Running in Laser 150
11-16-2008, 02:04 PM
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Running in Laser 150
I was planning on building a Miles Hawk Speed 6 from Phillip Kent plans then Seagull introduced their Miles Sparrowhawk with 71" span. Both planes begged for an English 4C so a call was placed to Laser Engines in the UK and six days, and 295 pounds later a new Laser 150 arrived in Georgia.
I was planning on building a Miles Hawk Speed 6 from Phillip Kent plans then Seagull introduced their Miles Sparrowhawk with 71" span. Both planes begged for an English 4C so a call was placed to Laser Engines in the UK and six days, and 295 pounds later a new Laser 150 arrived in Georgia.
Here is what it looks like:
The weather yesterday was terrible for flying, winds up to 25mph and temps in mid 50s, so no one would be at the flying field ... and excellent day though to break in a new engine.
Using Morgan Cool Power fuel, with 5% nitro and 17% all synthetic, an APC 16X4W prop, and OS Type F plug the engine was run for 50 minutes over five separate sessions.
As others have commented the engine seems to be very thirsty. Also the backplate breather puts out a lot of raw unburned fuel creating pretty large puddles on the test stand by the end of each run.
The high end needle was not set until 30 minutes of run time and it peaked at 9,050 rpms and is expected to climb above this as running time is accumulated. After the high end was set the low end idle was tach'd at a steady, consistent 1,860 rpms.
Overall the CHT at the plug was 230 degrees F and the temp at the rear of the head near the exhaust was 360-400 F.
Here is a short, low resolution video of the Laser 150 running at 5,100 rpms then brought down to idle.
Copy and past this URL to your browser to see the video: http://georgiacombat.com/Laser150/RunningLowRes.wmv
I was planning on building a Miles Hawk Speed 6 from Phillip Kent plans then Seagull introduced their Miles Sparrowhawk with 71" span. Both planes begged for an English 4C so a call was placed to Laser Engines in the UK and six days, and 295 pounds later a new Laser 150 arrived in Georgia.
Here is what it looks like:
The weather yesterday was terrible for flying, winds up to 25mph and temps in mid 50s, so no one would be at the flying field ... and excellent day though to break in a new engine.
Using Morgan Cool Power fuel, with 5% nitro and 17% all synthetic, an APC 16X4W prop, and OS Type F plug the engine was run for 50 minutes over five separate sessions.
As others have commented the engine seems to be very thirsty. Also the backplate breather puts out a lot of raw unburned fuel creating pretty large puddles on the test stand by the end of each run.
The high end needle was not set until 30 minutes of run time and it peaked at 9,050 rpms and is expected to climb above this as running time is accumulated. After the high end was set the low end idle was tach'd at a steady, consistent 1,860 rpms.
Overall the CHT at the plug was 230 degrees F and the temp at the rear of the head near the exhaust was 360-400 F.
Here is a short, low resolution video of the Laser 150 running at 5,100 rpms then brought down to idle.
Copy and past this URL to your browser to see the video: http://georgiacombat.com/Laser150/RunningLowRes.wmv
11-16-2008, 06:31 PM
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RE: Running in Laser 150
Jaka,
Laser Engines do not have valve covers. the valves are angled into the head. I believe the head is a semi-hemi, what we used to call a "squish band" design. The plastic spinner is safe and adequate if ... you do not load up the engine when starting causing it to hyrdolock whichin turn spins the cone against the blades and you make sure there is clearance between the spinner cone and the blades.
Laser Engines do not have valve covers. the valves are angled into the head. I believe the head is a semi-hemi, what we used to call a "squish band" design. The plastic spinner is safe and adequate if ... you do not load up the engine when starting causing it to hyrdolock whichin turn spins the cone against the blades and you make sure there is clearance between the spinner cone and the blades.
11-16-2008, 08:01 PM
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RE: Running in Laser 150
Lou, unless something has changed, Laser's do have valve covers, or at least every one I have seen does. Just go to the Laser site. I'd be willing to bet your engine was set up at the factory and the valve cover was not reinstalled. Email Neil to check.
Jim
Jim
11-16-2008, 08:15 PM
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RE: Running in Laser 150
A beautifully finished and machined engine. A little decorative bead blasting here? It sounds like a Super Marine Spitfire being run-up from idle. It sounds like a screamer too! A reaffirmation of why I must have a four cycle even if it never leaves the test stand.
Happy flying,
Bill
Happy flying,
Bill
