PowerArc Anomaly "Update"

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Re: PowerArc Anomaly

Pete,
The Power Arc can be programmed for single spark. Unfortunately that does not cure the stability problem it sounds like you are experiencing.
The power arc igntion was the only ignition I have tested that would not work when bolted to my testing stand until I removed all play from the distributor [cam] shaft and chain drive. The normal few thousandths of wiggle in the distributor shaft made the two units I tested do exactly what your bike does. Jim
 
Re: PowerArc Anomaly

comnoz said:
Pete,
The Power Arc can be programmed for single spark. Unfortunately that does not cure the stability problem it sounds like you are experiencing.
The power arc igntion was the only ignition I have tested that would not work when bolted to my testing stand until I removed all play from the distributor [cam] shaft and chain drive. The normal few thousandths of wiggle in the distributor shaft made the two units I tested do exactly what your bike does. Jim
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Thanks Jim. I keep forgetting the title to my own thread. Looks like I am trying to put lipstick on a pig.
 
Re: PowerArc Anomaly

swooshdave said:
Dkt26 said:
Yeah they are expensive for sure but gee I'm keen to try one.
I can get a brand new ARD but the maker is 83 years old so as time is inevitable, along with death and taxes, I fear that once the individual passes on from this mortal coli, so will the serviceability of the ARD. Hence the hunt setup.
I was a bit concerned about the straight ignition (no curve) but have subsequently read up about this and am less concerned.
Cheers
DKT
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I think they stopped offering ARDs quite a while ago.
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I can still get em brand new through a friend of a friend but they are expensive!!!
 
Re: PowerArc Anomaly

pvisseriii said:
comnoz said:
Pete,
The Power Arc can be programmed for single spark. Unfortunately that does not cure the stability problem it sounds like you are experiencing.
The power arc igntion was the only ignition I have tested that would not work when bolted to my testing stand until I removed all play from the distributor [cam] shaft and chain drive. The normal few thousandths of wiggle in the distributor shaft made the two units I tested do exactly what your bike does. Jim
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Thanks Jim. I keep forgetting the title to my own thread. Looks like I am trying to put lipstick on a pig.
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Do you know how good your cam chain is?
 
Re: PowerArc Anomaly

I'll call Fred and Gray to see if they have a rash of failure complaints but seems like complaining a belt kit is bad design because it won't stay on with worn out tranny components.
 
Re: PowerArc Anomaly

hobot said:
I'll call Fred and Gray to see if they have a rash of failure complaints but seems like complaining a belt kit is bad design because it won't stay on with worn out tranny components.
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But the engines I have experienced this on were by no means worn out. Just normal bearing clearance.

Cam chain play does seem to be part of the problem - but chain play is necessary. A performance cam that makes the cam and timing components jump and pulse more seems to make the problem much worse.

I don't know much about the Harley this ignition was designed for but I suspect they must have a had a better supported cam than a Norton.

Exactly why some engines seem to have trouble and yet others do not -I do not know. Jim
 
Re: PowerArc Anomaly

swooshdave said:
Sounds like a gear driven cam might be the solution. :mrgreen:
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Dave, the issue has to do with endplay not drive slop. If the encoder wheel moves in and out from the pickup eye, the program looses sync and things get funny. I have acceptable amount of end play and if it is out, it is very little. I am surely not going to split the cases just to use this item.

For the rest, I received a response from Fred. They can be set for single spark and I will send it to PowerArc for this service. It may not matter but I will give it a go.
 
Re: PowerArc Anomaly

Oh Ugh James, Ms Peel's low octane Hi CR boosted combo can not survive w/o the switchable programmed ignition curves with 3 spark anti-detonation help. If I can't get it stable sensing in Peel then your EFI may be my last resort to fall back on - like a mortar dropped down its launch tube. Peel will have charging power to spare. Leaves me trembling to imagine what that combo might do to me. Can it be configured to handle water injection, methanol and NOS? off topic so pm me.
 
Re: PowerArc Anomaly

From what I have seen the endplay is not so much the problem as is radial play, runout and pulsing of the cam speed as it slows as the valve is opening and then speeds up on the closing side. My guess -and it's just a guess- is the processor has a hard time keeping up with the fine tooth rotor when it is not creating a fairly steady signal. I know that on my bench tester the unit would loose sync and give miss-timed sparks every few revolutions when I had an old chain on the drive. It had some stiff links that caused the rotor to jump slightly every time the link would hit the motor sprocket. With a new chain it would only lose synch intermittently with no apparent reason. The problem got better if the chain was "tight" but it still seemed very touchy.

