Nova 1 compression ignition engine

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Nova 1 compression ignition engine

This topic has 17 replies, 5 voices, and was last updated 16 July 2010 at 10:57 by Ramon Wilson.

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7 January 2010 at 11:03 #47135
Ramon Wilson
Participant
@ramonwilson3
Hi,

I’m fairly new to the forum and thought that this might be of interest to someone.

I’ve had the drawings for this engine for many years with the thought that maybe- someday? but making the pattern to get the crankcase cast always put it on the back burner. Discussing it recently with a friend it was felt that it was worth having a go to machine it out of solid.

Prevaricating no longer a start was made and it was most surprising just how quickly it materialised and I have posted some photos of the process.

I’ve messed around with model aircraft engines for the best part of fifty years but never actually made one – it will be interesting to see if this lives up to expectation.

Regards – Ramon

Edited By Ramon Wilson on 07/01/2010 11:04:39
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7 January 2010 at 11:03 #2254
Ramon Wilson
Participant
@ramonwilson3
7 January 2010 at 13:08 #47138
Peter Gain
Participant
@petergain89847
Hi Ramon,

Looks like a very interesting engine. How about writing it up & offering it to David C for publication as a series in ME? The specified fuel seems to be a rather curious mixture compared to modern practice!

What is the capacity?

Peter Gain.
8 January 2010 at 11:42 #47164
Ramon Wilson
Participant
@ramonwilson3
Hullo Peter,

Nice to see someone is interested. Yes that fuel make up is unusal, the ether content seems very low. I will use the readilly available ‘sport’ mix to start.

The capacity is given as 4.5cc with a bore of 16mm and stroke of 22mm so that prop seems well oversize

I machined the case before early Dec but have only just been able to get back onto it.

I’ve added a pic of the drawing so you can get an idea of the layout. I haven’t worked out the timing yet but will do before I cut the ports. I see some one has made one on the Model Engine News site and got it to run succesfully. Has anyone else?

Machined the c’shaft bearing this morning, now going to start the shaft.

Regards – Ramon
8 January 2010 at 15:06 #47177
John Wood1
Participant
@johnwood1
Hi Ramon. Very interested in what you’re doing, the pics look excellent so I shall follow your progress with interest. Do keep us posted and, yes, please think about writing it up for ME, with those nice pictures you are halfway there already.

Keep up the good work

John
10 January 2010 at 22:57 #47259
Ramon Wilson
Participant
@ramonwilson3
Hullo John, nice to hear you are interested as well.

I would be quite happy to write it up if it was considered worthy enough but I have doubts about the quality of the images. They are only taken with a 2mp camera so I don’t think they will have enough ‘substance’ for publishing – I will find out though. Whatever I’ll continue posting updates on the progress and add to the photos. Whilst it can’t be considered anything but a small project if it helps someone somewhere then it’s worth doing. Questions and comments that will add to that sentiment can only be for the good.

Now surrounded by the white stuff, there’s simply been no other place to be but the workshop! so have spent a very pleasurable few hours making the crankshaft and making a start on the cylinder over the weekend.

The crank was made from two parts, the main outer part from EN 24T and the ‘secondary’ inner shaft from the shank of a long 8mm caphead. The reason for this was the small piece of EN24 – enough to do two at this size or one the full length. This way I had two chances!!

Having decided not to retain the conrod with a circlip as drawn the pin was shortened. This left quite a gap between pin and back plate that the rod could float hence the mod to the backplate. This mod will also allow a bolt to retain the fuel tank – the original is just a push fit.

That’s it so far but I must just say that tomorrow is a bit of a red letter day – 65th birthday -have guess where that is going to be spent?

regards for now – Ramon
11 January 2010 at 07:44 #47263
Martin Cottrell
Participant
@martincottrell21329
Happy birthday Ramon, have a great day in your workshop!

