High output coils

[tweety]

Have rebuilt ea81. Rebuilt distributer with module. I have the following questions

 

1/  Will the installation of a higher output coil (I have a master blaster 2 max 45,000 volts up from 32,000) cause any adverse effect on the module in the dizzy?

 

2/ What spark plug gap would you use with the higher output coil? Currently using .034" I have 9.5:1 CR reasonably high.  Using platinum plugs at the moment

 

3/ What are the obvious signs of a damaged or worn module? Is there a way of testing it?

 

I've ordered a new module and will use my current one as a spare.

 

4/ What are owners results in using a high output coil re: economy and power improvements

 

Thanks

 

[ihscout54]

1/ Will the installation of a higher output coil (I have a master blaster 2 max 45,000 volts up from 32,000) cause any adverse effect on the module in the dizzy?

Im not real sure about what you boys have down there, but it looks like you have the Hitachi with the module under the cap? I kinda think this thing might be a sorta copy of the HEI. This is probably the strongest of the units Subaru used for our cars. The resistance values on that coil will likely be lower than the stock unit. So in theory you are pushing it. I bet youde be fine if the values on the coil arent too much lower.

2/ What spark plug gap would you use with the higher output coil? Currently using .034" I have 9.5:1 CR reasonably high. Using platinum plugs at the moment

IMO stock ignition on these is more than adequate for what you need. Ide gap them at .043-.045. They arent real hard to change if you dont like the results.

3/ What are the obvious signs of a damaged or worn module? Is there a way of testing it?

Solid state devices dont exactly get damaged or wear out. They usually just die or burn out. Ive never seen one of these types go bad.

4/ What are owners results in using a high output coil re: economy and power improvements

As I said, the stock setup is pretty decent, so most of us would see little benefit from this. BUT your setup is not like what most of us are running. It will be an experiment. Edited June 3, 2015 by ihscout54

[bratman2]

I installed an Accel Super Stock yellow round coil maybe some 15 years or more ago. Have had no issue but really cannot claim any increase in power either. Seems they claimed up to 42K volts, do not what the actual is in my application. Some did have problems with these coils which was entirely related to poor quality control after out sourcing them. Only coil failure due to oil leaks if my memory serves me right! If it was me and I had it, I would install it. I would also probably use just standard NGK plugs gapped at .045, maybe even .048. The platinum plugs only benefit is longer change intervals, not performance.

 

I do average about 29-29.5 US mpg. Have broken 30mpg many times over the years. I also have a weber and 2-inch exhaust from the Y pipe back.

Edited June 3, 2015 by bratman2

[ihscout54]

Agreed bratman. His choice is fine, though I wanted to mention just using good old cheapy copper plugs. I did not since I hate starting arguements over things like plugs, filters and oil...

[naru]

Hi Tweety

I would not use it and I would not expect any benefit.

 

1-Yes,quite possibly.Masters blaster 2 has a lower primary resistance than stock and will make the module flow more current than designed.

 Master blaster primary is .7 ohms,average  Hitachi stock value is 1.12 ohms.

 That is a 60% increase compared to the master blaster.Pretty substantial.

DC resistance is not the whole story.

Inductive effects come into play in the pulsating voltage enviroment the coil lives in.

I expect the master blaster will have lower inductance

 

Higher secondary voltage means the module w/see higher reverse voltage spikes as well.

I think Subaru would have gladly used less copper in thier coils if they thought it would work.

 

Then again,all you have to lose is a module.

 

2-Good question.Increasing the gap will increse the secondary voltage developed/required.

 

3-Obvious signs are no spark.

    I`ve seen Hitachi modules fail such that the car still runs but poorly.

    One case I know for sure was because of high reverse voltage spikes caused by a very loose plug wire.

Diode test function of a multimeter can provide a simple test for opens.

Best to have a known good one to compare to.

Dwell meter reading on a running/cranking engine is a decent test of module functionality.

I`ve heard of bench testing them by triggering them w/the pulsating magnetic field of a soldering iron,but,I have not tried that yet.

[tweety]

mmm, those replies clarify a lot for me. Yes ihscout54 that is the "under the cap" module same as pictured.

 

Seems to me that changing the coil is simply not worth the potential trouble and that was what I wanted to assess. Possible future issues that are hard to trace.

 

However, it is interesting so many of you (and many on the internet that I've read) suggest opening the spark plug gap to .045-.048"....a huge leap from the stock .032". My engine has done about 3000 miles since total reco so eveything is new. I'll experiment with the plug gap and leave the rest alone.

 

Great to get so many quick replies. If anyone has a counter arguement for using the higher output coil with electrical proof it does not harm to the module or other parts feel free to post.

