electrical majic
XS650 Enthusiast
can a single point ignition be used on a re-phased engine ?
details
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details
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single point ignition
- Thread starter electrical majic
- Start date
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- Tags
- engine
Only if you design/engineer a distributor system, with distributor cap and rotor.
On a more sophisticated level, you could invent a solid-state crank triggered ignition that would sense the single point to know which cylinder to fire.
Otherwise, no...
On a more sophisticated level, you could invent a solid-state crank triggered ignition that would sense the single point to know which cylinder to fire.
Otherwise, no...
DIRTY DOG
XS650 Guru
have a custom point's lobe made and run it wast spark mr rigg's ran a wast spark on a rephase
weaselbeak
XS650 Junkie
A dual point lobe and dual output coil for a wasted spark will do it.
My ol' 45° panhead used single point wasted spark. Still have fond memories of foot-long Linkert carb flame belch. I guess I'm just not comfortable with the idea of a 90° or 83° rephase with wasted spark that deep into the intake stroke...
weaselbeak
XS650 Junkie
"Still have fond memories of foot-long Linkert carb flame belch."
Sense of adventure, entertainment factor, fond memories, character, all that stuff.
Sense of adventure, entertainment factor, fond memories, character, all that stuff.
mrriggs
XS650 Junkie
You need three things to make it go boom; fuel, spark, and COMPRESSION. There is no compression on the intake stroke so there is no problem with waste spark on a re-phase.
As mentioned already, you would need a custom cam to use a single set of points.
If you have your heart set on using points then it would be far easier and cheaper to use two sets of points. All you'd have to do then is drill and tap some holes to relocate one set of points for the new firing order. You could tie the points together to drive a single coil but there isn't much advantage to that since you already have two sets of points.
As mentioned already, you would need a custom cam to use a single set of points.
If you have your heart set on using points then it would be far easier and cheaper to use two sets of points. All you'd have to do then is drill and tap some holes to relocate one set of points for the new firing order. You could tie the points together to drive a single coil but there isn't much advantage to that since you already have two sets of points.
Reminds me of another combat story. Sister-in-law asked me to help get her car started, early '70s Comet with a 302. When she hit the starter, it just didn't sound right. Suspecting cam timing jump, I pulled a plug to do a quick impromptu compression test with my finger over the plug hole. She hit the starter, and I was sprayed with a jet of raw gas (She had been pumping the gas all morning, totally flooding the engine, putting it into hydrostatic lock). Then a spark jumped from the dangling plug cap to the block and 'FLOOM'! I was on fire! I jumped back onto the front lawn and rolled around like a shotgunned rattlesnake until the flames were out. Sure 'nuff, the nylon-sprocketed cam had jumped time, the engine needed overhaul.
On my ol' panhead, If I choked it enuff, the rear cylinder would ignite unburned fuel during the wasted spark event of the front cylinder compression, thru the opening intake valve, and do that crowd-pleasing flame belch outta that Linkert carb. Wouldn't do it without that extra gas...
mrriggs
XS650 Junkie
Patient, "Doc, it hurts when I move my arm like this."
Doctor, "Then don't move your arm like that."
I ran waste spark on my 277° re-phase for years. Rode it every day, hot or cold, rain or shine. It never once backfired out the intake like that. But then, I never tried to make it do it.
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Oh, yeah, I'd do it on purpose to *WAKE-UP* my friends.
Discovered it during an overchoked kickstarting session long ago. Decided to capitalize on the phenomena, impress your friends, terrify others. Ahh, fun days.
To prevent this, I would make sure I was kickstarting on the rear cylinder, not the front, and avoid overchoking...
NONclow
Confirmed Laquer Breather
Reminds me of when I blew my friends muffler off his car.....
"Just hold yer foot down, kill the motor..... keep holdin' down..... turn the key ooooooon, NOW!!!" BOOM! hehe.....
Hahaha, oh yeah! We had a plethora of muffler guts scattered around here in the '60s.
Kids.......
Kids.......
mrriggs
XS650 Junkie
The best one I did was in an old station wagon. The muffler ran right next to the rusted out spare tire well. When it let loose it blew the spare tire cover across the cargo area.
Hahaha, that would be good for 'inattentive' passengers...
