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Old 08-28-2010, 11:42 AM   #1
stevehuckss396
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Default V8 Ignition

I have been considering what to use for an ignition system for the small V8. Roy's module will only yield 12,000 sparks per minute.

(12,000 X 2) / 8 = 3000RPM

Unless my math is wrong, it will only support 3000 RPM on a V8 engine. Using the same math I think I need.

(8000 X eight) / 2 = 32,000 Sparks per minute.

Is there another module out there that will supply spark at that rate, or am I going to have to build my own. I have a drawing of a TIM type ignition that my pal Louis designed that might work. I won't need alot of energy (CDI) because the plugs will be so small.

This circuit will drive an automotive coil.






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Old 08-28-2010, 11:55 AM   #2
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Default Re: V8 Ignition

Yes, there is, but I have not finished designing it yet.

Frankly, I am not sure where your limitations come from, even the most basic of ignition circuits like you pictured should be capable of greater then 3k rpm on an 8 cyl. Perhaps your math is half off because there are only 4 sparks per rev of a 4 stroke 8 cyl.



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Old 08-28-2010, 12:03 PM   #3
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Default Re: V8 Ignition

Steve,

I don't know if this will help

http://www.5bears.com/tim4.htm

Maybe the TIM7 unit. I used to use the TIM6, and it performed faultlessly once I started to pot the hall sensor up to keep it away from any stray whatsits that could short it out. I was not quite up to your RPM, but I do know the model V8 lads were using the same sort of system a few years back by using a distributor and a steel interrupter plate. I used to make my own TIM boards up, but the last one I used was the generally available kit ones, and that seemed to work just as good as the others.

It is also worth rooting through the 5 bears site, as a few interesting things are going on there in the oldish stuff.


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Old 08-28-2010, 12:24 PM   #4
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Default Re: V8 Ignition

Quote:
Originally Posted by Lakc
Yes, there is, but I have not finished designing it yet.

Perhaps your math is half off because there are only 4 sparks per rev of a 4 stroke 8 cyl.
4 X 8000rpm = 32,000
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Old 08-28-2010, 12:28 PM   #5
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Default Re: V8 Ignition

Quote:
Originally Posted by Lakc
Frankly, I am not sure where your limitations come from
Not my limitations, Roy posted on his site that his CDI will only deliver 12,000 per minute. Being too lazy to build my own, I was hoping someone makes a module that delivers what i need. If I have to, I'll build the circuit that was posted.
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Old 08-28-2010, 12:29 PM   #6
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Default Re: V8 Ignition

Hi Steve,

When I sorted out the problems with my 302 ignition I pondered the same questions as you regarding Roy's ignition versus Jerry Howell's ignition. I have several of each type.

My 302 will rev to 7200 rpm so that's 28,800 sparks per minute. Not that I have held it there for any amount of time. I am currently running it on the Howell style ignition (TIM-6). I have switched over to Roy's and it seems to run fine but I have never taken it up to maximum rpm as I did with the other ignition installed. Once I found out how high it would rev I was satisfied and don't press the limits anymore. I don't need a box full of bent and broken pieces.

I had gone to the 5 Bears site quite awhile ago when I got into the electronic ignitions. I bookmarked it for reference. When I was having trouble with burning up or shorting out Hall sensors I thought that maybe it was the sensors themselves as the ones being supplied by Alan Howell now are different from the ones his Dad was providing. I did a search for the HAL 506-UA and found one place in California that sold them. Other places like DigiKey have replacement types but being as 5 Bears picked that one I ordered 6 from out west. I wired up a couple as replacements and have tested them for a long duration and have had no trouble.

I guess to answer your question, I would think that Roy's ignition or the TIM-6 would work fine for your engine.

I am planning on being at Zanesville in October so we can swap notes there.
George

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Old 08-28-2010, 12:51 PM   #7
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Default Re: V8 Ignition

Here's a link to a data sheet for HAL5** Hall Effect Sensor Family.

http://www.dsymcu.com/templates/200612199453300.pdf

Current information: http://www.micronas.com/en/automotive_and_industrial_products/by_function/hal_5xy/product_information/index.html?doc=1355238

Tim

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Old 08-28-2010, 03:16 PM   #8
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Default Re: V8 Ignition

FANTASTIC ............. See this

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

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Old 08-28-2010, 03:27 PM   #9
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Default Re: V8 Ignition

Quote:
Originally Posted by stevehuckss396
4 X 8000rpm = 32,000
I try to make it a habit not to do math before 8am, shame on me.

Ignition primary systems are mostly about current flow, as that is the factor that creates the magnetic field. Any installation that cannot provide large inrush current to the coil primary will limit spark energy to the point it could diminish at higher rpms. Same could be said for any coil with too high primary resistance. So, there are a lot of factors outside of the module itself to consider.
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Old 08-28-2010, 05:15 PM   #10
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Default Re: V8 Ignition

Quote:
Originally Posted by tonyengines
FANTASTIC ............. See this

http://www.cncengines.com/orderpage.html
Hi Tony!

This site is Roy's site for the CDI module.


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