Author Topic: 1909 Mercedes Aero Engine  (Read 22506 times)

Offline Jasonb

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Re: 1909 Mercedes Aero Engine
« Reply #270 on: August 31, 2019, 01:39:10 PM »
Engine is certainly looking good

I too have used the silicon insulated wire, usually get it from S/S who do the ignitions but for the older engines I have found that the cotton braided wire works fine and being about 3.5mm dia not too out of scale when compared to 8mm HT wire on the larger scale hit & miss engines.

S/S also do a couple of options for small plug caps as well as the flat "forked" type that clip onto the top of the plug but the later may well short on your engine even with heat shrink sleeve over most of them.

http://www.cncengines.com/ic.html

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #271 on: August 31, 2019, 07:05:56 PM »
Thanks Jason. I hadn't found them before.

Steve    :)

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #272 on: September 01, 2019, 08:40:40 PM »
I have started work on the ignition system. The drawings are not very helpful and specify 'insulation' as the material so I have taken some advice and have acquired some 'Delrin'. To practice with this material, I made the centre body of the distributor which is a simple tube and I must say that it turned beautifully. I then went onto the end plate which has a boss and pinch bolt to secure the unit to the camhaft bearing.



Rotor arm/contact breaker next. The rotor arm is a piece of brass rod pushed into the side and then partially machined away. I pressed the first one in with superglue but, not surprisingly, it hydrauliced and I couldn't push it home with the result that I couldn't make contact at the centre. I did a second one after drilling the centre hole and that was fine.







Four recesses for the magnets to operate the Hall switch. I have just found that Hall switches are polarity sensitive so I need to test which way the magnets should face before pressing them in.



Then the distributor cover. This was a fiendish bit of turning but went OK in the end.











A trial assembly and looking good. I have fitted the brass screw contacts with the nuts on the back. Connecting the wires without anything touching or shorting is going to be a challenge!







A quick fit to the engine and it looks OK although some more adjustment is needed to make it all sit in the right place.



Now waiting for the wire to turn up. In the meantime, I must have a think about the plug terminals, how to connect the Hall switch leads which come out of the side of the casing and also some sort of spring clip to keep the whole assembly together.

Steve  :)

Online Roger B

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Re: 1909 Mercedes Aero Engine
« Reply #273 on: September 02, 2019, 03:07:51 PM »
Nicely done  :ThumbsUp:  :ThumbsUp: I also used Delrin for my distributor, but white as that's what I had.

Conecting up with those nuts without getting sparks jumping in the wrong place may be a problem. I would suggest tubular nuts with a thread in one end and the wire soldered in the other end. These could also be a smaller diameter than your current nuts.
Best regards

Roger

Offline Lars

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Re: 1909 Mercedes Aero Engine
« Reply #274 on: September 02, 2019, 06:08:41 PM »
Steve,
I used the same approach as Mike described for my connectors. Only difference is I coiled it (slight undersize mandrel to the glowplug connector) myself as I didnt have a spring sizewise.

Even with a glowplug it is really tight and I have had some short cicuits to the pushrods occasionally..

I follow your progress with great interest, impressed that you go for the ignition straight away! My engine now starts great by hand and seems to be quite happy with the carb etc so I am leaning towards putting in the correct ignition type as well.

Have you been able to crank it and evaluate your compression?  I still think I should have more compression in my engine but it is hard to objectively substantiate that statement with the prop, but it turns too easily with one finger I think.   Oh well, it runs..

You are progressing fast to completion, looking great!

Offline Craig DeShong

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Re: 1909 Mercedes Aero Engine
« Reply #275 on: September 06, 2019, 01:03:55 AM »
Nice job on the distributor.  I'll build a project some day that will need one so it's nice to see how others approach the problem.
Craig

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #276 on: September 06, 2019, 09:48:15 PM »
Thank you Lars. I think I might end up with some ornamental connectors and then some to run. I have gone for the spark ignition because if I had it running on glow plugs then I would never get around to making the electrical bits. Not enough willpower!

When I turn the engine, there is some compression there but it is too stiff to really tell how much. It only wants running for half an hour to free it all up but it may be too stiff to actually run. I may well take the plugs out and turn it with the battery drill for a while to run it in a bit.

The distributor is a bit of a challenge as all of the terminals are so close together that keeping the sparks in the right place may well be an issue. No doubt time will tell!