 

p.s. nice to hear from you Naru. (Doug was nice enough to chase around for some parts for me not available near me)

 

 

Edited June 3, 2015 by tweety

[ihscout54]

Killer post NARU!

These Hitachi modules were used on other cars not, just our Subarus. Cant say they are all the same, but ive seen them on other cars. No idea what the coil values were. I also thought stock spec for these coils was like .9-1.29 or something. Just because Subaru used these coils doesnt mean the module couldnt handle switching more juice. Two of my cars had well run old flame thrower XL 1000 PRO gizmo coils attached to this system and they ran fine. Of corse Ive never checked the resistance on them either as I always dump these distributors for F.I. or a Nippon. The 4 Ive had all had excessive rotor shaft play and are now in a box burred in the shed .

[bratman2]

I don't know why the major difference in gap! Maybe Australia gets a different plug than US models? Seems everything I read had the EA81 gap at what was just posted by ihscout54 and myself.

[tweety]

Good write up.   http://www.ultimatesubaru.org/forum/topic/83354-help-identify-my-coil-ea81/

[comatosellama]

Are you still supercharged? If you are I'd say that changes the conversation a bit

[ihscout54]

I bet the gap specs hes using is for a points system. I didnt notice any evidence of being blown in the posted pic. If he is then he should ignore our gapping advice.

[comatosellama]

I bet the gap specs hes using is for a points system. I didnt notice any evidence of being blown in the posted pic. If he is then he should ignore our gapping advice.

I know at one point he had a sc12 super

[tweety]

The history of this engine is long guys so can be confusing.

 

Yes the SC12 supercharger went off the engine about 2 years ago after tuning issues with the suck through system. It was either go blow through or try something else. Then I put a SPFI system on it. I beleive the engine internals were damaged from the SC12 set up and hence the SPFI never was successful for that reason. (Had a broken ring, crank was stuffed)

 

The engine was then fully rebuilt including rebore to 1820cc (1mm larger pistons), a 15/55 cam, SPFI manifold, 9.5:1 CR and 38/38 weber carb. The engine is now fully run in and running well.

 

At this stage I'm fiddling with fuel octanes (I know they are different to yours so I wont go into that) for towing and economy reasons.

 

So yeh, I've got a stock set up and near everything is new except for the module which is, a new one is in the mail. I've had this module in the dizzy since the SC12 was on and at that time also had the MSD 2 coil on as well. Hence my questions about symptoms of module wear because if the higher output coil did any damage to the module then....I've been wasting a lot of time since with tuning.

 

So far with this thread I've realised that opening the gap to 0.45 would be the best thing I could do with the addition of installing the new module and using the current one for a spare. And keeping the current stock coil

Edited June 15, 2015 by tweety

[coxy]

EA81 chambers are not that bad a design and with the flat topped or slightly dished pistons they tend to run fuel burn is while not as good as a modern four valve pent roof design better than many engines of the era and similar design,One good option I have used for coils are the Suzuki 4WD coils, Samuarai to our US cousins.

 

They are designed for pretty much a similar system but are overall a beefier coil with better oil capacity and hence cooling ability, with anything Electrical and especially electronic Heat is a killer and the number one enemy of long life  for electronic componets hence the use of heat sink compounds under the modules when fitting them to transfer the heat and help them live.

 

Coil output voltage actually varies all the time the figure these people quote about there so called Super coils relate to the maximum they are capable of outputting and that only occurs under the woirst of conditions not seen all that often in the real world.

 

The reason Coil voltage varies is because the load varies and the coil output adjusts as needed with higher resistance meaning coil output will ramp up to what is required depending on load conditions as well as other variables such as plug gap, Increasing the plug gap will increase the coil output and of course place more load on the system, when looking to improve combustion in the search for efficiency try looking outside the normal with such things as dual earth electrode spark plugs with the area above the central electrode open to the chamber rather than partially shrouded by the earth electrode.

 

As one example the old Kawasali 900 Z1 motorcycles were notorious for having a flat spot around 3500 RPM once people fitted Pod Filters and four into one exhausts and richer or leaner on jetting did not cure that miss, What I found that did fix the miss was actually replacing the standard NGK B8ES plugs with BP8ES plugs with the projected nose placing the initial spark kernel further out into the Hemispherical combustion chamber making the flame front burn quicker and more effectively with better combustion actually being the cure for the miss not never ending Jetting changes as so many tried.

 

Your direction shows tweety you have a better understanding of where you need to be going and why than you realise. Improving Combustion and pumping efficiency will surprise many at how much Power and Economy it realises when done right, The two results of better power and economy are far from being mutually exclusive and will achieve more than people think possible if they go in that direction.

