Author Topic: The Damn CB650 ignition  (Read 12526 times)

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Offline Frankenkit

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Re: The Damn CB650 ignition
« Reply #25 on: May 01, 2010, 02:10:32 PM »
lol no, I just felt a little bad running roughshod over the OP's thread.
"Moderation in all things - especially moderation. Too much moderation is excessive. The occasional excess is all part of living the moderate life."
2012 CBR250R "Black Betty"
1980 CB650c- (sold) Delilah
1973 CL350- Lola?
Sweet, bubbly, Buddha - Say it ain't so!!!
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Offline Hush

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Re: The Damn CB650 ignition
« Reply #26 on: May 01, 2010, 02:21:59 PM »
Any 650 information is good information ;D
I think the thing I most like about motorcycling is the speed at which my brain must process information at to avoid the numb skulls who are eating pies, playing the ukulele, applying make-up etc in the comfort of their airconditioned armchairs as they make random attempts to kill me!!!!!!!

Offline Pinhead

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Re: The Damn CB650 ignition
« Reply #27 on: May 01, 2010, 04:03:59 PM »
  Pin,
   Getting back to your 650 project/ IgniTech:  Vacuum advance??!  Doesn't the mechanical advance satisfy any partial throttle/mileage issues ?  I'm not familiar with your project, so let me apologize in advance.
   The reason that I'm psyched about the GM ignitor is that I can make it "plug and play".  In other words, I can easily stow another Hei module with some dielectric grease in the event of failure at the worst possible time.  Because, as I'm sure you know, THAT is the time when Oki ignitors are likely to fail....

I agree completely about the GM ignitor system. However, as Kit said, I just can't leave well enough alone. ;D I've read articles most notably by David Vizard that stated that a correctly operating vacuum advance can increase mileage by 20% by itself. HERE is the article. :)

Quote from: David Vizard
Neither the canister on the distributor nor the MAP sensor, if you have an EFI engine, is there for decoration. Too many street rodders see that the pro racers use distributors without vacuum advance and figure if it’s good for the winning car it’s good for them. Unfortunately this is not so. Although a drag race car may not realize much in the way of an advantage, none of it performance related, it’s about the only type of race car that falls into this category. Here’s how the puzzle fits together.

When you back out of the throttle the manifold vacuum goes up. This means the compression pressure at the end of the compression stroke is way lower. When a spark timed for a normally fast burning charge (as it is at WOT) fires under these circumstances it is going to occur far too late for the pressure to be at it’s peak at 15 degrees after TDC. This means that less than optimal use of the energy content of the fuel has been made. That in turn means burning more fuel to get the level of power being demanded by the driver at that particular moment. By having vacuum advance pull in appropriately more timing you can let out of the throttle more and consequently cruise on less fuel.

...For you circle track racers here is something I want you to think about. If your car’s engine had vacuum advance it would get about 20% more mileage on the yellow flag laps. Just how many times have we seen a lead car run out of fuel with just half a lap to go?...

Just in case you want to take a look, HERE is the main thread. The cylinder head is outlined HERE and the pistons have been worked by Soos as shown HERE.

Called out by a pinhead.   ;D ;D

LOL!  ;D
« Last Edit: May 01, 2010, 04:12:09 PM by Pinhead »
Doug

Click --> Cheap Regulator/Rectifier for any of Honda's 3-phase charging systems (all SOHC4's).

GM HEI Ignition Conversion

Quote from: TwoTired
By the way, I'm going for the tinfoil pants...so they can't read my private thoughts.
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Offline Pinhead

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Re: The Damn CB650 ignition
« Reply #28 on: May 05, 2010, 09:40:07 AM »
I just got an email back from IgniTech and they said they have a plug-and-play harness for the CB650. :) You can either go programmable or non-programmable if you're still using the mechanical advancer.
Doug

Click --> Cheap Regulator/Rectifier for any of Honda's 3-phase charging systems (all SOHC4's).

GM HEI Ignition Conversion

Quote from: TwoTired
By the way, I'm going for the tinfoil pants...so they can't read my private thoughts.
:D

Offline Frankenkit

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Re: The Damn CB650 ignition
« Reply #29 on: May 05, 2010, 11:37:37 AM »
Sweet! Go forth, 650 Guineapig, to glory!

oh and a thanks to everyone here... retarding my bike seems to have solved the problem!!! :D :D :D I'm so happy I could kiss you all. :D
"Moderation in all things - especially moderation. Too much moderation is excessive. The occasional excess is all part of living the moderate life."
2012 CBR250R "Black Betty"
1980 CB650c- (sold) Delilah
1973 CL350- Lola?
Sweet, bubbly, Buddha - Say it ain't so!!!
Stuff for sale