Dimensionally smaller battery - need advice on cold cranking amp requirements

[philosopheriam]

You do not have a timing diagram about what you are trying to accomplish; I don't want to guess.

It is also not clear what the operation of the relay is when you have two active inputs. According to the description it will not operate with a +12V input on 87 and a ground on 87a simultaneously.

Note there is implicity 3 states available for each signal +12V, Open and Ground.

I apologize for the confusion, I should have been more specific.

The goal was to design a basic logic circuit with a timer that energizes the ignition coils 1s after the oil pressure switch opens. The coils will be DE-ENERGIZED under the following conditions:

1. If the oil pressure switch closes due to loss of oil pressure (the engine isn't running OR the engine isn't cranking fast enough to produce sufficient oil pressure to open the oil pressure switch).
2. If the deadman switch is opened
3. If the keyswitch is turned off

If someone attempts to start the bike yet releases the starter button midway, the oil pressure in the engine will drop, close the oil pressure switch, deactivate the timer, the coils will de-energize, and the delay sequence will be restarted when the bike is cranked again.


Detailed Sequence:
1. When the keyswitch is turned ON, power flows to terminal 30 on relay K1. Terminal 86 on K1 is permanently grounded.
2. When the deadman switch is closed, power flows to coil terminal 85 on relay K1 and K2 - at this point K1 will close and allow power to flow to terminal 30 on K2. Closing the deadman also allows power to flow to input terminal 87a on the timer.
3. If the engine is not running, the will be no oil pressure, and the oil pressure switch will be closed, causing coil terminal 86 or relay K2 to be grounded, causing K2 to open, preventing power from flowing to terminal 86 on the timer (this DEACTIVATES THE TIMER). Terminal 87 on the timer will also be grounded.
4. When the bike cranks, oil pressure opens the oil pressure switch causing relay K2 to revert to the NC state, allowing power to flow to terminal 86 on the timer. The open oil pressure switch also removed the ground path from terminal 87 on the timer, and thus, the only active input on the timer is the +12V on terminal 87A. Because the timer has power on terminal 86 and and 87a, it will activate and close in 1s, thus connecting terminal 86 to terminal 30 and allow power to flow to the ignition coil. At this point, the engine has been spinning for however long it takes to create oil pressure + 1s, which should be long enough to prevent kickback once the coils are energized.

The ground from the closed oil pressure switch to terminal 87 on the timer is a "safety" of sorts - if for some reason relay K2 malfunctions and allows power to flow to terminal 86 on the timer in all states, the timer will not activate until the oil pressure switch opens and the ground is removed from terminal 87. Thus, the only active input to the timer is +12V on terminal 87A.

[posplayr]

Questions:

1. Does your oil pressure switch open while cranking?
2. What is the minimum cranking RPM for the switch to open?
3. Have you resolved the ambiguity in having two simultaneous inputs?

[Fjbj40]

I tried the kill switch mod first. While it worked it was not 100% effective. I still had the occasional kick back, because of the low cca of the battery.

I then went with the ignition retard lever and all kick back problems ended, the same result that every person who has done the mod experienced. I still kept the kill switch mod in place but only use the retard lever for starting.

Just my opinion but I think you are way overdoing it with the extra relays. But it is your bike and what you are planning is going to be pretty cool if it works, and it should.

Do us all a favor if it works and add to the "how to prevent starter clutch death" post when you succeed.

By the way, your bike looks awesome!

Cheers

[posplayr]

I tried the kill switch mod first. While it worked it was not 100% effective. I still had the occasional kick back, because of the low cca of the battery.

I think "in a nut shell" you have confirmed the basic solution to kickback. Without changing the timing, you can't really get rid of it, unless you are always spinning very fast.

The issue is firing too early for a given cranking RPM. With a timing retard, the cranking RPM can be much lower and still avoid kickback. Basically there is a maximum ADV as a function of RPM you can have and not get kick back.

If the bike is stock and the battery healthy then you are at something less than the maximum advance. If battery voltage drops (or engine compression increases) and the cranking speed slows, there needs to be a corresponding drop in ADVANCE.

Relays will never solve kickback with low RPM cranking.

I add Dyna 2000 timing info to the other thread

http://www.thegsresources.com/_forum/showthread.php?123877-How-to-avoid-Starter-Clutch-Disaster-Modification&p=2234378#post2234378

[Fjbj40]

I think "in a nut shell" you have confirmed the basic solution to kickback. Without changing the timing, you can't really get rid of it, unless you are always spinning very fast.

The issue is firing too early for a given cranking RPM. With a timing retard, the cranking RPM can be much lower and still avoid kickback. Basically there is a maximum ADV as a function of RPM you can have and not get kick back.

If the bike is stock and the battery healthy then you are at something less than the maximum advance. If battery voltage drops (or engine compression increases) and the cranking speed slows, there needs to be a corresponding drop in ADVANCE.

Relays will never solve kickback with low RPM cranking.

I add Dyna 2000 timing info to the other thread

http://www.thegsresources.com/_forum...78#post2234378

Yes, you are correct about timing retard for starting.

