How much spark strengthe is needed for Alky?

[Beck]

I have been researching alcohol fuel and boost. It seems it takes quite a bit of spark strength to get a big load of alcohol under boost lit. How Much?

I am not planning big boost. I am looking at 10 psi. Alcohol must be harder to get lit, or is that just at higher boost where more fuel is needed?

Would a standard HEI do it? Do I need to step up to a MSD 6al or all the way to a MSD 8?

I am going to be working on a distributorless ignition soon and need to start the serious planning. The intake I'm building will not clear the distributor. I could belt drive it, but want to explore other options.

[Beck]

Here is my intake project

[kb426]

Any modern ignition will be strong enough. The question will be how much rpm? I believe the hei looses strength above around 6 grand or less. If you're going to turn this to 9 grand, you will need something with those capabilities. I ran smaller gaps from day 1 in blown applications at the strip which was the normal deal. I haven't kept up with what they do now but they also have 50 lbs of boost. I never had more than 36.

[wayne petty]

MSD uses basicly a ford duraspark pickup coil and reluctor for their magnetic trigger ignitions..  so instead of looking at an HEI.. i would be looking at duraspark 2.   should be able to either use a 4 cylinder reluctor off a 2300 pinto from the 75 to the mid 80s in a modified V8 housing so you can use the conventional cap adapter and large cap..  you will have to modify a cap with a hole to check for rotor verses reluctor phasing with spark going across  the gap..

there were also really trick reluctors that had adjustable arms on it..  if you needed to remove 4 to make it a 4 banger....

don't worry about it being an 8 cylinder cap.. use some angled cap boots and fill them with clear silicone sealer to prevent any possibility of  spark jumping to them.

please don't sand blast the reluctor.. it changes the magnetic retention properties of its design.  ah.. the reason its called a reluctor.  reduced the ability to create a nice AC sine wave output with enough voltage to trigger the pickup coil..  needs to be over 1.0 volts AC measured directly at the pickup coil wiring..

since the housings may be aluminum.. you may be able to machine off  some of the length  and weld on stands and replace the bushings with bearings to support the belt load.  i would probably use some kind of idler roller mid belt span to reduce the possible whipping of the middle of the belt.  or use two.. one on the the outside of the belt so it does not try to become an oval at high speeds..

paying close attention to the side of the positive and negative wiring so you don't end up with voltage drop and slow filling of the ignition coil..

Capacitor ignitions use caps as mechanical storage of electrons.  so the coils fill faster.. instead of waiting for the battery to supply electrons in an electrochemical reaction.. they are stored in a big azz capacitor..  this will take some experimentation with a high speed high voltage scope to monitor the current flow... MSD gets around this by increasing the voltage to the coil primary..  sort of super charges it. by running several hundred volts to the coil primary..  and the reason that automotive diagnostic tools blow up when hooked to cap ignition systems.  the best sounding car stereos use massive caps as mechanical storage for the electrons for a faster amplifier response to push and pull the  speaker..  

on your intake.. i don't know how much time you have into that.. but i personally and that is just me.. don't like straight tube intakes.. i like slight tapered..  as in my broken brain.. it causes the enertia of the air charge to pack the bowl behind the valve head and increase the pressure there whiles its closed and not create a reversion pulse back up the intake..

even with super charged motors.. you have the intake valve closed for just under 3/4 of the time.  so that is time the charge can reflect.

i am also a fan of some heads that never made it to the track with reduced bowl volume..  as the volume trapped behind the valve is stopped.. when the valve is opened.. the stopped flow needs to accelerate past the valve seat.  the tapered intake and valve port may use the center of the air charge to focus down on the bowl behind the valve..

all i know is i can see the stop and go flow in my head and this makes total sense to me.  like the tuning tube that creates a low pressure in the primaries and collector in the header using enertia to create an 2 stroke extractor exhaust out of a set of automotive headers.

i book marked this article  some time ago.. never did read all the way thru it..  just breezed and saved the link for future..

http://www.hotrod.com/how-to/engine/1402-the-manifold-tech-engine/

it was in circle track magazine.. not hot rod.

this was a image i saw that looked like the best design i had seen.  some slight taper like the blue drawing.. not a lot of taper.

its just a thought.. most of this is known.. but there are rodders that have not run across this..

