Engine projects

[jeff2wings]

Got too spend a few hours on this over the last couple of days 

 

 

 

 

 

 

Hi 

 

 

[jeff2wings]

Having got out of jail with the exhaust duct time to finish the cylinder and make the head and intake rotor 

shaping the combustion chamber 

snug fit !

 

[brokenenglish]

Here's my Atom Minor running on glow, at a time when I didn't have an ignition circuit.
I'll run it on sparks as soon as we get some decent weather (reasonable light for photos/video).
 

[jeff2wings]

It would be interesting to see if there was any increase in performance over petrol/ignition vs methanol/ignition vs straight glow,l will using a altered head shape for increased compression ratio along with a ringed aluminium piston as used in the Mk2 Atom Minor 

[911hillclimber]

Are those Hemmingway castings?

Mine look nothing like as 'matched' as those in the running engine.

[brokenenglish]

Here's the "other side" of my engine. Note the adapter, under the glow plug. I don't think the castings can be "Hemmingway" (whassat?), as this engine has been in my possession for more than 40 years.

Your build threads have motivated me to run the Atom on sparks ASAP. I'm looking forward to it, but the weather is b-awful.

I would expect the Atom to perform a bit better on sparks than on glow, but that's of no importance for me. "Nice running" is far more important than minor performance differences.

I seem to remember that, decades ago, castings sets were marketed by a model engineering firm in Oundle, maybe my engine is from those.

Edited May 2 by brokenenglish

[911hillclimber]

Thanks for the details. Hemmingway are the company now selling the materials/castings for the Atom Minor Mk3.

[brokenenglish]

Following my earlier post, a bit of Web browsing confirmed that the castings source I mentioned in Oundle was called "Woking Precision Models", and that their range was taken over by Hemingway around 2006.

[jeff2wings]

Last major component now finished, now need to finish the induction side ,make prop driver and a pair of piston rings, oh and several hours hand finishing the castings so they don't look like I made them with a blunt chisel. 

 

 

[jeff2wings]

Still plodding along whenever I can, not too much of a problem with the weather as it is😒 made the prop driver ,took two attempts in order to get the look/fit that I wanted and did a bit more to the second set of castings 

 

 

[jeff2wings]

With the weather forcing a break in flying activities it's back to engine work, rebuilt a ASP 180 with new bearings, camshaft, lifters and valves, TT 91 new bearings and clean, Jones 61 new bearings and clean and something I have been meaning to do for some time, Laser intake mod ...........😈

This is the Jones 61 it's a home built from a set of castings, I got this one of e-bay but I do have a full set and drawings to build later 

 

and the intake tube for the Laser so I can use it without having to butcher the front end too get the tank somewhere near the right place

 

 

 

running on a late model merco 35 carb very nicely, it's a  straight swap for the original intake and carb

 

 

[Ron Gray]

I have placed a bet with myself on how long it will be before a certain person will respond with a massive thumbs up regarding the Laser mod. But nice work Jeff.

Edited June 16 by Ron Gray

[Paul De Tourtoulon]

Well done Jeff, a shame that the last post didn't recognise all the work on the repaired Asp,,,,

 

say no more,, opps where's 'someone else' ?.

 

 

blablabla,,,,🥱grow up don,,,,

Edited June 16 by Paul De Tourtoulon

[Engine Doctor]

well done Jeff on the Laser Mod . It will allow simple no problem inverted installations . Is the carb supported onto the  c/case ?  Cant quite see in the pic.

I did this on a OS 52 FS some years ago . It improved overall running of the engine at the expense of a couple of hundred RPM at WOT .

As usual Jeff excellent work.

[Paul De Tourtoulon]

Be careful Jeff at what you post,

 

Posting your Laser engine will bring, as you have already witnessed, an opening up of Pandoras box,🤢 you are summoning the wrath of the Laser gods,😨 just by improving it.

This Laser engine sect goes back in time when some people worshipped them, and I see that a couple of them on the forum still do, they believe that this engine is an effigy of the model Gods, and isn't to be touched as it represents perfection, as you have made it better and more useable you have walked on sacred ground to the believers, and have woken up the wrath of the Laser Gods, and sometime a curse with it. I don't believe in this sect and I have also improved this effigy, in changing the valve springs, carburettor like you to make it more useable inverted without fuel tank problems, and I also use the magic 'potion' from the local sorcerer Castor oil, and blue fuel, used in small doses neutralises the curse set upon it,🤫 touching a Laser engine is considered a blasphemy to the two of the 'believers'.

