cadebytiger
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| posted on 16/5/07 at 11:56 AM |
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Where do people stand on multispark devices?
as title. Have heard they are supoosed to be good on pinto engine but is it just a myth?
These are the thinks which split the spark into 5 seperate sparks which i suppose just acts to increase the spark duration. They had a demo at the
show which i'm sure alot of people saw
Rupert
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flange nut
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| posted on 16/5/07 at 12:08 PM |
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I don't stand on them, I normally stand well back.
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craig1410
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| posted on 16/5/07 at 12:27 PM |
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I am of the opinion that if your ignition system is in good condition (dizzy not worn, good HT components, good quality spark plugs etc) then you
should only need one spark. After all, ignition timing is important so surely only one spark can occur at the right time!
I would recommend good HT components, routed nicely and I would fully recommend the best quality spark plugs you can buy. Beyond that I would consider
a good aftermarket dizzy and an enhanced coil pack but I doubt that a multispark system would do anything more than potentially cover up for a poorly
performing system.
Cheers,
Craig.
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C10CoryM
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| posted on 16/5/07 at 02:06 PM |
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Actually the idea of MSD is multiple sparks in the same time as a single spark normally.
There are other advantages, but the place where they are very important is in boosted applications where you can run into spark blow out.
Cheers.
"Our watchword evermore shall be: The Maple Leaf Forever!"
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02GF74
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| posted on 16/5/07 at 02:34 PM |
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I stand with craig1410 on this; BTW how much?
Capacitive discharge is where it is at.
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MikeRJ
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| posted on 16/5/07 at 04:01 PM |
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quote:
Originally posted by cadebytiger
They had a demo at the show which i'm sure alot of people saw
That thing is an utter load of crap. The demo's are very funny though, they usualy have an upside down spark plug, fill it with fuel and then
show the difference in the flame burning with and without the snake-oil producer in circuit. Like it bares any resemblance to actual conditions in a
cylinder!
And then there is inevitably some waffle about how long lasting the spark plugs will be as the spark is unable to burn a piece of paper with said
device in-circuit. Personaly I want a nice hot spark, and spark plugs generaly last 30,000 miles in modern engines anyway, or about 10 years with a
typical 7's anual mileage.
True multi-spark igntion systems can be useful for maintaning reliable ignition under arduous conditions in the cylinder e.g. they can give smoother
idle with a hot cam fitted.
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flak monkey
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| posted on 16/5/07 at 04:04 PM |
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Just get yourself a decent electronic ignition system, job done.
Sera
http://www.motosera.com
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MkIndy7
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| posted on 16/5/07 at 04:51 PM |
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They do look impressive but they would probably only improve the ignition on a car that has something else wrong with it.
Its another one of those things.. if it helped you get 10mpg more or 10BHP more for the little that it costs then car Mfr's would fit them.
I have never even seen them used in industrial applications either where the conditions are much harsher like industrial Gas or Oil burners.. they use
losts of rapid BIG sparks to ignite things with.
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oliwb
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| posted on 16/5/07 at 05:54 PM |
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I was interested in this sort of thing. Thought about copying the Alfa twin spark on my pinto but never took it any further than thinking. Oli.
If your not living life on the edge you're taking up too much room!
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MkIndy7
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| posted on 16/5/07 at 06:14 PM |
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The Alfa multi-spark is a different idea to do with the Flame front and flame speed I believe
They ignite the mixture in 2 seperate places to get a more even burn rather than it flashing as 1 side of the cylinder and the flame having to
"travel" over the other side.
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snapper
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| posted on 16/5/07 at 06:33 PM |
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quote:
I was interested in this sort of thing. Thought about copying the Alfa twin spark on my pinto but never took it any further than thinking. Oli.
One of the Davids tried this on a Pinto, Visard or Walker and found that you could not space the plugs far enough apart to do the Alfo twin spark
thing properly.
As for multi sparks and splitfire plugs etc. a bit like stuffing things in the petrol tank and claiming 200+ bhp and a 1000 miles to the gallon for 2
quid.
I do think that if there is any free or cheap BHP for any engine then this site would know about it and we would all be buying it, IMHO.
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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paulf
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| posted on 16/5/07 at 07:22 PM |
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The device I have seen demonstrated at the shows is more like going backwards to the model T Ford, that had a trembler ignition coil which sparked all
the while.
As all ready mentioned only the first spark will be correctly timed anyway, so of no benefit on a correctly set up engine.
Ford edis units have a multispark output but it only operates at low ie idle revs.
Paul.
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NS Dev
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| posted on 16/5/07 at 07:23 PM |
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Actually Dave Walker (Emerald one) found a VERY useful power gain using the twin plugs setup.
This is a very complex subject, but as I have a streaming cold and don't feel like going into the garage i will write a line or two.
Note this may or may not apply to the device demo'd, probably not!!
