I have recently installed my 505/515 cam in my 2002 883 with the 1200 upgrade done awhile back. Stock 883 heads with straight drag pipes for now. My question is on the initial timing for that particular cam, do I still use the 20° advance timing as the stock cam would. This is according to the manual I have for the bike.

I know with the setup I have I have to get some good exhaust and re-jetting the carburetor. Really first time setting the timing on an upgraded cam and I didnt want to do a mistake right off the rip. Ant help with that initial timing would be greatly appreciative.

 

At what compression ratio was your conversion done?

 

Im not 100% sure on the compression ratio, but I think I saw STD stamped on the top of the pistons when I had the heads off. I think there was a comment on another thread that I was still inquiring about this upgrade that it would be around 10:1 to 10.5:1 compression ratio.

 

Well, 10:1 to 10.5:1 is a good range for the Feuling 505/515 cams. Raising compression however speeds the burn. And the squish band you gained by leaving your heads stock and using dished conversion pistons (as opposed to hogging out the chambers and using flat tops) makes for a faster burn as well. So almost certainly, your motor is going to make more power with a softer curve to match. Personally, I would not use the stock ignition. Although you can back off some timing and make it run better, what the motor wants is a softer curve. Your stock ignition has a curve that's suitable for a 9:1 compression ratio with a hemi chamber.

Look into the Dyna 2000i. It's curve 4 is well suited to what you've done to the motor.

 

I thank you for that insight. That particular ignition was what I have been pondering into getting. Speaking of that with ignitions, what difference in single fire versus dual fire. I did order a coil already made for the single fire ignition with the (3) connections on it for wiring. Right now its stock ignition with stock coil. So dual fire I'm assuming. I'm curious about sound when it comes to the difference as well. I've always like that chop sound when idling. Does single fire give a different sound as well as only firing one cylinder at a time.

Talking timing with the Dyna 2000i ignition module, is timing with a timing light the same as a stock ignition as far as lining up the (2) dots in the window at RPM's around 1000. This is where I kinda started this thread with timing with a timing light. Stock it tells you to set advance timing mark at 20° BTDC. Having a different cam does that value stay the same when lining the (2) dots in the window. Or would that value change even while still having the stock ignition. Now the Dyna 2000i would the procedure pretty much be the same or do you set the dials to what setting you are wanting to set the ignition to. I read some articles and it talks about retarding the timing at times.

Im kind of learning as I go, so any help I will take it with great appreciation.

 

Single fire hits each cylinder individually. That's why a single fire coil has three terminals. Internally, it's two separate coils, one for each cylinder.

Dual fire (stock through 2003) hits both cylinders at the same time, even though only one is positioned for combustion. The other one gets a "wasted spark". It's only one coil in the package, albeit with two outputs on it.

On whether single is worth the upgrade, it's kind of a long story. But the short answer is that on more than 95% of the bikes out there, you won't gain one iota of power by converting to single fire. Only in one specific set of conditions have I ever been able to find power with single fire, and I've tried numerous times.

The longer explanation goes like this, as briefly as I can explain it. When the rear cylinder fires, the front cylinder is on it's exhaust stroke. So the front has it's exhaust valve open and the exhaust is rushing out of it, and there's no fresh fuel to light. So the wasted spark that happens on the front cylinder doesn't do a thing. Even if there was residual fuel left to ignite, it won't create cylinder pressure with the exhaust valve hanging open.

On the other hand, when the front cylinder fires, the rear cylinder is on overlap. During overlap, both valves are open, as the exhaust cycle is finishing and the next intake cycle is beginning. Depending on how much overlap your cams have and how effective your exhaust is at creating a vacuum right then, air/fuel mix *may* be already coming in through the intake valve, through a phenomena known as "exhaust augmented intake flow". If so, the wasted spark right then can flare out and disrupt that incoming charge. It won't generate cylinder pressure because both valves are open, but it can reduce cylinder fill. So if you have a wide overlap window in your cams, and you have an exhaust that pulls well during overlap, a conversion to single fire can deliver a slight power gain. But it's real slight, like around 1hp on a 100hp engine. And most bikes won't set up the conditions where it's even measurable. Almost all bikes I've run the test on, I can't find a power gain with single fire. It's the rare bike that I can.

Regarding sound and vibration, well, I once set up a bike so that I could switch between single fire and dual fire on the fly. I put the bike on the dyno, and I tried going back and forth at numerous steady state speed ranges. I could not have told you whether it was set on single or dual fire based on the sound or vibration levels. If someone claims it changes those two things, well, okay, I can only speak for myself, I couldn't detect a bit.

