Dolphin Engine - Lumenition Ignition - Long shot

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dhippey

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Hi Chaps,

My Dolphin engine has two sets of points located in an almost inaccessible location at the front of the engine. To adjust these means removing the engine!
While this is an easy'ish option in port it is not something I would try in anything of a seaway. So my mind wandered over to my old MG which has a 'fit and forget' set of points made by Lumenition, (it's the Magnetronic ignition system). My thoughts are would it be possible to fit something similar to the Dolphin.

So I ask have any of you converted a Dolphin petrol engine to electronic ignition with this type of point set?
If so any hints & tips?
Which parts did you use?

Thanks.
 
dhippey said:
Hi Chaps,

So my mind wandered over to my old MG which has a 'fit and forget' set of points made by Lumenition, (it's the Magnetronic ignition system). My thoughts are would it be possible to fit something similar to the Dolphin.

So I ask have any of you converted a Dolphin petrol engine to electronic ignition with this type of point set?
If so any hints & tips?
Which parts did you use?

Thanks.
Click to expand...
Sorry, I have no knowledge of the Dolphin engine, but I had Lumenition in my MG distributor too. As the distributor got worn, I exchanged it and bought bits from 'Simon's best' on Ebay. Now called 'Accuspark' (still on Ebay) I believe; certainly looks the same. MUCH cheaper than Lumenition, runs fine for over a year now, and the parts (£30) might somehow just fit your engine . If not, you have spares for the MG!
 
The Dolphin 10 in Arelia, my Invicta 26, had electronic ignition - so it can be done. I never investigated further as in 5 years East Coast sailing the engine started on the button every time. The other very worthwhile mod. to the engine was a large flywheel which gave very smoote running - but at the cost of a hand start option.
 
Of course it can be done. How easily depends on your own skill and creativity. Its just a basic petrol engine, not much different to the old one in the MG.
My old '71 Mini now has an A series engine with a mappable ECU with 4 seperate coil packs, and electric injectors fitted into a much modified Weber carburettor for fuelling and sensors everywhere. Anything is possible! Runs a 296 race cam and big head as smooth as a road cam would thanks to a clever map created on a rolling road.
I also have an old Dolphin engine, that is for my Hillyard 2.5ton. Thanks for the info on the Accuspark by the way thalassa! I may just look into using it on the Dolphin myself when the time comes.
 
This engine is a two stroke so advance should be fixed.Four stroke electronic ignitions have automatic(electronic) advance which might make them unsuitable.You should get one suitable for two stroke engines.
 
thalassa said:
Sorry, I have no knowledge of the Dolphin engine, but I had Lumenition in my MG distributor too. As the distributor got worn, I exchanged it and bought bits from 'Simon's best' on Ebay. Now called 'Accuspark' (still on Ebay) I believe; certainly looks the same. MUCH cheaper than Lumenition, runs fine for over a year now, and the parts (£30) might somehow just fit your engine . If not, you have spares for the MG!
Click to expand...

Hi Thalassa,

They look interesting. I may go for one to see if I can make something work. Otherwise, as you say, it becomes a spare for the MG. Cheap enough to experiment with. Thanks.

Regards,
David H.
 
Why not ask Dolphin? The new engines they build are fitted with Lumenition systems so sure they will be able to advise on a retrofit.
 
Tranona said:
Why not ask Dolphin? The new engines they build are fitted with Lumenition systems so sure they will be able to advise on a retrofit.
Click to expand...

Thanks evenchance and 30boat, yes I'm sure it can be done. The post is to see how others have achieved it to shorten the development.

Tranona, thanks for the input, but dolphin do not supply a retrofit, the new engine has a different layout because it does not use the dynostart.


All good info so far chaps, please keep the ideas flowing.

Regards,
David H.
 