 

I can send you the Magic words that go with the potion to rid your Laser from the curse of this sect, but because they are very powerful, they can only be sent en MP.😂

Edited June 17 by Paul De Tourtoulon
potion

[Engine Doctor]

I agree with paul about most except Castor oil . The Emporers suit of clothes story comes to mind re the doubters when it comes to improving an already good product that just needs that tweak. 

Again good work Jeff . I spoke on here about that mod with Jon but he always poured cold water on the idea. But it appears that the company gave him little if any support so we cant blame him entirely.

[jeff2wings]

😏oh boy! Well thanks for the comments ED ,I could relate an encounter with someone in the modeling 'press ' about 30 + years ago regarding NT'S engineering choice for the intake but given some of the guff I read with regards not just laser,but other engines like the SC61 carb issue, l'm not going to have that conversation....

 

Anyhow, it was just a proof of concept for a particular model, a Seagull i sport ,l did try a couple of 2 strokes (3 actually) but due too the tank sitting back from the firewall somewhat ,the idle was inconsistent despite using hot /4s plugs ,plugs with idle bar even a Perry pump

Anyway the laser is going back in ,ended up cutting an 1" off the front in order too get the cg right, ho hum 😅 

 

 

 

[jeff2wings]

Final version for the intake for this model 

 

[Paul De Tourtoulon]

Nice job Jeff, any reason why you didn't extend it so that the needle valve would be in line with the crankshaft, like other 4 strokes ?.

[jeff2wings]

The tank sits quite low in this model (but not low enough for a laser) so it's were it needs to be now,it will be nice to finally get this airborne with the engine it was brought for after sitting in my workshop for the last 8-9 years ☺

 

[Paul De Tourtoulon]

I like your silencer, you won't even hear the nice sound of your Laser.

Did you get the throttle linkage from a yoga catalogue ?.😂

[Manish Chandrayan]

Jeff

If the bendy pipe is touching the ply it will eventually start singeing the wood. A fiberglass bandage around that part should prevent it. I also hope that you will install support for the pipe and the muffler 

[alec james]

Interesting about the .61 Jones motor on an earlier post as Colin Jones was a member of the same Model Flying Club as me in the 1970's (Hereford Model Flyers).

I collaborated with Colin over these engines although only in a low key way as Colin did all the drawings and made the patterns etc. Several castings were ordered at the time but when they were returned the patterns were not included, never to be seen again, so a cleaned up set of the original castings were then used as patterns.

My motor was made about 1975 and if you notice it has J J  ( Jones /James) cast into it on one of the transfer ports so the earlier eBay buy could have been made from a set of original casting as after the building article in the MODEL ENGINEER in 1975 Colin sold the rights etc to a Company and the J J was removed. Hemingway Kits now have the motor as a plan and castings but the transfer port which had the JJ is not shown in their catalogue that I have.

I used to fly my motor in a bitsa aerobatic plane and it was absolutely fine on a 11 "x 7 3/4"  KAVAN Prop

My crankshaft and cylinder liner were made from two pieces of a lorry half shaft as that's all I had at the, not the easiest of material to machine!

 

 

Jones .605 Glow engine | Model Engineer & Model Engineers Workshop (model-engineer.co.uk)

[KEITH BEAUMONT 1]

Seeing this mention of the Jones .61 made me reach for my note book for when I made one from the Hemmingway kit,6 years ago. A friend had made one a year before and warned me that it was very noisy, as no provision is made for fitting a silencer. To enable me to fit one I altered the size of the exhaust aperture to allow fitting an extention plate with mounting holes for an OS silencer. My notes show that I had a lot of problems with overheating. I was getting top speed of around 10,000 RPM and slow at around 2500RPM,I tried different fuels , changed spacers in the head to try various swish band sizes,etc,but still it would always show signs of overheating. At one run that had some odd results, I found after a check that the main PH bearing had twisted in the housing, having the obvious changes to the timing and fuel intake. I the decided to remove the silencer. My notes say, in capital letters, THIS IS A DIFFERENT ENGINE !. Further testing was therfore carried out without the silencer and the overheating problem stopped

Keith.

[jeff2wings]

That's a very nice build, the finish on the crankcase and anodising look very smart and silencer fitting very neat, however the os E 3030 is to small for this engine as it's meant to fit engines of .35-46 range and will cause excessive back pressure resulting in over heating and poor top end performance.

This has more volume and a 10mm outlet