Author Topic: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’  (Read 8988 times)

Offline Tennessee Whiskey

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #30 on: July 30, 2018, 10:29:57 AM »
Splendid news to awaken to Tug. Just tell the neighbors that the muffler fell off of your electric string trimmer  :naughty:

Whiskey

Online Admiral_dk

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #31 on: July 30, 2018, 11:40:02 AM »
Another pair of beautiful engines from you Ramon  :praise2: looking forward to see a video of them running  :cheers:

Offline Ramon Wilson

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #32 on: July 30, 2018, 10:53:39 PM »
Well guys it's been a good day in the ol shid though it had it's 'moments' - I bet my neighbours didn't exactly agree though  ;D


As said previously I gave the first one assembled a quick one minute run before breakfast then began assembling the second. All went well until placing the cylinder on the piston - it wasn't going to go :o Sudden realisation that despite being ultra careful to keep the cylinder and pistons matched as lapped somehow I had been ultra careless and got them switched about  :facepalm:. Keeping my fingers crossed that I hadn't ruined the first piston I swapped them around only to find the compression in both to be absolutely superb. Phew! Instant anxiety crisis rapidly diminished  :) Without a prop its very difficult to turn both of them over compression with the prop driver so am well chuffed. 

Here's the first assembled post run (with it's correct piston ::))


And the parts for the second (but before realising the pistons were wrong!)


I ran a couple of tanks through later in the morning. Starting was relatively easy once I realised that the fuel tube had come off the needle valve :facepalm2: but once that was back on securely it was not long before the right settings were found. They do need a bloody good whack though


Once the second was assembled correctly it too had a couple of tankfuls and performed as well as the first.
Here's the pair post running the next outing will be at Forncett


And here they are with the original 3.46 version as a comparison


Well that's another couple of diesels done to add to those before - hope you've enjoyed the ride

Regards - Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline zeeprogrammer

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #33 on: July 30, 2018, 11:07:57 PM »
Beautiful work.  :ThumbsUp:

Well guys it's been a good day in the ol shid though it had it's 'moments' -

You may have no idea how it helps to see craftsmen struggle sometimes. Sort of makes sense. If it was easy for them...there'd be no challenge or learning.

I always enjoy seeing your work.  :ThumbsUp:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Tennessee Whiskey

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #34 on: July 30, 2018, 11:49:52 PM »
Just wonderful Tug. I’m chuffed for you  :cheers:

Whiskey

Offline Dave Otto

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #35 on: July 31, 2018, 01:07:06 AM »
Beautiful engines Tug! I'm sure they run as nice as they look.

Have you ever gone over your procedure on creating the beautiful finishes on your parts? I know we all have our techniques, if you are willing to share I would be interested. Or if you have covered this before a point in that direction would be nice.

Thanks,
Dave

Online Kim

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #36 on: July 31, 2018, 05:33:17 AM »
Really beautiful engines, Tug!
Thanks for sharing your work with us,
Kim

Offline Jasonb

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #37 on: July 31, 2018, 07:21:12 AM »
Very nice Ramon and good to see the magic glove still works resulting in a couple of runners.

can I ask why they were made with such a long crankshaft? Was it to get teh CoG back or to allow the endine to fit into a more aerodynamic cowel.

J

Offline Allen Smithee

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #38 on: July 31, 2018, 07:43:35 AM »
AIUI they were designed as marine engines and then converted to aero. The long free-end of the shaft was to give a decent gripping area for the (quite large) flywheel  needed by the marine engine.

€0.0002 supplied,

AS
Quidquid latine dictum sit altum sonatur

Offline Ramon Wilson

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #39 on: July 31, 2018, 11:08:33 AM »
Hi guys - thanks for looking in  :ThumbsUp:

Zee - we all struggle - at all levels - so don't despair when things go wrong. It's the ability to overcome the mistakes we make that makes it worth the struggle ;)

Dave - I think I may have mentioned it in passing but nothing specific as I recall. I'd be happy to pop something a bit more detailed up later as/if you think it's worth doing