Steve  :)

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #277 on: September 26, 2019, 08:55:04 PM »
Hi Chaps.

I have managed to do a little more with the aim of getting the engine to a state suitable for exhibition. All the work is to get it to a runnable state eventually. In the mean time, through reading this forum, I have realised that Hall effect sensors are sensitive to the polarity of the activating magnets so it is critical which side faces the sensor. A pal of mine is a retired telecoms engineer and he kindly set up the switch with an oscilloscope so that we could hold a magnet nearby and see which face worked. We started off by putting some tape on one face so that we coulld tell the difference! I then wrote down the result and came home to push the magnets into place in the rotor.



Then onto the terminals. After reading your various thoughts and comments, I simply filed up a fork which could be pushed on to the plug. The challenge here was handling them and seeing them!





I bent the cable ends up with a piece of steel in the drill chuck and the brass resting on the top of the machine vice.







I cut some silicone rubber insulated meter lead, tinned the ends and then secured them inside the distributor cap taking great care to keep them as far apart as possible. I will fill the cap with Araldite before I try to run it. Actually, would Silicone sealant do as well?



I soldered the terminals.



Then a bit of felt on the underside and some brasso on the shiny bits and it is ready for show.









Sooner or later, I am going to have to try to make it run. In the meantime, many thanks for all of your interest, advice and encouragement. I will let you know if I get it to work!

Steve   :) 

Offline Admiral_dk

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Re: 1909 Mercedes Aero Engine
« Reply #278 on: September 26, 2019, 10:13:05 PM »
Quote
would Silicone sealant do as well?

Yes and No - there are at least to different versions and the one that smells somewhat like vinegar will (like acid) destroy ALL metal parts it is in contact with  :hammerbash: - so please avoid that one.

Online Roger B

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Re: 1909 Mercedes Aero Engine
« Reply #279 on: September 27, 2019, 07:42:56 AM »
Almost ready to run  :)  :)  :wine1:

Potting the distributor connections brings a couple of thoughts:

If it fails will you make a new cap or do you hope to dig it out?

If you use Araldite will you be able to get any air bubbles out? I have used Araldite in HV applications, but in simple open moulds.

It may be better to use a purpose made HV potting compound, RS (for example) supply a range:

https://uk.rs-online.com/web/c/adhesives-sealants-tapes/adhesives-glues/potting-compounds/?sra=p
Best regards

Roger

Online Jo

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Re: 1909 Mercedes Aero Engine
« Reply #280 on: September 27, 2019, 07:51:03 AM »
Looks good Steve  :)

I have managed to do a little more with the aim of getting the engine to a state suitable for exhibition.

Have I missed a ME show? Other than the Midlands one next month I didn't think any were due  :noidea:

Jo
Enjoyment is more important than achievement.

Online sco

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Re: 1909 Mercedes Aero Engine
« Reply #281 on: September 27, 2019, 08:02:05 AM »
Fantastic job Steve - really looks impressive mounted on the plinth.

Simon.
Ars longa, vita brevis.

Offline Jasonb

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Re: 1909 Mercedes Aero Engine
« Reply #282 on: September 27, 2019, 09:14:19 AM »
Looking good

If you want to use a silicon then something like a mirror adhesive eg Dow 817 will be OK on the metal as it does not contain acetic acid.

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #283 on: September 27, 2019, 10:24:30 PM »
Thank you for your thoughts on potting. I think that buying the proper stuff may well be the best solution. If it fails then I will have to make a new cap so the proper stuff should reduce that risk. It's not too much effort but I don't really want to make another if I can avoid it.

I have had my arm twisted to enter it into the Midlands Exhibition so it will be on show there. As I drive past the place twice a day on the way to work, I haven't really got an excuse not to! The test run will be afterwards so I don't have the risk of spoiling it beforehand.

Steve  :) 

Offline Steamer5

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Re: 1909 Mercedes Aero Engine
« Reply #284 on: September 28, 2019, 01:17:27 AM »
Hi Steve,
 Very nice!

Now we just have to wait for the running video!

On the silicon front the 2 types are acidic, ie smells like vinegar (its acetic acid), the other is natural cure. Pays to read the label carefully! But it sounds like you have it sorted going with proper stuff.

Cheers Kerrin
Get excited and make something!