30cc petrol engine or a Laser 180 ?

[Rocker]

Does the Laser 180.four stroke have the same kind of power has a 30cc 2 stroke petrol engine .Been offered a aerobatic model for a 30cc petrol engine but the model has a Laser 180 fitted.The model has not been flown yet so want to make sure before I buy it ?

[Paul De Tourtoulon]

To start have a look here,,

 

Some 150 numbers

https://www.rcuniverse.com/forum/tachometer-readings-173/3914577-laser-150-four-stroke-glow-results.html

Edited July 15, 2023 by Paul De Tourtoulon

[Chris Walby]

Petrol 30cc props Specification of the aircraft propeller: 18x8,18x10,20x8

Laser 180 17×8-10 18×8-10 19×6-8 20×6

 

Looking at the recommended prop sizes I think it will be very close, but the Laser will sound much better 🙂 

 

[Ron Gray]

4 hours ago, Rocker said:

Does the Laser 180.four stroke have the same kind of power has a 30cc 2 stroke petrol engine

Simple answer, no! I had a 180 in an SBach then swapped it out for a DLE30. The DLE had quite a bit more power (and noise despite a canister). But my Laser 320FT surprises me with nearly as much power as a DLE55!

[Jon H]

6 hours ago, Rocker said:

Does the Laser 180.four stroke have the same kind of power has a 30cc 2 stroke petrol engine .Been offered a aerobatic model for a 30cc petrol engine but the model has a Laser 180 fitted.The model has not been flown yet so want to make sure before I buy it ?

 

what model is it? If the engine was bought new for the model i likely confirmed its suitability 

 

when it comes to power not all 30cc petrol engines are created equal. Recently a club mate swapped an evo33 for a 180 in a Spitfire and gained substantial amounts of performance. I would expect a dle30 to have more power though. 

 

Depending on the price i would buy it, fly it, and then if the engine isnt man enough sell that and replace it. I would be surprised if its going to be a big issue though. 

Edited July 15, 2023 by Jon - Laser Engines

[Paul De Tourtoulon]

1 hour ago, Ron Gray said:

Simple answer, no! I had a 180 in an SBach then swapped it out for a DLE30. The DLE had quite a bit more power (and noise despite a canister). But my Laser 320FT surprises me with nearly as much power as a DLE55!

I also have a couple of Dle engines two 20ra, and you cannot compare the power with a canister, this is what I got 8.800 on the ground and a maximum 11.800 rpm en air,,

[Ron Gray]

39 minutes ago, Paul De Tourtoulon said:

and you cannot compare the power with a canister

With respect Paul that’s bull muck. A proper canister, not one made out of an old baked bean can can actually improve the performance.

[Paul De Tourtoulon]

1 hour ago, Ron Gray said:

With respect Paul that’s bull muck. A proper canister, not one made out of an old baked bean can can actually improve the performance.

No it isn't !, Here is a video that I did with my Dle canister in my P 40, I did it as the prop tips made that noise what I thought was subsonic, and I wondered what sort of speed the engine was doing in the air, watch the video, then you can apologize,,,,

 

Edited July 15, 2023 by Paul De Tourtoulon

[Ron Gray]

Wow, I’m truly sorry Paul, that brilliant video proves it all!

 

All I did when testing was to fly the models, back to back, with and without can and see how they performed. It proved to me that performance was better with a can. To be fair, I never had a DLE20 all of mine were 30, 35, 55 and 60s.

[Jon H]

each dle20 i have ever met ran about 8500rpm on 16x8 apc. Even with unloading the air, the rpm rise claimed is rather excessive. Unless you were doing full throttle dives i cant imagine how, and more importantly why you would want it to rev that fast

[Ron Gray]

44 minutes ago, Jon - Laser Engines said:

why you would want it to rev that fast

I’m sure that our resident expert Paul was testing the engine to destruction trying to disprove the commonly held understanding that the life of a DLE is somewhat shortened by over revving.

[Paul De Tourtoulon]

Straight and level flying, Jon, no expert Ron just 55 years of model planes and 20 years owning my own model shop, which of course does

include building and regulating 95% of the helicopters, 50% of the planes including teaching them to fly, and not forgetting IC cars,,,,

 

 Although my real proper job😄is fixing real engines, from 2hp 2 stroke outboards to 10+ litre bulldozers, and tuning my 2-stroke motorbikes on the way,,,

 

But still learning, and listening to both of you, even if I have to take a spoonful of Castor to digest it all.😅

[Ron Gray]

15 minutes ago, Paul De Tourtoulon said:

from 2hp 2 stroke outboards to 10+ litre bulldozers

Ah, that explains a lot but must come in handy for when flying off water and retrieving those Castor soaked crashed models 😂

Edited July 16, 2023 by Ron Gray

[Jon H]

5 hours ago, Paul De Tourtoulon said:

Straight and level flying

 

what size is yourp40? an increase of that amount makes no sense at all unless the speed is excessive

[Paul De Tourtoulon]

It's 1m62, heavy with the big HK retracts that I made into twist and turn, probably around 5 kilos, as you can see the engine cowl is enormous, the 20cc engine is lost in it,

 Ps spot and identify the other plane bits in the photo.

 

pps I forgot we do have dog fights with our IC powered planes and no way am I going to lose to the French, so speed and manoeuvrability is the key.

Edited July 16, 2023 by Paul De Tourtoulon
pps

[Ron Gray]

As this is now so far off the OP, and I think that I've already answered his question, I'm out.

[Jon H]

14 hours ago, Paul De Tourtoulon said:

It's 1m62

 

ook so its a small model brutally over powered. Even so, while we might be getting closer to the how we are still left wondering why. Another of life's great mysteries. 

[Paul De Tourtoulon]

Not a lot of difference in the power to weight ratio from the real version ?.

Horsepower is like Spitfires, you can't have to many 😅

[Jon H]

8 minutes ago, Paul De Tourtoulon said:

Horsepower is like Spitfires, you can't have to many

 

In fact, you can. in both cases. 

 

In any event as i actually had to just go and check the thread title to remind myself what were actually supposed to be discussing i think Ron has the right idea. 

[Martin McIntosh]

A Laser 180 will easily fly an eighteen pound Spit if that is any help. 18x8 prop.