Bottom line is that I don't, as a matter of course, go around recommending that guys spend money on a single fire setup. In most cases I don't think you'll ever get a measurable difference in power or sound or vibration.

However, aftermarket ignition modules almost all support single fire. For the longest time, Dyna offered a cheaper version of it's 2000 external module that only supported dual fire, as opposed to the more expensive version that supports both single and dual fire. But just this year, they started pricing the two modules the same. So there's no longer any reason to get the dual fire version over the single/dual version. And if you're changing to an ignition anyway, to get a better curve for a hopped up motor, then you're just a single-fire coil away from completing the upgrade.

The 2000i nose cone version (the one that's applicable to your bike) has always been offered in single/dual only.

I do not recommend timing with a light, either for the stock nose cone module or the Dyna. Pointing a timing light at a Harley is just an inherently error prone and difficult process. You have the choice of oil in your face or attempting to look through a clear plastic plug that's almost impossible to see through. You've got to control the rpm carefully while you do this. If it's dual fire, you've also got extraneous flashes of the light because of the wasted spark. It's just not a good process. I've always found that done carefully, static timing is better. That's just me though.

 

Great feedback on the difference of the single versus dual fire ignitions. Now talking about the static timing procedure. Reading in my manual, I would turn ignition on and loosen the (2) screws. Next I would rotate the module plate until the red LED light comes on then rotate back until light is extinguished. Then just tighten the screws and put back together. Is that pretty much the basic of setting the timing with the static process? Once I do that, would I just crank it up and and see what it does? Or is there anything afterwards I may need to do.

My goal really is to get it going best I can and maybe let someone more experienced fine tune it and maybe put it on a dyno machine and see what they suggest. Or is that a waste of money at this time.

I have rebuilt the carburetor recently with all stock internals including jets. Should I play around with different jets ahead of time?

 

Yes, but make sure the TDC line on the flywheel (a vertical line) is centered in the window, and also you need to be on the TDC that happens between the compression and power strokes. The other TDC, which happens between the exhaust and intake strokes, won't work. On an assembled motor, you can tell which one you're on by putting your finger over the spark plug hole while you or someone else rotates the elevated rear wheel, with the trans in top gear. When it blows your finger off the hole, you're on the compression stroke. Proceed from there until the vertical line is centered in the timing window. That's compression TDC.

Also the key needs to be on AND the run/stop switch needs to be in the "run" position. You would not believe how many people contact me complaining the LED never lights up, and they didn't have that switch in the run position.

And also, the direction you're turning the module matters. You want to turn it fully CCW. The LED should be on. Then you want to carefully turn it clockwise until the LED *just* turns off. At that point, push in on the module so that it doesn't accidentally turn, and tighten the screws.

However, like I said, since you've raised compression and added a squish band, you've got a faster burn. So now take a sharp, small knife and put a scratch mark on the perimeter of the ignition plate, extending onto the inside of the nose cone. This mark indicates static timed. Then loosen the screws and rotate the module about .065" (a big spark plug gap) counter clockwise, using your scratch mark as a reference. That'll retard the timing 5 degrees, to better match the speed of your burn with your motor mods.

Well, far be it from me to tell you it's a waste of time to dyno tune it.

Proper jetting is important to not only the power production, but also to the health of your motor. If you've got the stock 883 jetting, then almost certainly it will benefit from changes to match your mods. Given your 1200 conversion and cams, I would probably start with a 185 main, 45 pilot, and three turns out on the idle mixture screw. But that's just a ballpark. Nobody can precisely jet your bike by internet, there are too many variables.

The best way to evaluate jetting is with an air/fuel monitor, as commonly found in a dyno environment. Absent that, or one of these add-on AFR monitoring kits, you can use the conventional methods like plug reading. Also, if you're running it hard and you can back off the throttle ever so slightly and it pulls harder, that indicates it's lean.

 

I want to thank you AWSracing for the information. I followed step by step and the motor fired up first try. I played around with the air/fuel a little bit which was screwed in about a quarter turn and seems to run OK. 3 turns fully out you could just smell the gas being rich. Screwed in some and not as bad. No popping through the carburetor so far. I did by some cheap baffles to slide in my exhaust pipes which quieted the sound just a bit. There was definitely a noticeable difference in sound with the new cam versus the one I had. Much louder, so baffles didnt hurt having them in. If I run into any issues Ill get back to the forum and see what direction to go.

Got to love the internet. Years ago you would just be lost and hope you were doing it right. These days a quick search on line and next thing you are attempting to fix something on your own. If mechanically capable.

Thanks again!