Regards, Martin.
18 January 2010 at 14:35 #47526
Ramon Wilson
Participant
@ramonwilson3
Hi All,

Just to say I’ve had a most enjoyable first week of retirement in the workshop. Work on the Nova has progressed considerably and I have just posted some more pics of it’s state of play. Current situation is that it is now fully assembled with all internals but the induction parts are still needing to be made. Couldn’t resist squirting a bit of fuel in it last night and giving it a quick flick or two. I think the comp screw needs to be just a little longer as it was bottoming out on the head but it did give an encouraging ‘pop’ or two.

More later

Regards for now – Ramon
24 January 2010 at 22:59 #47801
Ramon Wilson
Participant
@ramonwilson3
Hi all,
Just added the last 4 pics to the album.

I finished the engine late on Wednesday but not so late as to try another drop of fuel and this time it fired and ran on the prime.

Thursday saw it’s first run. No problems once the fuel was up (about 15-20 flicks) and the right compression found. Swung a 13 x 5 prop with ease at very moderate rpm – I would guess 4-5,000. It also ‘idles’ nicely when the comp is backed off and the needle opened.

The drawings were very good, no dimensional errors and only two omissions which had to be worked out by scaling. Other than the addition of the ‘screw in port’ for the intake tube and the slight change to NVA it was made to drawn dimensions. The porting gives reasonable timing – also done to dimensions given.

I’ve made lots of bits for engines over the years but never the whole thing. When it burst into life it brought a grin from ear to ear so I very much doubt it will be my last. Thanks to those who expressed an interest – I’m under no illusions – I fully appreciate it’s not a ‘Merlin’ or similar grand undertaking but it’s give me a lift so I hope it’s inspired someone somewhere to have a go.

Regards – Ramon
5 February 2010 at 13:20 #48267
John Wood1
Participant
@johnwood1
Hi Ramon

Congratulations on getting the engine running so well, you must be very pleased indeed. I have to confess to a little envy as my two attempts from scratch so far have refused to start. I can get them to cough but they just won’t keep going. I put it down to a lack of experience and machining skills but I will keep trying and, hopefully, re-visit them later on. Your pics are very good and really do give a good idea of what’s involved, I for one would certainly like to see it written up in ME so I hope you do consider it.

Glad you have started retirement on a positive note, I have a couple of years to go and must admit to being a bit aprehensive about it, ‘still, Im making a start as I’m looking for a new house with a MUCH BIGGER WORKSHOP, now I consider that to be positive thinking and a step in the right direction!!

All the best

John
7 February 2010 at 12:21 #48324
Ramon Wilson
Participant
@ramonwilson3
Hi John,

Thank you for your kind words and posting. Yes I was very pleased but not half as much as my friend John who phoned on Friday to say that he couldn’t get his to run. He brought it over and the cause turned out to be nothing more than a raher small prop (7 x 6) and some old fuel. A change of both brought it (and him!) to life and it too ran very well. Here’s a pic of the two – it’s now gone off to have a tank made and then we’ll have a twin run.

This has proved to be an ideal i/c project. The drawings were excellent, it was easy to machine – even that crankcase. and it was relatively quick to build. I see ‘Hemingway’ are going to produce castings from the Roger Schroeder patterns later in the year and the Nova is among them.

Some of ‘lifes circumstances’ lead to a total lack of interest in machining about five/six years ago and though there has been the ‘odd flicker’ this project has done more than anything to resurect my passion for it. It’s certainly fired me up to continue.

On that note I’m sorry to hear of your disappointment in not being able to get yours to run. What kind and type have you made? and when you say ‘scratch’ do you mean entirely to your own design or scratch building to anothers. My experience is limited to two stroke diesel and glow I’m afraid but normally, if it will fire but not run it’s usually the fault of porting/timing anomalies and or fuel/air mixture problems. Lack of crankcase pressure is another cause. How about telling us more about what you have done to see if anything can be done to improve them.

Regarding your suggestion of writing it up. I am quite happy to have a go and did infact contact the editor to see if the images were suitable but have had no reply. I notice in ME that he has had computer problems so perhaps this is the reason – I will try once more.

Don’t be apprehensive about retirement John, just get prepared! though it sounds like you are already thinking that way with your thoughts on that larger workshop. I’m sure you don’t need telling but you should be prepared for the time over the next two years to disappear at the most alarming rate!!