Edited June 4, 2015 by coxy

[jono]

all that text coxy and you didn't tell us what your Brumby runs, or ran in the ignition department - came via Italy ? Externally heatsunked marinelli ignition module ?? Hail coxy !!

 

What coxy says about opening up the gap on plugs, increases load on coil - module too ? dunno ?

 

I recall when the big thing was to open up the gaps to make the EA81 go better , feel crisper. I also recall how much better mine went after I regapped again down to 0.8mm

 

The more comp Tweety has got, a smaller gap may be better ! I run higher... I ran higher comp and propane 7.7:1 @ 12 psi boost and ran 0.6mm plug gaps on a colder plug BCP7ES  the C is the 5/8" plug socket type 14mm seat - allows better socket outer clearance on EA82 mpfi head castings.

[ihscout54]

Jono brings another good thought to the table...

I thought the origional reason manufactured installed hot coils and used big gaps was for emissions reasons. Or just too fire those lean mixtures on low compression engines. Definitely not whats going on here. With forced induction or high compression youll just run into problems with big gaps. But is .043 that big? Is 9.5:1 compression that high? Will he notice anything with the regap? Im thinking "not really".

Hell have to keep us posted

[DaveT]

Waaaay back, when I had my first Subaru.  1976 4WD wagon.  I put a Mallory marine racing coil on it.  And their electronic pickup / replacement for mechanical breaker points.  The only thing I can say with certainty is that it started really well.  I would also drive through big puddles at high speed, and never had it falter.  Don't have proof that it made a difference though.

[tweety]

Well guys I'm stoked with the great responses.

 

Today I received my new OEM module in the mail. Before I installed it though I replaced the platinum plugs with stock plugs and regapped them to .045", made sure all 8mm plug leads had good tight end connections and tested the leads for resistance. .065-1.3 ohms depending on length...good. Went for a ride. Still misfired and it was not a consistance misfire.

 

Out came the old module...mmmm...whats this collar here, and another- both lying down sideways. Seems a good reason NOT to work in the dark as I did the other night. For the sake of those less knowledgable the module has two bolts securing it to the distributor inner plate. Between the module and the base are two collars about 5/16" long. see pic of module and collars are number 19 in pic 2. In my inexperience I didnt know the existence of these collars and just screwed the module down over them but they werent on the bolts.

 

 

 

So, new module comes with small bag of silicone. Told by seller to put silicone under module.  tighten all down.

 

Much better power/acceleration. No miss. Revs up to high range easily. Problem fixed.

 

Am still interested in toying with plugs. Coxy raised many ideas. I remember in Oz in the 1970's there were plugs with 4 earth probes and one centre rod. But wont fiddle now, just interested.

[tweety]

While we are on to the topic of ignition improvements. I found this on the internet-

 

http://www.powerstarsparkplugs.com/performance     Click on the video. has eight sparks. Is much different than the more common multispark plugs and has those 8 sparks on the outside of the plug no the inside.

 

 

The following web site is a test of 4 different types of plugs.- one ground strap, 2,4 and not ground strap. As Coxy indicated, ground straps tke away the ability for spark to directly be exposed to fuel/air mixture. Of the 4 types the no ground strap plug was the most favoured.

 

http://www.sciencedirect.com/science/article/pii/S2090447912000883 

[jono]

for a change, someone elses writing confuses me....Tony, are you saying you continued to delete the little brass? cylindrical "spacers" and stuck the module in directly on the plate with the gunk heatsink stuff? Don't recall you telling us you were looking for a miss either ??

 

Interesting to note if the OEM module came with heatsink goo, for there ain't none in original fittings with spacers.

 

These modules are used in a wide variety of makes and models and not just Subie EA specific

 

On the more than one ground electrode plugs - surprised to see them make a return for cars - thought they were debunked in the early eighties ?

 

I recall Golden Lodge were the four 'trode brand to be desired. Be nice to try something like that on a dyno

[tweety]

The "science" site above at the end of my last post tests these multi ground electrodes and find that the more the grounded arms there are the less effiecient they are. The Powerstar are new design with 8 arms and the spark is on the outside of the plug. watch the video on that site.

 

I was chasing a "miss"  since last Saturday but put it down to raining conditions and cold. Led me to think it was condensation under the dizzy cap. So never thought it relevant here.  Yes the two cylindrical spacers/collars were not even seen when the module was taken off and the spare put on. This meant the spacers were clamped down horizontally squeezed down by the bolts and the module. lol (one cant see directly over my dizzy unless the roof and body are lifted). All clamped down good now with spacers in place and a new module and I just smeared the gunk on the bottom of the module..no harm there but like you say the modules and therefore the gunk is used on other vehicles.

