Single ignition thoughts, or lack of thought??

[joedrum]

well I will have to say something here .....wasted spark is wasted..on oldwings number one cause weak spark at idle and crappy timing when dyne is use as they are not very accurate at all...as ive said before ...if I was going to do a caveman wasted spark remover id use two sets of points and convert fuel pimp head into a points head ...that would provide a set of points for each piston ..you have to have four coils too ...do I think it would help...yes but not like a c5 impact is keeping the wasted spark .....but don't know for sure never done it ....

 

[dan filipi]

My own personal observation how hot the spark is with the wasted spark when used with the c5, there would be very little benefit if any to using 4 coils.
Converting the stock ignition to a single coil per cylinder or distributor with no wasted spark, I believe there would be benefit.
It would need to be tried to see if it's worth the effort.
The c5 with its 3 full sparks at every fire and it's dead on timing is proven better, no question of that.
Even one coil per cylinder isn't even in the same league.

 

[ekvh]

I think the three sparks has merit. I also think upgraded coils provide ample spark, even with the waste spark. I thought I read that the reason for waste spark systems was to help keep the coils cooler as they would get too warm at idle waiting to spark again. Nowadays, computers can decide when the coil should be energized. I tend to be in the "floppy timing belt" camp as a reason for the uneven idle of early wings. Turning the motor over slowly shows the belts getting slack a bit as valve springs work. The three sparks give them a better chance of firing at the appropriate time. The 1100's and 1200's have the timing on the crank. The problem with the 12's is the black boxes are becoming more and more rare, and the box controls timing.

 

[joedrum]

im with you on the belts eric....the c5 has all what you said to keep coils right the point it gose the other way ...there so good it can fire three times as much and can recharge to do so ...the c5 is the best thing ever for oldwings ..

 

[ekvh]

But they cost more than any of my bikes.

 

[joedrum]

I know but it is what it is ...your bike eric deserves it it is one of the few on the planet and a great build I know me and you work on this for yrs .....

on my part and yours to I think ...mostly due to lack of resorces :mrgreen:

 

[C5Performance]

ekvh » Mon Oct 21, 2013 6:37 am[/url]":162m3tj1]
I think the three sparks has merit. I also think upgraded coils provide ample spark, even with the waste spark. I thought I read that the reason for waste spark systems was to help keep the coils cooler as they would get too warm at idle waiting to spark again. Nowadays, computers can decide when the coil should be energized. I tend to be in the "floppy timing belt" camp as a reason for the uneven idle of early wings. Turning the motor over slowly shows the belts getting slack a bit as valve springs work. The three sparks give them a better chance of firing at the appropriate time. The 1100's and 1200's have the timing on the crank. The problem with the 12's is the black boxes are becoming more and more rare, and the box controls timing.

Has anyone measured the exact variation in timing on a belt driven cam?

Boxer engine owners seem to really focus on belt play as the cause of running issues.
When first getting into early Wings I never understood why it was such a big deal. When the engine is running the belt slack should be on the "back" side of the system, so timing will only be inaccurate at low idle, correct?
I'd guess at least half of motorcycles ever made had points located on the cam, even though most were chain driven. You can get chain slop just like belt slop, so why do Wing guys fret over it so much? Nobody on the Honda CB websites worry about chain slop, and every CB175 and CB350 made used a cam driven ignition.

My thinking is the actual variation in timing when the engine is under acceleration would be less than 1 degree. If that is true, are we chasing the wrong problem?
Points can be horribly inaccurate
Magnetic triggers are up to 7 degrees off at any rpm
Optic triggers are within 1-2 degrees depending on the quality of the trigger.

The goal of any ignition is to help the engine reach PCP (peak cylinder pressure) at 14-16 degrees ATDC. If you set timing to accomplish this, and it's accurate and repeatable (not randomly accurate) then every running issue after that is not related to ignition.