[Beck]

kb426 - Hopefully the motor will turn about 7500 rpm. I have been looking at the idea of placing 1 rib of a Ford duraspark reluctor on the harmonic balancer. Then using 2 duraspark pickup coils 180 deg apart. Each pickup would feed a GM HEI module. Each module would fire a dual coil. This would be a wasted spark system.  

The HEI drops off at about 6000 on a V8. That means the coil is firing 48000 times a minute. This coil would be firing at 6000 times a minute since it is only once per revolution. In this range it should still be producing multiple sparks.  

Each pickup would need to be timed separately

I have to be missing something! It cannot be this easy!

[Beck]

Wayne - My tubes are not straight. They do have a slight taper.

In this photo the right tube bell looks smaller. It is a photo thing. All the bells are the same size with square corners.

[phat46]

What about a magneto?

[chimp koose]

a good source of info would be a site called inside top alcohol . many many experienced people running alcohol , either injected or blower /turbo and injection . some are using efi as well . Mostly drag stuff but I have seen comments from pullers as well.

[Beck]

What about a magneto?

I copied this from another site. It is the output of various ignition system systems.
MSD Pro-Mag 44.........950mj
MSD 10 Plus...............700mj
MSD Pro-Mag 20........600mj
MSD-8........................315mj
MSD Pro-Mag 12........300mj
MSD Digital 7..............190mj
MSD 7al3....................160mj
MSD Diital 6.................135mj
MSD 7al2....................105-115mj
MSD 6al.......................105-115mj

Online searching for power output of the HEI is about 85 mj for a stock GM coil in cap. If the coil and module are upgraded it is possible to put out in excess of 150 mj. These aren't my figures. I copied them so they may not be correct.

Now for the costs.
MSD Pro-Mag 44 --------$2200
MSD Pro-Mag 20 --------$1750
Vertex Mag --------------$1100
MSD 8 -------------------$1150
MSD 7al-2 ----------------$500
MSD 6al-2 ----------------$250

For the boxes you need to add the distributor cost also.

The distibutorless system I was considering building would be completed for about $250. I just don't know if it would have the power needed to lite the alcohol.

[Beck]

a good source of info would be a site called inside top alcohol . many many experienced people running alcohol , either injected or blower /turbo and injection . some are using efi as well . Mostly drag stuff but I have seen comments from pullers as well.

I just looked that site over. I don't feel I know enough to ask an intelligent question there. Those guys are SO above me! I'm a little guy with a little motor on low boost and a LOW budget compared to them.

[kb426]

I may have told this story before but probably before you were a member. In the 70's, the Mr. Gasket trailer used to come to all the national events. The Mallory mag tester was in the trailer. Back then when had super mag 2's with a less than 3 amp generator. The tester had 8 plugs in free air. The high tension lead was connected to pointed rods that could be adjusted to open the gap several inches. I watched them test mags and with a little rpm, the high tension lead would send a red ionized column of fire about a 1/2" in diameter between the gaps. They could open these to more than 1 inch and it just kept going. A little after that, MSD introduced the multi-spark discharge system. I saw them use the same kind of tester.  a standard ignition system with the high tensions gaps around 3/4" would shoot a normal spark plug firing spark between the posts. They put a sheet of paper in the area between the rods and it killed the spark. The same test with a the MSD 6 sent a column of fire like the super 2. It shot right through the paper and kept going. I believe you will find that alky is no more difficult to ignite than gas. Boost is the only factor that causes it to become more difficult. Don Zig had a tester with the spark plugs mounted with the electrodes into a chamber with 120lbs. of nitrogen. He explained that simulated combustion pressures. I have never had a mag that passed that test fail. The Mallory open air tester wasn't as effective. I would try anything that you want to and see how it works. I think at 7500 with less than 15 lbs of boost, it would be good. Coil saturation time with rpm would be my only concern. One of the reasons people like methanol is it's very forgiving.  You can do way more than with gas without bad results. On a blown engine, the fuel system and how much boost and how quick it does it are the most important concerns. You have a great project going. Try your ignition idea in a testor and see how hot the coil lead is. If you see the ionized large diameter charge and it shoots through a sheet of paper, I think you'll have a winner. My last engine was 11.75 comp. with 36 lbs. of boost. The super mag in it had a 3.4 amp generator which is probably half of what they have now.