It's no big deal, I'm sure.All you need is a two stroke dedicated ignition system that suits your engine layout eg 180º 2 cylinder and then fix it at the end of the crankshaft were the points go.The trigger unit needs to be finely timed,two strokes are very finicky about timing and holed pistons are a risk if you don't get it right.The data is certainly available from Dolphin.All you need is a bit of ingenuity.
These people know a thing or two about igniton systems.http://www.boyerbransden.com/productinfo.html
http://www.pazon.com/ignition/true-fire-ignitions/
 
Setting points on a Dolphin is quite simple, had a direct drive one for 18 years. On end of dynastart is a cap held on with 3 small bolts, remove. Now you can see 2 sets of points. There is sight hole in the casing of dynastart, which lines up with a dimple where point should spark. Picture of my old one on Yachtsnet site here
http://www.yachtsnet.co.uk/archives/invicta-26/invicta-26.htm . Turn engine over slowly by hand and adjust points so they spark when dimple is visible in centre of hole. To make dimple easier to spot, mark it with white paint on end of pointed stick.
Hope this helps.
 
Electronic ignition is fitted to cars and high speed 2 stroke engines because if you use old style ignition of 12v supply to points and coil at high engine speed the spark power falls because the coil does not have time to recover its current before the points interupt.
The other advantage is that points can carry a lower current or be replaced by a sensor coil or light interupter type actuation.
The OP mentioned 2 sets of points which would indicate 2 coils and no "distributor" as such. (distrubutor here meaning a rotating switch to distribute the spark to the applicable spark plug.) So Op would need to fit a distributor of some sort or better fit 2 electronic ignition systems.
My old Johnson O/b has electronic ignition. It picks up in a coil from a rotating magnet under the flywheel an AC voltage which is rectified and turned into a high voltage aprox 200 volts which is switched via a silicon controlled rectifier to 2 individual coils. The rising of the AC cycle is sensed to provide timing for the SCR to fire. It seems to fire 2 plugs simultaneously the inappropriate firing being of no significance.
Back to the Dolphin engine you do not need the high speed performance of electronic ignition being just one firing per turn of engine per ignition system. The mechanical points will burn with time due to high current. You could fit transistor switching type ignition to reduce the current through the points but this will not help the wear on the cam that is the other reason points need to be adjusted. Further very low current through points can cause its own bad contact problems.
So as I see it you could fit 2 light breaking sensors into the original points box. Ideal if this is rotated to provide spark advance.
Or an alternative might be to a magnet to the outside of the flywheel and 2 magnetic sensors to switch 2 transistors ie 2 electronic ignition systems to 2 coils and plugs. This might require an arrangement to advance spark by moving sensors around the circumference. Buit the whole thing could be more accessible.
Or just leave as is. good luck olewill
 
theoldplucker said:
Setting points on a Dolphin is quite simple, had a direct drive one for 18 years. On end of dynastart is a cap held on with 3 small bolts, remove. Now you can see 2 sets of points. There is sight hole in the casing of dynastart, which lines up with a dimple where point should spark. Picture of my old one on Yachtsnet site here
http://www.yachtsnet.co.uk/archives/invicta-26/invicta-26.htm . Turn engine over slowly by hand and adjust points so they spark when dimple is visible in centre of hole. To make dimple easier to spot, mark it with white paint on end of pointed stick.
Hope this helps.
Click to expand...

Lovley pictures theoldplucker. BUT I did say in the original post that in my installation I do not have access to the front of the engine. I would love to have the access you had, however I am stuck with the bulkhead blocking anything like this. Hence the whole point of this thread. See engine bay pic in next post.


Regards,
David H.
 
Last edited:
William_H and 30boat, spot on, this looks like the right avenue to explore.
PaulM299, yes it is the original type reversing engine.

The set up is 2x 12v Coils, 2x independent point sets feed the sparks, one set for each cylinder. The electric control box deals with reversing by swapping over which set fires which plug.

An interesting, but irrelevant, point it that the dynostart uses the two batteries in series to draw 24v for starting, whereas at any other time apart from starting the batteries are in parallel feeding the 12v system.

The whole system works well apart from having no access to the points without removing the engine (Not like the access the invicta_26 has). But even this is only a 20min job to get out and about 30 mins to put back. However I'd sooner fit some fit and forget solution.
engine.jpg
Picture of the beast in its lair! :-)

Regards,
David H.
 
Last edited:
Ahoy !
Appreciate this is an old thread but suspect that the owners of the early reversing Dolphin will be able to help. My engine has stopped firing on No. 2 cylinder, ahead and astern, so suspect a faulty condenser as I have a poor orange spark. Problem is where are they ? Nasty instalation, control panel is obscured by engine.
 
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