he wasn't flying.

[Jon H]

Hi Martin

The La7 does have a 310 in it. The engine was an experiment and is a twin cylinder 155. As things stand there are no plans to produce it as while its very powerful, it is not easy to find the optimum tuning which would make it difficult for customers to get the best out of it. Long term it may reappear in a different guise, but I don't know when or if that will happen. Flying the La7 at OW is a real challenge as the airfield is very tight on space with the farm on front and FF area to the left.

If my sea fury is not ready in time I will take the La7 to wings and wheels where it can really stretch its wings.

As for the 180 petrol, I was pleased with its performance and discovering the issue with the bubbles. This confirms what I had already found in earlier testing that petrol engines have no sense of humour when it comes to bubbles in the fuel.

[MattyB]

Good to hear this is running nicely - I am a long time glider guider and electric flier, but my Dad's experiments with a 4 stroke petrol engine (an NGH38, which he now has running nicely on the bench) have been interesting enough to convince me a 1/5 scale warbird is in my future. Do you have an ETA on this engine Jon? Is it likely to be available this year?

Edited By MattyB on 25/05/2015 23:57:47

[Jon H]

Hi Matty

The master plan was to have the engine ready in febuary but that went a bit pear shaped for reasons external to the company.

Now I have a carb setup that I am happy with I can get on with the 5 pre production engines and test them for a bit longer until the new parts for the production spec engines are ready. I would like to see the engine available before the end of the summer.

As for the NGH38, the laser 180 on petrol out performs it by a considerable margin. That said, depending on the 5th scale warbird you have in mind you might need something larger than a 180. Which model do you have in mind?

[Bob Cotsford]

Jon, do you need any volunteers to test the petrol 180? I am currently putting together a 92" Glen's Models Maule

[Jon H]

We may have 3 or the pre production engines available. Of the 5 I plan to make I will use one, Most likely Neil will take one as well and that leaves 3 that need homes. As you can imagine people are tripping over themselves trying to get to the head of the line!

Please note that these engines will not be of production spec and will be missing a few improvements that the production engines will have. It will not make any difference to the power of the engine or its reliability but its looks might not be as nice as they will be.

Edited By Jon Harper on 26/05/2015 12:43:40

[MattyB]

Posted by Jon Harper on 26/05/2015 08:47:30:

Hi Matty

The master plan was to have the engine ready in febuary but that went a bit pear shaped for reasons external to the company.

Now I have a carb setup that I am happy with I can get on with the 5 pre production engines and test them for a bit longer until the new parts for the production spec engines are ready. I would like to see the engine available before the end of the summer.

As for the NGH38, the laser 180 on petrol out performs it by a considerable margin. That said, depending on the 5th scale warbird you have in mind you might need something larger than a 180. Which model do you have in mind?

Not 100% certain, but the Seagull Spitfire (which my Dad has and is already flying nicely on an NGH 38) or the H9 Spit are the two most probable. Nased on your previous posts I think both should fly fine on the 180, correct?

A German(!) Seagull Spit on the NGH38 (ignore the crash at the end, he had a Powerbox power supply failure ):

Edited By MattyB on 29/05/2015 17:41:06

[Jon H]

Our 180 should be man enough for either. There are some people flying the H9 spitfire on our glow 180 with success so I have no doubt the petrol will be fine.

So far our 180 seems to be approx. 500rpm faster than the NGH when using an 18x8 menz prop.

And as for the powerbox, I hate them as a concept, just another thing to go wrong!

[Gordon Whitehead 1]

Posted by Jon Harper on 26/05/2015 08:47:30:

Hi Matty

The master plan was to have the engine ready in febuary but that went a bit pear shaped for reasons external to the company.

<snip> I would like to see the engine available before the end of the summer.

Hi Jon

Summer ended a couple of months ago

Have you any more news on the release of the 180 petrol?

Kind regards, Gordon

[Don Fry]

Is this the God Whitehead speaking, requesting service from the Titan, Harper, or have a got the wrong bloke.

[Jon H]

Hi Guys, sorry for the lack of news but things have been somewhat hectic and my time on the petrol engine has been low.

I have moved on to the next stage of my intended testing which was to install the engine in a cowling to test cooling etc in that environment. These tests have revealed a problem with carburettor overheating and I will be doing a mod to counter this asap.