Here is my ignition tester. There is around .001 clearance in the bushings and the end play is adjustable, down to zero. The motor speed is variable from 0 to 8000 rpm. I used the chain drive as the unit was originally designed to test magnetos and the advancer. It seemed like a good way to keep an ignition test as close as possible to real conditions. Jim

PowerArc Anomaly "Update"


PowerArc Anomaly "Update"
 
Re: PowerArc Anomaly

Well, my cam is new'ish and the bushing were great. Buttery type of contact.

Somewhere in the instructions it says that endplay should not exeed .020".

I will recheck my camchain chain. Having the MK3 cover comes in handy sometimes.

My hopes are that the single spark curve will offer some grace and not have such finite requirements to function as advertised. Wishfully thinking, a single spark PA might be awesome :)
 
Re: PowerArc Anomaly

I'm hoping for better results on mine! If the electronics are too slow to "count" the times the beam is broken/made then that would be a sad fact indeed! I once built an electronic voltage regulator for an old style generator that used to have an "anti flicker" device hooked to the engine points. (The old regulator used clickity clack switches to ease off on excitation during the single cylinder power stroke so the voltage wouldn't go up when the crank was moving it's fastest during the power stroke.) I worried out loud that our electronic voltage regulator had no mechanism for detecting that fluctuation and the designer of the one-off regulator just smiled and said that it would be adjusting the voltage 10,000 times per second. I built the regulator and installed it and it worked flawlessly from day one. digital circuits that count things happening (like a beam being made and broken) should be lazily waiting around for something to happen at RPMs as low as 7000.

What I am really hoping is that you guys have gotten a hold of some defective units!! But, my Rita is working great so I'll keep it ready to put back on.
Dan.
 
Re: PowerArc Anomaly

I have an update to the power arc situation.

I sent my unit into the company with a referral from Fred.

I request that the unit be reprogrammed to a single situation. I have had it back from powerArc for a couple weeks now, but have not had time to try it out.

Today I put it on and it works great. Idles steady and is really strong all the way through from bottom to top. It really runs great. This is only after a short 5 mile romp.

In addition, Gary from PowerArc sent another unit with 4 single spark curves to try out. This unit has two extra wires to ground or unground as a switch between curves. I am going to use the one I have on for awhile to see how it shakes out. I really like it.
 
Here something interesting.
I went out for another 20 mile. Ran great.

When I got home I decide to put the timing light on it. It read 28 degrees right on the nose. Because of only one spark, it read steady

Now for the interesting part, There is no curve. No advance. 28degrees all the time, just like the mag. I really do not know what to make of it. I have a feeling they are all that way but because you cannot really read the strobe with a multispark, how would you know.

All that being said, it sure works great this way. Only downside is a slight kickback. Not so suprizing.
 
Ambivalent news to me, if goes straight to full advance them my project engine will flat explode. Not exploding was the sales pitch that sold me so pensive now.
 
Pete, it would seem it's time to try the unit with 4 curves that they sent you, something wierd with the original with no curve at all...Mark
 
I'm sorry to hear of the woes with Power Arc. I should have bought a couple of Boyer units when they were on sale. My Norton has an older version that works with stock coils, stock plug wires and stock plugs, no hassles.
 
If ya really know what Norton response to fast rise curve is like Boyers will bore ya a bit. Its costs hundreds extra for a 4 curve model so don't think that sold by Old Brits, though any curve can be put in with the connection kit and 'puter program downloaded. If no one else pulls on the Powerarc's dudes ear I will be about these funny findings.
 
marksterrtt said:
Pete, it would seem it's time to try the unit with 4 curves that they sent you, something wierd with the original with no curve at all...Mark
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Well I gave it a try today. This is the break down of the grounding.
PowerArc Anomaly "Update"


I started with both blue and brown ungrounded, least advanced, and it ran just fine with the curve (yes, there was a curve to this C2 unit) at 20 degrees at idle to 29 on the run up.

I then tried the brown wire connected, second stage so to speak and was ok but did not notice any real change. I then went to the blue wire, third stage and felt the pep. It was still at 20 degrees at idle but when up to 32 on the rev up. I find this rather suitable for the 110 leaded fuel, the stage one cam and raised compression.

So, no wires connect for easy going, and blue wire for sport. I really don't feel the need to go to the forth stage, 32 BTDC is as far as i want to go. Gary from PowerArc say the forth level is around 36 degrees.
The instruction say that normal operation is when both are grounded. This unit may be suited for a Triumph.

One thing is for sure, the single spark configuration and setup for wasted spark is good way to go. That multispark stuff just did not agree with my bike.

The last thing is the question of why the reprogrammed C1 did not show an advance. Oh well, it sure runs good that way.
 
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