Again, i ask the question...what is the timing variation on belt driven engines? I dont' think I have ever read an actual number but it's critical to know before we can attempt to fix an issue related to belt deflection.

 

[dan filipi]

I'm with ya Paul.
These ideas hit the forums randomly with no proof to back it up.

Would be easy to check variation, turn the engine forward and back.

 

[joedrum]

well paul on oldwings when they spit backwards throught the carbs ...carbs dont work that way either ...but it happens ...same thing happens on belts ...and it puts the slack in belt or chain in the area where it dose matter ....on boxer motors and at idle ...the motor are so perfectly balanced this creates a stutter on the low end rpm that can take quite a bit of power away from low speed getting around .....that just wont happen on inline fours and other set ups .....but there no doubt that an oldwing is the smoothest hard mount to frame setup ever ...and yes the ignitions are more the cause but oldwings take this flaw to a higher level .....

the c5 is the cure in my opinion as it is as good as the motor ...and belt issue will not have anything to build on to get out of hand

 

[mcgovern61]

My two cents on the belts......I agree about slack on the loose side of the belt, but the belts are always tight on the tensioned side which is also the timing side of the cams. These belts have very little stretch to them if any. They will more than likely break before they stretch. What little stretch they get (over a very long period of time) is less than the distance of one tooth of the cam sprocket. Gear belts (like timing chains) have very little leeway for stretch in their design. If stretch was allowed, timing could never be assured by the manufacturers.

I am under the opinion that when the belts are properly installed, they are not an issue with the timing or ignition anymore.

 

[AApple]

Hook yer timing light up, take yer belt covers off, and see how much flop there is with it running. With the timing light pointed at the belts, you should be able to see the belts fluctuating.
ANY rubberized belt will have some flexing at speed, but it is normally a non-issue, unless there is a loooong space between the pulleys. At speed that long space of unsupported belt WILL flop. In theory, this will also allow the pulleys to speedup/slow down imperceptibly. On a cam driven ignition, it has no choice but to be effected by this....but...can it actually be measured? Soitany..if you have a bazillion dollars worth of equipment....like Honda has. In the end, any fluctuations caused by belt flop has been apparently deemed acceptable....at least until they decided it would be better to move the iggy to the rear(or front, on the 1200), and run it directly from the crank
So....I doubt that belt drive cams such as ours have will have any measurable downsides to ignition issues, assuming the belts are good, the cams/pulleys are machined correctly, and all assembled properly.
Unless yer planning on setting a land speed record, or fastest quarter mile time, I can't see then need to get THAT accurate....factory stuff has been working for years and years. The C5 set-up is a new mousetrap that improves the end game. It takes some of the built in margin of error out, and adds some new tech, without having to redesign the wheel in the process. :yes: :wave: opcorn:

 

[joedrum]

gee how well said k: :mrgreen:

 

[Steve83]

If loose belts cause all these problems, do they all go away when new belts are installed? Every Wing engine I've worked on has had the belts replaced before I started it, so I don't have a "before and after" comparison. If a belt is loose enough to cause a noticeable change in timing, it will be close to jumping teeth, IMHO.

 

[joedrum]

many do and its always blamed on the belts

 

[Ansimp]

The problem with belts IMHO is not from slop but incorrect installation or not changing them at regular intervals. The EJ series of Subaru engines have been some of the best that they have built and all have used timing belts( one long belt). The earlier EA82s used two belts as per the GWs and most of the problems with timing belts came about because of the alignment procedure( special marks on the flywheel and you need to rotate the engine 180 degrees for the second belt alignment) I have owned at least 3 Subarus with over 450k kilometres on them without any issues attributed to belts and they are all still running well. :good:

 

[slabghost]

Belts are really a non issue in the timing equation in my opinion.

 

[Ansimp]

+1 no real problems on high horsepower WRXs but they are individual cop (coil on plug) units

 

[ekvh]

Uncle.