Best Regards – Ramon

Edited By Ramon Wilson on 07/02/2010 12:25:03

Edited By Ramon Wilson on 07/02/2010 12:38:03
10 February 2010 at 23:01 #48511
Ramon Wilson
Participant
@ramonwilson3
Hi again,

Just like to add my friend John finally finished his engine and I went over to his today for a twin run. In a word – Magic!

He had made a mount out of a nice piece of wood, the engines were bolted in and the flicking began. Not too good at first but we put that down to the cold – it was a bit parkie with the windows and doors open and snowing outside. Anyway finally got them running – bet his neigbours were impressed – and they performed well.

By cunning reduction of his spray bar diameter his has a much larger venturi area and was doing a consistent 5100 to mine steady at 4000 – his has a nicer beat too so having chided him for already ‘tuning it up’ it’s a now question of ‘if you can’t beat ’em’ etc.’

It was a good end to a short, very enjoyable project – on to the next? You bet.

Thanks for all your interest on this one back with another I/C soon

Regards – Ramon

PS Often taken for brothers I’ve known John since I was four years old – I’m the good looking one with the white beard!
18 June 2010 at 19:47 #52743
Sub Mandrel
Participant
@submandrel
Hi Ramon,

Thanks for you kind words elsewhere.

Seeing Nova in ME convinces me that it could be the IC engine for me to make! I have several old glow and diesel engines (and a few planes…) I also have a half made Seal I inherited – the builder appears to have aborted when his beautifully made bushed big-ends proved too-big for the milled-out crankcase. Finally a Sparey Diesel that’s half done, but a bit too fiddly for me.

But Nova I like! Is it possible for you to share your cleaned up drawings? I was disappointed they aren’t in with your article!

Regards

Neil
18 June 2010 at 22:28 #52748
Ramon Wilson
Participant
@ramonwilson3
Hi Neil,

Yes of course. You are the second person to say this but I purposefully left the drawings out because I wasn’t sure about copyright. The original magazine they appeared in – a 1946 copy of ‘Model Aircraft’ (as opposed to ‘Aeromodeller’) – was, I believe, published by Percival Marshall. Long gone I think but whether they are technically part of some ‘corporation’ of today I wouldn’t know.

Hemingways are going to produce castings and materials for a few engines from the Roger Schroeder ‘collection’ – about eight I believe and one of these will be the Nova1. They are not due to come on stream until the autumn but where the Nova will figure in the release schedule I have no idea.

In the meantime if you fancy machining a crankcase from solid then send me a PM with your address.

Peter Gain – would you check your messages when you can – I have returned yours ref the above.

Regards – Ramon
14 July 2010 at 21:45 #53399
Sub Mandrel
Participant
@submandrel
Ramon,

I’ve been using a lack of ‘chrome steel’ as an excuse, now ME arrives and I see you used EN1A… and I happen to have a 3 1/2″ long by 1 1/2″ diameter chunk i was using as a drift at the weekend.

Have to think of another excuse now.

Neil
14 July 2010 at 22:11 #53401
Ramon Wilson
Participant
@ramonwilson3
Now thereby lies the nub Neil.

The En1a was chosen because of machining those very thin fins. In combination with cast it makes for a reasonably good bearing so given it’s not going to be flogged to death I though that that combination for this rather slow rev-ver would be okay – seems to be holding up so far.

Time to get cutting?

Regards – Ramon
15 July 2010 at 21:33 #53432
Sub Mandrel
Participant
@submandrel
This weekend, lets hope it gets finished. I have too many half finisdhed projects. I had a model that took me over twenty years to finish – it was a simple air sea rescue launch to a Vic Smeed design – the 1/16 true-scale version (see my avatar for the full size) is still on the slipway after about 8 years

Neil
16 July 2010 at 10:57 #53444
Ramon Wilson
Participant
@ramonwilson3
Well I guess youre not alone there Neil – theres one or two residing under the bench and up the loft here too but getting ‘side tracked’ can have its virtues – big thing with these small engines is that they are not, on the scale of things, very long projects.

I wish you well on your start and look forward to seeing your progress on here

Regards – Ramon
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