Vince Findlay Posted May 5, 2021 Share Posted May 5, 2021 The engine sounds great, Definitely would suit an inline warbird. Wonder how it would sound with straight through exhaust pipes ? Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted May 7, 2021 Author Share Posted May 7, 2021 One thing I haven't mentioned about this engine in particular is how clean it runs. I know that on the low oil fuel I'm now using for all of my Laser engines they do run a lot cleaner but this in-line twin just seems to be even better. After the last flying session of 5 flights each of approximately 8 minutes of hard, full throttle flying, the only cleaning I had to do was a few oil spits around the breather pipe exit, the rest of the underside of the airframe needed no cleaning at all, better than some of my petrol engined 'planes! In fact my flying buddy commented that you could be forgiven for thinking that it was leccy powered (well, until it started running of course then, simply no comparison). So I will continue to run it some more in this airframe before moving on to a warbird I have waiting 'in the wings' - watch this space. 1 Quote Link to comment Share on other sites More sharing options...
Steve Dunne Posted May 7, 2021 Share Posted May 7, 2021 Here is a youtube video of the Laser inline twin flying in my Acrowot XL on Wednesday - good friend Phil Jarman filmed it with his phone! It was a very blustery, cold day, you can hear the wind (and not much else, sadly) in the background. Steve. 2 Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted May 7, 2021 Author Share Posted May 7, 2021 For a bit of fun I extracted the sound only from another one of the vids I took during the last flying session - great with sound up and multiple speakers! Eat your hearts out leccy flyers!!!!! Sound1.wav 3 1 Quote Link to comment Share on other sites More sharing options...
Dwain Dibley. Posted May 7, 2021 Share Posted May 7, 2021 We can nick that for our in flight sound systems... ? D.D. 1 Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted May 8, 2021 Share Posted May 8, 2021 Don't tell him! 1 Quote Link to comment Share on other sites More sharing options...
Ted Khinsoe Posted May 9, 2021 Share Posted May 9, 2021 On 26/04/2021 at 15:34, Jon - Laser Engines said: it was at my request Ron give filters a try. The debris we are talking about is quite chunky grains of very sharp sandy material and they are not the recommended diet for anything mechanical. Also as we are trying to test this engine for reliability, external damage will not help us! Beyond that though i have been thinking of recommending filters for some time as the two most common types of damage we see are bearing corrosion/failure and debris ingestion. Both of these are more common than crash damage when it comes to engines on the bench for rebuild. The reason is simple enough. How often do we clean out the engine bays? not often i would wager, and certainly not after every nose over/trip into the weeds at the edge of the strip. All of that sort of thing accumulates dust and grit in the cowl and eventually it will find its way into the carb area. My poor Hurricane needs its face cleaned up after a belly landing last weekend. Its a chore, but i dont want to have to pay the boss for new engine parts! Word of warning be very cautious with a filter, pre flight check. Once had my OS90 heli engine suck in the foam mesh of a filter mid flight the sudden stoppage of engine sound was not good! Scored the innards pretty well. This was one of the rubber boots with a plastic ring and foam inner. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted May 9, 2021 Author Share Posted May 9, 2021 Whilst I’m no longer using the ‘nylon tights’ air filters they were very well secured around the carb intake the lip of which provides and excellent ‘stop’ for a zip tie. If I did revert back to the mouth filters I would use some excellent metal gauze kindly donated to the ‘cause’ by a fellow formulite. However, now that I’m using the intake pipes running into the fuse I fell that there is less of a need for filters on the pipes themselves but I have put a filter on a new air intake hole I formed in the side of the fuse. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted May 10, 2021 Share Posted May 10, 2021 On 05/05/2021 at 18:16, Ron Gray said: Thanks Steve, yes, I’m really pleased with how it’s running with the air pipes in place. You can’t really tell from the vids but they have also really cut the noise down. Interesting, beneficial, side effect. Any ideas how the big Laser fares as regarding the standard 82dbA checks on that 18x8? Was there any change to top end rpm at all with / without pipes? Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted May 10, 2021 Author Share Posted May 10, 2021 I haven’t checked the noise as we don’t have an official restriction at our site. Next time I’m up there I’ll check it out but my guess is that it falls below the 82dbA limit. No adverse change to top end rpm, I’m getting about 2600 after retuning. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted May 10, 2021 Share Posted May 10, 2021 21 minutes ago, Ron Gray said: I haven’t checked the noise as we don’t have an official restriction at our site. Next time I’m up there I’ll check it out but my guess is that it falls below the 82dbA limit. No adverse change to top end rpm, I’m getting about 2600 after retuning. 2600 must have the reduction gearbox as well ? IMHO that's nowhere near 82dB...I am running a 18 x 8 on a Laser 150 + the throttle trimmed down from WOT and its just on 82dB, but would be interested to be corrected if the test is carried out in accordance within BMFA guidelines. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted May 10, 2021 Author Share Posted May 10, 2021 Oops, should have read 8600! At least it proves someone else is reading this thread! Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted May 10, 2021 Share Posted May 10, 2021 I've got to agree with Chris, if it passes at 82dBa then my advice would be to get the noise meter calibrated! In my years flying IC at a noise sensitive site where every model was tested using an officially calibrated meter I never got anything over a 100 through short of a nod and a wink and an unofficial agreement to avoid full throttle and to keep the model low and close. I think 83-84dBa for an 18" prop was doing well, but the soft exhaust tone of low revving engines (<9K) makes them appear quieter hence the nod'n'wink tolerance. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted May 10, 2021 Author Share Posted May 10, 2021 It will be interesting to see what the readings are when I test it away from the hangar and on the grass runway. Amazing what a difference exhausts printing down into grass makes, when I used to race lawn mowers (yes!) one of our big meetings was a 12 hour, overnight race, and for that we had to have baffled silencers fitted but the biggest sound deadening 'trick' was to point the exhaust outlet down! Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted July 2, 2021 Author Share Posted July 2, 2021 (edited) Post to follow! Edited July 2, 2021 by Ron Gray Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted July 2, 2021 Author Share Posted July 2, 2021 An update on the 200i fitted to the Sportster. I've been flying it for a while now but decided to address the slightly rich running, it had also started to exhibit some hesitation when exiting banked turns. Tuning the engine in the garden showed that the rear pot was quite a bit out (rich) but I also found that I had left off the horizontal baffle plate from within the cowl! So I made a new one as I couldn't find the old one (probably has been repurposed and is now built into another model!), whilst doing this work I also lowered the fuel tank as I felt that wan't helping fuelling matters. I took it out last night for a quick blast and it appeared to be running a lot better but the real test was going to be today. So having fired it up I took it out and threw it around a bit to try and upset the fuelling, I couldn't. This is the vid of the first flight of the day, I further tweaked the rear pot tuning later in etc day and it was even better! 5 Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted September 8, 2021 Author Share Posted September 8, 2021 Hot weather running update. It has been stated the the engine cooling ducting is a very important part of the engine's installation so I was interested to see how mine would fair in this bout of rather warm weather we are currently experiencing, I know that up at the field yesterday it was showing 30 degrees C. I decided that, ss today was forecast to be more of the same, then this would be the acid test. Having started the engine I let it run on a fast idle for a few minutes in the pit, this resulted in the engine losing power and cutting out and despite repeated attempts I couldn't restart it. After a 15 minute break I was able to get it running again so this time out was then straight out onto the runway and take off. The engine didn't sound like it was on full song, sounding very much as if one pot was running too rich but I continued flying and after about 4 circuits it started to improve and for the rest of the 8 minute flight it performed really well. Back in the pits I did a quick cylinder temp check and found that they were within 5 degrees of each other, with the front one the hotter of the two. Air temp was 29 degrees. I left it for half an hour then took it up again, this time the engine sounded better right from the start and completed another 8 minute routine of nearly full throttle work. Again back in the pits I checked the temps and once again they were within 5 degrees of each other. Several other flights took place with the same results. My conclusion? - in hot weather do not let it idle for too long as it will overheat but once up in the air the ducting is working very well. All good information for when I fit the 160 in-line into the P51. 2 Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 8, 2021 Share Posted September 8, 2021 Good work Ron. WIth the cooling setup used on the inline, or any other engine that uses a venturi effect within the cooling system, they flat out dont cool unless in the air. Until you have a good few tens of MPH on the model the cooling just wont work. My P39, La7, Sea Fury and Acrowot XL all dislike long periods of time on the ground. This was confirmed yesterday when i had to hold my Sea Fury while another chap landed. He missed the first go but refused to let me get in the air. Another two attempts later he was down in the weeds short of the runway but my Fury was not amused! I could tell the engine was hot as the idle came up. This happens due to heat soak into the carbs. Eventually the methanol begins to boil as it hits the nipple so you effectively lean the mix. This raises the idle RPM and, in Ron's case, prevents a restart as no fuel will go through at all. Anyway a half throttle takeoff, gradual climb and a shallow power off dive had it back to normal and off it went. Its not just us either. Full size Spitfires are notorious for their cooling not working on the ground and it even gave Michael Caine his famous line in Battle of Britain. When Full power engine checks are done on warbirds cold water is often sprayed through the radiators to give some evaporative cooling while ground running. Quote Link to comment Share on other sites More sharing options...
RottenRow Posted September 8, 2021 Share Posted September 8, 2021 37 minutes ago, Jon - Laser Engines said: Its not just us either. Full size Spitfires are notorious for their cooling not working on the ground and it even gave Michael Caine his famous line in Battle of Britain. When Full power engine checks are done on warbirds cold water is often sprayed through the radiators to give some evaporative cooling while ground running. Shuttleworth Spitfire on it’s first engine run in December 2017 after its long rebuild. Note the hosepipe running along the ground into the front of the radiator. It was fed from a tap on the bar / ice-cream hut near the fuel pumps. Sounds even better than a Laser twin (sorry Jon…). Brian. IMG_1283.MOV Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 8, 2021 Share Posted September 8, 2021 Computer says no on the video ? And vs a merlin i will admit a Laser is inferior Quote Link to comment Share on other sites More sharing options...
RottenRow Posted September 8, 2021 Share Posted September 8, 2021 Hi Jon, Do you get any particular error message with the video? I uploaded it using my phone as I’m away from home at the moment. It did take 3 attempts to upload due to the poor phone signal here. But the third time said ‘ok’. Sorry about that. Brian. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted September 8, 2021 Author Share Posted September 8, 2021 Works for me and sounds just like my 200i! Quote Link to comment Share on other sites More sharing options...
RottenRow Posted September 8, 2021 Share Posted September 8, 2021 It seems that it needs converting to MP4 format for some computers. Hopefully this converted version will work… somehow it comes out a much smaller file size. IMG_1283.mp4 Brian. 1 Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 8, 2021 Share Posted September 8, 2021 that got it. First time it said the file was missing so not sure what that was all about. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted September 9, 2021 Author Share Posted September 9, 2021 This is what I mean about a similar sound 2 Quote Link to comment Share on other sites More sharing options...
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