 

So in summary Jono I made a mistake. I'm like a lot of guys. Except I excel where it comes to sex appeal....and general all round handsomeness   

Edited June 5, 2015 by tweety

[bratman2]

It was a simple mistake and happens to the best of us. Happens to me a lot so maybe I am the best of the best, lol!!! Glad your miss is gone and you are running smooth!

[coxy]

Jono regarding at least the Dual earth Electrode plugs I can tell you where they originated and why, BMW another Flay engine maker actually worked with Bosch to develop the twin earth electrode spark plugs to solve an issue with the K series Engines in their Bikes (K Series Inline four not across the frame like Japanese Four Cylinders and laid horizontal sump on RHS head on left) because lazy weakling owners ie Norton Street Leichardt Latte Sippers would not pull the bike up onto it's centrestand and parked overnight on the sidestand oil ran past the rings into the chambers often leading to Oil fouled plugs, The Twin Electrode plugs solved that issue which means they are a good thing in high mileage Subaru's that burn some oil as they do not foul as easily.

 

 

Oh and that Ignition you talk about on my Brumby is a Suzuki 4WD Coil fitted to a Magneti Marelli Coil heatsink mount from an Alfa Romeo Alfasud sprint, Mounted Piggyback style to the coil with a fancy Nismo Bracket is a genuine Works Nissan Stanza CDI with a Stanza factory Distributor suitably modified and tweaked to fit into a Subaru.

 

Ignition Output, Lets say that bench testing by hooking the system up to a 12 volt battery and spinning the distributor slowly by hand results in a strong Blue spark that easily finds it's way to earth through an average 150 page newspaper about maybe 8 to 10 mm thickness, Siffice to say Ignition is not an issue with mere compression to deal with.

[tweety]

MMMM...amazing what you learn. Most members know of my rebuilt ea81 in my trike. SPFI manifold, 38/38 weber, 16/56 cam 9.5:1 CR etc. Then why did it only reach 53hp at the dyno with the right jets? I had platinum plugs
that were black. Economy was not so good at 23 mpg (Oz).

 

Recently due to this thread I started wondering about my ignition module....if it wasnt performing normally. Two years ago I had a master blaster 2 coil when my ea81 was supercharged. But after the rebuild I purchased a new stock one. I never
thought the module would be damaged.
I installed a new module this week. Safely can say about 20% more power. Then swapped the platimum
plugs for stock new ones and opened the gap from my usual 34 thou to 45 thou". Safely say another 20% more kick. Refuelled and went for a long run today. Much much better uphills, much less throttle needed in general riding. Better throttle response. Economy - have to wait and see but is looking good on the gauge. Am using 95PULP (Australian measures). Spark plugs are perfect- light tan colour- not black.

So dont use a high output coil, it could damage your module. Replace your module and use the old one as a spare in the glovebox. Use 8mm plug leads. Open up your plug gap if the rest of the ignition is A1- to .045". And tune it with 95PULP. ps
my timing is 11 degrees BTDC. This was the timing set by the dyno operator that got the max hp at that point and wasnt changed during my latest experimenting with plugs.

 

This all means that the 53hp at the rear wheels (through a VW type 3 auto trans axle) was not near its potential. I'm not going to take it back and get an updated reading. $60,000 spent on this machine over 6 years is enough. But I'm guessing
that with the increase in power and torque I might have 70-75hp ATW now. More than enough for some thrills on a 660 kgm trike. Cheers

 

[coxy]

Tony I would go back to the guy who Dynoed it the last time and point out maybe he should do some learing about just how igntiion systems affect fuel burn as obviously he may have adjusted the mixtures and in so doing was in fact trying to compensate for poor ignition performance, Do not be surprised even though it shows a nice color on the plugs that at some point it is too rich and elsewhere too lean.

 

Especially as with our modern unleaded fuels the old trick of reading the plug color does not apply to unleaded fuel only the old super fuels a trap many fall into, With correct mixtures and clean burning the proper color will be much whiter than you think it would be us older members sometimes forget what once was is no longer and we have to relearn some things.

 

Heck We have found on the Dyno at work that over the last three years jetting that once worked only four or five years ago with certain models and modifications is no longer correct the fuel has changed that much with the adoption in Australia of more Eurocentric standards for our Petrol (Gasoline to our Cousins over the Big Ditch) and Diesel.

 

If he tried to tune something that must have had an Igntiion issue even back then he really owes you a free touch up of his previous efforts as he should have picked up the problem himself on the Dyno only 53 HP was not that good for the work done to the engine.

Remember I do the exact same thing he does where I work, sorry but he should surely offer to do it right this time after you found and fixed the problem he should have found, Approach him nicely and explain what you found and see if he is willing to help out He should do so if he has any pride in his workmanship and reputation.