The model of choice for my experiments was a precedent 1/4 scale stampe. As you can see in the video or the maiden flight its a very nice combination when using the torque of the 180 for drive a nice big prop. Unfortunately the model was damaged on its second flight after the engine stopped on takeoff. This stoppage was most unexpected as the engine had been faultless in the wot4 and the issue on the maiden flight of the stampe was not serious.

In any event, the purpose of a prototype is to find these issues and then find a solution. I am not that concerned by it, just annoyed that my model was damaged!

Anyway, this is the video of the maiden. On a few occasions when inverted the engine lean cuts due to bubbles in the carb caused by heat. The engine recovers as soon as it turns the other way up. I took some temperature readings of the carb and will be doing comparisons after my mods. But, I hope you like the video and enjoy the commentary of my very enthusiastic club mate!

**LINK**

[Adrian Smith 1]

Nice flight Jon. Not that I know much about anything, but as an observation is the overheating in the stampe more a case of airflow through the cowl rather than the engine itself? it seemed okay in the Wot4 which is more open. It's not clear on the stampe vid but with these scale subjects it's difficult to put enough intake/outlet holes in the cowl without spoiling the effect of the scale look. Just a thought.

[Artto Ilmanen]

Hi Jon,

Sorry to hear of your loss!

And thanks for the update. I think it's very important to carry out the testing in a proper manner, to avoid problems such as those associated to premature launch of Saito petrol line engines. At least I am willing to wait a little more to have then a top quality product like is the case with Laser glow engines. As far as the 4-stroke petrol carburettor is concerned it seems to be the challenging component of other model engine manufacturers, too. This is the case with Roto 85, to name one example.

P.S. Gordon, nice to hear of you! Any news on your / Morris's attampts to convert your 300v & 240V to run on petrol?

-Artto

[Jon H]

Hi Adrian

I did a good bit of investigating and the engine itself never got that hot. The carb however was getting up near 50'c and that is not good for a petrol engine.

I compared the temps with/without cowl and the carb was about 30'c cooler without the cowling. Currently the engine has no insulation block between the head and the carb. In the wot4 this was no problem, but it is possible that one is required now. I have a series of tests planned to see if the problem is heat sink from the head, ambient cowl temp or the ingestion of hot air from the cowl.

I will test each systematically so as not to jump to a conclusion that is wrong.

Artto, I too have heard bad things about the roto 85 from one of our customers. He got a refund in the end it was so bad. The problem is testing a new engine is exceptionally difficult as its very hard to replicate how modellers will use the engine.

[Artto Ilmanen]

Posted by Jon Harper on 06/08/2015 10:26:18:..

..The problem is testing a new engine is exceptionally difficult as its very hard to replicate how modellers will use the engine.

I think you have learned quite a bit of this when talking to me, huh?

[Manish Chandrayan]

We modellers intend to use the engine just one way.. To pull a model airplane by it's nose (though some may certainly want to use it the push their steads ).

[cymaz]

I know my laser 150 was running very warm in my Rothmans Stampe, despite all the baffling around the engine. I even had a fan on the front !

Could there be some way to fabricate a nylon spacer as used in other 2T petrol engines? Both my Evo's and Zenoah have them.

So to hear about the misfortune of your Stampe. I just now have to do a balance check on the Rothmans and then it's up in the air to finish running in the new 33gx I put on it.

Good luck John

[Jon H]

I have some 50mm x 300mm white plastic bar that I found loafing around the factory. no one knows exactly what it is but its far less conductive than aluminium so I will make a block out of that when I get the opportunity.

[Gordon Whitehead 1]

Posted by Donald Fry on 05/08/2015 20:57:50:

Is this the God Whitehead speaking, requesting service from the Titan, Harper, or have a got the wrong bloke.

@ Donald and Percy:

I'm more the old white-haired dog these days I'm afraid I did have a really enjoyable time designing and writing back in the day, and hope you enjoyed my efforts.

@ Artto:

Hi Artto, good to hear from you too. I received both engines back from Morris a couple of months ago but have only today found time to start testing. Rather than go off-topic on Jon's thread I'll report back on my RCMF thread in due course.

Cheers for now,

Gordon