[enjenjo]

The information you are missing is the time factor.

Coil saturation rates vary with different coils.  At a minimum they need .0050 seconds to saturate, or make the maximum output. The best info I can find says a vertex mag outputs 1500mj/second. That has to be divided by one half the RPM( only half the plugs fire on each revolution) times the number of cylinders to find the output for the number of events that are happening per second.

I only have experience with a magneto running alcohol, both normally aspirated and supercharged. In both cases we had to run tight gaps on the plugs, in the .020" to .025" range to get a reliable fire. I do know the new mags have more output. I checked with my brother, he used to run a limited sprint car, the rules required a 305 Chevy block and heads, and a GM HEI. They used the good stuff HEI parts, and could only run about .030" plug gaps with alcohol.

To use a crank trigger it has to be set to full advance, and then retarded by electronics to give you a variable advance, or by adjustable pickups to give you a fixed advance. I have seen flat screwdriver bits used as triggers on the crank, inserted in a hole on the outside of the damper, and held in place by a set screw.

Just my experience, and probably no help.

[Beck]

I checked with my brother, he used to run a limited sprint car, the rules required a 305 Chevy block and heads, and a GM HEI. They used the good stuff HEI parts, and could only run about .030" plug gaps with alcohol.

I have seen flat screwdriver bits used as triggers on the crank, inserted in a hole on the outside of the damper, and held in place by a set screw.

Just my experience, and probably no help.

These items were of great help.

I expected the reluctors were made of some special type of steel.   A screwdriver tip... I didn't know how I was going to machine the balancer to install and retain one of the reluctor webs. Fairly easy to make a part that is round on one end and a flat web on the other... Then the set screw to retain it... I like it.

The 7 pin HEI modules pass more current than the 4 pin. I was planning on using those.

Can anyone recommend a dual coil? I know several of the Ford and GM used the coil packs. On my HEI converted distributor I used a coil from a GM truck. I believe they are called E-coils? I need 4 in a block or 2 in a block. I see a lot of these in the salvage yard, but I don't know their primary resistance. I'm thinking most would work. They are all from the newer era ignitions. Are these internally wired for a pair?

[Beck]

kb426 - I like the idea of using a mag. I don't like the idea of making all of the bracketry to hold and adjust it. I don't want to run a battery due to weight. Some mags don't need external power.  The newer/bigger MSDs (12, 20, 44) have external coils and control boxes I think. I expect that requires battery power.  

The other problem is I'm tight $$.... A new Pro-Mag 44 with all components would be about $3000. I don't know enough about them to buy a used one. I'm afraid I would be buying someone else's junk. I would need a specialty mag probably. It would have to be belt drive from the cam or crank or reverse rotation to cam mount.    When I read about guys asking about the MSD 12 or 20 mags they are always recommended to spend more and buy the 44. Parts are not as available for the smaller ones. The 20 likes to eat control boxes.

I keep telling myself I am not building a Top Fuel or Top Alcohol motor. If I keep the boost low it shouldn't be that hard to get it lit.

[Beck]

I spoke with an ex-MSD tech today about a distributorless system.  He is still very supportive of their products. His budget suggestion if I would persue this is - one rib on the balancer to trigger 2 pickups. Each pickup feeds a MSD Street Fire ($150 ea). Each Street Fire feeds 2 Blaster coils ($50 each)(4 total) in series. So $500 in MSD parts plus 2 pickups and a single rib reluctor on the balancer.

I could buy a used Vertex mag for that, but not a MSD mag. It would still need a coil, and I would need to do some machine work to mount it. I would need to check that the rotation was right.. The mag would be more compact and less wiring. Starting would be worse, but high rpm would probably be better with the mag.

I am studying enjenjo's link (https://electromotive.com/our-products/)from another of my threads now. Their TECs looks promising. It has full ignition and efi.