Basically, imagine your engines cylinder (take 1 on its own) as a big bonfire. On a 16v engine with the plug in the centre of the combustion chamber,
when you light the bonfire, the flames quickly spread to the extremeties of it in an even fashion.
Now imagine the same but lighting the fire at one edge (like on a pinto engine). The flames now reach one side long before the other.
If you then fit a second plug the other side of the bonfire, it burns more evenly. This is the principle of multiple plugs. The performance benefit is
not that it burns like that in itself, but that you can then rev the engine higher before you run out of flame front propagation time at sensible
ignition advance. With the single offset plug, you will eventually, once the rest of the engine is up the scratch, hit the point where you can't
"light the fire" early enough (ign advance x lots! ) to burn all the fuel before the point where the flame front loses effect the the
power stroke.
The multiple spark idea is used for a lot of other things. One is similar to the above in that with decent squish and swirl, plus a propagating flame
front from the first spark, the turbulence in the chamber is pretty fierce, and in effect (relative the the burning bits of mixture) you are moving
the spark plug all over the place and repeatedly firing it (the fact it has not physically moved means little at the gas speeds involved)
The other main reasons for using it are as was mentioned, with high boost pressures it can help to avoid misfires, though so can an ultra high power
coil (the old principle of doing it once properly rather than 5 times badly! ) and also on big, offset plugged nitroused engines (like big chevies
etc) a big multiple spark guarantees to kick off the fire, which if it fails, will usually blow the bottom end/sump off the engine a couple of revs
later when the hot nitrous reches the engine oil.
PS a "proper" multi spark ignition on a sub 200hp pinto is like gold plating a bean can
[Edited on 16/5/07 by NS Dev]
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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snapper
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| posted on 16/5/07 at 07:54 PM |
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quote:
PS a "proper" multi spark ignition on a sub 200hp pinto is like gold plating a bean can
Heard something less polite about polishing T.......
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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cadebytiger
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| posted on 16/5/07 at 10:33 PM |
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alright alright enough pinto bashing! lol
It does the job for now.
Looking forward to a ride in you vx nesdev! When you think it will all be sorted?
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stevebubs
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 posted on 16/5/07 at 11:32 PM |
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quote:
Originally posted by NS Dev
Actually Dave Walker (Emerald one) found a VERY useful power gain using the twin plugs setup.
Good info, but don't think he was planning on drilling a second plug hole into the cylinder head
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iank
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| posted on 17/5/07 at 07:37 AM |
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In his A-series bible David Vizard mentions Multispark only in the (brief) economy chapter, where he suggests they can allow the mixture to be run a
little leaner than a normal ignition. Since he doesn't suggest them for performance I doubt they show any gains at all (on the A-series
anyway).
The one he mentions is something from these people I think --> linky <--
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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NS Dev
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| posted on 17/5/07 at 11:58 AM |
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quote:
Originally posted by cadebytiger
alright alright enough pinto bashing! lol
It does the job for now.
Looking forward to a ride in you vx nesdev! When you think it will all be sorted?
Its ready to rock and roll now!!
Just need:
a) some sun
b) My brother not to have so many cars blocking my garage that I can't get the bugger out!!!!!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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cadebytiger
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| posted on 17/5/07 at 04:48 PM |
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quote:
Originally posted by NS Dev
quote:
Originally posted by cadebytiger
alright alright enough pinto bashing! lol
It does the job for now.
Looking forward to a ride in you vx nesdev! When you think it will all be sorted?
Its ready to rock and roll now!!
Just need:
a) some sun
b) My brother not to have so many cars blocking my garage that I can't get the bugger out!!!!!
brilliant - so when we all going to meet up - can i request that it is not thursday evenings cos i am in the lab late. Cannot wait to see it. Whats
cal got on the go at the moment then?
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NS Dev
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| posted on 17/5/07 at 09:05 PM |
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At the moment we have: My fiat twin engine grasser, the locost, spare fiat 126, manta coupe rolling shell awaiting rebuild, slightly biffed up 16v mk6
escort awaiting sale, jag XJ40 4.0 awaiting sale, my sierra 4x4, cal's manta (not the I200 you saw, but another white one) plus my gf's
focus................................................
I reckon a good place for a meetup would be the Bulls Head on the A47 near Desford Cross Roads (BP petrol station on A47)
Its pretty central between leics and nuneaton where most of the cars seem to be, and it has a huge car park, and seeing as loads of bikes meet up
there, i guess the landlord is petrol friendly.
Easy to see as well, no probs finding it.
I think you wanted somewhere a bit further north, any ideas or would there be ok with you?
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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cadebytiger
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| posted on 17/5/07 at 09:10 PM |
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should be able to make this once in a while. how often you thinking?
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NS Dev
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| posted on 17/5/07 at 09:17 PM |
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I've just started a thread in the clubs and event bit, now you've prompted me!
I reckon either 1st wed of the month or fortnightly.
At the mo I've gone for fortnightly on wed from 7:30 starting next week.....................
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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