In piston powered aircraft there are magnetos used for ignition. Simple very reliable devices that need no battery or voltage input to produce spark. The flaw is the slow cranking speed of the engine for starting. The majority of magnetos use some form of ignition retard for starting. These aircraft, when there is an ignition retard failure are very hard to start, engine basically stops turning if the spark occurs at 20-35 degrees BTDC, which is normal during a running state but not for starting.

I do not know why I did not do this first when I know better

[philosopheriam]

I tried the kill switch mod first. While it worked it was not 100% effective. I still had the occasional kick back, because of the low cca of the battery.

I then went with the ignition retard lever and all kick back problems ended, the same result that every person who has done the mod experienced. I still kept the kill switch mod in place but only use the retard lever for starting.

Just my opinion but I think you are way overdoing it with the extra relays. But it is your bike and what you are planning is going to be pretty cool if it works, and it should.

Do us all a favor if it works and add to the "how to prevent starter clutch death" post when you succeed.

By the way, your bike looks awesome!

Cheers

Here's the issue - I'm smart enough to realize that there are others out there that know more about these bikes than me. If delaying the energizing of the ignition coils isn't the 100% solution, than what's the point? Spend $60+ for a 1/2 solution...

It appears that either a manual timing retard or an electronic one is the ticket. Does anyone know for certain if the Dyna 2000 ignition will do what we are discussing - either retard or limit the timing under certain RPM's? If so, It may be the solution that I will pursue.

[philosopheriam]

Here's the instruction manual to the Dyna 2000

http://www.dynaonline.com/skins/downloads/instruct/DDK3-3.pdf

It appears that a timing retard can be triggered by grounding a wire in the ignition harness - the retard is adjustable from 4 to 16 degrees. Sounds like an excellent solution. Have a relay triggered by the starter that grounds the retard wire. Done....

[posplayr]

Here's the instruction manual to the Dyna 2000

http://www.dynaonline.com/skins/downloads/instruct/DDK3-3.pdf

It appears that a timing retard can be triggered by grounding a wire in the ignition harness - the retard is adjustable from 4 to 16 degrees. Sounds like an excellent solution. Have a relay triggered by the starter that grounds the retard wire. Done....

I don't think you interpreted the manual correctly. The diagrams I posted are from the Dynz manual znd the only thing relevant to the discussion of kickback.

[philosopheriam]

I don't think you interpreted the manual correctly. The diagrams I posted are from the Dynz manual znd the only thing relevant to the discussion of kickback.

Posplayr,

Forgive me, I'm not trying to be an argumentative jerk, but I'm missing what you're trying to say - how did I misinterpret the manual?

[philosopheriam]

I don't think you interpreted the manual correctly. The diagrams I posted are from the Dynz manual znd the only thing relevant to the discussion of kickback.

Okay, I may have figured out what you're saying - at 1000 rpm or under the triggered retard doesn't take effect.

[posplayr]

Okay, I may have figured out what you're saying - at 1000 rpm or under the triggered retard doesn't take effect.

Did you see this????

http://www.thegsresources.com/_forum/showthread.php?123877-How-to-avoid-Starter-Clutch-Disaster-Modification&p=2234378#post2234378

[Big T]

While this is all a good idea, I believe you're over thing a problem that may not exist.
Most 1085 owners have no problem starting the bike.
Just modify your headlight lever and run it off when you start up

[posplayr]

While this is all a good idea, I believe you're over thing a problem that may not exist.
Most 1085 owners have no problem starting the bike.
Just modify your headlight lever and run it off when you start up

Whut? a smaller battery does not exist?

[wymple]

Not to start any arguments, JMO, I doubt you "need" more than 175 CCA. Only one cylinder at a time comes up to compression, and on a liter bike, those cylinders are only 250cc. A four cranks over much easier than a big twin, which has larger cylinders by far. My Guzzi has 475cc per cylinder, and it starts up just fine with 170 CCA battery in it. I stuck it in there temporarily and haven't seen the need to go buy a bigger one. My GS850 starts with a very low charge (from past experience) on a 200 CCA battery. I believe that unless you have one that seems to have to crank awhile it won't matter much. I only put a 175 CCA battery in a custom 750 Virago and with starter problems it cranked a long time.

[Fjbj40]

Not to start any arguments, JMO, I doubt you "need" more than 175 CCA. Only one cylinder at a time comes up to compression, and on a liter bike, those cylinders are only 250cc. A four cranks over much easier than a big twin, which has larger cylinders by far. My Guzzi has 475cc per cylinder, and it starts up just fine with 170 CCA battery in it. I stuck it in there temporarily and haven't seen the need to go buy a bigger one. My GS850 starts with a very low charge (from past experience) on a 200 CCA battery. I believe that unless you have one that seems to have to crank awhile it won't matter much. I only put a 175 CCA battery in a custom 750 Virago and with starter problems it cranked a long time.

You are not accounting for the higher compression ratio, the biggest factor applicable here.

Factory compression ratio is much lower, on either a twin or 4 cylinder. Bump it up to 10.25:1 and you will see the problems with 175 CCA!