Jason - I'm afraid AS is off track here. The Hunter was first introduced to the aeromodelling fraternity in 1949 as very much a new aero engine. It would appear as a marine version a year or so later. I don't recall any specific advertising feature with regard to that long prop driver but would hazard a guess that it was influenced by several Italian diesels of that time that featured long front ends and well described as you surmise by being able to be fitted well back in a cowl in order to help streamlining. As I said at the beginning my original suffered from that long shaft exerting enough leverage to break the crankcase. I don't know if that was a common occurrence but the engine was produced much later as a 'short shaft' version. It has a venerable history as an engine produced for many years, indeed it is still manufactured as a marine version (under the Hunter name) by Weston engines. Another British engine that exhibited a long shaft (but shorter prop driver length) was the Amco 3.5 PB (plain bearing) Another very powerful 3.5 it did have a reputation for breaking crankshafts ! Incidentally 'long' prop drivers were available as an accessory for many engines for just this reason of getting the engine further back.

Here's a short video for Per - turn the sound up  ;)
<a href="https://www.youtube.com/watch?v=sHLk0Su84jc" target="_blank">http://www.youtube.com/watch?v=sHLk0Su84jc</a>


Whilst finishing these parts of I've also done a bit more on the 14cc spark ignition JLE engine - 'Jefs Engine' as featured on MEM a while back.

The major parts have been finish machined - just the ancillary pieces to do


Now, just to show we really do all struggle Zee  ::)

This first liner on the left is a bin job - I miscounted the holes on the dividing device and these holes are some 36 degrees out of phase  to the second version on the right::)


Something good came out of it though as looking at it as drawn after machining I felt the exhaust was potentially rather wide for a ring to pass without catching so the second liner was done with a smaller cutter and the exhaust and inlet barred to prevent that


And - when making the 'Tufnol' rotors for the Hunters one had the blind holes drilled right through  ::) so yep ''it happens to all of us ;D

Y'all have a good time now - I'm off to tha ol shid

Ol Tug




 
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Roger B

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #40 on: July 31, 2018, 05:50:12 PM »
Splendid work  :praise2:  :praise2:  :wine1: I can't see the video though  :( just a space.
Best regards

Roger

Offline Allen Smithee

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #41 on: July 31, 2018, 06:47:50 PM »
Jason - I'm afraid AS is off track here.

Hah! Hardly the first time! I tried to remember where I got that idea from. When I was a kid a schoolfriend's dad gave me an old model boat which had six channel reeds and an ED Hunter which he had converted from aero to marine. I think he said that you could see from the long front end that it was "obviously designed to fit a flywheel". When you're 12 you just accept these pronouncements as gospel!

AS
Quidquid latine dictum sit altum sonatur

Online Admiral_dk

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #42 on: July 31, 2018, 09:03:16 PM »
Hi Ramon

Fantastic job and I really, really like the sound and how well it runs and starts  :whoohoo:

I was going to ask you about the prop size, but you mention it being a 13"x5" in the video and that explains why it looks so substantial BIG to me  :D

Roger : 
Quote
I can't see the video though  :( just a space.
Well this is the same for me when I use my standard browser (IE11) - so I just copy paste the internet address into Chrome and it shows fine there  ;)

Best wishes

Per

Offline Roger B

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #43 on: August 01, 2018, 08:28:43 AM »
I pasted the address into Edge and could see the video  :)

Excellent, lots of noise and lots of smells  :ThumbsUp:  :ThumbsUp:  :wine1:
Best regards

Roger

Offline Ramon Wilson

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Re: An English Classic ? A 5cc version of the ‘ED Mk IV 3.46 Hunter’
« Reply #44 on: August 01, 2018, 09:08:11 AM »
Morning Guys, Thanks as usual and glad you could smell the ether Roger  :ThumbsUp:

I can't explain why some can see the video and some can't. It shows, and is accessible, in the thread on my PC well enough. I did have this problem with the video on the Corliss build so maybe it's to do with the way it's uploaded at this end. Whatever, thanks Per for a quick solution.

The 13 x 5 prop is usually only used on those initial runs - the next runs will be on a 12 x 5 and eventually it will run with a 11 x 5 which should let it really open up ;)

Ah Allen, now that's how urban myths begin  :ROFL:

Well I guess that's the end of this thread - thanks to all who have taken time to comment, as always much appreciated :ThumbsUp:

Time to move on now and tweak a bit more on the Mc'Onie before getting back on the Corliss.

Regards from the ol shid then

Ol Tug

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

 

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